Abstract 4137939: Mosaic loss of Y chromosome is associated with increased all-cause mortality in patients with ST-segment elevation myocardial infarction

Introduction: Mosaic loss of Y chromosome (LOY), a common subtype of somatic mosaicism, is characterized as loss of the entire Y chromosome in a mosaic manner and increases with age. Accumulating evidence has manifested the positive link between LOY and shorter life expectations in elderly men as well as common age-associated diseases, such as cancer and cardiovascular diseases. Experimental studies also demonstrated that hematopoietic LOY in mice induced cardiac fibrosis and led to increased mortality. However, little is known about LOY and prognosis of ST-segment elevation myocardial infarction (STEMI). Hypothesis: We hypothesized that LOY may be associated with lower survival rate of patients with STEMI. Aims: Investigating the impact of LOY in peripheral blood cells on prognosis of patients with STEMI. Methods: This study prospectively 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. Results: During a median follow-up of 3.99 years, 93 males (10.0%) and 45 females (16.5%) died. After adjusting for traditional cardiovascular risk factors, the risk of all-cause mortality in males with LOY ≥ 18% (the 90th percentile of LOY) increased to 2.45 (95% confidence intervals [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 risk of all-cause mortality 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. Female patients had a 1.71-fold (95%CI: 1.04–2.81; P = 0.035) increased risk of all-cause mortality than males with LOY < 18%, whereas the risk was similar to males with LOY ≥ 18%. Conclusion: LOY was associated with an increased risk of all-cause mortality in male STEMI patients, particularly in those without prior MI. Detecting LOY in STEMI patients could help further refine sex differences in prognosis and assist in identifying male patients with better prognoses.