The association between mosaic loss of Y chromosome and mortality in patients with ST-segment elevation myocardial infarction: A prospective cohort study

Objective While loss of Y chromosome (LOY) has been associated with cardiovascular diseases, its specific impact on ST-segment elevation myocardial infarction (STEMI) remains underexplored. This study aimed to investigate the impact of LOY in blood cells on all-cause mortality in male patients with STEMI. Methods This study enrolled 928 males and 272 females undergoing primary percutaneous coronary intervention for STEMI. LOY was measured in 928 males using droplet digital polymerase chain reaction technique. The primary outcome was all-cause mortality. Results During 3.99-year follow-up, 93 males (10.0%) and 45 females (16.5%) died. After adjusting for traditional cardiovascular risk factors, the mortality risk in males with LOY ≥ 18% (the 90th percentile of LOY) increased to 2.45 (95% confidence interval [CI]: 1.16–5.15, P  = 0.018), 2.11 (95% CI: 1.11–4.01, P  = 0.024), and 1.88 (95% CI: 1.02–3.45, P  = 0.043) times during 1-, 2-, and 3-year follow-up, respectively, compared to males with LOY < 18%. Among males without prior MI, those with LOY ≥ 18% had an increased mortality risk compared to those with LOY < 18% (adjusted hazard ratio 1.93, 95% CI: 1.01–3.67; P  = 0.045); this was not observed for males with prior MI. Females had a 1.71-fold (95% CI: 1.04–2.81; P  = 0.035) increased mortality risk than males with LOY < 18%, whereas a similar risk to males with LOY ≥ 18%. Conclusions LOY tended to be associated with increased mortality in male STEMI patients, particularly in those without prior MI.