A strategy to achieve CRT response in permanent atrial fibrillation without obligatory atrioventricular node ablation. Cardiac resynchronization therapy in patients with atrial fibrillation: a 2-year follow-up study. Four-year efficacy of cardiac resynchronization therapy on exercise tolerance and disease progression: the importance of performing atrioventricular junction ablation in patients with atrial fibrillation. Effect of Cardiac Resynchronization on the Incidence of Atrial Fibrillation in Patients With Severe Heart Failure Atrioventricular nodal ablation predicts survival benefit in patients with atrial fibrillation receiving cardiac resynchronization therapy. Comparison of usefulness of cardiac resynchronization therapy in patients with atrial fibrillation and heart failure versus patients with sinus rhythm and heart failure. Assessment of upgrading to biventricular pacing in patients with right ventricular pacing and congestive heart failure after atrioventricular junctional ablation for chronic atrial fibrillation. Long-term effects of cardiac resynchronisation therapy in patients with atrial fibrillation Effect of QRS Duration and Morphology on Cardiac Resynchronization Therapy Outcomes in Mild Heart Failure: Results From the Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction (REVERSE) Study Cardiac Resynchronization Therapy in Patients With Permanent Atrial Fibrillation: Results From the Resynchronization for Ambulatory Heart Failure Trial (RAFT) Atrial fibrillation in patients with heart failure: Role of catheter ablation therapies. The effect of left ventricular electrical delay on the acute hemodynamic response with cardiac resynchronization therapy. Randomized trial of cardiac resynchronization in mildly symptomatic heart failure patients and in asymptomatic patients with left ventricular dysfunction and previous heart failure symptoms. Outcomes of cardiac resynchronization therapy in patients with intermittent atrial fibrillation or atrial flutter in the COMPANION trial. Radiofrequency catheter ablation of the atria reduces inducibility and duration of atrial fibrillation in dogs. Surface electrocardiogram to predict outcome in candidates for cardiac resynchronization therapy: a sub-analysis of the CARE-HF trial. Effects of atrioventricular conduction delay on the outcome of cardiac resynchronization therapy. Impact of cardiac resynchronization therapy on exercise performance, functional capacity, and quality of life in systolic heart failure with QRS prolongation: COMPANION trial sub-study. Implantable Defibrillators Improve Survival in Patients With Mildly Symptomatic Heart Failure Receiving Cardiac Resynchronization Therapy: Analysis of the Long-Term Follow-Up of Remodeling in Systolic Left Ventricular Dysfunction (REVERSE) Catheter ablation for atrial fibrillation in congestive heart failure. Frequency and Outcomes of Postrandomization Atrial Tachyarrhythmias in the Resynchronization/Defibrillation in Ambulatory Heart Failure Trial Cardiac-resynchronization therapy for mild-to-moderate heart failure. Female gender is associated with a better outcome after cardiac resynchronization therapy.
BACKGROUND Cardiac resynchronization therapy ( CRT ) is an established method in patients with severe heart failure and wide QRS configuration , particularly during sinus rhythm ( SR ) . In CRT patients with permanent atrial fibrillation ( AF ) , there is no general consensus regarding the need for atrioventricular node ( AVN ) ablation . The aim of this study was to evaluate the benefit of CRT in permanent AF with and without AVN ablation . METHODS New York Heart Association classification , QRS duration , and echocardiographic parameters were assessed before and after CRT with a follow-up of 12 ± 3 months . Two hundred thirty patients in SR and 46 patients with permanent AF of 2.1 ± 0.5 years duration were studied .  AVN ablation was performed only in AF patients with insufficient pharmacological rate control evidence d by ≤80 % ventricular stimulation . RESULTS Fifteen AF patients underwent AVN ablation . Biventricular pacing comparably improved functional status , left ventricular ejection fraction , and left ventricular end-diastolic dimensions in all treated groups . Biventricular stimulation percentage was 10 % lower in pharmacologically treated AF patients over 1 year as compared to patients in SR and to AF patients undergoing AVN ablation , which did not affect outcome in this patient population . CONCLUSION In patients with permanent AF and CRT , an AVN ablation strategy might not be strictly required in all patients INTRODUCTION Atrial fibrillation ( AF ) is the most common arrhythmia in patients with heart failure ( HF ) and represents an important comorbidity in these patients . Cardiac resynchronization therapy ( CRT ) has been shown to be beneficial in patients with HF . Whether patients with AF benefit similarly from CRT as their counterparts in sinus rhythm is controversial . METHODS AND RESULTS We conducted a cohort analysis of 175 patients ( 138 men ; age range 57 - 79 years ) who underwent CRT implantation during 2004 - 2008 in our institution . AF was documented in 66 patients ( 37.7 % of patients , 52 men ) . There were no differences in 1- or 2-year mortality between patients with and without AF ( 13.6 % vs 11.79 % , P = 0.7 ; 25.8 % vs 16.9 % , P = 0.2 , respectively ) . There were no differences between the groups in the rate of complications after CRT implantation or in the rate of appropriate electrical shocks . In the subgroup of AF patients with cardiac resynchronization therapy