Sex differences in treatment and outcomes of patients with in-hospital ST-elevation myocardial infarction

Background and Hypothesis: Two cohorts face high mortality after ST-elevation myocardial infarction (STEMI): females and patients with in-hospital STEMI. The aim of this study was to evaluate sex differences in ischemic times and outcomes of in-hospital STEMI patients. Methods: Consecutive STEMI patients treated with percutaneous coronary intervention (PCI) were prospectively recruited from 30 hospitals into the Victorian Cardiac Outcomes Registry (2013−2018). Sex discrepancies within in-hospital STEMIs were compared with out-of-hospital STEMIs. The primary endpoint was 12-month all-cause mortality. Secondary endpoints included symptom-to-device (STD) time and 30-day major adverse cardiovascular events (MACE). To investigate the relationship between sex and 12-month mortality for in-hospital versus out-of-hospital STEMIs, an interaction analysis was included in the multivariable models. Results: A total of 7493 STEMI patients underwent PCI of which 494 (6.6%) occurred in-hospital. In-hospital versus out-of-hospital STEMIs comprised 31.9% and 19.9% females, respectively. Female in-hospital STEMIs were older (69.5 vs. 65.9 years, p =.003) with longer adjusted geometric mean STD times (104.6 vs. 94.3 min, p <.001) than men. Female versus male in-hospital STEMIs had no difference in 12-month mortality (27.1% vs. 20.3%, p =.92) and MACE (22.8% vs. 19.3%, p =.87). Female sex was not independently associated with 12-month mortality for in-hospital STEMIs which was consistent across the STEMI cohort (OR: 1.26, 95% CI: 0.94–1.70, p =.13). Conclusions: In-hospital STEMIs are more frequent in females relative to out-of-hospital STEMIs. Despite already being under medical care, females with in-hospital STEMIs experienced a 10-min mean excess in STD time compared with males, after adjustment for confounders. Adjusted 12-month mortality and MACE were similar to males.