Unplanned hospital readmissions after acute myocardial infarction: A nationwide analysis of rates, trends, predictors and causes in the United States between 2010 and 2014

Capers I, Q; Fischmann, D; Kwok, CS; Savage, M; Gulati, M; Potts, J; Mohamed, MO; Nagaraja, V; Patwala, A; Heatlie, G; Kontopantelis, E; Mamas, M

Abstract

Background
Unplanned hospital readmissions are an important quality metric for benchmarking but there is limited data following an acute myocardial infarction (AMI). This study aims to examine the 30-day unplanned readmission rate, predictors, causes and outcomes after hospitalization for AMI.

Methods
The U.S. Nationwide Readmission Database was utilized to analyze patients with a primary diagnosis of AMI between 2010-2014. Rates of readmissions, causes and costs were determined and multiple logistic regressions were used to identify predictors of readmissions.

Results: Of 2,204,104 patients with AMI the 30-day unplanned readmission rate was 12.3%(n=270,510), which changed from 13.0%-11.5% between 2010-2014. The estimated impact of readmissions in AMI was ~694 million USD and ~279,000 additional bed days per year. Comorbidities such as diabetes (OR 1.27 95%CI 1.25-1.29), chronic lung disease (OR 1.29 95%CI 1.26-1.31), renal failure (OR 1.38 95%CI 1.35-1.40) and cancer (OR 1.35 95%CI 1.30-1.41) were independently associated with unplanned readmission. Discharge against medical advice was the variable most strongly associated with unplanned readmission (OR 2.40 95%CI 2.27-2.54). Non-cardiac causes for readmissions accounted for 52.9% of all readmissions. The most common cause of cardiac readmission was heart failure (14.3%) and for non-cardiac readmissions was infections (8.8%).

Conclusions: Readmissions during the first month after AMI occur in more than 1 in 10 patients resulting in a healthcare cost of ~694 million USD per year and ~279,000 additional bed days per year. These finding have important public health implications. Strategies to identify and reduce readmissions in AMI will dramatically reduce health care costs for society.

• Acceptance Date: Nov 26, 2019
• Publication Date: Jan 15, 2020
• Journal: Coronary Artery Disease
• Print ISSN: 0954-6928
• Publisher: Lippincott, Williams & Wilkins
• Pages: 354-364
• DOI: https://doi.org/10.1097/MCA.0000000000000844
• Keywords: acute myocardial infarction, readmissions, cost
• Publisher URL: https://doi.org/10.1097/mca.0000000000000844