Ab-452665-4 atrial scar: gender difference in prevalence and prognosis of additional substrate modification in patients with atrial fibrillation results from stable-sr-iii trial

Female gender has long been recognized to present a higher burden of low-voltage area (LVA), and tend to have an increased atrial fibrillation (AF) recurrence rate than male after circumferential pulmonary vein isolation (CPVI). However, benefits of additional LVA modification in female patients with AF remain unknown. This study was to describe the prevalence of LVA and outcomes of additional substrate modification according to sex at entry STABLE-SR-III trial. Patients aged 65-80 years were randomly assigned to either CPVI plus LVA modification during sinus rhythm (STABLE-SR) group or “golden-standard” CPVI alone group. The primary outcome was freedom from atrial arrhythmias lasting for ≥30 s after a single ablation procedure. Of 414 patients included in the STABLE-SR-III, 204 (49.3%) were female, mean age was 70.5±4.7 years. Females demonstrated significant higher LVA prevalence (51.5% vs. 32.9%, P=0.000) and burden [6.5% (2.7-12.4) vs. 2.9% (1.9-5.9), P=0.000] than males. Female sex, age and large left atrial diameter were independent predictors of LVA. For the primary outcome, additional LVA ablation was associated with a 65% reduction in atrial arrhythmias recurrence for females (hazard ratio 0.35; 95% CI 0.19-0.65, P=0.002). Females with LVA who received CPVI alone had significantly higher recurrence rate than those females without LVA and those females with LVA receiving substrate modification (P=0.003). Female sex was found to have a higher LVA prevalence, LVA burden, and greater benefit of additional LVA modification than male. Addictive LVA ablation has emerged as a promising solution to improve the success rate in this population.