Abstract P111: Sex Differences in Rate or Rhythm Control and Outcomes Among Elderly Patients With Atrial Fibrillation

Abstract

Introduction: Women with atrial fibrillation (AF) experience greater symptomatology, worse quality of life, and have a higher risk of stroke as compared to men, but are less likely to receive rhythm control for the treatment of AF. Whether these differences exist in elderly patients with AF, and whether sex modifies the effectiveness of rhythm versus rate control therapy has not been assessed. Methods: We studied 135,850 men and 139,767 women 75 years or older diagnosed with AF in the MarketScan Medicare database between 2007-2015. Rate control was defined as use of rate control medication or atrioventricular node ablation. Rhythm control was defined by use of anti-arrhythmics, catheter ablation or cardioversion. Participants on both rate and rhythm were coded under rhythm control. We used multivariable logistic and Cox regression models to estimate 1) the association of sex and treatment strategy (within 30-day post AF diagnosis and entire follow-up) and, 2) the association of treatment strategy with incident heart failure, stroke and major bleeding. Results: Men were on average (SD) 82.5 (5.2) years old and women 83.8 (5.6) years, respectively. Women were less likely to receive rhythm control treatment as compared to men in the 30-day post AF diagnosis period (22% vs 27%), (OR 0.91, 95% CI 0.88, 0.94) and over the entire duration of follow-up (28% vs 32%) (HR 0.93, 95% CI 0.90, 0.96). Rhythm (vs. rate) control was associated with a higher risk of heart failure in women [HR 1.41, 95% CI 1.34, 1.49] than in men [HR, 1.21 95% CI 1.15, 1.28] (p for multiplicative interaction < 0.001, Table ). Sex did not modify associations between treatment and incident stroke or major bleeding events. Conclusion: Women aged 75 years and older were less likely to be prescribed rhythm control as compared to men, and experienced higher risk of heart failure than men when receiving rhythm (vs rate) control. Future studies will need to delve into the mechanisms underlying these differences.