STAR-AF 2: Pulmonary vein isolation alone achieved successful outcomes

BARCELONA, Spain — In patients with persistent atrial fibrillation, pulmonary vein isolation alone resulted in successful outcomes without the need for additional ablation, according to results from the STAR-AF 2 study.

Atul Verma, MD, and colleagues enrolled 589 patients with persistent AF who were randomly assigned to only pulmonary vein isolation (PVI; n=67), PVI plus ablation of complex electrograms (n=263) or PVI plus linear ablation (n=259). Three-quarters of patients had been experiencing continuous AF for at least 6 months (median duration, 2.2 years) before receiving treatment.

“This is the largest randomized trial to examine outcomes of catheter ablation in persistent AF,” Verma, a cardiologist at Southlake Regional Heart Center in Newmarket, Ontario, Canada, said during a press conference. “Pulmonary vein isolation alone achieved reasonable success rates. It was comparable to prior published success rates in paroxysmal AF. [This technique alone] may be an effective strategy for persistent AF.”

Successful PVI was achieved in 97% of all patients. The researchers observed no differences between the three groups.

Patients assigned PVI only had a significantly shorter procedural time (167 minutes) compared with patients assigned PVI plus ablation of complex electrograms (229 minutes) and PVI plus linear ablation (222 minutes; P<.001).

At 18 months, freedom from AF recurrence with or without antiarrhythmic medication was similar (59% PVI only; 48% PVI plus ablation of complex electrograms; 44% PVI plus linear ablation; P=.15). The researchers also observed no difference between the groups in the number of patients who were free from AF recurrence without antiarrhythmic medication (48% PVI only, 37% PVI plus ablation of complex electrograms, 33% PVI plus linear ablation; P=.11). After two procedures, freedom from AF recurrence with or without antiarrhythmic medication was also similar (72% PVI only, 60% PVI plus ablation of complex electrograms, 58% PVI plus linear ablation; P=.18). This suggests that “even repeated attempts to create lines or do additional electrogram ablation do not increase success,” Verma said.

These findings have important implications for procedural safety and duration, according to Verma.

“Additional ablation with lines or electrograms increased procedural time, and may increase risk, without any additional benefit in AF reduction. We may need to change [our] thinking from the current guidelines,” he said. – by Katie Kalvaitis

For more information:

Verma A. Hot Line III. Heart Failure: Devices and Interventions. Presented at: the European Society of Cardiology Congress; Aug. 30-Sept. 3, 2014; Barcelona, Spain.

Disclosure: The study was funded by St. Jude Medical. Verma reports receiving research funding from Bayer, Biosense Webster, Biotronik, Medtronic and St. Jude Medical, and serving on the steering committee of trials by Boehringer Ingelheim and Medtronic.