Atrial fibrillation in patients with cryptogenic stroke. Left ventricular systolic dysfunction and atrial fibrillation in older people in the community--a need for screening? Asymptomatic or "silent" atrial fibrillation: frequency in untreated patients and patients receiving azimilide. Continuous Stroke Unit Electrocardiographic Monitoring Versus 24-Hour Holter Electrocardiography for Detection of Paroxysmal Atrial Fibrillation After Stroke Prevalence of atrial fibrillation and eligibility for anticoagulants in the community Impact of long-term ECG recording on the detection of paroxysmal atrial fibrillation in patients after an acute ischemic stroke. Effect of Age on Stroke Prevention Therapy in Patients With Atrial Fibrillation: The Atrial Fibrillation Investigators Does left atrial appendage closure with a cardiac plug system reduce the stroke risk in nonvalvular atrial fibrillation patients? A single-center case series. Cost-Effectiveness of Dabigatran Compared With Warfarin for Stroke Prevention in Atrial Fibrillation Patients with nonvalvular atrial fibrillation at low risk of stroke during treatment with aspirin: Stroke Prevention in Atrial Fibrillation III Study. The SPAF III Writing Committee for the Stroke Prevention in Atrial Fibrillation Investigators. Anticoagulation therapy for stroke prevention in atrial fibrillation: how well do randomized trials translate into clinical practice? Subclinical atrial fibrillation and the risk of stroke. Stroke, Bleeding, and Mortality Risks in Elderly Medicare Beneficiaries Treated With Dabigatran or Rivaroxaban for Nonvalvular Atrial Fibrillation. Prognostic implications of left atrial spontaneous echo contrast in nonvalvular atrial fibrillation. Warfarin for atrial fibrillation. The patient's perspective. Focused 2012 update of the Canadian Cardiovascular Society atrial fibrillation guidelines: recommendations for stroke prevention and rate/rhythm control. Predictors of thromboembolism in atrial fibrillation: II. Echocardiographic features of patients at risk. The Stroke Prevention in Atrial Fibrillation Investigators. Cost-effectiveness of warfarin and aspirin for prophylaxis of stroke in patients with nonvalvular atrial fibrillation. Echocardiographic predictors of stroke in patients with atrial fibrillation: a prospective study of 1066 patients from 3 clinical trials. Antiarrhythmic drug therapy and cardiac mortality in atrial fibrillation. The Stroke Prevention in Atrial Fibrillation Investigators. Improving the quality of anticoagulation of patients with atrial fibrillation in managed care organizations: results of the managing anticoagulation services trial. Management of Newly Detected Atrial Fibrillation: A Clinical Practice Guideline from the American Academy of Family Physicians and the American College of Physicians Unexpected low prevalence of atrial fibrillation in cryptogenic ischemic stroke: a prospective study
BACKGROUND Atrial fibrillation is a leading preventable cause of recurrent stroke for which early detection and treatment are critical . However , paroxysmal atrial fibrillation is often asymptomatic and likely to go undetected and untreated in the routine care of patients with ischemic stroke or transient ischemic attack ( TIA ) . METHODS We r and omly assigned 572 patients 55 years of age or older , without known atrial fibrillation , who had had a cryptogenic ischemic stroke or TIA within the previous 6 months ( cause undetermined after st and ard tests , including 24-hour electrocardiography [ ECG ] ) , to undergo additional noninvasive ambulatory ECG monitoring with either a 30-day event-triggered recorder ( intervention group ) or a conventional 24-hour monitor ( control group ) . The primary outcome was newly detected atrial fibrillation lasting 30 seconds or longer within 90 days after r and omization . Secondary outcomes included episodes of atrial fibrillation lasting 2.5 minutes or longer and anticoagulation status at 90 days . RESULTS Atrial fibrillation lasting 30 seconds or longer was detected in 45 of 280 patients ( 16.1 % ) in the intervention group , as compared with 9 of 277 ( 3.2 % ) in the control group ( absolute difference , 12.9 percentage points ; 95 % confidence interval [ CI ] , 8.0 to 17.6 ; P<0.001 ; number needed to screen , 8) . Atrial fibrillation lasting 2.5 minutes or longer was present in 28 of 284 patients ( 9.9 % ) in the intervention group , as compared with 7 of 277 ( 2.5 % ) in the control group ( absolute difference , 7.4 percentage points ; 95 % CI , 3.4 to 11.3 ; P<0.001 ) . By 90 days , oral anticoagulant therapy had been prescribed for more patients in the intervention group than in the control group ( 52 of 280 patients [ 18.6 % ] vs. 31 of 279 [ 11.1 % ] ; absolute difference , 7.5 percentage points ; 95 % CI , 1.6 to 13.3 ; P=0.01 ) . CONCLUSIONS Among patients with a recent cryptogenic stroke or TIA who were 55 years of age or older , paroxysmal atrial fibrillation was common . Noninvasive ambulatory ECG monitoring for a target of 30 days significantly improved the detection of atrial fibrillation by a factor of more than five and nearly doubled the rate of anticoagulant treatment , as compared with the st and ard practice of short- duration ECG monitoring . ( Funded by the Canadian Stroke Network and others ; EMBRACE Clinical Trials.gov number , NCT00846924 . ) BACKGROUND Heart failure and stroke are major causes of morbidity and mortality in older people .  Angiotensin converting enzyme inhibitors improve symptoms and survival in left ventricular systolic dysfunction . Anticoagulants are effective in stroke prevention in atrial fibrillation with aspirin being a less effective alternative . OBJECTIVES To determine the prevalence of left ventricular systolic dysfunction , health services utilisation and prescribing of diuretics and angiotensin converting enzyme inhibitors in left ventricular systolic dysfunction , and the prevalence of atrial fibrillation and anti-platelet/thrombotic therapy in atrial fibrillation in older people in the community . METHODS 500 subjects were drawn by two-stage r and om sampling from 5,002 subjects aged 70 years and over living at home . Subjects were screened for atrial fibrillation and left ventricular systolic dysfunction using electrocardiography and echocardiography . RESULTS The population prevalence amongst older people of left ventricular systolic dysfunction was 9.8 % and of atrial fibrillation 7.8 % . More than two-thirds of those with left ventricular systolic dysfunction were not on angiotensin converting enzyme inhibitors . Of those in atrial fibrillation , 35 % were taking aspirin , 24 % were taking warfarin and 41 % were on neither aspirin nor warfarin . Nearly 90 % of older people in the community have had contact with their general practitioner over the past year , and over half of those with left ventricular systolic dysfunction have had contact with hospital-based services over the past 2 years . CONCLUSIONS Left ventricular systolic dysfunction is under-treated in older people in the community . Despite the high level of contact with hospital and community-based services , the majority of those with systolic left ventricular dysfunction are not on angiotensin converting enzyme inhibitors and a significant proportion of those in atrial fibrillation are not on any treatment for stroke prevention BACKGROUND Asymptomatic , or " silent " atrial fibrillation could increase the risk of stroke . Little is known about the frequency of asymptomatic atrial fibrillation in patients who also have symptomatic atrial fibrillation ; similarly , little is known about the effect of antiarrhythmic drug therapy on asymptomatic atrial fibrillation . METHODS AND RESULTS Patients in sinus rhythm with a history of symptomatic atrial fibrillation or atrial flutter received placebo or azimilide ( 35 to 125 mg ) once daily for 6 or 9 months in 4 similar double-blind trials . The end point was the first recurrence of a symptomatic ECG-documented supraventricular arrhythmia . Routine transtelephonic electrocardiograms , in the absence of symptoms , were recorded for 30 seconds every 2 weeks until patients completed follow-up or documented a symptomatic supraventricular arrhythmia . Of the 1380 patients , 489 received placebo .  