Relation of female sex to left atrial diameter and cardiovascular death in atrial fibrillation: The AFFIRM Trial

BACKGROUND: Female sex is associated with thromboembolism related to atrial fibrillation (AF). Left atrial (LA) diameter independently predicted incident cardiovascular (CV) major events in the general population. In AF patients, LA enlargement is associated to AF occurrence and recurrence. No data have previously been reported on the relationship between LA enlargement, sex and CV death in AF patients.

METHODS AND RESULTS: All patients enrolled in the AFFIRM Trial with available data about LA dimension were included in this post-hoc analysis. Of the 2615 eligible for the present analysis, LA enlargement was recorded in 67.0%, more commonly in women than in men (p=0.032). Patients with LA enlargement had higher body mass index (BMI), and were more frequently hypertensive, diabetic, and diagnosed with a structural heart disease, prior coronary artery disease (CAD) and heart failure (HF). BMI, left ventricular mass, female sex and mitral valve insufficiency (p<0.001) were associated with LA enlargement. AF female patients with LA enlargement had a higher risk for CV death (p=0.011). LA diameter showed a significant association with CV death (p<0.001). Cox regression analysis demonstrated that LA diameter was an independent predictor of CV death in female AF patients (p=0.003).

CONCLUSIONS: LA diameter enlargement is associated with female sex, and carries a higher risk for CV death, particularly in females. LA diameter was an independent predictor of CV death in female AF patients.