defibrillator ( CRT-D ) ( n = 32 , 48.5 % ) , the 1-year mortality was 3.1 % as compared to 23.5 % in AF patients with cardiac resynchronization therapy pacemaker ( P = 0.03 ) . This difference was no longer evident after 2 years ( 25.0 % vs 26.5 % , P = 0.8 , respectively ) . Ten patients ( 15.2 % ) with AF underwent atrioventricular ( AV ) node ablation . The 2-year mortality of these patients was 10.0 % as compared to 28.6 % in AF patients who did not undergo AV-node ablation ( P = 0.4 ) . CONCLUSIONS In this study , no difference in mortality appears to exist between patients with or without AF and who undergo CRT implantation . Our findings of the beneficial effects of AV-node ablation and CRT-D in AF patients deserve further investigation OBJECTIVES The goal of this study was to investigate the effects of cardiac resynchronization therapy ( CRT ) in heart failure patients with permanent atrial fibrillation ( AF ) and the role of atrioventricular junction ( AVJ ) ablation . BACKGROUND Cardiac resynchronization therapy has been proven effective in heart failure patients with sinus rhythm ( SR ) . However , little is known about the effects of CRT in heart failure patients with permanent AF . METHODS Efficacy of CRT on ventricular function , exercise performance , and reversal of maladaptive remodeling process was prospect ively compared in 48 patients with permanent AF in whom ventricular rate was controlled by drugs , thus result ing in apparently adequate delivery of biventricular pacing ( > 85 % of pacing time ) , and in 114 permanent AF patients , who had undergone AVJ ablation ( 100 % of resynchronization therapy delivery ) . The clinical and echocardiographic long-term outcomes of both groups were compared with those of 511 SR patients treated with CRT . RESULTS Both SR and AF groups showed significant and sustained improvements of all assessed parameters ( model p < 0.001 for all parameters ) . However , within the AF group , only patients who underwent ablation showed a significant increase of ejection fraction ( p < 0.001 ) , reverse remodeling effect ( p < 0.001 ) , and improved exercise tolerance ( p < 0.001 ) ; no improvements were observed in AF patients who did not undergo ablation . CONCLUSIONS Heart failure patients with ventricular conduction disturbance and permanent AF treated with CRT showed large and sustained long-term ( up to 4 year ) improvements of left ventricular function and functional capacity , similar to patients in SR , only if AVJ ablation was performed Background — Atrial fibrillation/flutter ( AF ) and heart failure often coexist ; however , the effect of cardiac resynchronization therapy ( CRT ) on the incidence of AF and on the outcome of patients with new-onset AF remains undefined . Methods and Results — In the CArdiac REsynchronisation in Heart Failure ( CARE-HF ) trial , 813 patients with moderate or severe heart failure were r and omly assigned to pharmacological therapy alone or with the addition of CRT . The incidence of AF was assessed by adverse event reporting and by ECGs during follow-up , and the impact of new-onset AF on the outcome and efficacy of CRT was evaluated . By the end of the study ( mean duration of follow-up 29.4 months ) , AF had been documented in 66 patients in the CRT group compared with 58 who received medical therapy only ( 16.1 % versus 14.4 % ; hazard ratio 1.05 ; 95 % confidence interval , 0.73 to 1.50 ; P=0.79 ) . There was no difference in the time until first onset of AF between groups . Mortality was higher in patients who developed AF , but AF was not a predictor in the multivariable model ( hazard ratio 1.17 ; 95 % confidence interval , 0.82 to 1.67 ; P=0.37 ) . In patients with new-onset AF , CRT significantly reduced the risk for all-cause mortality and all other predefined end points and improved ejection fraction and symptoms ( no interaction between AF and CRT ; all P>0.2 ) . Conclusions — Although CRT did not reduce the incidence of AF , CRT improved the outcome regardless of whether AF developed BACKGROUND Cardiac resynchronization therapy ( CRT ) benefits patients with advanced heart failure . The role of atrioventricular nodal ( AVN ) ablation in improving CRT outcomes , including survival benefit in CRT recipients with atrial fibrillation , is uncertain . OBJECTIVE The purpose of this study was to assess the impact of AVN ablation on clinical and survival outcomes in a large atrial fibrillation and heart failure population that met the current indication for CRT and to determine whether AVN ablation is an independent predictor of survival in CRT recipients . METHODS Of 154 patients with atrial fibrillation who received CRT-D , 45 ( 29 % ) underwent AVN ablation ( + AVN-ABL group ) , whereas 109 ( 71 % ) received drug therapy for rate control during CRT ( -AVN-ABL group ) . New York Heart Association ( NYHA ) class , electrocardiogram , and echocardiogram were assessed before and after CRT .  