Among these patients receiving placebo , 303 transmitted at least one routine ECG while asymptomatic . Asymptomatic atrial fibrillation was recorded in 50 ( 17 % ) within 6 months and before recurrence of symptomatic supraventricular arrhythmia . In the 3 trials evaluating azimilide in therapeutic doses ( 100 and 125 mg ) , asymptomatic atrial fibrillation occurred in 49 of 382 ( 13 % ) receiving azimilide and 43 of 233 ( 18 % ) receiving placebo . Although drug effect on time to first asymptomatic event was not statistically significant ( hazard ratio , 0.70 ; P=0.09 ) , there was a 40 % reduction in asymptomatic atrial fibrillation on azimilide compared with placebo ( P=0.03 ) when repeated observations were considered . CONCLUSIONS Asymptomatic atrial fibrillation is common in untreated patients with a history of symptomatic atrial fibrillation ( and is likely underestimated by this analysis ) . Azimilide may reduce the occurrence of this silent arrhythmia Background and Purpose — Cardioembolism in paroxysmal atrial fibrillation ( pxAF ) is a frequent cause of ischemic stroke . Sensitive detection of pxAF after stroke is crucial for adequate secondary stroke prevention ; the optimal diagnostic modality to detect pxAF on stroke units is unknown . We compared 24-hour Holter electrocardiography ( ECG ) with continuous stroke unit ECG monitoring ( CEM ) for pxAF detection . Methods — Patients with acute ischemic stroke or transient ischemic attack were prospect ively enrolled . After a 12-channel ECG on admission , all patients received 24-hour Holter ECG and CEM . Additionally , ECG monitoring data underwent automated analysis using dedicated software to identify pxAF . Patients with a history of atrial fibrillation or with atrial fibrillation on the admission ECG were excluded . Results — Four hundred ninety-six patients ( median age , 69 years ; 61.5 % male ) fulfilled all inclusion criteria ( ischemic stroke : 80.4 % ; transient ischemic attack : 19.6 % ) . Median stroke unit stay lasted 88.8 hours ( interquartile range , 65.0–122.0 ) .  ECG data  for automated CEM analysis were available for a median time of 64.0 hours ( 43.0–89.8 ) . Paroxysmal AF was documented in 41 of 496 patients ( 8.3 % ) . Of these , Holter detected pxAF in 34.1 % ; CEM in 65.9 % ; and automated CEM in 92.7 % . CEM and automated CEM detected significantly more patients with pxAF than Holter ( P<0.001 ) , and automated CEM detected more patients than CEM ( P<0.001 ) . Conclusions — Automated analysis of CEM improves pxAF detection in patients with stroke on stroke units compared with 24-hour Holter ECG . The comparative usefulness of prolonged or repetitive Holter ECG recordings requires further evaluation BACKGROUND Anticoagulants are effective in the prevention of stroke in atrial fibrillation and flutter ( AF ) . We aim ed to find out the prevalence of AF in the UK and to estimate the proportion of patients with AF who might benefit from anticoagulation . METHODS We screened with electrocardiography a r and om sample of 4843 people from the community aged 65 years and older for AF . Participants with AF had further investigations to identify risk factors for stroke and contraindications to anticoagulants . We used three sets of criteria to assess risk and eligibility for anticoagulation . FINDINGS 228 ( 4.7 % ) participants had AF . According to analyses derived from risk stratifications based on the Stroke Prevention in Atrial Fibrillation ( SPAF ) study 61 % of these patients would have benefited from anticoagulation , 49 % according to pooled analysis of trial results , and 41 % according to the inclusion criteria for the SPAF 3 study .  Anticoagulants  were used by 1114 ( 23 % ) of all patients and were least used among elderly women , who may be the most likely to benefit . Echocardiography would be useful to assess the need for anticoagulation only in patients younger than 75 years with no contraindications to treatment and no clinical risk factors for stroke . INTERPRETATION Anticoagulants seem to be underused and misdirected in treatment of AF , according to various criteria . Efforts to promote and support wider and more appropriate use of anticoagulants would seem to be justified , and should decrease the incidence of stroke amongst elderly patients An ECG recording time of 24 hours has a low yield to detect atrial arrhythmias in patients after an acute ischemic stroke . The present study investigated whether a recording time of 72 instead of 24 hours detects paroxysmal atrial fibrillation in more patients . The study prospect ively included 82 consecutive patients 2 - 3 weeks after an acute ischemic stroke . All patients had sinus rhythm in the resting ECGs and no history of atrial fibrillation or flutter . The frequency of atrial fibrillation was assessed after 24 , 48 , and 72 hours of ambulatory ECG monitoring . An ECG monitoring time of 72 hours documented paroxysmal atrial fibrillation in five ( 6 % ) patients . The episode of paroxysmal atrial fibrillation occurred in only one patient within 24 hours . The other patients had their first episode of atrial fibrillation between 24 and 48 hours ( n = 2 ) and between 48 and 72 hours ( n = 2 ) . These five patients were older ( age = 70 + /- 5 years ) , whereas the mean age of the remaining patients was 59 + /- 13 years . All five patients had cardiovascular disease in comparison to 36 of 77 patients and reported palpitations in comparison to 6 of 77 of the remaining patients . In conclusion , ambulatory ECG monitoring over 72 hours detected after the first recording day four of five patients in whom paroxysmal atrial fibrillation could be documented for the first time . The 72-hour recording time improved , compared to the 24-hour period , the detection of paroxysmal atrial fibrillation in patients after an ischemic stroke . It seems to be more efficient to perform prolonged ECG recording mainly in older patients with a cardiovascular disease and /or a history of palpitations Background and Purpose — Stroke risk increases with age in patients who have nonvalvular atrial fibrillation . It is uncertain whether the efficacy of stroke prevention therapies in atrial fibrillation changes as patients age . The objective of this study was to determine the effect of age on the relative efficacy of oral anticoagulants ( OAC ) and antiplatelet ( AP ) therapy ( including acetylsalicylic acid and triflusal ) on ischemic stroke , serious bleeding , and vascular events in patients with atrial fibrillation . Methods — This is an analysis of the Atrial Fibrillation Investigators data base , which contains patient level- data from r and omized trials of stroke prevention in atrial fibrillation . We used Cox regression models with age as a continuous variable that controlled for sex , year of r and omization , and history of cerebrovascular disease , diabetes , hypertension , and congestive heart failure . Outcomes included ischemic stroke , serious bleeding ( intracranial hemorrhage or systemic bleeding requiring hospitalization , transfusion , or surgery ) , and cardiovascular events ( ischemic stroke , myocardial infa rct ion , systemic embolism , or vascular death ) . Results — The analysis included 8932 patients and 17 685 years of observation from 12 trials . Patient age increased risk of ischemic stroke ( adjusted hazard ratio per decade increase 1.45 ; 95 % CI , 1.26 to 1.66 ) , serious bleeding ( 1.61 ; 1.47 to 1.77 ) , and cardiovascular events ( 1.43 ; 1.33 to 1.53 ) . Compared with placebo , OAC and AP significantly reduced the risk of ischemic stroke ( OAC , 0.36 ; 0.29 to 0.45 ; AP , 0.81 ; 0.72 to 0.90 ) and cardiovascular outcomes ( OAC , 0.59 ; 0.52 to 0.66 ; AP , 0.81 ; 0.75 to 0.88 ) , whereas OAC increased risk of serious bleeding ( 1.56 ; 1.03 to 2.37 ) . The relative benefit of OAC versus placebo or AP did not vary by patient age for any outcome . Compared with placebo , the relative benefit of AP  for preventing ischemic stroke decreased significantly as patients aged ( P=0.01 ) . Conclusions — As patients with atrial fibrillation age , the relative efficacy of AP to prevent ischemic stroke appears to decrease , whereas it does not change for OAC . Because stroke risk increases with age , the absolute benefit of OAC increases as patients get older BACKGROUND Atrial fibrillation ( AF ) is the most common sustained cardiac arrhythmia and it is associated with an increased stroke risk , due mainly to cardiac embolism from the left atrial appendage ( LAA ) . Percutaneous LAA closure is a method to reduce stroke risk in AF without using anticoagulant agents . In this study we report data from an Italian experience with the LAA occluder Amplatzer Cardiac Plug ( ACP ) device ( Aga Medical Corporation , Plymouth , MN , USA ) . METHODS The study was design ed to evaluate the safety of LAA closure using ACP and the efficacy of the procedure in preventing strokes during a 1-year follow-up . Patients with permanent or paroxysmal AF , high stroke risk , and contraindication to warfarin therapy were selected for the procedure . RESULTS The LAA closure was attempted in 37 patients and succeeded in 34 cases ( 91.9 % ) . Four patients experienced serious complications ( one cardiac tamponade requiring pericardiocentesis , two device embolizations , one low-rate response AF requiring artificial pacing ) . During a 1-year follow-up , ischemic stroke occurred in one of 34 patients , result ing in a stroke rate of 2.94 % ; thus there was a stroke rate reduction of 50.2 % and 26.5 % compared to the expected stroke rate , according to CHADS2 and CHA2 DS2 VASc score . None of the patients who received ACP experienced major bleeding during the follow-up . CONCLUSION LAA closure using ACP is a relatively feasible procedure which can be performed by highly experienced operators to reduce stroke rate in patients with AF , high stroke risk , and contraindication to oral anticoagulants BACKGROUND Warfarin reduces the risk for ischemic stroke in patients with atrial fibrillation ( AF ) but increases the risk for hemorrhage . Dabigatran is a fixed-dose , oral direct thrombin inhibitor with similar or reduced rates of ischemic stroke and intracranial hemorrhage in patients with AF compared with those of warfarin . OBJECTIVE To estimate the quality -adjusted survival , costs , and cost-effectiveness of dabigatran compared with adjusted-dose warfarin for preventing ischemic stroke in patients 65 years or older with nonvalvular AF . DESIGN Markov decision model . DATA SOURCES The RE-LY ( R and omized Evaluation of Long-Term Anticoagulation Therapy ) trial and other published studies of anticoagulation . The cost of dabigatran was estimated on the basis of pricing in the United Kingdom . TARGET POPULATION Patients aged 65 years or older with nonvalvular AF and risk factors for stroke ( CHADS₂ score ≥1 or equivalent ) and no contraindications to anticoagulation . TIME HORIZON Lifetime . PERSPECTIVE Societal . INTERVENTION Warfarin anticoagulation ( target international normalized ratio , 2.0 to 3.0 ) ; dabigatran , 110 mg twice daily ( low dose ) ; and dabigatran , 150 mg twice daily ( high dose ) . OUTCOME MEASURES Quality -adjusted life-years ( QALYs ) , costs ( in 2008 U.S. dollars ) , and incremental cost-effectiveness ratios . RESULTS OF BASE-CASE ANALYSIS The quality -adjusted life expectancy was 10.28 QALYs with warfarin , 10.70 QALYs with low-dose dabigatran , and 10.84 QALYs with high-dose dabigatran . Total costs were $ 143 193 for warfarin , $ 164 576 for low-dose dabigatran , and $ 168 398 for high-dose dabigatran . The incremental cost-effectiveness ratios  compared with warfarin were $ 51 229 per QALY for low-dose dabigatran and $ 45 372 per QALY for high-dose dabigatran . RESULTS OF SENSITIVITY ANALYSIS The model was sensitive to the cost of dabigatran but was relatively insensitive to other model inputs . The incremental cost-effectiveness ratio increased to $ 50 000 per QALY at a cost of $ 13.70 per day for high-dose dabigatran but remained less than $ 85 000 per QALY over the full range of model inputs evaluated . The cost-effectiveness of high-dose dabigatran improved with increasing risk for stroke and intracranial hemorrhage . LIMITATION Event rates were largely derived from a single r and omized clinical trial and extrapolated to a 35-year time frame from clinical trials with approximately 2-year follow-up . CONCLUSION In patients aged 65 years or older with nonvalvular AF at increased risk for stroke ( CHADS₂ score ≥1 or equivalent ) , dabigatran may be a cost-effective alternative to warfarin depending on pricing in the United States . PRIMARY FUNDING SOURCE American Heart Association and Veterans Affairs Health Services Research & Development Service CONTEXT Nonvalvular atrial fibrillation ( AF ) carries an increased risk for stroke , but absolute rates of stroke vary widely within the broad spectrum of AF patients . OBJECTIVE To prospect ively vali date a risk stratification scheme identifying patients with AF with low rates of stroke when given aspirin .  DESIGN Prospect i ve cohort study with mean duration of follow-up of 2.0 years , conducted between 1993 and 1997 . SETTING Outpatient clinics affiliated with academic medical centers . PATIENTS Patients with AF categorized as " low risk " based on the absence of 4 prespecified thromboembolic risk factors : recent congestive heart failure or left ventricular fractional shortening of 25 % or less , previous thromboembolism , systolic blood pressure greater than 160 mm Hg , or female sex at age older than 75 years . INTERVENTION All participants given aspirin , 325 mg/d . MAIN OUTCOME MEASURES Ischemic stroke ( considered disabling when Rankin score was II or worse 1 - 3 months later ) and systemic embolism ( primary events ) . RESULTS Among 892 participants , the mean ( SD ) age was 67 ( 10 ) years , 78 % were men , and histories of hypertension , diabetes , and ischemic heart disease were present in 46 % , 13 % , and 16 % , respectively . The rate of primary events was 2.2 % per year ( 95 % confidence interval [ CI ] , 1.6%-3.0 % ) , of ischemic stroke was 2.0 % per year ( 95 % CI , 1.5%-2.8 % ) , and of disabling ischemic strokes was 0.8 % per year ( 95 % CI , 0.5%-1.3 % ) . Those with a history of hypertension had a higher rate of primary events ( 3.6 % per year ) than those with no history of hypertension ( 1.1 % per year ) ( P<.001 ) . The rate of disabling ischemic stroke was low in those with and without a history of hypertension ( 1.4 % per year and 0.5 % per year , respectively ) . The rate of major bleeding during aspirin therapy was 0.5 % per year . CONCLUSION Patients with AF who have relatively low rates of ischemic stroke , particularly disabling stroke , during treatment with aspirin can be reliably identified CONTEXT Warfarin has been shown to be highly efficacious for preventing  thromboembolism in atrial fibrillation in r and omized trials , but its effectiveness and safety in clinical practice is less clear . OBJECTIVE To evaluate the effect of warfarin on risk of thromboembolism , hemorrhage , and death in atrial fibrillation within a usual care setting . DESIGN Cohort study assembled between July 1 , 1996 , and December 31 , 1997 , and followed