Rate, causes, and predictors of 90‐day readmissions and the association with index hospitalization coronary revascularization following non‐ST elevation myocardial infarction in the United States

To assess the causes and predictors of readmission after NSTEMI.Studies on readmissions following non-ST elevation myocardial infarction (NSTEMI) are limited. We investigated the rate and causes for readmission and the impact of coronary revascularization on 90-day readmissions following a hospitalization for NSTEMI in a large, nationally representative United States database.We queried the National Readmission Database for the year 2016 using appropriate ICD-10-CM/PCS codes to identify all adult admissions for NSTEMI. We determined the 90-day readmissions for major adverse cardiac events (MACE). All-cause readmission was a secondary endpoint. The association between coronary revascularization and the likelihood of readmission was analyzed using multivariate Cox regression analysis.A total of 296,965 adult discharges following an admission for NSTEMI were included in this study. The rate of readmissions for MACE was 5.2% (n = 15,637) and for any cause was 18.0% (n = 53,316). 38% of MACE readmissions and 40% of all-cause readmissions occurred between 30- and 90-days following the index hospitalization. During index hospitalization, 51.0% underwent coronary revascularization (40.8% with PCI and 10.2% with CABG). This was independently predictive of a lower risk of 90-day readmission for MACE (adjusted HR 0.59, 95% confidence interval (CI) 0.56-0.63, p < .001) and for any cause (adjusted HR 0.65, 95% CI 0.63-0.67, p < .001). In-hospital mortality for MACE readmissions was significantly higher compared to that of index hospitalization (3.8% vs. 2.6%, p < .001).Readmissions following NSTEMI carry higher mortality than the index hospitalization. Coronary revascularization for NSTEMI is associated with a lower readmission rate at 90 days.