Novel findings raise generalizability issues
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.
Mitchel L. Zoler/MDedge News
Dr. Mark S. Link
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.