Abstract 4142913: Characteristics and Prognosis of In-Hospital Onset Non-ST-Segment Elevation Acute Myocardial Infarction in Patients Hospitalized for Non-Cardiac Diseases: Comparison of Cardiology Referral vs. Non-Referral

Background: NSTEMI accounts for the majority of the in-hospital MI. However, whether differences exist between in-hospital NSTEMI patients referred to cardiology and those who are not remains unclear. Aims This study aims to compare the characteristics and prognosis of in-hospital NSTEMI patients referred to cardiology with those who are not. Methods: Data for this study were obtained from a retrospective cohort comprising patients from 72 hospitals between 2010 and 2023. Patients who developed NSTEMI during hospitalization were identified and classified into the referral and the non-referral group based on whether they were referred to cardiology. The primary endpoint was Major Adverse Cardiovascular and Cerebrovascular Events (MACCE), comprising cardiovascular death(CD), recurrent MI, stroke, and repeat revascularization at 1 year. The secondary endpoints were in-hospital all-cause mortality, 1-year all-cause mortality, CD, and Net Adverse Clinical Events (NACE), including CD, recurrent MI, BARC≥3 bleeding events, and repeat revascularization. Kaplan-Meier curves were used to depict survival between the two groups. A multivariable Cox regression model, adjusted for age, sex, Killip classification, and medical history, was utilized to analyze the association between referral and 1-year outcomes. Additionally, multivariate logistic regression analysis was employed to examine the factors related to in-hospital mortality. Results: The study included 6218 patients were in the non-referral group (mean age 73 years, 43.4% women) and 1260 in the cardiology referral group (mean age 70.8 years, 43.4% women). The non-referral group was less likely to take antiplatelet drugs, statins, or undergoing PCI (p<0.001). Multivariate logistic regression showed that cardiology referral was a significant factor affecting in-hospital mortality (OR: 0.405, 95%CI: 0.310-0.528). All the 1-year endpoints-free survival rates were better in the referral group than in the non-referral group (Log-rank p<0.001). Multivariate Cox regression analysis showed that referral were associated with a lower risk of 1-year MACCE (HR: 0.878, 95%CI: 0.801-0.964), NACE (HR: 0.882, 95%CI: 0.805-0.967), all-cause mortality (HR: 0.729, 95%CI: 0.658-0.808) and CD (HR: 0.743, 95%CI: 0.657-0.840). Conclusion: In-hospital NSTEMI patients referred to cardiology had better outcomes compared to those who were not, partly due to higher rates of revascularization and adherence to guideline-recommended medical therapy.