Survival data were obtained from the national death and location data base ( Accurint ) . RESULTS CRT comparably improved left ventricular ejection fraction ( 8.1 % + /- 10.7 % vs 6.8 % + /- 9.6 % , P = .49 ) and left ventricular end-diastolic diameter ( -2.1 + /- 5.9 mm vs -2.1 + /- 6.7 mm , P = .74 ) in both + AVN-ABL and -AVN-ABL groups . Improvement in NYHA class was significantly greater in the + AVN-ABL group than in -AVN-ABL group ( -0.7 + /- 0.8 vs -0.4 + /- 0.8 , P = .04 ) . Survival estimates at 2 years were 96.0 % ( 95 % confidence interval [ CI ] 88.6%-100 % ) for + AVN-ABL group and 76.5 % ( 95 % CI 68.1%-85.8 % ) for-AVN-ABL group ( P = .008 ) . AVN ablation was independently associated with survival benefit from death ( hazard ratio [ HR ] 0.13 , 95 % CI 0.03 - 0.58 , P = .007 ) and from combined death , heart transplant , and left ventricular assist device ( HR 0.19 , 95 % CI 0.06 - 0.62 , P = .006 ) after CRT . CONCLUSION Among patients with atrial fibrillation and heart failure receiving CRT , AVN ablation for definitive biventricular pacing provides greater improvement in NYHA class and survival benefit . Larger-scale r and omized trials are needed to assess the clinical and survival outcomes of this therapy The prevalence of atrial fibrillation ( AF ) in patients with heart failure is high , but data about the effects of cardiac resynchronization therapy ( CRT ) in patients with chronic AF are scarce . In this prospect i ve observational study of 263 consecutive patients , CRT was performed in 96 patients ( 37 % ) with chronic AF and 167 patients ( 63 % ) with sinus rhythm ( SR ) .  Echocardiographic and clinical parameters were evaluated at baseline and 3 and 12 months . Reverse left ventricular ( LV ) remodeling is defined as LV end-systolic volume decrease > or = 10 % . Hospitalization rates for heart failure in the year before and after implantation were compared . Baseline characteristics between patients with and without AF were similar , but the AF group had smaller LV end-systolic and end-diastolic volumes and larger left atrial dimensions . New York Heart Association class , 6-minute walking distance , quality -of-life score , LV ejection fraction , and mitral regurgitation improved significantly at 3 and 12 months in both groups , and the changes were similar . Reverse LV remodeling after 3 and 12 months was 74 % and 82 % ( AF group ) versus 77 % and 83 % , respectively ( SR group , p = 0.79 ) . After 1 year , cardioversion had occurred in 25 % of patients with AF . In the year after implantation , significant decreases in hospitalizations for heart failure in both groups ( 84 % and 90 % ) were documented . Long-term mortality was almost equal in both groups . In conclusion , this large-scale study shows that the benefit of CRT in patients with chronic AF and heart failure is similar to that in patients with SR . Patients with chronic AF and heart failure should be considered c and i date s for CRT AIMS Effects of cardiac resynchronization therapy ( CRT ) in patients with right ventricular pacing and congestive heart failure ( CHF ) have only been reported in limited series . CRT in patients with atrial fibrillation remains controversial . Patients with AV junctional ablation offer a unique opportunity to study the effects of CRT in patients with right ventricular pacing combined with atrial fibrillation . The aims of the present study were to evaluate the effects of upgrading to biventricular pacing patients with CHF , permanent atrial fibrillation , and prior ablation of the atrioventricular ( AV ) junction followed by conventional right ventricular pacing . METHODS AND RESULTS We studied 16 consecutive patients with permanent atrial fibrillation treated by AV junctional ablation .  After a mean follow-up of 20+/-19 months ( 6 weeks to 5 years ) they were successfully up grade d to biventricular pacing for severe CHF . Parameters were prospect ively evaluated at baseline and at 6 months . The 14 surviving patients at 6 months demonstrated significant improvement ( P<0.02 ) in New York Heart Association class but the exercise test parameters remained unchanged . Cardiothoracic ratio decreased by 5 % ( P=0.04 ) , end-systolic diameter by 8 % ( P=0.001 ) , end-diastolic diameter by 4 % ( P=0.08 ) , systolic pulmonary artery pressure by 17 % ( P<0.0001 ) and mitral regurgitation area by 40 % ( P<0.05 ) . Ejection fraction increased by 17 % ( P=0.11 ) and fractional shortening by 24 % ( P=0.01 ) . CONCLUSION CRT improves left ventricular performance and functional status in patients with permanent atrial fibrillation and prior remote right ventricular pacing Objective : To compare the effects of cardiac resynchronisation therapy ( CRT ) in patients with heart failure ( HF ) in either atrial fibrillation ( AF ) or sinus rhythm ( SR ) . Design : Prospect i ve observational study . Patients : 295 consecutive patients with HF ( permanent AF in 66 , paroxysmal AF in 20 , SR in 209 ; New York Heart Association ( NYHA ) class III or IV ; left ventricular ejection fraction ( LVEF ) ⩽35 % , QRS ⩾120 ms ) . Interventions : All patients underwent CRT without atrioventricular junction ablation . Main outcome measures : The primary end point was the composite of cardiovascular death or unplanned hospitalisation for major cardiovascular events . Secondary end points included the composite of cardiovascular death or hospitalisation for worsening HF . Cardiovascular mortality , total mortality and changes in NYHA class , 6-minute walking distance , quality of life ( Minnesota Living with Heart Failure question naire ) and echocardiographic variables were also considered . Results : Over a follow-up period of up to 6.8 years , no differences emerged between patients in AF or SR in any of the mortality or morbidity end points . The AF and SR groups derived similar improvements in mean NYHA class ( −1.3 vs –1.2 ) , 6-minute walking distance ( 92.3 vs 78.4 m ) and quality of life scores ( −25.2 vs –18.7 ) ( all p<0.001 ) . In both the AF and the SR groups , reductions were seen in left ventricular end-systolic ( −25.9 vs –34.5 ml , both p<0.001 ) and end-diastolic ( −20.2 ml , p = 0.001 vs 26.2 ml , p<0.001 ) volumes and improvements in LVEF ( 