Women still have higher risk vs. men for adverse outcomes after coronary artery grafting

Women remain at significantly higher risk than men for adverse outcomes after coronary artery bypass grafting with no substantial improvements observed in the last decade, according to a retrospective cohort study published in JAMA Surgery.

“Women undergoing coronary artery bypass grafting experience significantly higher observed operative mortality compared with men and are at increased risk of major postoperative adverse events, including myocardial infarction and stroke. These differences persist despite adjustment for differences in baseline risk factors,” Mario Gaudino, MD, PhD, MSCE, professor of cardiothoracic surgery in the department of cardiothoracic surgery at Weill Cornell Medicine, and colleagues wrote. “On a national scale, the outcomes of coronary artery bypass grafting surgery have generally improved significantly over the past decades despite an increase in the risk profile of patients referred for surgery. It is not known, however, whether the ... gap between women and men has been mitigated or removed over the past decade.”

To evaluate trends in outcomes of women who underwent coronary artery bypass in the U.S. over the past decade, Gaudino and colleagues analyzed data from 1,297,204 adults (mean age, 66 years) who underwent primary isolated coronary artery bypass from 2011 to 2020 in hospitals that contributed to the Adult Cardiac Surgery Database of the Society of Thoracic Surgeons. Of these patients, 317,716 (24.5%) were women.

The primary outcome was operative mortality. Secondary outcomes included operative mortality, stroke, kidney failure, reoperation, deep sternal wound infection, prolonged mechanical ventilation and prolonged hospital stay.

Women experienced higher unadjusted operative mortality (2.8% vs. 1.7%) and higher overall unadjusted incidence of the composite of operative mortality and morbidity (22.9% vs. 16.7%) compared with men (P < .001 for both). Researchers observed no significant change in the attributable risk of female sex for operative mortality during the study, with variation from 1.28 in 2011 to 1.41 in 2020.

In addition, researchers noted no significant change in the attributable risk for the composite of operative mortality and morbidity during the study, with a risk of 1.08 in 2011 and 2020.

According to the researchers, reducing mortality for women after coronary artery bypass grafting will likely require a multifactorial approach with possible different indications to revascularization for women compared with men due to differences in the processes and pathology of coronary artery disease.

“Further investigation in the determinants of operative outcomes in women is urgently needed,” the researchers wrote.