Risk Factors, Ischemic Delay, and In-Hospital Outcomes by Sex in Adults Aged 18-50 Years with STEMI Undergoing Primary Percutaneous Coronary Intervention: An Exploratory Single-Center Cohort.

OBJECTIVE: To describe sex differences in cardiovascular risk factors and reperfusion delays and explore in-hospital outcomes in adults aged 18-50 years with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). METHOD: This retrospective single-center cohort included 497 consecutive patients (71 [14.3%] women) treated during 2023-2024. Hard major adverse cardiac and cerebrovascular events (MACCE) comprised all-cause death, recurrent myocardial infarction, or stroke. A nonstandard expanded clinical deterioration composite additionally included incident cardiogenic shock and, among patients admitted in Killip class I, incident heart failure. Sex comparisons and Firth penalized logistic models were exploratory. RESULTS: Mean age was 40.7 +- 5.3 years. Current smoking was more frequent in men (69.0% vs 39.4%; P < 0.001), whereas obesity was more frequent in women (54.9% vs 26.8%; P < 0.001). Age-adjusted median symptom-to-first-medical-contact, first-medical-contact-to-device, and total ischemic times were 46, 10, and 48 minutes longer in women, respectively (all P < 0.001). Hard MACCE occurred in 21 patients (4.2%), incident heart failure occurred in 13 of 390 eligible patients (3.3%), and the expanded composite occurred in 46 patients (9.3%). The expanded composite occurred in 12 of 71 women and 34 of 426 men (16.9% vs 8.0%; unadjusted P = 0.025), and incident cardiogenic shock occurred in 7 women and 13 men (9.9% vs 3.1%; unadjusted P = 0.015). In the parsimonious baseline model, the adjusted odds ratio (OR) for female sex was 2.61 (95% confidence interval [CI], 1.21-5.42), attenuating to 1.90 (95% CI, 0.83-4.18) after adding admission Killip class ≥II. CONCLUSION: Women had a different risk-factor distribution and longer documented ischemic delays. The association between sex and the expanded composite was sensitive to adjustment for baseline clinical severity. Sex-specific outcome estimates are hypothesis-generating given the small female subgroup and event counts. The retrospective single-center design, absence of post-discharge follow-up, and unavailable care- and referral-pathway variables limit causal interpretation.