EAST-AF: Antiarrhythmic drugs after AF ablation fail to improve clinical outcomes
LONDON — Patients given antiarrhythmic drugs for 90 days after catheter ablation for atrial fibrillation did not have improved clinical outcomes at 1 year, according to the results of the EAST-AF study.
Researchers hypothesized that prescribing short-term antiarrhythmic drugs to those who underwent catheter ablation for AF might reduce early arrhythmia recurrence and promote left atrial reverse remodeling, which could improve long-term clinical outcomes, Kazuaki Kaitani, MD, said at a European Society of Cardiology Congress press conference.
Kaitani, from Tenri Hospital in Tenri City, Nara, Japan, and colleagues randomly assigned 2,044 patients with AF (mean age, 63 years) who had undergone catheter ablation to antiarrhythmic drugs for 90 days or a control group.
The primary endpoint was recurrent atrial tachyarrhythmia at 1 year after a blanking period of 90 days. Secondary endpoints included recurrent atrial tachyarrhythmia within the 90-day blanking period and safety events. The researchers defined recurrent atrial tachyarrhythmia as AF, atrial flutter or atrial tachycardia lasting for at least 30 seconds or requiring repeat ablation, hospitalization or treatment with antiarrhythmic drugs.
Antiarrhythmic drugs prescribed to the intervention group included pilsicanide (25%), flecanide (22.8%), bepridil (19.7%), civenzoline (15.4%), amiodarone (5.2%), propafenone (4.2%), aprindine (3.2%), disopyramide (3.2%) and sotalol (0.8%), Kaitani said. Apridine, civenzoline, flecanide and pilsicanide are not approved for use in the United States. “There might be differences in the recommended [antiarrhythmic drugs] and their dosages between the present study and the Western AF guidelines,” he said.
During the 90-day blanking period, the intervention group had a higher rate of freedom from recurrent atrial tachyarrhythmia compared with controls (59% vs. 52.1%; adjusted HR = 0.84; 95% CI, 0.73-0.96), Kaitani said. However, at 1 year, the difference had disappeared (69.5% vs. 67.8%; adjusted HR = 0.93; 95% CI, 0.79-1.09).
The 1-year results were consistent among those with paroxysmal AF (intervention, 72.5%; control, 72.3%; adjusted HR = 0.97; 95% CI, 0.79-1.2) and persistent or long-lasting AF (intervention, 63%; control, 58.7%; adjusted HR = 0.87; 95% CI, 0.68-1.12), according to the researchers.
Adverse event rates were similar in both groups, and there were no serious adverse events associated with antiarrhythmic drugs such as Torsade de Pointes observed in the intervention group, Kaitani said.
“Therefore, in the EAST-AF study, we concluded that although the temporal treatment with antiarrhythmic drugs for symptomatic patients with early recurrence is acceptable as a symptom reliever, empirical use of antiarrhythmic drugs for improved long-term clinical outcomes is not justified,” Kaitani told Cardiology Today.
EAST-AF was part of a 2 x 2 factorial randomized controlled trial in which the same population also was assigned adenosine triphosphate-guided pulmonary vein isolation or conventional ablation in the UNDER-ATP study. Assignment in the UNDER-ATP trial did not influence the EAST-AF results, and vice versa, Atsushi Kobori, MD, who presented the UNDER-ATP results, said at the press conference.
The results are expected to be published soon in the European Heart Journal, Kaitani said. – by Erik Swain
Kaitani K, et al. Hot Line II: Atrial Fibrillation/Pacing. Presented at: European Society of Cardiology Congress; Aug. 29-Sept. 2, 2015; London.
Disclosure: Kaitani reports no relevant financial disclosures.