Background: The CABANA trial randomized 2200 patients (pts) between drug vs ablation therapy. Outcomes of the composite endpoint of death, stroke, severe bleeding, or cardiac arrest, and the secondary endpoint of mortality, were indeterminate by intention to treat (ITT) analysis. Nevertheless, there was a benefit in these outcomes by an As Treated and Per Protocol Analyses.
Objective: To determine if the presence of sinus rhythm (NSR) produces a benefit on the composite endpoint or mortality regardless of treatment group.
Methods: 2204 pts were randomized to ablation vs drug therapy. The median age was 68, 37% were women, and 35% had HFpEF or HFrEF HF. In order to determine the value of NSR, all patients underwent assessment for the occurrence of NSR vs ongoing atrial fibrillation (AF) and benefit on overall outcome.
Results: In terms of the NSR patients, 48% of the ablation group had no recurrent AF at 48 months (mo) with 29% in drug treated patients. During this timeframe 2.7% of those with no recurrence and 10.3% of those with a recurrence had an event counting against the primary endpoint, while 0.2% of pts without vs 7.4% of those with a recurrence died. Similarly, at 36 mo there was no recurring AF in 51% in the ablation group and 32% in the drug treated group, with 123 (6%) patients having a primary and 72 (3%) a mortality endpoint event. At 48 mo 51% of patients who were actually ablated had no recurrent AF, with 35% in actual drug treated patients. At 12 mo post-blanking, 1.2% of those without and 3.% of these with a recurrence met the composite endpoint while 0.2% of those without and 1.7% of those with a recurrence had a mortality endpoint. Overall, the HR for those with exclusive NSR vs recurring AF, was 0.57 (95% CI: 0.37, 0.80; p =0.04). Based on this information, those patients in NSR at each time point showed a significantly lower composite or mortality endpoint when compared to those with recurrent AF.
Conclusion: This comparison which was prescribed at the time the original protocol was written, indicates that there are significant composite and mortality benefits due to NSR, not seen in those with ongoing AF.