Does prior coronary artery bypass surgery alter the gender gap in patients presenting with acute coronary syndrome? A 20-year retrospective cohort study

OBJECTIVES: Previous studies demonstrated women presenting with acute coronary syndrome (ACS) have poor outcomes when compared with men ‘the gender gap phenomenon’. The impact of prior coronary artery bypass graft (CABG) on women presenting with ACS is unknown. We hypothesised that the gender gap is altered in ACS patients with prior CABG. The aim of this study was to evaluate patients presenting with ACS according to their gender and history of prior CABG. DESIGN: Retrospective, observational (cohort) study. SETTING: Data were collected from hospital-based registry of patients hospitalised with ACS in Doha, Qatar, from 1991 through 2010. The data were analysed according to their gender and history of prior CABG. PARTICIPANTS: A total of 16 750 consecutive patients with ACS were studied. In total, 693 (4.3%) patients had prior CABG; among them 125 (18%) patients were women. PRIMARY AND SECONDARY OUTCOME MEASURES: Comparisons of clinical characteristics, inhospital treatment, and outcomes, including inhospital mortality and stroke were made. RESULTS: Women with or without prior CABG were older, less likely to be smokers, but more likely to have diabetes mellitus (DM), hypertension and renal impairment than men (p=0.001). Women were less likely to receive reperfusion and early invasive therapies. When compared with men, women without prior CABG carried higher inhospital mortality (11% vs 4.9%; p=0.001) and stroke rates (0.9% vs 0.3%; p=0.001). Female gender was independent predictor of poor outcome. Among prior CABG patients, despite the fact that women had worse baseline characteristics and were less likely to receive evidence-based therapy, there were no significant differences in mortality or stroke rates between the two groups. CONCLUSIONS: Consistent with the world literature, women presenting with ACS and without prior CABG had higher death rates compared with men. Patients with prior CABG had comparable death rates regardless of the gender status.