up through August 31 , 1999 . SETTING Large integrated health care system in Northern California . PATIENTS Of 13,559 adults with nonvalvular atrial fibrillation , 11,526 were studied , 43 % of whom were women , mean age 71 years , with no known contraindications to anticoagulation at baseline . MAIN OUTCOMES Ischemic stroke , peripheral embolism , hemorrhage , and death according to warfarin use and comorbidity status , as determined by automated data bases , review of medical records , and state mortality files . RESULTS Among 11,526 patients , 397 incident thromboembolic events ( 372 ischemic strokes , 25 peripheral embolism ) occurred during 25,341 person-years of follow-up , and warfarin therapy was associated with a 51 % ( 95 % confidence interval [ CI ] , 39%-60 % ) lower risk of thromboembolism compared with no warfarin therapy ( either no antithrombotic therapy or aspirin ) after adjusting for potential confounders and likelihood of receiving warfarin . Warfarin was effective in reducing thromboembolic risk in the presence or absence of risk factors for stroke . A nested case-control analysis estimated a 64 % reduction in odds of thromboembolism with warfarin compared with no antithrombotic therapy . Warfarin was also associated with a reduced risk of all-cause mortality ( adjusted hazard ratio , 0.69 ; 95 % CI , 0.61 - 0.77 ) . Intracranial hemorrhage was uncommon , but the rate was moderately higher among those taking vs those not taking warfarin ( 0.46 vs 0.23 per 100 person-years , respectively ; P = .003 , adjusted hazard ratio , 1.97 ; 95 % CI , 1.24 - 3.13 ) . However , warfarin therapy was not associated with an increased adjusted risk of nonintracranial major hemorrhage . The effects of warfarin were similar when patients with contraindications at baseline were analyzed separately or combined with those without contraindications ( total cohort of 13,559 ) . CONCLUSIONS Warfarin is very effective for preventing ischemic stroke in patients with atrial fibrillation in clinical practice while the absolute increase in the risk of intracranial hemorrhage is small . Results of r and omized trials of anticoagulation translate well into clinical care for patients with atrial fibrillation BACKGROUND One quarter of strokes are of unknown cause , and sub clinical atrial fibrillation may be a common etiologic factor . Pacemakers can detect sub clinical episodes of rapid atrial rate , which correlate with electrocardiographically documented atrial fibrillation . We evaluated whether sub clinical episodes of rapid atrial rate detected by implanted devices were associated with an increased risk of ischemic stroke in patients who did not have other evidence of atrial fibrillation . METHODS We enrolled 2580 patients , 65 years of age or older , with hypertension and no history of atrial fibrillation , in whom a pacemaker or defibrillator had recently been implanted . We monitored the patients for 3 months to detect sub clinical atrial tachyarrhythmias ( episodes of atrial rate > 190 beats per minute for more than 6 minutes ) and followed them for a mean of 2.5 years for the primary outcome of ischemic stroke or systemic embolism .  Patients with pacemakers  were r and omly assigned to receive or not to receive continuous atrial overdrive pacing . RESULTS By 3 months , sub clinical atrial tachyarrhythmias detected by implanted devices had occurred in 261 patients ( 10.1 % ) . Sub clinical atrial tachyarrhythmias were associated with an increased risk of clinical atrial fibrillation ( hazard ratio , 5.56 ; 95 % confidence interval [ CI ] , 3.78 to 8.17 ; P<0.001 ) and of ischemic stroke or systemic embolism ( hazard ratio , 2.49 ; 95 % CI , 1.28 to 4.85 ; P=0.007 ) . Of 51 patients who had a primary outcome event , 11 had had sub clinical atrial tachyarrhythmias detected by 3 months , and none had had clinical atrial fibrillation by 3 months . The population attributable risk of stroke or systemic embolism associated with sub clinical atrial tachyarrhythmias was 13 % . Sub clinical atrial tachyarrhythmias remained predictive of the primary outcome after adjustment for predictors of stroke ( hazard ratio , 2.50 ; 95 % CI , 1.28 to 4.89 ; P=0.008 ) . Continuous atrial overdrive pacing did not prevent atrial fibrillation . CONCLUSIONS Sub clinical atrial tachyarrhythmias , without clinical atrial fibrillation , occurred frequently in patients with pacemakers and were associated with a significantly increased risk of ischemic stroke or systemic embolism . ( Funded by St. Jude Medical ; ASSERT Clinical Trials.gov number , NCT00256152 . ) Importance Dabigatran and rivaroxaban are non-vitamin K oral anticoagulants approved for stroke prevention in patients with nonvalvular atrial fibrillation ( AF ) . There are no r and omized head-to-head comparisons of these drugs for stroke , bleeding , or mortality outcomes . Objective To compare risks of thromboembolic stroke , intracranial hemorrhage ( ICH ) , major extracranial bleeding including major gastrointestinal bleeding , and mortality in patients with nonvalvular AF who initiated dabigatran or rivaroxaban treatment for stroke prevention . Design , Setting , and Participants Retrospective new-user cohort study of 118 891 patients with nonvalvular AF who were 65 years or older , enrolled in fee-for-service Medicare , and who initiated treatment with dabigatran or rivaroxaban from November 4 , 2011 , through June 30 , 2014 . Differences in baseline characteristics were adjusted using stabilized inverse probability of treatment weights based on propensity scores . The data analysis was performed from May 7 , 2015 , through June 30 , 2016 . Exposures Dabigatran , 150 mg , twice daily ; rivaroxaban , 20 mg , once daily . Main Outcomes and Measures Adjusted hazard ratios ( HRs ) for the primary outcomes of thromboembolic stroke , ICH , major extracranial bleeding including major gastrointestinal bleeding , and mortality , with dabigatran as reference . Adjusted incidence rate differences ( AIRDs ) were also estimated . Results A total of 52 240 dabigatran-treated and 66 651  rivaroxaban-treated patients ( 47 % female ) contributed 15 524 and 20 199 person-years of on-treatment follow-up , respectively , during which 2537 primary outcome events occurred . Rivaroxaban use was associated with a statistically nonsignificant reduction in thromboembolic stroke ( HR , 0.81 ; 95 % CI , 0.65 - 1.01 ; P = .07 ; AIRD = 1.8 fewer cases/1000 person-years ) , statistically significant increases in ICH ( HR , 1.65 ; 95 % CI , 1.20 - 2.26 ; P = .002 ; AIRD = 2.3 excess cases/1000 person-years ) and major extracranial bleeding ( HR , 1.48 ; 95 % CI , 1.32 - 1.67 ; P < .001 ; AIRD = 13.0 excess cases/1000 person-years ) , including major gastrointestinal bleeding ( HR , 1.40 ; 95 % CI , 1.23 - 1.59 ; P < .001 ; AIRD = 9.4 excess cases/1000 person-years ) , and with a statistically nonsignificant increase in mortality ( HR , 1.15 ; 95 % CI , 1.00 - 1.32 ; P = .051 ; AIRD = 3.1 excess cases/1000 person-years ) . In patients 75 years or older or with CHADS2 score greater than 2 , rivaroxaban use was associated with significantly increased mortality compared with dabigatran use . The excess rate of ICH with rivaroxaban use exceeded its reduced rate of thromboembolic stroke . Conclusions and Relevance Treatment with rivaroxaban 20 mg once daily was associated with statistically significant increases in ICH and major extracranial bleeding , including major gastrointestinal bleeding , compared with dabigatran 150 mg twice daily OBJECTIVES This study examined the influence of left atrial spontaneous echo contrast on the subsequent stroke or embolic event rate and on survival in patients with nonvalvular atrial fibrillation . BACKGROUND Left atrial spontaneous echo contrast is associated with atrial fibrillation and a history of previous stroke or other embolic events . However , the prognostic implication s of spontaneous contrast in patients with nonvalvular atrial fibrillation are unknown . METHOD The study group comprised 272 consecutive patients with nonvalvular atrial fibrillation undergoing transesophageal echocardiography .  