4.69 % vs 7.86 % , both p<0.001 ) . Conclusions : Cardiac resynchronisation therapy leads to similar prognostic and symptomatic benefits in patients in AF and SR , even without atrioventricular junction ablation . Echocardiographic improvements are also comparable Background — Cardiac resynchronization therapy ( CRT ) decreases mortality , improves functional status , and induces reverse left ventricular remodeling in selected population s with heart failure . We aim ed to assess the impact of baseline QRS duration and morphology and the change in QRS duration with pacing on CRT outcomes in mild heart failure . Methods and Results — Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction ( REVERSE ) was a multicenter r and omized trial of CRT  among 610 patients with mild heart failure . Baseline and CRT-paced QRS duration s and baseline QRS morphology were evaluated by blinded core laboratories . The mean baseline QRS duration was 151±23 milliseconds , and 60.5 % of subjects had left bundle-branch block ( LBBB ) . Patients with LBBB experienced a 25.3-mL/m2 mean reduction in left ventricular end-systolic volume index ( P<0.0001 ) , whereas non-LBBB patients had smaller decreases ( 6.7 mL/m2 ; P=0.18 ) . Baseline QRS duration was also a strong predictor of change in left ventricular end-systolic volume index with monotonic increases as QRS duration prolonged . Similarly , the clinical composite score improved with CRT for LBBB subjects ( odds ratio , 0.530 ; P=0.0034 ) but not for non-LBBB subjects ( odds ratio , 0.724 ; P=0.21 ) . The association between clinical composite score and QRS duration was highly significant ( odds ratio , 0.831 for each 10-millisecond increase in QRS duration ; P<0.0001 ) , with improved response at longer QRS duration s. The change in QRS duration  with CRT pacing was not an independent predictor of any outcomes after correction for baseline variables . Conclusion — REVERSE demonstrated that LBBB and QRS prolongation are markers of reverse remodeling and clinical benefit with CRT in mild heart failure . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT00271154 Background —Cardiac resynchronization ( CRT ) prolongs survival in patients with systolic heart failure and QRS prolongation . However , most trials excluded patients with permanent atrial fibrillation . Methods and Results —The Resynchronization for Ambulatory Heart Failure Trial ( RAFT ) r and omized patients to an implantable cardioverter defibrillator ( ICD ) or ICD+CRT , stratified by the presence of permanent atrial fibrillation . Patients with permanent atrial fibrillation were r and omized to CRT-ICD ( n=114 ) or ICD ( n=115 ) . Patients receiving a CRT-ICD were similar to those receiving an ICD  : age ( 71.6±7.3 versus 70.4±7.7 years ) , left ventricular ejection fraction ( 22.9±5.3 % versus 22.3±5.1 % ) , and QRS duration ( 151.0±23.6 versus 153.4±24.7 ms ) . There was no difference in the primary outcome of death or heart failure hospitalization between those assigned to CRT-ICD versus ICD ( hazard ratio , 0.96 ; 95 % CI , 0.65–1.41 ; P=0.82 ) . Cardiovascular death was similar between treatment arms ( hazard ratio , 0.97 ; 95 % CI , 0.55–1.71 ; P=0.91 ) ; however , there was a trend for fewer heart failure hospitalizations with CRT-ICD ( hazard ratio , 0.58 ; 95 % CI , 0.38–1.01 ; P=0.052 ) . The change in 6-minute hall walk duration between baseline and 12 months was not different between treatment arms ( CRT-ICD : 19±84 m versus ICD : 16±76 m ; P=0.88 ) . Patients treated with CRT-ICD showed a trend for a greater improvement in Minnesota Living with Heart Failure score between baseline and 6 months ( CRT-ICD : 41±21 to 31±21 ; ICD : 33±20 to 28±20 ; P=0.057 ) . Conclusions — Patients with permanent atrial fibrillation who are otherwise CRT c and i date s appear to gain minimal benefit from CRT-ICD compared with a st and ard ICD . Clinical Trial Registration —URL : http://www . clinical trials.gov . Unique identifier : NCT00251251 Atrial fibrillation ( AF ) represents the most common sustained cardiac arrhythmia in patients with heart failure ( HF ) . AF in HF patients is associated with worsening of symptoms and also results in a substantial increase in mortality . Although HF patients in sinus rhythm have a better outcome than patients with AF , several r and omized studies investigating pharmacological rhythm control versus rate control have shown no advantage of one strategy over the other in terms of patient outcomes . Catheter-based ablation therapy is a newer therapeutic option with a rapidly evolving and changing role in the management of this arrhythmia . In the present review , the authors discuss the epidemiology , pathophysiology and prognostic significance of AF in patients with HF . Exclusively addressed are studies investigating catheter-based ablation for rhythm-control and rate-control therapies in the management of AF in HF patients INTRODUCTION Cardiac resynchronization therapy ( CRT ) improves hemodynamic function , as well as reduces hospitalizations and mortality among patients with systolic dysfunction , QRS prolongation , and heart failure . The magnitude of the hemodynamic response is associated with improved outcomes , so optimization of this parameter is a goal of therapy . The purpose of this study was to evaluate the effect of left ventricular ( LV ) electrical delay , as assessed by the QLV interval , on the acute hemodynamic response to CRT . METHODS AND RESULTS This study included 31 patients undergoing biventricular ICD placement .  