Abstract 12520: Thirty-Day Readmission Rates and Causes Among Patients Admitted With Acute Myocarditis: Insights From the Nationwide Readmissions Database

Introduction:Myocarditis is a serious inflammatory process that can result in acute and chronic cardiomyopathy. Data on patient characteristics, predictors and national readmission rates related to myocarditis are limited. We sought to evaluate the causes and predictors of 30-day readmission rate of patients admitted with acute myocarditis.Methods:Using the Nationwide Readmission Database, we included adult patients (age>18 years old) who were hospitalized between January 2016 to November 2018 for acute myocarditis. Thirty-day readmission rates, causes, and predictors of readmission were assessed.Results:We analyzed 9482 patients who were discharged alive with a primary diagnosis of acute myocarditis, without requiring advanced therapies (HTX or LVAD) during the index admission. Within 30 days, 641 (6.8%) were readmitted and half of the readmissions occurred in the first 10 days. The readmitted patients were older (mean age of 50 ± 19 vs 41 ± 17, p =<0.001) and were more females (49 % vs 35%, p= <0.001). Using multivariate logistic regression (Fig 1A), the odds of 30-day readmission was higher in diabetics (OR 1.47: 95% CI 1.05-2.04), smokers (OR 1.39: 95% CI 1.05-1.84), prior MI (OR 2.17: 95% CI 1.36-3.44), chronic lung disease (OR 1.55: 95% CI 1.16-2.07) and renal failure (OR 1.97: 95% CI 1.31-2.96). Recurrent myocarditis (15%), and heart failure (15%) were the most common causes of readmission (Fig 1B).Conclusions:The readmission rate among acute myocarditis patients is high and is driven by recurrent myocarditis and heart failure. Early identification of patients at increased risk for readmission may help develop prevention strategies and improve outcomes in acute myocarditis.