Clinical and echocardiographic data were collected at baseline , and patients were prospect ively followed up , and all strokes , other embolic events and deaths were documented . The relation between spontaneous contrast at baseline and subsequent stroke , other embolic events and survival was analyzed . RESULTS Left atrial spontaneous echo contrast was detected at baseline in 161 patients ( 59 % ) . The mean follow-up was 17.5 months . The stroke or other embolic event rate was 12%/year ( 15 strokes , 3 transient ischemic attacks , 2 peripheral embolisms ) in patients with , compared with 3%/year ( 5 strokes ) in patients without , baseline spontaneous contrast ( p = 0.002 ) . In 149 patients without previous thromboembolism , the event rate was 9.5%/year in patients with and 2.2%/year in patients without spontaneous contrast ( p = 0.003 ) . There were 25 deaths in patients with and 11 deaths in patients without spontaneous contrast . Patients with spontaneous contrast had significantly reduced survival ( p = 0.025 ) . On multivariate analysis , spontaneous contrast was the only positive predictor ( odds ratio 3.5 , p = 0.03 ) and warfarin therapy on follow-up the only negative predictor ( odds ratio 0.23 , p = 0.02 ) of subsequent stroke or other embolic events . CONCLUSIONS Transesophageal echocardiography can risk stratify patients with nonvalvular atrial fibrillation by identifying left atrial spontaneous echo contrast . These patients have both a significantly higher risk of developing stroke or other embolic events and a reduced survival , and they may represent a subgroup in whom the risk/benefit ratio of anticoagulation may be most favorable OBJECTIVE To determine the minimal clinical ly important difference ( MCID ) of warfarin therapy for the treatment of nonvalvular atrial fibrillation from the perspective of patients using 2 different elicitation methods . DESIGN All patients completed 2 face-to-face interviews , which were 2 weeks apart . For each interview , they were r and omized to receive 1 of 2 elicitation methods : ping-ponging or starting at the known efficacy . SETTING The practice s of 2 university-affiliated family medicine centers ( 8 physicians each ) , 14 community-based family physicians , and 2 cardiologists . PATIENTS Sixty-four patients with nonvalvular atrial fibrillation who were initiated with warfarin therapy at least 3 months before the study . INTERVENTION During each interview , the patients ' MCIDs were determined by using ( 1 ) a pictorial flip chart to describe atrial fibrillation ; the consequences of a minor stroke , a major stroke , and a major bleeding episode ; the chance of stroke if not taking warfarin ; the chance of a major bleeding episode if taking warfarin ; examples of the inconvenience , minor side effects , and costs of warfarin therapy ; and then ( 2 ) 1 of the 2 elicitation methods to determine their MCIDs ( the smallest reduction in stroke risk at which the patients were willing to take warfarin ) . Patients ' knowledge of their stroke risk , acceptability of the interview process , and factors determining their preferences were also assessed . MAIN RESULTS Given a baseline risk of having a stroke in the next 2 years , if not taking warfarin , of 10 of 100 , the mean MCID was 2.01 of 100 ( 95 % confidence interval , 1.60 - 2.42 ) . Fifty-two percent of the patients would take warfarin for an absolute decrease in stroke risk of 1 % over 2 years . Before eliciting their MCIDs , patients showed poor knowledge of their stroke risk , which improved afterward . The interview process was well accepted by the patients . The MCID using the ping-ponging elicitation method was 1.015 of 100 smaller compared with use of the starting at the known efficacy method ( P = .01 ) . CONCLUSIONS We were able to determine the MCID of warfarin therapy for the prevention of stroke from the perspective of patients with nonvalvular atrial fibrillation . Their MCIDs were much smaller than those that have been implied by some experts and clinicians . The interview process , using the flip chart approach , appeared to improve the patients ' knowledge of their disease and its consequences and treatment . The method used to elicit the patients ' MCIDs can have a clinical ly important effect on patient responses . The method used in our study can be generalized to other conditions and , thus , could be helpful in 3 ways : ( 1 ) from a clinical decision-making perspective , it could facilitate patient-physician communication ; ( 2 ) it could clarify the patient perspective when interpreting the results of previously completed trials ; and ( 3 ) it could be used to derive more clinical ly relevant sample sizes for r and omized treatment trials The Canadian Cardiovascular Society ( CCS ) published the complete set of 2010 Atrial Fibrillation ( AF ) Guidelines in the January , 2011 issue of the Canadian Journal of Cardiology . During its deliberations , the CCS Guidelines Committee engaged to a timely review of future evidence , with periodic composition of focused up date s to address clinical ly important advances . In 2011 , results were published from 3 pivotal AF trials : the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonist for Prevention of Stroke and Embolism Trial in Atrial Fibrillation ( ROCKET-AF ) , the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation ( ARISTOTLE ) study , and the Permanent Atrial Fibrillation Outcome Study Using Dronedarone on Top of St and ard Therapy ( PALLAS ) , comparing dronedarone with placebo in patients with permanent AF and additional cardiovascular disease risk-factor burden . Each of these large r and omized trials provided clear results with major implication s for AF management . Other important evidence that has emerged since the 2010 Guidelines includes findings about prediction instruments for AF-associated stroke and bleeding risk , stroke risk in paroxysmal-AF patients , risk-benefit considerations related to oral anticoagulation in patients with chronic kidney disease , and risk/benefit considerations in the use of antiplatelet agents , alone and in combination with each other or with oral anticoagulants , in AF patients . The Guidelines Committee judged that this extensive and important new evidence required focused updating of the 2010 Guidelines with respect to stroke prevention and rate/rhythm control . This report presents the details of the new recommendations , along with the background and rationale OBJECTIVE To identify echocardiographic predictors of arterial thromboembolism in patients with nonrheumatic atrial fibrillation and to determine whether these add to clinical variables for risk stratification . DESIGN Cohort study of patients assigned to placebo in a r and omized clinical trial . SETTING Five hundred sixty-eight in patients and out patients with nonrheumatic atrial fibrillation assigned to placebo therapy at 15 U.S. medical centers from 1987 to 1989 in the Stroke Prevention in Atrial Fibrillation study . Patients were followed for a mean of 1.3 years . MEASUREMENTS M-mode and two-dimensional ( 2-D ) echocardiograms performed at study entry and interpreted by local cardiologists . The predictive value of 14 echocardiographic variables for later ischemic stroke or systemic embolism was assessed by multivariate analysis . MAIN RESULTS Left ventricular dysfunction from 2-D echocardiograms ( P = 0.003 ) and the size of the left atrium from M-mode echocardiograms ( P = 0.02 ) were the strongest independent predictors of later thromboembolism . Multivariate analysis of these two independent echocardiographic predictors with the three independent clinical predictors of thromboembolism ( history of hypertension , recent congestive heart failure , previous thromboembolism ) identified 26 % of the cohort with a low risk for thromboembolism ( 1.0 % per year ; 95 % Cl , 0.2 % to 4.0 % ) . Compared with risk stratification using clinical variables alone , echocardiographic results altered thromboembolic risk stratification in 18 % of the entire cohort and in 38 % of those without clinical risk factors . CONCLUSIONS Both left ventricular and left atrial variables are significant predictors of thromboembolism in patients with nonvalvular atrial fibrillation . Our results challenge traditional views of the pathogenesis of ischemic stroke in patients with atrial fibrillation and suggest that st and ard echocardiography contributes to risk stratification , differentiating the one third of patients without clinical risk factors who are at increased risk for stroke from the remainder who may not need antithrombotic prophylaxis OBJECTIVE To examine the cost-effectiveness of prescribing warfarin sodium in patients who have nonvalvular atrial fibrillation ( NVAF ) with or without additional stroke risk factors ( a prior stroke or transient ischemic attack , diabetes , hypertension , or heart disease ) . DESIGN Decision and cost-effectiveness analyses . The probabilities for stroke , hemorrhage , and death were obtained from published r and omized controlled trials . The quality -of-life estimates were obtained by interviewing 74 patients with atrial fibrillation .  Costs were estimated from literature review , phone survey , and Medicare reimbursement . PATIENTS In the base case , the patients were 65 years of age and good c and i date s for warfarin therapy . INTERVENTIONS Treatment with warfarin , aspirin , or no therapy in the decision analytic model . MAIN OUTCOME MEASURES Quality -adjusted survival and marginal cost-effectiveness of warfarin  as compared with  aspirin  or no therapy . RESULTS For patients with NVAF and additional risk factors for stroke , warfarin therapy led to a greater quality -adjusted survival and to cost savings . For patients with NVAF and one additional risk factor , warfarin therapy cost $ 8000 per quality -adjusted life-year saved . For 65-year-old patients with NVAF alone , warfarin cost about $ 370,000 per quality -adjusted life-year saved , as compared with aspirin therapy . However , for 75-year-old patients with NVAF alone , prescribing warfarin cost $ 110,000 per quality -adjusted life-year saved . For patients who were not prescribed warfarin , aspirin was preferred to no therapy on the basis of both quality -adjusted survival and cost in all patients , regardless of the number of risk factors present . CONCLUSIONS Treatment with warfarin is cost-effective in patients with NVAF and one or more additional risk factors for stroke . In 65-year-old patients with NVAF but no other risk factors for stroke , prescribing warfarin instead of aspirin would affect quality -adjusted survival minimally but increase costs significantly BACKGROUND Clinical features that consistently predict ischemic stroke in patients with nonvalvular atrial fibrillation have been identified , while echocardiographic risk factors are less well defined . OBJECTIVE To determine whether the results of transthoracic echocardiography add independent information to the clinical risk factors for stroke in patients with atrial fibrillation . METHODS Transthoracic echocardiographic findings and clinical features from 1066 patients with atrial fibrillation assigned to placebo or control in 3 r and omized trials ( Boston Area Anticoagulation Trial for Atrial Fibrillation , Stroke Prevention in Atrial Fibrillation I Study , and Veterans Affairs Prevention in Atrial Fibrillation Study ) were correlated with subsequent ischemic stroke by multivariate analysis . RESULTS The mean + SD age of patients was 67 + /- 10 years , 78 % were men , 55 % had a history of hypertension , 19 % had a history of diabetes , 7 % had a previous transient ischemic attack or stroke , and 27 % had a history of heart failure . During a mean follow-up of 1.6 years , 78 ischemic strokes occurred ( annual rate , 4.7 % ) . Moderate to severe left ventricular systolic dysfunction shown via 2-dimensional echocardiography was a strong independent predictor of stroke ( relative risk , 2.5 ; P<.001 ) in the 1010 patients in whom echocardiographic values for left ventricular function were available . Left atrial diameter by M-mode echocardiography did not predict stroke ( relative risk , 1.02/mm ; P = .10 ) . Of 163 patients categorized as low risk based on clinical features ( annual stroke rate , 0.8 % ; 95 % confidence interval , 0.2%-3.0 % ) , 10 had moderate to severe left ventricular dysfunction shown via 2-dimensional echocardiography and a 9.3 % per year risk of stroke ( 95 % confidence interval , 1.3%-66 % ) . Conversely , 728 of the 847 patients at high risk for stroke based on clinical criteria had normal or mildly abnormal left ventricular function ; their stroke rate was 4.4 % ( 95 % confidence interval , 3.4%-5.8 % ) . CONCLUSIONS Left ventricular systolic dysfunction shown via 2-dimensional transthoracic echocardiography independently predicts risk of stroke in patients with atrial fibrillation . Echocardiography may prove most useful in a small group of patients who have a low risk of stroke according to clinical factors BACKGROUND AND OBJECTIVES The relation between cardiac mortality and antiarrhythmic drug administration has not been fully determined . This relation was analyzed in 1,330 patients enrolled in the Stroke Prevention in Atrial Fibrillation Study , a r and omized clinical trial comparing warfarin , aspirin and placebo for the prevention of ischemic stroke or systemic embolism in patients with nonvalvular atrial fibrillation . METHODS Patients who received antiarrhythmic drug therapy for atrial fibrillation in this study were compared with patients not receiving antiarrhythmic agents . The relative risk of cardiac mortality , including arrhythmic death , in patients receiving antiarrhythmic drug therapy  was determined and adjusted for other cardiac risk factors . RESULTS In patients receiving antiarrhythmic drug therapy , cardiac mortality was increased 2.5-fold ( p = 0.006 , 95 % confidence interval [ CI ] 1.3 to 4.9 ) and arrhythmic death was increased 2.6-fold ( p = 0.02 , 95 % CI 1.2 to 5.6 ) . Among patients with a history of congestive heart failure , those given antiarrhythmic medications had a relative risk of cardiac death of 4.7 ( p less than 0.001 , 95 % CI 1.9 to 11.6 ) compared with that of patients not so treated ; the relative risk of arrhythmic death in the treated group was 3.7 ( p = 0.01 , 95 % CI 1.3 to 10.4 ) . Patients without a history of congestive heart failure had no increased risk of cardiac mortality ( relative risk 0.70 , 95 % CI 0.2 to 3.1 ) during antiarrhythmic drug therapy . After exclusion of 23 patients with documented ventricular arrhythmias and adjustment for other variables predictive of cardiac death , patients receiving antiarrhythmic drugs were not at increased risk of cardiac death or arrhythmic death . However , in patients with a history of heart failure who received antiarrhythmic drug therapy , the relative risk of cardiac death was 3.3 ( p = 0.05 , 95 % CI 0.99 to 11.1 ) and that of arrhythmic death was 5.8 ( p = 0.009 , 95 % CI 1.5 to 21.7 ) compared with the risk in patients not taking antiarrhythmic medications . CONCLUSIONS Although antiarrhythmic drug therapy was not r and omly determined in this trial , the data suggest that in patients with atrial fibrillation and a history of congestive heart failure , the risk of such therapy may outweigh the