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.