The incidence of graft failure in CABG is higher among women than men, and is associated with adverse cardiac events; however, the excess mortality risk in women was not mediated by graft failure, according to a study published July 1 in JACC.

Sigrid E. Sandner, MD, MSCE, et al., conducted a pooled analysis of individual patient data from randomized clinical trials with systematic imaging follow-up to examine the incidence of CABG graft failure in women, its association with cardiac events, and its potential impact on sex differences in clinical outcomes. Seven randomized clinical trials including 4,413 total patients – 777 of whom were women – were included in the analysis. The primary outcome was the association of graft failure with myocardial infarction and repeat revascularization between the initial CABG procedure and follow-up imaging. Death after imaging was a secondary outcome.

The authors found that at the median imaging follow-up of 1.03 years, graft failure was more frequent among women vs. men (37.3% vs. 32.9% at the patient-level and 20.5% vs. 15.8% at the graft level; p=0.02 and p<0.001, respectively). An association was observed for both the primary and secondary outcome in women (odds ratio [OR], 3.94; 95% CI, 1.79-8.67 and OR, 3.18; 95% CI, 1.73-5.85, respectively).

Although female sex was independently associated with risk of death (direct effect HR, 1.84; 95% CI, 1.35-2.50), the association was not mediated by graft failure (indirect effect HR, 1.04; 95% CI, 0.86-1.26).

“Our data showed that graft failure did not mediate the excess risk of death associated with female sex,” state the authors. “This highlights the need to address other disparities in the diagnosis and treatment of coronary disease in women to reduce the gap in CABG outcomes between sexes.”

In an accompanying editorial comment, Amy A. Sarma, MD, and Jared A. Spitz, MD, FACC, add: “… it is time to move beyond simply describing these disparities and develop evidence-based strategies for ensuring delivery of optimal preventive therapy, improving enrollment and engagement with cardiac rehabilitation programs, and better understanding of nonatherosclerotic contributors to risk among women, including endothelial dysfunction.”

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention

Keywords: Coronary Disease, Sex Characteristics, Coronary Artery Bypass