At implant , invasive LV dP/dt was measured by a micromanometer catheter during biventricular ( BV ) or LV only pacing . Both atrial sensing ( AS ) and atrial pacing ( AP ) modes were evaluated at 5 different AV delays , tested in r and omized order . The QLV interval was measured at the LV pacing site . Compared with intrinsic rhythm , CRT  increased LV dP/dtmax by 9.5 ± 8.8 % with BV pacing and 10.0 ± 9.2 % with LV pacing ( P = 0.38 ) during AS . With AP , CRT  increased LV dP/dtmax by 16.0 ± 10.8 % and 15.3 ± 11.1 % , respectively ( P = 0.47 ) . QLV was strongly correlated with the hemodynamic response in all pacing configurations . Multivariate analysis showed that with BV pacing QLV was an independent predictor of the hemodynamic response with a 1.7 % increase in % LV dP/dt for every 10 milliseconds prolongation of QLV . CONCLUSIONS LV electrical delay is a strong predictor of the acute hemodynamic response to CRT . This relationship is independent of pacing mode OBJECTIVES We sought to determine the effects of cardiac resynchronization therapy ( CRT ) in New York Heart Association ( NYHA ) functional class II heart failure ( HF ) and NYHA functional class I ( American College of Cardiology/American Heart Association stage C ) patients with previous HF symptoms . BACKGROUND Cardiac resynchronization therapy improves left ventricular ( LV ) structure and function and clinical outcomes in NYHA functional class III and IV HF with prolonged QRS . METHODS Six hundred ten patients with NYHA functional class I or II heart failure with a QRS > or = 120 ms and a LV ejection fraction < or = 40 % received a CRT device ( + /-defibrillator )  and were r and omly assigned to active CRT ( CRT-ON ; n = 419 ) or control ( CRT-OFF ; n = 191 ) for 12 months . The primary end point was the HF clinical composite response , which scores patients as improved , unchanged , or worsened . The prospect ively powered secondary end point was LV end-systolic volume index . Hospitalization for worsening HF was evaluated in a prospect i ve secondary analysis of health care use . RESULTS The HF clinical composite response end point , which compared only the percent worsened , indicated 16 % worsened in CRT-ON compared with 21 % in CRT-OFF ( p = 0.10 ) . Patients assigned to CRT-ON experienced a greater improvement in LV end-systolic volume index ( -18.4 + /- 29.5 ml/m2 vs. -1.3 + /- 23.4 ml/m2 , p < 0.0001 ) and other measures of LV remodeling . Time-to-first HF hospitalization was significantly delayed in CRT-ON ( hazard ratio : 0.47 , p = 0.03 ) . CONCLUSIONS The REVERSE ( REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction ) trial demonstrates that CRT , in combination with optimal medical therapy ( + /-defibrillator ) , reduces the risk for heart failure hospitalization and improves ventricular structure and function in NYHA functional class II and NYHA functional class I ( American College of Cardiology/American Heart Association stage C ) patients with previous HF symptoms . ( REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction [ REVERSE ] ; NCT00271154 ) BACKGROUND Controlled clinical trial data are lacking for cardiac resynchronization therapy ( CRT ) outcomes in patients with advanced heart failure ( HF ) from reduced left ventricular ejection fraction ( HFrEF ) and intermittent atrial fibrillation or flutter ( IAF/AFL ) . OBJECTIVE The purpose of this study was to describe CRT outcomes in patients with IAF/AFL and advanced HF . METHODS HF outcomes in patients in the COMPANION ( Comparison of Medical Therapy , Pacing , and Defibrillation in Heart Failure ) trial with New York Heart Association class III or IV HFrEF , left ventricular ejection fraction ≤0.35 , sinus rhythm at r and omization , and no history of baseline arrhythmia were compared with those with a history of IAF/AFL . RESULTS In those with no history of baseline arrhythmia ( n = 887 ) , compared with optimal pharmacological therapy ( OPT ) with no CRT , the CRT + OPT arms exhibited a significant reduction in the end points of death or any hospitalization ( hazard ratio [ HR ] 0.73 [ 95 % Confidence Interval ( CI ) : 0.60 to 0.89 ] ; P = .002 ) and death or HF hospitalization ( HR 0.53 [ 95 % CI : 0.41 to 0.68 ] ; P < .001 ) . In contrast , in the IAF/AFL subgroup ( n = 293 ) , CRT did not result in improved outcomes compared with OPT ( death or any hospitalization : HR 1.16 [ 95 % CI : 0.83 to 1.63 ] ; P = .38 ; death or HF hospitalization : HR 0.97 [ 95 % CI : 0.64 to 1.46 ] ; P = .88 ) . The interaction between history of AF/AFL and CRT was statistically significant for both outcomes ( P < .05 ) . CONCLUSION In the COMPANION trial , patients with moderate to severe HFrEF and a history of IAF/AFL had no benefit from CRT BACKGROUND The purpose of this study was to prevent induction of sustained atrial fibrillation ( AF ) by radiofrequency catheter ablation ( RFCA ) of the atria in an open-chest canine model . METHODS AND RESULTS In dogs r and omized to acute studies , RFCA of the atria was performed after reproducible induction of sustained AF ( lasting > 30 minutes ) with burst stimulation or premature atrial pacing and perpetuation by low level cervical vagal stimulation or IV infusion of methacholine . Additionally , in four dogs , the long-term effectiveness of RFCA was assessed 7 to 21 days after ablation . Continuous discrete transmural lesions were produced with radiofrequency energy pulses ( 20 to 40 W for 60 seconds ) delivered to five atrial epicardial sites and endovascularly to the coronary sinus wall . RFCA electrically isolated regions of the atria that became dissociated from the nonisolated