Sex-Related Differences in Thrombus Burden in STEMI Patients Undergoing Primary Percutaneous Coronary Intervention

Background: Women have a worse prognosis after ST-segment elevation myocardial infarction (STEMI) than men. The prognostic role of thrombus burden (TB) in influencing the sex-related differences in clinical outcomes after STEMI has not been clearly investigated. Objectives: The aim of this study was to assess the sex-related differences in TB and its clinical implications in patients with STEMI. Methods: Individual patient data from the 3 major randomized clinical trials of manual thrombus aspiration were analyzed, encompassing a total of 19,047 patients with STEMI, of whom 13,885 (76.1%) were men and 4,371 (23.9%) were women. The primary outcome of interest was 1-year cardiovascular (CV) death. The secondary outcomes of interest were recurrent myocardial infarction, heart failure, all-cause mortality, stroke, stent thrombosis (ST), and target vessel revascularization at 1 year. Results: Patients with high TB (HTB) had worse 1-year outcomes compared with those presenting with low TB (adjusted HR for CV death: 1.52; 95% CI: 1.10-2.12; P = 0.01). In unadjusted analyses, female sex was associated with an increased risk for 1-year CV death regardless of TB. After adjustment, the risk for 1-year CV death was higher only in women with HTB (HR: 1.23; 95% CI: 1.18-1.28; P < 0.001), who also had an increased risk for all-cause death and ST than men. Conclusions: In patients with STEMI, angiographic evidence of HTB negatively affected prognosis. Among patients with HTB, women had an excess risk for ST, CV, and all-cause mortality than men. Further investigations are warranted to better understand the pathophysiological mechanisms leading to excess mortality in women with STEMI and HTB.