Outcomes of paroxysmal atrial fibrillation ablation studies are affected more by study design and patient mix than ablation technique

Objective We tested whether ablation methodology and study design can explain the varying outcomes in terms of atrial fibrillation (AF)‐free survival at 1 year. Background There have been numerous paroxysmal AF ablation trials, which are heterogeneous in their use of different ablation techniques and study design. A useful approach to understanding how these factors influence outcome is to dismantle the trials into individual arms and reconstitute them as a large meta‐regression. Methods Data were collected from 66 studies (6941 patients). With freedom from AF as the dependent variable, we performed meta‐regression using the individual study arm as the unit. Results Success rates did not change regardless of the technique used to produce pulmonary vein isolation (PVI). Neither was adjunctive lesion sets associated with any improvement in outcome. Studies that included more males and fewer hypertensive patients were found more likely to report better outcomes. The electrocardiography method selected to assess outcome also plays an important role. Outcomes were worse in studies that used regular telemonitoring (by 23%; P