This US nationwide database analysis showed that diabetes significantly increases the risk of heart failure in patients hospitalized with myocarditis, highlighting the adverse interaction between metabolic disease and myocardial inflammation.
The impact of diabetes on non-atherosclerotic cardiac disease has not been studied extensively. We aimed to assess the in-hospital and long-term effects of diabetes in patients hospitalized for myocarditis.
The Nationwide Readmissions Database (2016-2020) was used to identify adults hospitalized with a primary diagnosis of myocarditis. Patients were stratified by the presence of diabetes, and those discharged alive were followed for a calendar year. The primary outcome was in-hospital mortality. Secondary outcomes included in-hospital ventricular fibrillation, ventricular tachycardia, acute renal failure, cardiogenic shock, heart failure, and one-year all-cause readmission, readmission for heart failure, and mortality. Multivariable logistic and Cox regression models were applied, and propensity score matching was performed as a sensitivity analysis.
Among 8,826 adults with myocarditis, 951 (11%) had diabetes. Compared with patients without diabetes, those with diabetes were older, had a higher prevalence of comorbidities, and showed an increased adjusted risk of in-hospital acute renal failure [aOR=1.74 (95% CI: 1.42-2.12)], heart failure [aOR=1.62 (95% CI: 1.37-1.91)], cardiogenic shock [aOR=1.36 (95% CI: 1.04-1.78)], but not of mortality, ventricular fibrillation, and ventricular tachycardia. In one year, diabetes was not associated with higher adjusted risks of all-cause readmission or mortality [aHR=0.81 (95% CI: 0.41-1.60) and aHR=0.81 (95% CI: 0.68-0.97), respectively]. However, it was associated with a higher risk of readmission for heart failure [aHR=1.16 (95% CI: 1.02-1.31)]. These associations remained consistent in propensity score-matched analyses.
Diabetes independently increases the risk of in-hospital and one-year heart failure in patients with myocarditis.
