Thirty-Day Hospital Readmission After Acute Myocardial Infarction in China

Background Readmission after acute myocardial infarction in low- and middle-income countries like China is not well characterized. Methods and Results We approached consecutive patients with acute myocardial infarction hospitalized within 24 hours of symptom onset and discharged alive from 53 geographically diverse hospitals in China. We described rates of unplanned 30-day readmission, their timing and admitting diagnoses, and fit Cox proportional hazards models to identify factors associated with readmission. Among 3387 patients, median (interquartile range) age was 61 (52-69) years, and 76.9% were men. The index median length of stay was 11 (8-14) days. Unplanned 30-day readmission occurred in 6.3% of the cohort; most readmissions (77.7%) were for cardiovascular diagnoses. Nearly half (41.9% of all-cause readmissions; 44.3% of cardiovascular readmissions) occurred within 5 days of discharge. Mini-Global Registry of Acute Coronary Events scores at admission (hazard ratio [HR], 1.15 for every 10-point increase; 95% CI, 1.05-1.25), longer length of stay (HR, 1.03; 95% CI, 1.00-1.06 for each extra day), and in-hospital recurrent angina (HR, 1.40; 95% CI, 1.04-1.89) were associated with higher unplanned all-cause readmission. Revascularization during the index hospitalization (70.2% of the cohort) was associated with lower risks of all-cause readmission (HR, 0.27; 95% CI, 0.18-0.42). In addition, left ventricular ejection fraction <0.4 (HR, 1.79; 95% CI, 1.05-3.07) and in-hospital complication (HR, 1.20; 95% CI, 1.03-1.39) were associated with higher risk of unplanned cardiovascular readmission, and ST-segment-elevation myocardial infarction (HR, 0.60; 95% CI, 0.36-0.98) was associated with lower risk of unplanned cardiovascular readmission. Sex, family income, depression, stress level, lower social support, disease-specific health status, and medications were not associated with readmission. Conclusions In China, most readmissions are for cardiovascular events, and almost half occur within 5 days of discharge. Clinical factors identify patients at higher and lower unplanned readmissions. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT01624909.