parts . Atrial RFCA markedly attenuated vagally induced shortening of effective refractory period ( ERP ) at both isolated and nonisolated test sites located in the left and right atria ( P < .001 , n = 5 ) . RFCA rendered noninducible sustained AF maintained by cervical vagal stimulation . The dose-response curve relating the dose of methacholine required to maintain AF was shifted down and to the right . AF was only inducible with high doses of methacholine . Atrial RFCA reduced the maximal sinus rate and prolonged the corrected sinus-node recovery time ( P < .001 , n = 6 ) . However , RFCA did not affect atrial contractile function , AV-nodal ERP , or AV-nodal or His-Purkinje conduction times . In dogs in the chronic group , normal sinus rhythm and normal AV conduction were preserved and AF was only inducible with a high dose of methacholine . No atrial perforations result ed . CONCLUSIONS RFCA in open-chest dogs produces partial vagal denervation and reduces the inducibility of AF AIMS In CARE-HF , cardiac resynchronization therapy ( CRT ) lowered morbidity and mortality in patients with moderate to severe heart failure . We examined whether baseline and follow-up electrocardiographic characteristics might predict long-term outcome . METHODS AND RESULTS CARE-HF r and omly assigned 409 patients to medical therapy ( MT ) plus CRT , and 404 patients to MT alone .  Electrocardiographic measurements were made at baseline during sinus rhythm , and at 3 months during paced or spontaneous rhythm depending on treatment assignment . Favourable outcome was defined as freedom from death , urgent transplantation , or cardiovascular hospitalization . Among patients assigned to CRT , 39 % had unfavourable outcomes including 55 deaths . By single variable analysis , ( i ) prolonged PR interval , left QRS axis ( but not QRS duration ) , and left bundle branch block ( BBB ) at baseline , and ( ii ) heart rate , PR , and QRS duration at 3 months predicted unfavourable outcome . By multiple variable analysis , treatment assignment ( P = 0.0001 ) , PR ( P = 0.0004 ) , and right BBB ( P < 0.00013 ) at baseline predicted outcome , whereas baseline JTc and QRS duration at 3 months predicted all-cause mortality and heart failure hospitalization ( P = 0.0071 ) . CONCLUSION In CARE-HF , QRS duration at baseline did not predict outcome , but QRS at 3 months was a predictor by single variable analysis . Patients with prolonged PR interval and the 5 % of patients with right BBB had a particularly high event rate BACKGROUND AND PURPOSE First-degree atrioventricular ( AV ) block in relation to the outcome of cardiac resynchronization therapy ( CRT )  has not been well examined . METHODS Patients who received a CRT defibrillator or pacemaker between January 2002 and September 2010 at Mayo Clinic were classified into 2 groups : normal PR interval and prolonged PR interval . St and ard sensed ( 100 milliseconds ) and paced ( 130 milliseconds ) AV delay was programmed after CRT .  Clinical presentations and echocardiography were assessed before CRT and at a median of 6 months after CRT . RESULTS The normal PR interval group ( n=199 ) had greater improvements in heart failure functional class ( mean [ SD ] , 0.7 [ 0.8 ] vs 0.5 [ 0.9 ] ; P=.03 ) and left ventricular ejection fraction ( 9.4 % [ 12.4 % ] vs 5.9 % [ 9.5 % ] ; P=.007 ) than the prolonged PR group ( n=204 ) . CONCLUSION Compared with prolonged PR interval , the presence of normal PR interval was associated with a greater improvement in heart failure BACKGROUND A total of 405 participants in the Comparison of Medical Therapy , Pacing , and Defibrillation in Heart Failure trial were prospect ively enrolled in an exercise sub- study design ed to study the influence of cardiac resynchronization therapy ( CRT ) on measures of exercise capacity , functional capacity , and quality of life ( QOL ) . METHODS AND RESULTS Sub study eligibility included New York Heart Association ( NYHA ) functional Class III or IV heart failure , left ventricular ejection fraction < or = 0.35 , QRS interval of > or = 120 ms , normal sinus rhythm , a heart failure hospitalization ( or equivalent ) within 1 year , a peak VO2 < or = 22 mL x kg x min , the ability to walk 150 to 425 meters in 6 minutes , forced expiratory volume in 1 second/forced vital capacity > or = 50 % , and no clinical indication for a pacemaker or implantable cardioverter-defibrillator . Patients were r and omized in a 1:4 ratio to optimal medical therapy ( OPT ) or to OPT plus CRT .  Cardiopulmonary exercise testing ( peak VO2 and 6-minute walk distance [ 6MWD ] ) and assessment of NYHA functional class and QOL were assessed at baseline and at 3 and 6 months of assigned therapy . There was no significant improvement in peak VO2 at 6 months in the CRT group compared with the OPT group ( + 0.63 mL x kg x min ) by unadjusted analysis ( P = .05 ) or by analyses adjusted for missing data . Thus the primary end point of the study was not met . There was significantly greater improvement in the 6MWD in the CRT group compared with the OPT group at both 3 and 6 months by both statistical methods ( P < or = .045 ) . Likewise , a greater proportion of CRT patients improved by 1 or more NYHA functional classes ( P < .01 ) at 3 months and had better QOL scores ( P < .01 ) at 3 and 6 months compared with the OPT patients . Baseline peak VO2 predicted clinical events ( time to death , time to death or first hospitalization , or time to death and first heart failure hospitalization : P < .05 ) in CRT participants . CONCLUSION CRT patients with moderate to advanced symptoms of systolic heart failure and prolonged QRS intervals benefit from the addition of CRT to OPT in terms of exercise capacity , functional status , and QOL .  