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 .
Primary Results From the SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial: A Randomized Trial Comparing Empirical, Echocardiography-Guided, and Algorithmic Atrioventricular Delay Programming in Cardiac Resynchron
Background — One variable that may influence cardiac resynchronization therapy response is the programmed atrioventricular ( AV ) delay . The SmartDelay Determined AV Optimization : A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy ( SMART-AV ) Trial prospect ively r and omized patients to a fixed empirical AV delay ( 120 milliseconds ) , echocardiographically optimized AV delay , or AV delay optimized with SmartDelay , an electrogram-based algorithm . Methods and Results — A total of 1014 patients ( 68 % men ; mean age , 66±11 years ; mean left ventricular ejection fraction , 25±7 % ) who met enrollment criteria received a cardiac resynchronization therapy defibrillator , and 980 patients were r and omized in a 1:1:1 ratio . All patients were programmed ( DDD-60 or DDDR-60 ) and evaluated after implantation and 3 and 6 months later . The primary end point was left ventricular end-systolic volume . Secondary end points included New York Heart Association class , quality -of-life score , 6-minute walk distance , left ventricular end-diastolic volume , and left ventricular ejection fraction . The medians ( quartiles 1 and 3 ) for change in left ventricular end-systolic volume at 6 months for the SmartDelay , echocardiography , and fixed arms were −21 mL ( −45 and 6 mL ) , −19 mL ( −45 and 6 mL ) , and −15 mL ( −41 and 6 mL ) , respectively . No difference in improvement in left ventricular end-systolic volume at 6 months was observed between the SmartDelay and echocardiography arms ( P=0.52 ) or the SmartDelay and fixed arms ( P=0.66 ) . Secondary end points , including structural ( left ventricular end-diastolic volume and left ventricular ejection fraction ) and functional ( 6-minute walk , quality of life , and New York Heart Association classification ) measures , were not significantly different between arms . Conclusions — Neither SmartDelay nor echocardiography was superior to a fixed AV delay of 120 milliseconds . The routine use of AV optimization techniques assessed in this trial is not warranted . However , these data do not exclude possible utility in selected patients who do not respond to cardiac resynchronization therapy . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT00677014
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 .