VIDEO: CASTLE-AF suggests atrial fibrillation burden better predicts outcomes

May 16, 2018|Cardiology News

AF ablation succeeds despite recurrences

REPORTING FROM HEART RHYTHM 2018

Ablation was significantly more effective than drug therapy for cutting atrial fibrillation burden, which started at an average of about 50% in all patients at baseline. AF burden fell to an average of about 10%-15% among the ablated patients when measured at several time points during follow-up, whereas AF burden remained at an average of about 50% or higher among the drug-treated patients.

The analysis showed that, among patients who achieved an AF burden of 5% or less during the 1-year follow-up, the rate of freedom from death or hospitalization for heart failure was 3.3 fold higher than it was in patients with an AF burden of 6%-80% and 2.5 fold higher than it was in patients with an AF burden of 81% or greater, both statistically significant between-group differences, Dr. Brachmann said.

A receiver operating characteristic analysis showed that change in AF burden after ablation produced a statistically significant 0.66 area-under-the-curve for the primary endpoint, which suggested that reduction in AF burden post ablation could account for about two-thirds of the drop in deaths and hospitalizations for heart failure. Among the nonablated patients the area-under-the-curve was an insignificant 0.49 showing that with drug treatment AF burden had no discernible relationship with outcomes.

One further observation in the new analysis was that a drop in AF burden was linked with improved outcomes regardless of whether or not a “blanking period” was imposed on the data. Researchers applied a 90-day blanking period after ablation when assessing the treatment’s efficacy to censor from the analysis recurrences that occurred soon after ablation. The need for a blanking period during the first 90 days “was put to rest” by this new analysis, Dr. Brachmann said.