CRT should be considered st and ard therapy in this select group of heart failure patients Background —Cardiac resynchronization therapy ( CRT ) decreases mortality , improves functional status , and induces reverse left ventricular remodeling in selected population s with heart failure . These benefits have been noted with both CRT-pacemakers as well as those devices with defibrillator backup ( CRT-D ) . However , there are little data comparing mortality between these 2 device types . Methods and Results —REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction ( REVERSE ) was a multicenter , r and omized trial of CRT among patients with mild heart failure . Long-term annual follow-up for 5 years was preplanned . The present analysis was confined to the 419 patients who were r and omized to active CRT group .  CRT-pacemakers or CRT-D devices were implanted based on national guidelines at the time of enrollment , with 74 patients receiving CRT pacemaker devices and the remaining 345 patients receiving CRT-D devices .  After 12 months of CRT , changes in the clinical composite score , left ventricular end systolic volume index , 6-minute walk time , and quality of life indices were similar between CRT pacemaker and CRT-D patients . However , long-term follow-up showed lower morality in the CRT-D group . Specifically , multivariable analysis showed that CRT-D ( hazard ratio , 0.35 ; P=0.003 ) was a strong independent predictor of survival . Female sex , longer unpaced QRS duration , and smaller baseline left ventricular end systolic volume index also were also associated with better survival . Conclusions —REVERSE demonstrated that the addition of implantable cardioverter-defibrillator therapy to CRT is associated with improved long-term survival compared with CRT pacing alone in mild heart failure . Clinical Trial Registration —URL : http:// clinical trials.gov . Unique Identifier : NCT00271154 BACKGROUND Congestive heart failure and atrial fibrillation often coexist , and each adversely affects the other with respect to management and prognosis . We prospect ively evaluated the effect of catheter ablation for atrial fibrillation on left ventricular function in patients with heart failure . METHODS We studied 58 consecutive patients with congestive heart failure and a left ventricular ejection fraction of less than 45 percent who were undergoing catheter ablation for atrial fibrillation .  We selected as controls 58 patients without congestive heart failure who were undergoing ablation for atrial fibrillation , matched according to age , sex , and classification of atrial fibrillation . We evaluated the patients ' left ventricular function and dimensions , symptom score , exercise capacity , and quality of life at baseline and at months 1 , 3 , 6 , and 12 . RESULTS After a mean ( + /-SD ) of 12+/-7 months , 78 percent of the patients with congestive heart failure and 84 percent of the controls remained in sinus rhythm ( P=0.34 ) ( 69 percent and 71 percent , respectively , were in sinus rhythm without the administration of antiarrhythmic drugs ) . The patients with congestive heart failure had significant improvement in left ventricular function ( increases in the ejection fraction and fractional shortening of 21+/-13 percent and 11+/-7 percent , respectively ; P<0.001 for both comparisons ) , left ventricular dimensions ( decreases in the diastolic and systolic diameters of 6+/-6 mm and 8+/-7 mm , respectively ; P=0.03 and P<0.001 , respectively ) , exercise capacity , symptoms , and quality of life . The ejection fraction improved significantly not only in patients without concurrent structural heart disease ( 24+/-10 percent , P<0.001 ) and those with inadequate rate control before ablation ( 23+/-10 percent , P<0.001 ) , but also in those with coexisting heart disease ( 16+/-14 percent , P<0.001 ) and adequate rate control before ablation ( 17+/-15 percent , P<0.001 ) . CONCLUSIONS Restoration and maintenance of sinus rhythm by catheter ablation without the use of drugs in patients with congestive heart failure and atrial fibrillation significantly improve cardiac function , symptoms , exercise capacity , and quality of life Background —Whether adding cardiac resynchronization therapy ( CRT-D ) to an implanted cardioverter – defibrillator alters the risk of atrial fibrillation or other atrial tachyarrhythmias ( AF/AT ) , or if postimplantation AF/AT modulate the benefits of CRT-D , remain unknown . Methods and Results —We studied 972 Resynchronization/Defibrillation in Ambulatory Heart Failure Trial ( RAFT ) participants without permanent AF , who were r and omized to CRT-D ( n=495 ) versus nonresynchronization defibrillator ( implanted cardioverter – defibrillator ; n=477 ) within the predefined stratum eligible for an atrial lead . Occurrence of postr and omization AF/AT was prospect ively assessed , and Cox models were used to test the independent association between the postr and omization AF/AT and the RAFT primary composite outcome of all-cause mortality or hospitalization for heart failure . Over 41 ( ±19 ) months , postr and omization AF/AT occurred in 216 ( 45.3 % ) patients r and omized to implanted cardioverter – defibrillator and 249 ( 50.3 % ) r and omized to CRT-D. After adjusting for competing risk of death , r and omization to CRT-D increased risk of postr and omization AF/AT ( hazard ratio , 1.20 ; 95 % confidence interval , 