Catheter ablation was found to be superior to optimal drug therapy for the primary treatment of atrial fibrillation (AFib) in the randomized CABANA trial presented May 10 at the Heart Rhythm Society’s annual scientific sessions in Boston. However, there was a caveat.
Ablation didn’t produce a significant reduction in the primary composite endpoint of death, disabling stroke, serious bleeding or cardiac arrest in the intention-to-treat analysis. It was found to reduce this endpoint by 14 percent and all-cause mortality by 15 percent—both of which were statistically insignificant.
But, considering the higher crossover rate from medical therapy to ablation than vice versa, the catheter-based procedure showed more significant reductions in these outcomes among patients who received treatment. In the on-treatment analysis, those receiving ablation had a 33 percent reduction in the primary composite endpoint (7 percent versus 10.9 percent) after a median follow-up of four years. They also showed a 40 percent reduction in all-cause mortality (4.4 percent versus 7.5 percent).
“We believe CABANA is a landmark trial that provides the evidence we have been looking for in the effectiveness and safety of catheter ablation when compared to drug therapy,” principal investigator Douglas L. Packer, MD, a Mayo Clinic cardiologist and past president of the Heart Rhythm Society (HRS), said in a press release. “Not only is CABANA the largest randomized trial of ablation, but it is also the most comprehensive and inclusive study to show results for outcomes such as mortality, stroke, and CV hospitalization.
“We were able to capture an incredible amount of data that shows ablation is an acceptable treatment strategy for treating AF with low adverse event rates even in higher risk patients. The data from this trial has the potential to guide treatment of atrial fibrillation for years to come.”
The trial included 2,204 patients from 126 worldwide sites who were randomized 1:1 to either catheter ablation or drug therapy. All patients had either new-onset or undertreated AFib and were deemed eligible for ablation and at least two rhythm or rate control drugs. Participants were an average of 68 years old, 63 percent male and 81 percent had hypertension.
According to the release, Packer and colleagues expect to publish multiple subgroup analyses analyzing the outcomes of ablation versus drug therapy based on age, type of AFib and underlying comorbidities.
“We applaud Dr. Packer and the entire investigative team for leading this groundbreaking study that represents sound, challenging, provocative science,” said HRS president George Van Hare, MD. “It’s studies like these that help propel the EP (electrophysiology) field forward and allow us to improve patient care for people living with heart arrhythmias worldwide.”