Geographic and racial representation and reported success rates of studies of catheter ablation for atrial fibrillation: Findings from the SMASH-AF meta-analysis study cohort

Introduction: We performed a systematic review and meta-analysis of geographic and racial representation and reported success rates of studies of catheter ablation for atrial fibrillation (AF). Methods and results: We searched PubMed, Scopus, and Cochrane databases from 1/1.11990 to 8/1/2016 for trials and observational studies reporting AF ablation outcomes. Major exclusion criteria were insufficient reporting of outcomes. non-English language articles, and ablation strategies that were not prespecified and uniform. We described geographic and racial representation and single-procedure ablation success rates by country, controlling for patient demographics and study design characteristics. The analysis cohort included 306 studies (49,227 patients) from 28 countries. Over half of the paroxysmal (PAF) and nonparoxysmal AF (NPAF) treatment arms were conducted in 5 and 3 countries, respectively. Reporting of race or ethnicity demographics and outcomes were rare (1 study, 0.3%) and nonexistent, respectively. Unadjusted success rates by country ranged from 63.5% to 83.0% for PAF studies and 52.7% to 71.6% for NPAF studies, with substantial variation in patient demographics and study design. After controlling for covariates, South Korea and the United States had higher PAF ablation success rates, with large residual heterogeneity. NPAF ablation success rates were statistically similar by country. Conclusions: Studies of AF ablation have substantial variation in patient demographics, study design. and reported outcomes by country. There is limited geographic representation of trials and observational studies of AF ablation and a paucity of race- or ethnicity-stratified results. Future Al ablation studies and registries should aim to have broad representation by race, geography, and ethnicity to ensure generalizability.