Understanding sex-based differences in acute coronary syndrome

Sex differences in acute coronary syndrome (ACS) presentation, management, and outcomes remain incompletely understood. Female patients often present at older ages with different cardiovascular risk profiles, which may influence in-hospital complications and mortality.

To evaluate sex-related differences in baseline characteristics, ACS presentation, in-hospital complications, and short-term outcomes in patients admitted with ACS.

Single-centre study of patients admitted with ACS between October 2010 and June 2025. Patients were stratified according to sex. Baseline clinical characteristics, ACS presentation, and in-hospital complications, and a composite outcome (in-hospital mortality, cardiogenic shock, new-onset heart failure, reinfarction) were assessed.

A total of 1,260 patients were included (mean age 66.6 ± 12.9 years; 28.7% female). Female patients were older (72 vs. 65 years, p<0.001) and had slightly lower body mass index (26.8 vs. 27.3 kg/m², p<0.001), smoked less (11.8% vs. 29.4%, p<0.001), and had higher prevalence of hypertension (75.3% vs. 60.0%, p<0.001) and diabetes (36.2% vs. 27.7%, p=0.002). Dyslipidaemia, LDL cholesterol levels, and family history of coronary artery disease were similar between sexes. Female patients had lower rates of chronic obstructive pulmonary disease and similar prevalence of prior atrial fibrillation/flutter, cerebrovascular events, and chronic kidney disease. They also had a lower prevalence of prior ACS (6.7% vs. 15.4%, p<0.001).

Regarding ACS presentation, females had a trend toward more NSTEMI (47.8% vs. 43.7%, p=0.330), higher Killip class (Killip I: 79.9% vs. 88.6%, p<0.001) and more frequent normal coronary angiography (4.6% vs. 1.1%, p<0.001). Left ventricular ejection fraction at discharge was similar (51% vs. 50%, p=0.138). New-onset heart failure (26% vs. 17.2%, p<0.001) and atrial fibrillation (10.0% vs. 6.5%, p=0.022) were more frequent in females, whereas rates of reinfarction, cardiogenic shock, and other mechanical or arrhythmic complications were comparable. In-hospital mortality was higher among females (3.1% vs. 1.1%, p=0.009), but this difference was not significant after adjustment. One-year mortality was similar. The composite outcome was higher in females (27.0% vs. 18.7%, p<0.001); however, this association was no longer significant after multivariate adjustment.

Female patients were older, less frequently smokers, with more hypertension and diabetes. They more often had NSTEMI, higher Killip class, normal coronary angiography, and higher rates of new-onset heart failure and atrial fibrillation, whereas other complications and long-term mortality were similar. These findings emphasize the importance of sex-specific risk assessment and management in ACS.