Sex differences in atrial myocardial fibrosis and degeneration: evaluation using left atrial low-voltage areas during catheter ablation of atrial fibrillation

Background Atrial myocardial degeneration predisposes to atrial fibrillation (AF), ischemic stroke, and heart failure. Studies suggest the presence of sex differences in atrial myocardial degeneration. This study aimed to delineate sex differences in the prevalence, predictors, and prognostic impact of left atrial low-voltage areas (LVAs). Methods This observational study included 1,488 consecutive patients undergoing initial ablation for AF. Voltage mapping was performed after pulmonary vein isolation during sinus rhythm. LVAs were defined as regions where bipolar peak-to-peak voltage was < 0.50 mV. Results: LVA prevalence was higher in women (37.6%) than in men (16.0%). High age, persistent form of AF, diabetes mellitus, and a large left atrium were shown to be common predictors in both sex categories. Heart failure and history of stroke/thromboembolic events were men-specific predictors of LVA existence. Women experienced more AF recurrence than men (31.1% vs. 25.7%, p = 0.027). LVA existence was significantly associated with increased AF recurrence in each sex category, with a respective hazard ratio, 95% confidence interval and p value of 2.45, 1.87-3.22, and < 0.0001 in men and 1.82, 1.33-2.49, and < 0.0001 in women. Conclusions LVA was more frequent in women than men, and predicted frequent AF recurrence irrespective of sex category.