BACKGROUND: There is no consensus on whether biological differences account for the higher risk of stroke seen in females compared to males with atrial fibrillation (AF).
METHODS: Capitalizing on The Losartan Intervention for Endpoint study, a multicenter randomized clinical trial randomizing 9,193 patients and followed for at least four years, we aimed to identify sex differences in the risk of stroke in the presence of AF in patients with hypertension and left ventricular hypertrophy (LVH).
RESULTS: 342 Patients had a history of AF, and 669 developed new-onset AF. History of AF and new-onset AF were more prevalent among males (5.0% vs. 2.9% and 3.0% vs. 0.9%) in patients aged 55-63 years, but the relative difference decreased with age. Females with new-onset AF tended to have a higher risk of stroke than males (HR 1.52 [95% CI 0.95-2.43]). However, females with a history of AF did not have a higher risk than males (HR 0.88 [95% CI 0.5-1.6]). In patients with new-onset AF, the relative higher stroke risk in females increased with age. Among patients with a history of AF, stroke risk was comparable and increased with age in both sexes.
CONCLUSIONS: Among patients with hypertension and LVH, females with new-onset AF had a higher risk of stroke than males, especially in patients above 64 years. However, the risk did not differ between the sexes among patients with a history of AF.