Advanced Left Atrial Remodeling and Appendage Contractile Dysfunction in Women Than in Men Among the Patients With Atrial Fibrillation: Potential Mechanism for Stroke

Abstract

Background

The risk of stroke imposed by atrial fibrillation ( AF) is significantly greater in women than men; however, the mechanism remains elusive. We hypothesized that left atrial ( LA) remodeling and poor contractile function of LA appendage ( LAA) would be more predominant in women than men among AF patients.

Methods and Results

A total of 579 AF patients (216 women vs age‐, AF type–, and incidences of heart failure, hypertension, diabetes mellitus, stroke or transient ischemic attack, and vascular disease–matched 363 men, 61.3±10.2 years old, 70.1% paroxysmal AF) who underwent AF catheter ablation were included. Sex differences in LA volume index ( LAVI) and LAA emptying flow velocity ( FV) were analyzed in risk factor 0, 1, and ≥2 groups, according to their CHA ₂ DS ₂‐ VASc scores beyond sex category. LAA‐ FV was more significantly reduced in women with risk factor ≥2 than in men of the same risk group ( P=0.022). Women showed greater LAVI than their male counterparts in the risk factor ≥2 group ( P<0.001). The majority of female patients with a history of stroke had a large LAVI and low LAA‐ FV ( P<0.001); however, no such distribution was observed in men ( P=0.596). LA volume index (odds ratio [ OR], 1.038; 95% CI, 1.003–1.075, P=0.035) or LAA‐ FV ( OR, 0.976; 95% CI, 0.952–0.999; P=0.047) was significantly associated with a history of stroke in women.

Conclusions

More‐extensive LA remodeling and deterioration in LAA function were noted in women than in men with high calculated risk of stroke in AF.