Women Face Higher Mortality Risk from Postoperative Atrial Fibriliation Despite Lower Incidence Postsurgery

Although men are more likely to develop postoperative atrial fibrillation (poAF) after open-heart surgery, women with poAF have a higher risk of long-term mortality compared with men, according to a study published in JAMA Network Open. However, the link between sex and poAF, the most common post-surgical complication, has remained unclear.

“To address this gap in understanding the role of sex in poAF and associated long-term mortality after cardiac surgery, we designed this multi-institutional retrospective cohort study,” explained Sergey Karamnov, MD, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, and coauthors. “We hypothesized that (1) men are more likely to develop poAF than women and (2) the association of poAF and long-term mortality differs between men and women.”

The study analyzed 21 568 patients who underwent cardiac surgery at Brigham and Women’s Hospital and Massachusetts General Hospital, with data spanning from 2002 to 2016 and follow-up until December 2022. Of these patients, 6601 (30.6%) were women and 14 967 (69.4%) were men. The mean age was 66.5 years. The racial composition included 92.2% White, 1.9% Black, 2.9% Hispanic, and 1.2% other or multiple races.

Findings showed that while women had a slightly higher unadjusted incidence of poAF (40.8%) compared with men (38.8%), adjusted multivariable logistic regression revealed that women were at a lower risk for developing poAF (odds ratio [OR], 0.85; 95% confidence interval [CI], 0.79-0.91; P <.001). When accounting for patient and surgical risk factors, the predicted probability of poAF was 40.5% for men and 37.0% for women.

The study also examined the relationship between poAF and long-term mortality, finding significant sex differences. Men with poAF had a higher risk of mortality compared with men without poAF (hazard ratio [HR], 1.17; 95% CI, 1.11-1.25; P <.001), but the association was even stronger for women. Women with poAF had a 31% higher risk of mortality (HR, 1.31; 95% CI, 1.21-1.42; P <.001), and when compared with men without poAF, women with poAF showed a 40% increased relative hazard of mortality (HR, 1.40; 95% CI, 1.30-1.51; P <.001).

At the 10-year follow-up, the probability of mortality for men without poAF was 31.9%, compared with 36.3% for those with poAF. For women, the probabilities were 33.7% without poAF and 41.7% with poAF, indicating a poAF-associated 10-year mortality gap of 4.4 percentage points for men and 8.0 percentage points for women.

“Our findings suggest that women may have protective factors against the development of poAF,” concluded the study authors. “However, once poAF takes place, women may be more vulnerable to the associated long-term morbidities.”

Reference

Karamnov S, Sarkisian N, Wollborn J, et al. Sex, atrial fibrillation, and long-term mortality after cardiac surgery. JAMA Netw Open. 2024;7(8):e2426865. doi:10.1001/jamanetworkopen.2024.26865