Dallas—A prospective, multi-center, single-blind, randomized trial found that patients with paroxysmal, symptomatic, drug-refractory atrial fibrillation (AF) had no significant difference in freedom from AF or atrial tachyarrhythmias after 1 year if they received high frequency source ablation (HFSA) or circumferential pulmonary vein isolation (CPVI). For patients with persistent AF, there were no statistical differences between using CPVI alone or adding HFSA to CPVI.
Felipe Atienza, MD, lead author of the study, presented the results at the AHA Scientific Sessions during a late-breaking abstract session. He said that the mental and physical quality of life improved in all treatment groups.
“These results may offer a novel mechanistic treatment paradigm for paroxysmal AF patients,” Dr. Atienza said.
Dr. Atienza noted that empiric CPVI is the standard therapy for patients with drug-refractory AF because most of the triggers of the disease come from pulmonary veins. However, the results of the procedure are suboptimal, according to Dr. Atienza. He added that only a few small pilot studies have been completed and strategies to target the drivers of AF are still unknown.
In the RADAR-AF (Radiofrequency Catheter Ablation of Drivers vs. Circumferential Pulmonary Vein Isolation in Patients with Atrial Fibrillation) trial, the authors randomized 232 patients: 115 had paroxysmal AFand 117 had persistent AF. Patients in the paroxysmal AF cohort underwent CPVI or HFSA, while patients in the persistent AF group underwent CPVI or a combination of CPVI and HFSA.
At baseline, the characteristics between patients undergoing CPVI or HFSA were similar. Dr. Atienza said that patients with persistent AF typically had large atria, more comorbidities, and higher CHADS2 scores compared with patients with paroxysmal AF.
At 1 year, 82% of patients with paroxysmal AF who underwent HFSA were free from the disease compared with 79% of patients who underwent CPVI. At 6 months, 73% and 83% of patients, respectively, were free from AF.
In addition, after a year, 74% and 72% of patients, respectively, were free from atrial tachyarrhythmias compared with 66% and 69% at 6 months. Procedure-related adverse events were found in 6% and 14% of patients, respectively, while 9% of patients undergoing HFSA and 24% of patients undergoing CPVI had a serious adverse event.
Further, after a year, 69% of patients with persistent atrial fibrillation who underwent CPVI and HFSA were free from the disease compared with 65% of patients who underwent CPVI. At 6 months, 61% and 60% of patients, respectively, were free from AF.
After a year, 66% and 61% of patients, respectively, were free from atrial tachyarrhythmias compared with 56% and 60% at 6 months. Procedure-related adverse events were found in 10% and 3% of patients, respectively, while 24% of patients undergoing CPVI and HFSA and 10% of patients undergoing CPVI had a serious adverse event.
For the paroxysmal group, a mean of 3.79 pulmonary veins and 2.22 pulmonary were isolated in the CPVI group and HFSA group, respectively. The difference was highly significant, according to Dr. Atienza. There was no difference in the isolated pulmonary veins for patients in the persistent group.