potential benefit of maintaining sinus rhythm R and omized trials have indicated that well-managed anticoagulation with warfarin could prevent more than half of the strokes related to atrial fibrillation . However , many patients with atrial fibrillation who are eligible for this therapy either do not receive it or are not maintained within an optimal prothrombin time-international normalized ratio ( INR ) range . We sought to determine whether an anticoagulation service within a managed care organization would be a feasible alternative for providing anticoagulation care . We performed a multi-site r and omized trial in six large managed care organizations in the United States . Subjects were aged 65 years or older and had nonvalvular atrial fibrillation . At each site , physician practice s were divided into two geographically defined practice clusters ; each site was r and omly assigned to have one intervention and one control cluster . The intervention cluster received an anticoagulation service that satisfied specifications for high- quality anticoagulation care and was coordinated through the managed care organization . Control clusters continued with their usual provider-based care . We measured the proportion of time that warfarin-treated patients in each of the clusters ( intervention and control ) were in the target range for the INR at baseline , and again during a follow-up period . Five of the six selected sites succeeded at developing an anticoagulation service . Patients in the intervention and control clusters had similar demographic characteristics , contraindications to warfarin , and risk factors for stroke . Among patients ( n = 144 in the intervention clusters ; n = 118 in the control clusters ) for whom data were available during the baseline and follow-up periods , the changes in percentages of time in the target range were similar for those in the intervention clusters ( baseline : 47.7 % ; follow-up : 55.6 % ) and in the control clusters ( baseline : 49.1 % ; follow-up : 52.3 % ; intervention effect : 5 % ; 95 % confidence interval : -5 % to 14 % ; P = 0.32 ) . Although it was feasible in a managed care organization to implement anticoagulation services that were tailored to local circumstances , provision of this service did not improve anticoagulation care compared with usual care . The effect of the anticoagulation service was limited by the utilization of the service , the degree to which the referring physician supports strict adherence to recommended target ranges for the INR , and the ability of the anticoagulation service to identify and to respond to out-of-range values promptly Atrial fibrillation is the most common type of arrhythmia in adults . It is more common as patients age ; the prevalence is 1 % among those younger than age 60 years and increases to more than 8 % in those older than age 80 years . When data are adjusted for age , men are affected more often than women . Cardiac conditions associated with the development of atrial fibrillation are hypertension , rheumatic mitral valve disease , coronary artery disease , and congestive heart failure . Noncardiac causes include hyperthyroidism , hypoxic pulmonary conditions , surgery , and alcohol intoxication . Patients with atrial fibrillation may have symptoms of hemodynamic compromise , such as irregular palpitations and lightheadedness , or more vague symptoms , such as malaise , but may be asymptomatic . Patients with atrial fibrillation are at increased risk for thromboembolic disease . The purpose of this guideline is to make recommendations on the pharmacologic management of newly detected atrial fibrillation in primary care . The target patient population is adult patients with first-detected atrial fibrillation , defined as the presence of symptoms or electrocardiographic evidence of atrial fibrillation . The American College of Cardiology/American Heart Association has recommended using first-detected atrial fibrillation regardless of whether it is symptomatic or self-limited , recognizing that there can be uncertainty about the duration of the episode and about previous undetected episodes ( 1 ) . This guideline does not apply to patients with postoperative or postmyocardial infa rct ion atrial fibrillation , patients with class IV heart failure , patients already taking antiarrhythmic drugs , or patients with valvular disease . The target physician audience is internists and family physicians dedicated to primary care . This guideline is based on the accompanying background paper by McNamara and colleagues ( 2 ) and on the evidence report Management of New-Onset Atrial Fibrillation ( 3 ) , which was produced by the Johns Hopkins Evidence -based Practice Center under contract to the Agency for Healthcare Research and Quality ( AHRQ ) , Rockville , Maryl and . The American Academy of Family Physicians ( AAFP ) and the American College of Physicians ( ACP ) created this guideline in collaboration . The Joint AAFP/ACP Panel review ed the evidence and developed and grade d the recommendations ( Table 1 ) . The guideline was then approved by both organizations . The guideline makes recommendations in the following areas : rate control versus rhythm control , stroke prevention and anticoagulation , electrical cardioversion versus pharmacologic cardioversion , the role of transesophageal echocardiography in guiding therapy , and maintenance therapy . Table 1 . The Guyatt Approach to Grading Recommendations * Section 1 : Rate Control versus Rhythm Control One of the fundamental questions in the management of atrial fibrillation is whether to attempt cardioversion . The answer to this question depends on whether rate control or rhythm control provides more effective protection from thromboembolic events , improved mortality , better relief of symptoms , or improved quality of life . Another significant clinical question is whether certain population s , such as women , patients with hypertension or congestive heart failure , or young people with structurally healthy hearts , have better outcomes with one or the other strategy . Four studies have compared rate control with rhythm control . The study sample s have generally involved older patients ( > 65 years of age ) , and women and younger patients with healthy hearts and paroxysmal atrial fibrillation have not been well represented ( 5 ) . The Atrial Fibrillation Follow-up Investigation of Rhythm Management ( AFFIRM ) trial compared rhythm control versus rate control , and use of anticoagulation was recommended in both arms ( 6 ) . More than 4000 patients who were at least 65 years of age or who had at least 1 risk factor for stroke or death , such as hypertension , diabetes , previous stroke , or poor ventricular function , were followed for a mean of 3.5 years . Slightly more than one third of the patients were enrolled after their first episode of atrial fibrillation , and more than 90 % had had their qualifying episode within the previous 6 weeks . In more than two thirds of patients , the qualifying episode lasted at least 2 days . The average patient age was 70 years . Sixty-one percent of patients were men , and 89 % were white . Seventy-one percent of patients had hypertension , 38 % had coronary heart disease , 18 % had previously had failure of antiarrhythmic therapy , and 12 % had no apparent heart disease ( lone atrial fibrillation ) . Patients were r and omly assigned to rate or rhythm control , and their physicians chose the specific therapies ( pharmacologic first , then nonpharmacologic if needed ) . Anticoagulation was continued indefinitely in the rate-control group and was encouraged in the rhythm-control group but could be stopped at the physician 's discretion if sinus rhythm had been maintained for at least 4 , and preferably 12 , consecutive weeks with antiarrhythmic therapy . The prevalence of sinus rhythm in the rhythm-control group was 82 % , 73 % , and 63 % at 1 , 3 , and 5 years , respectively . The prevalence of sinus rhythm in the rate-control group was 34.6 % at 5 years . The primary end point in the AFFIRM trial , overall mortality , was not statistically significantly different between the groups . However , the rhythm-control strategy was associated with a higher risk for death than the rate-control strategy among older patients , those without congestive heart failure , and those with coronary disease .  