Studies of RFA for treatment of atrial fibrillation report higher efficacy rates than do studies of AAD therapy and a lower rate of complications
BACKGROUND Although radiofrequency catheter ablation ( RFA ) has evolved from an experimental procedure to an important treatment option for atrial fibrillation , the relative safety and efficacy of catheter ablation relative to that of antiarrhythmic drug ( AAD ) therapy has not been established .
Mechanisms Underlying the Lack of Effect of Implantable Cardioverter-Defibrillator Therapy on Mortality in High-Risk Patients With Recent Myocardial Infarction: Insights from the Defibrillation in Acute Myocardial Infarction Trial (DINAMIT)
Background — Although implantable cardioverter-defibrillators ( ICDs ) lower mortality in stable patients with low ejection fraction late after myocardial infa rct ion , r and omized trials of ICD versus control subjects implanted early after myocardial infa rct ion do not show mortality benefit . Our objective was to investigate possible mechanisms underlying the lack of mortality benefit in the Defibrillation in Acute Myocardial Infa rct ion Trial ( DINAMIT ) . Methods and Results — This is a secondary analysis of the prospect i ve r and omized clinical trial . Out patients with recent ( 6 to 40 days ) acute myocardial infa rct ion , left ventricular dysfunction ( ejection fraction < 35 % ) , and low heart rate variability were r and omized to ICD ( n=311 ) or to st and ard medical therapy  ( n=342 ) . In a competing-risks analysis , those factors that increased the risk of arrhythmic death also increased the risk of nonarrhythmic deaths . After adjustment for these factors , receiving an ICD was associated with a decreased risk of arrhythmic death ( hazard ratio , 0.33 ; 95 % confidence interval , 0.15 to 0.71 ) but an increase in nonarrhythmic death ( hazard ratio , 1.70 ; 95 % confidence interval , 1.00 to 2.80 ) . In an adjusted time-dependent analysis , patients receiving an ICD and having appropriate ICD therapy had a 15.1 % yearly hazard of mortality compared with 5.2 % in ICD patients with no appropriate therapy ( P<0.001 ) . The reduction in sudden death in ICD patients was completely offset by increased nonarrhythmic deaths , which were greatest in patients receiving ICD shock therapy ( hazard ratio , 6.0 ; 95 % confidence interval , 2.8 to 12.7 ) . Conclusions — In patients receiving ICDs early after myocardial infa rct ion , those factors that are associated with arrhythmia requiring ICD therapy are also associated with a high risk of nonsudden death , negating the benefit of ICDs in this setting
Studies of RFA for treatment of atrial fibrillation report higher efficacy rates than do studies of AAD therapy and a lower rate of complications
BACKGROUND Although radiofrequency catheter ablation ( RFA ) has evolved from an experimental procedure to an important treatment option for atrial fibrillation , the relative safety and efficacy of catheter ablation relative to that of antiarrhythmic drug ( AAD ) therapy has not been established .