Sex differences based on the timing of invasive management among patients with non-ST-elevation acute coronary syndrome: an individual patient data meta-analysis

AIMS: Studies investigating the timing of coronary angiography in non-ST-elevation acute coronary syndrome (NSTE-ACS) have not evaluated sex differences. This study aims to investigate the sex-related differences in outcomes of NSTE-ACS patients undergoing early or delayed invasive management. METHODS AND RESULTS: An individual patient data (IPD) meta-analysis was performed after systematic review of randomized controlled trials (RCTs) comparing early vs. delayed invasive strategy among NSTE-ACS patients. The primary endpoint was a composite of all-cause death or myocardial infarction (MI) at 6 months. Secondary endpoints included all-cause death, MI, recurrent ischaemia, stroke, and major bleeding. One-stage, random-effects Cox models were conducted. This meta-analysis was registered with PROSPERO (CRD42023468604). Six RCTs including 6654 patients were identified, of whom 2257 (33.9%) were females with a median age of 69 years [interquartile range (IQR) 60-76], significantly higher than males (64.5 years, IQR 55-72.1, < 0.001). Among patients undergoing early strategy, there was no sex difference in the occurrence of the primary [Hazard ratio (HR) 1.08, 95% confidence interval (CI) 0.83-1.41, = 0.560] and secondary endpoints. Among patients undergoing delayed strategy, there was no difference in the occurrence of the primary endpoint (HR 1.12, 95% CI 0.88-1.43, = 0.350). Female sex undergoing delayed strategy was associated with higher risk of recurrent ischaemia (HR 1.52, 95% CI 1.06-2.19, = 0.023) and major bleeding (HR 1.88, 95% CI 1.22-2.87, = 0.004) using univariable analysis but not using multivariable analysis. CONCLUSION: No sex-related differences in the composite of all-cause death or MI were identified among NSTE-ACS patients undergoing early and delayed invasive management.