Purpose: Readmission reduction remains a national priority in improving quality of care and reducing healthcare costs. Previous studies have shown that readmissions following surgical aortic valve replacement (SAVR) are frequent and contribute to increased healthcare costs, yet no studies have analyzed risk factors for thirty-day readmission following SAVR.
Methods: We used the Nationwide Readmissions Database (NRD), containing 17 million annual discharges in the U.S., to identify all adult patients undergoing SAVR using ICD-9-CM codes 35.21 and 35.22 from 2010 to 2015. Patients with index hospitalization mortality, endocarditis, prior cardiac surgery and concurrent procedures were excluded from the study. Incidence, baseline patient characteristics, causes, resource utilization, and predictors of 30-day readmission were analyzed. Continuous and categorical variables were analyzed using Student t-test and chi-squared test, respectively. Multivariable logistic regression was used to identify predictors of readmission.
Results: Of 136,051 SAVR patients, 18,631 (13.7%) were readmitted to the hospital within 30 days of surgery. Readmitted patients were more commonly female (47.4 vs. 41.6%, P<0.001), older (70.4 vs. 68.3 years, P<0.001), and had increased Elixhauser comorbidity indices (5.4 vs. 4.8, P<0.001), rates of postoperative complications (44.0 vs. 37.3%, P<0.001), and lengths of stay (10.9 vs. 8.5 days, P<0.001). The mean cost of readmission was $13,426, accounting for an estimated annual excess expenditure of $41,689,968. Female gender, age > 75 years, emergent index admission, length of stay longer than 8 days, Medicare and Medicaid insurance, baseline comorbidities, lower SAVR hospital volume, discharge to a destination other than home, and postoperative cardiovascular, infectious and renal complications were identified as independent predictors of readmission. Cardiac issues accounted for 49.1% of readmissions (heart failure=13.2%, arrhythmia 12.5%).
Conclusion: In this large nationwide study, we found that 30-day readmission following SAVR are frequent and costly to the healthcare system. Baseline comorbidities, hospital operative volume, postoperative complications, and discharge disposition were identified as risk factors for readmission. Enhanced management of comorbidities and optimized discharge follow up may reduce readmissions and associated costs.