Women who develop postoperative atrial fibrillation following cardiac surgery may face a 31% higher risk of long-term mortality compared with women without the condition, a relative increase that is greater than the 17% higher risk observed in men with postoperative atrial fibrillation compared with men without it, according to a recent cohort study.
In the study, published in JAMA Network Open, investigators examined the association between sex, postoperative atrial fibrillation (AF), and long-term mortality in patients undergoing cardiac surgery. The retrospective analysis included 21,568 patients from two tertiary care centers in Massachusetts who underwent open-heart surgery between 2002 and 2016.
The average age of the study population was 66.5 years (standard deviation = 12.4). A majority of the patients were White (92.2%), whereas 2.9% of them were Hispanic, 1.9% were Black, and 1.2% identified as American Indian, Alaska Native, Native Hawaiian, Other Pacific Islander, or multiracial.
The investigators found that postoperative AF occurred in 40.8% (n = 2,694/6,601) of the women and 38.8% (n = 5,805/14,967) of the men who underwent cardiac surgery. The odds ratio for women developing postoperative AF compared with men was 0.85 (95% confidence interval [CI] = 0.79–0.91, P < .001), suggesting that women may have a lower likelihood of developing postoperative AF than men.
The adjusted hazard ratio (HR) for long-term mortality was 1.31 (95% CI = 1.21–1.42) in women with postoperative AF and 1.17 (95% CI = 1.11–1.25) in men with postoperative AF. The study found that the relationship between postoperative AF and mortality was significantly influenced by sex, with an interaction HR of 1.11 (95% CI = 1.02–1.23, P = .02).
The estimated 10-year mortality probability was 31.9% among men without postoperative AF and 36.3% among men with postoperative AF. Among women, the mortality probability was 33.7% in those without postoperative AF and 41.7% in those with postoperative AF. During the follow-up period, mortality in the postoperative AF group was 50.4% (n = 1,294/2,694) among women and 48.9% (n = 2,376/5,805) among men. In contrast, in the non–postoperative AF group, mortality was 49.6% (n = 1,273/2,694) among women and 51.1% (n = 2,484/5,805) among men.
The study suggested that hormonal or genetic factors may play a role in the observed sex differences in both the incidence and mortality associated with postoperative AF, warranting further investigation into these potential mechanisms.
Full disclosures can be found in the published study.