SAN DIEGO — At 2-year follow-up, 70% of patients with HF and atrial fibrillation who underwent catheter ablation demonstrated freedom from atrial fibrillation compared with 34% of patients who used amiodarone, researchers reported at the American College of Cardiology Scientific Sessions.
The multicenter, randomized, parallel-group, open-label study included 203 patients with NYHA class II to III HF, left ventricular ejection fraction < 40% and a dual-chamber implantable cardioverter defibrillator or cardiac resynchronization therapy device. Half of the patients underwent catheter ablation and half received the antiarrhythmic drug amiodarone.
Luigi Di Biase
Luigi Di Biase, MD, from the Texas Cardiac Arrhythmia Institute at St. David’s Medical Center and Albert Einstein College of Medicine and Montefiore Medical Center, New York City, and colleagues sought to investigate whether catheter ablation is superior to amiodarone for the treatment of persistent AF in this population.
The primary endpoint was long-term procedural success.
Mean duration of follow-up was 26 ± 8 months. Patients in the ablation group underwent an average of 1.4 ± 0.6 procedures. The range of successful ablation procedures was 29% at the low end and 61% at the highest end.
According to results presented, freedom from AF recurrence was significantly different in favor of ablation (P < .001). Among the patients assigned ablation, those who underwent pulmonary vein isolation plus posterior wall and non-pulmonary vein trigger ablation had a higher success rate compared with patients who underwent pulmonary vein isolation alone (78.8% vs. 36.4%; P < .001).
According to multivariate analysis, after adjustment, patients on amiodarone therapy were 2.5 times more likely to fail (HR = 2.5; 95% CI, 1.5-4.3) and diabetes was associated with higher recurrence (HR = 1.1; 95% CI, 1.07-1.26).
At the 2-year follow-up, all-cause mortality was 8% in the ablation group vs. 18% in the amiodarone group (P = .037). Thirty-one percent of patients in the ablation group were hospitalized vs. 57% of patients in the amiodarone group (P < .001). This yielded a relative risk reduction for hospitalization of 45% (RR = 0.55; 95% CI, 0.39-0.76).
Among recurrence-free patients, LVEF improved by an average of 9.6% compared with a 4.2% for patients who experienced recurrence (P < .001). Similarly, 6-minute walk distance (mean change, 27 vs. 8; P < .001) and Minnesota functioning score (mean reduction, 14 vs. 2.9; P < .001) were also improved in recurrence-free patients compared with those who experienced recurrence.
The amiodarone failure rate due to adverse events was 10.4%, according to Di Biase. There were four cases of thyroid toxicity, two cases of pulmonary toxicity and one case of liver dysfunction.
“The potential socio-economic repercussion of these results will require further investigation,” Di Biase said. – by Rob Volansky
Di Biase L, et al. Late Breaker IV Session. Presented at: American College of Cardiology Scientific Sessions; March 14-16, 2015; San Diego.
Disclosure: Di Biase reports associations with Atricure, Biosense Webster, Biotronik, Boston Scientific, Epi EP, Medtronic and St. Jude Medical.