EMBARGO : 30 August 2015 at 09:00 BST
Results of the study, presented as a Hot Line at ESC Congress 2015, were published simultaneously in The European Heart Journal (to be confirmed).
The study did show a temporary benefit of AAD, but the effect disappeared as soon as medication was stopped, suggesting no benefit to making post-ablation AAD therapy standard practice, said study investigator Kazuaki Kaitani, MD, from Tenri Hospital in Tenri, Nara, Japan.
Radiofrequency ablation around the pulmonary veins, known as “pulmonary vein isolation” (PVI), is the standard treatment for AF, but recurrence is common.
Short-term (6 weeks) therapy with AADs after PVI for paroxysmal AF has been previously shown to reduce early arrhythmia recurrence rates compared to no AADs, but this benefit disappeared after treatment discontinuation.
The EAST-AF trial investigated whether a longer treatment period might extend the benefit beyond AAD discontinuation.
The study included 2,044 patients (mean age 63 years) undergoing first radiofrequency catheter ablation for AF at 19 cardiovascular centres in Japan.
Patients were randomised to treatment with AADs (n=1,016) or a control group (n=1,022) for 90 days after the procedure.
The primary endpoint of the study was arrhythmias lasting for more than 30 seconds or requiring repeat ablation, hospital admission, cardioversion or AADs between 3 months and 1-year post ablation.
While there was a significantly lower rate of early arrhythmia recurrences in the AAD group compared with the control group during the treatment period (41.0% versus 47.9%, respectively; P=0.013), this benefit did not persist after AAD discontinuation.
The 1-year recurrence-free rate was 69.5% in the AAD group and 67.8% in the control group, with no significant difference between the two groups (adjusted hazard-ratio [HR] 0.93; 95% confidence-interval, 0.79 to 1.09; P=0.38).
In addition, this finding was consistent across all prespecified subgroups, including patients with paroxysmal AF versus those with persistent or long-lasting AF.
“Therefore, we concluded that the short-term use of AADs for 90-days following catheter ablation of AF reduces the incidence of recurrent AF during the 90-day treatment period, but does not lead to improved clinical outcomes in the later phase,” he said.