Trends in the Incidence of Cardiogenic Shock, and Utilization of Mechanical Circulatory Support in Myocarditis: Insights from the National Inpatient Sample 2016 to 2019.

A subset of patients with myocarditis present with cardiogenic shock. There is a lack of contemporary data assessing the use of mechanical circulatory support (MCS) in these patients. Myocarditis hospitalizations were analyzed using the National Inpatient Sample between 2016 and 2019. Characteristics of patients with and without cardiogenic shock were assessed. Trends in mortality, MCS, right-sided cardiac catheterization (RHC) and endomyocardial biopsy were evaluated. The impact of RHC on consequent MCS and mortality was studied. A total of 38,300 hospitalizations for myocarditis were included in the study, of which 3,490 hospitalizations (9.1%) had cardiogenic shock. Patients with cardiogenic shock were older (p <0.001) and had more chronic kidney disease and atrial fibrillation. Between 2016 and 2019, there was an increase in myocarditis admissions but no difference in rates of cardiogenic shock and mortality and the use of extracorporeal membrane oxygenation, percutaneous ventricular assist devices, intra-aortic balloon pumps, left ventricular assist devices, and cardiac transplant. The most common form of MCS used in myocarditis was extracorporeal membrane oxygenation. The rates of RHC (p = 0.02) and endomyocardial biopsy (p = 0.03) increased over time. Patients who underwent RHC were more likely to receive mechanical support, and in patients with shock, RHC was associated with lower mortality (adjusted odds ratio 0.34, p <0.01). Myocarditis admissions increased over time but with no increase in the rates of cardiogenic shock and MCS. In patients with cardiogenic shock, RHC resulted in lower mortality.