1.00–1.42 ; P=0.045 ) . Postr and omization AF/AT , which remained paroxysmal in 69.5 % , did not reduce biventricular pacing percentage . In adjusted models , postr and omization AF/AT was not associated with the primary outcome ( hazard ratio , 1.04 ; 95 % confidence interval , 0.84–1.30 ) . However , AF/AT was associated with a borderline decreased risk of mortality ( hazard ratio , 0.75 ; 95 % confidence interval , 0.58–1.00 ) but increased risk of heart failure hospitalization ( hazard ratio , 1.43 ; 95 % confidence interval , 1.08–1.90 ) . Conclusions —In RAFT , nearly half of the patients developed postr and omization AF/AT , and those r and omized to CRT-D had borderline significant higher risk . Postr and omization AF/AT was associated with risk of heart failure hospitalization , but not with the primary composite outcome . Clinical Trial Registration —URL : http://www . clinical trials.gov . Unique identifier : NCT00251251 BACKGROUND Cardiac-resynchronization therapy ( CRT ) benefits patients with left ventricular systolic dysfunction and a wide QRS complex . Most of these patients are c and i date s for an implantable cardioverter-defibrillator ( ICD ) . We evaluated whether adding CRT to an ICD and optimal medical therapy might reduce mortality and morbidity among such patients . METHODS We r and omly assigned patients with New York Heart Association ( NYHA ) class II or III heart failure , a left ventricular ejection fraction of 30 % or less , and an intrinsic QRS duration of 120 msec or more or a paced QRS duration of 200 msec or more to receive either an ICD alone or an ICD plus CRT . The primary outcome was death from any cause or hospitalization for heart failure . RESULTS We followed 1798 patients for a mean of 40 months . The primary outcome occurred in 297 of 894 patients ( 33.2 % ) in the ICD-CRT group and 364 of 904 patients ( 40.3 % ) in the ICD group ( hazard ratio in the ICD-CRT group , 0.75 ; 95 % confidence interval [ CI ] , 0.64 to 0.87 ; P<0.001 ) . In the ICD-CRT group , 186 patients died , as compared with 236 in the ICD group ( hazard ratio , 0.75 ; 95 % CI , 0.62 to 0.91 ; P = 0.003 ) , and 174 patients were hospitalized for heart failure , as compared with 236 in the ICD group ( hazard ratio , 0.68 ; 95 % CI , 0.56 to 0.83 ; P<0.001 ) . However , at 30 days after device implantation , adverse events had occurred in 124 patients in the ICD-CRT group , as compared with 58 in the ICD group ( P<0.001 ) . CONCLUSIONS Among patients with NYHA class II or III heart failure , a wide QRS complex , and left ventricular systolic dysfunction , the addition of CRT to an ICD reduced rates of death and hospitalization for heart failure . This improvement was accompanied by more adverse events . ( Funded by the Canadian Institutes of Health Research and Medtronic of Canada ; Clinical Trials.gov number , NCT00251251 . ) BACKGROUND Some studies have suggested that women respond differently to cardiac resynchronization therapy ( CRT ) . We sought to determine whether female gender influences long-term clinical outcome , symptomatic response as well as echocardiographic response after CRT . METHODS AND RESULTS A total of 550 patients ( age 70.4 ± 10.7 yrs [ mean ± st and ard deviation ] ) were followed up for a maximum of 9.1 years ( median : 36.2 months ) after CRT-pacing ( CRT-P ) or CRT-defibrillation ( CRT-D ) device implantation . Outcome measure included mortality as well as unplanned hospitalizations for heart failure or major adverse cardiovascular events ( MACE ) . Female gender predicted survival from cardiovascular death ( hazard ratio [ HR ] : 0.52 , P = 0.0051 ) , death from any cause ( HR : 0.52 , P = 0.0022 ) , the composite endpoints of cardiovascular death /heart failure hospitalizations ( HR : 0.56 , P = 0.0036 ) and death from any cause/hospitalizations for MACE ( HR : 0.67 , P = 0.0214 ) . Female gender predicted death from pump failure ( HR : 0.55 , P = 0.0330 ) but not sudden cardiac death . Amongst the 322 patients with follow-up echocardiography , left ventricular ( LV ) reverse remodelling ( ≥ 15 % reduction in LV end-systolic volume ) was more pronounced in women ( 62 % vs 44 % , P = 0.0051 ) . In multivariable Cox proportional hazards analyses , the association between female gender and cardiovascular survival was independent of age , LV ejection fraction , atrial rhythm , QRS duration , CRT device type , New York Heart Association ( NYHA ) class , and LV reverse remodelling ( adjusted HR : 0.48 , P = 0.0086 ) . At one year , the symptomatic response rate ( improvement by ≥ 1 NYHA classes or ≥ 25 % increase in walking distance ) was 78 % for both women and men . CONCLUSIONS Female gender is independently associated with a lower mortality and morbidity after CRT
AV nodal ablation was associated with a substantial reduction in all-cause mortality and cardiovascular mortality and with improvements in New York Heart Association functional class compared with medical therapy in CRT-AF patients .
OBJECTIVES The aim of this study was to systematic ally review the medical literature to evaluate the impact of AV nodal ablation in patients with heart failure and coexistent atrial fibrillation ( AF ) receiving cardiac resynchronization therapy ( CRT ) .
BACKGROUND CRT has a substantial evidence base in patients in sinus rhythm with significant systolic dysfunction , symptomatic heart failure , and prolonged QRS duration .
The role of CRT is less well established in AF patients with coexistent heart failure .
AV nodal ablation has recently been suggested to improve outcomes in this group .