Rates of stroke also did not differ between groups ; 70 % of all strokes occurred in patients who had stopped receiving anticoagulation or who had subtherapeutic international normalized ratios ( < 2.0 ) . More hospitalizations were reported in the rhythm-control group ( P < 0.001 ) . Another recent study , the RAte Control versus Electrical cardioversion for persistent atrial fibrillation ( RACE ) study , r and omly assigned patients to receive aggressive rhythm control or rate control ( 7 ) . This was a smaller study , involving 522 patients ( mean age , 68 years ) . Sixty-four percent of patients were men , 49 % had hypertension , and 27 % had coronary artery disease . All patients had persistent atrial fibrillation lasting less than 1 year and had had at least 1 previous electrical cardioversion ( a maximum of 2 previous cardioversions was permitted for study inclusion ) . The primary end point was a composite of cardiovascular mortality , heart failure , thromboembolic complications , bleeding , pacemaker implantation , and severe side effects of antiarrhythmic drugs . Again , no difference was seen between groups in the primary composite end point . As in the AFFIRM study , most of the strokes occurred in patients whose anticoagulation had been halted or patients whose international normalized ratio was subtherapeutic ( < 2.0 ) . In post hoc analysis , a benefit for rate control over rhythm control was seen in patients with hypertension and in women . Since this was a post hoc analysis , these results will need to be confirmed by further studies . Of note , despite an aggressive treatment protocol , at the end of follow-up only 39 % of the patients in the rhythm-control group were in sinus rhythm . The Pharmacological Intervention in Atrial Fibrillation ( PIAF ) trial r and omly assigned 252 patients 18 to 75 years of age with new-onset or permanent symptomatic atrial fibrillation ( mean duration of atrial fibrillation , approximately 4 months ) to rate control with diltiazem or aggressive conversion ( many times if necessary ) and maintenance therapy with amiodarone ( 8) . The primary end point of the study was improvement in symptoms related to atrial fibrillation . After 1 year of follow-up , relief of symptoms was similar in both groups , as were quality -of-life measures . Walking distance was improved in the rhythm-control group , but hospital admissions were more frequent in this group . Although final results are not yet available , preliminary reports of the Strategies of Treatment of Atrial Fibrillation ( STAF ) trial have been presented ( 9 ) . Patients were r and omly assigned to receive anticoagulation for 3 weeks before conversion and for 4 weeks after attempted conversion , with antiarrhythmic therapy to maintain sinus rhythm , or to long-term anticoagulation and rate control . ( Patients included in this study had at least 1 previous conversion attempt . ) After more than 1.5 years of follow-up , no difference was seen between the groups in rates of the primary end points of death , stroke , transient ischemic attacks , cardiopulmonary resuscitation , or thromboembolism . Of interest , only 40 % of patients in the rhythm-control group were still in sinus rhythm at 1 year , and all primary end points occurred in patients in atrial fibrillation , even in the rhythm-control group . This result has created speculation about whether fewer events would have occurred if anticoagulation had been continued indefinitely in the conversion group . It also suggests that despite aggressive rhythm management , a substantial number of patients can not maintain sinus rhythm . In general , the trial sample s were older and male and had risk factors for stroke , such as hypertension , congestive heart failure , and coronary disease . Certain subgroups of patients with atrial fibrillation , such as younger patients with healthy hearts or paroxysmal atrial fibrillation , were not well represented in the trials . Therefore , it is not certain whether these subgroups of patients may benefit from more aggressive rhythm control or rate control . Recommendation 1 : Rate control with chronic anticoagulation is the recommended strategy for the majority of patients with atrial fibrillation . Rhythm control has not been shown to be superior to rate control ( with chronic anticoagulation ) in reducing morbidity and mortality and may be inferior in some patient subgroups to rate control . Rhythm Purpose Ischemic stroke is a frequent pathology with high rate of recurrence and significant morbidity and mortality . There are several causes of stroke , affecting prognosis , outcomes , and management , but in many cases , the etiology remains undetermined . We hypothesized that atrial fibrillation was involved in this pathology but underdiagnosed by st and ard methods . The aim of the study was to determine the incidence of atrial fibrillation in cryptogenic ischemic stroke by using continuous monitoring of the heart rate over several months . The secondary objective was to test the value of atrial vulnerability assessment in predicting spontaneous atrial fibrillation . Methods and results We prospect ively enrolled 24 patients under 75 years of age , 15 men and 9 women of mean age 49 years , who within the last 4 months had experienced cryptogenic stroke diagnosed by clinical presentation and brain imaging and presumed to be of cardioembolic mechanism . All causes of stroke were excluded by normal 12-lead ECG , 24-h Holter monitoring , echocardiography , cervical Doppler , hematological , and inflammatory tests . All patients underwent electrophysiological study . Of the patients , 37.5 % had latent atrial vulnerability , and 33.3 % had inducible sustained arrhythmia . Patients were secondarily implanted with an implantable loop recorder to look for spontaneous atrial fibrillation over a mean follow-up interval of 14.5 months . No sustained arrhythmia was found . Only one patient had non-significant episodes of atrial fibrillation . Conclusion In this study , symptomatic atrial fibrillation or AF with fast ventricular rate has not been demonstrated by the implantable loop recorder  in patients under 75 years with unexplained cerebral ischemia . The use of this device should not be generalized in the systematic evaluation of these patients . In addition , this study attests that the assessment of atrial vulnerability is poor at predicting spontaneous arrhythmia in such patients
Conclusions and Relevance Although screening with ECG can detect previously unknown cases of atrial fibrillation , it has not been shown to detect more cases than screening focused on pulse palpation .
Treatments for atrial fibrillation reduce the risk of stroke and all-cause mortality and increase the risk of bleeding , but trials have not assessed whether treatment of screen-detected asymptomatic older adults results in better health outcomes than treatment after detection by usual care or after symptoms develop
Importance Atrial fibrillation is the most common arrhythmia and increases the risk of stroke .
Objective To review the evidence on screening for nonvalvular atrial fibrillation with electrocardiography ( ECG ) and stroke prevention treatment in asymptomatic adults 65 years or older to inform the US Preventive Services Task Force .