Predictors and etiologies of 30‐day readmissions in patients with non‐ST‐elevation acute coronary syndrome

Background Despite improvements in acute care and survival after non‐ST‐elevation acute coronary syndrome (NSTE‐ACS) hospitalization, early readmissions remain common, and have significant clinical and financial impact. Objectives Determine the predictors and etiologies of 30‐day readmissions in NSTE‐ACS. Method The study cohort was derived from the National Readmission Database 2014 identifying patients with a primary diagnosis of NSTE‐ACS using ICD9 code. Results We identified a total of 300,269 patients admitted with NSTE‐ACS; 13.4% were readmitted within 30‐day. The most common cause of readmission was heart failure (HF) (15.6%), followed by a recurrent myocardial infarction (MI) (10%). Predictors of increased readmissions were age ≥ 75 years (OR: 1.34, 95% CI: 1.30–1.39), female gender (OR 1.12, 95% CI 1.09–1.16), a Charlson Comorbidity Index (CCI) >3 (OR 2.11, 95% CI: 2.04–2.18), ESRD (OR 2.01, 95% CI 1.89–2.14), CKD (OR: 1.58, 95% CI: 1.51–1.64), length of stay ≥5 days (OR: 1.51, 95% CI 1.46–1.56) and adverse events during the index admission such as AKI (OR:1.31, 95% CI: 1.25–1.36), major bleeding (OR:1.20, 95% CI: 1.12–1.24); whereas admission to a teaching hospital (OR 0.92, 95% CI 0.89–0.95) and PCI (OR 0.70, 95% CI 0.67–0.72) were associated with less likelihood of 30‐day readmission. Conclusion Readmission rate at 30‐days is high among NSTE‐ACS patients and the most common readmission etiologies are HF and recurrent MI. A CCI more than 3 and ESRD were the most significant predictors for readmission; patients undergoing PCI had less odds of readmission.