Predictors of Mechanical Circulatory Support in Fulminant Acute Myocarditis

Abstract

<h3>Purpose</h3> Fulminant acute myocarditis (FAM) is rare but with high acute mortality. Mechanical circulatory support (MCS) may be needed to bridge to recovery or heart transplantation. We aim to determine predictors of MCS and evaluate long-term outcomes. <h3>Methods</h3> Observational prospective study of patients admitted to a third-level hospital with FAM between 2007 and 2021. FAM was defined as an acute myocardial inflammation in endomyocardial biopsy (EMB) or magnetic resonance, with hemodynamic instability and left or right ventricular dysfunction. We performed multivariate logistic regression analysis to determine predictors of need of MCS. Survival was analyzed with Kaplan-Meier curves and the log rank. <h3>Results</h3> We included 71 patients with a diagnosis of FAM by EMB (53) or magnetic resonance (15). Mean age was 42 years and mean left ventricular ejection fraction (LVEF) was 27%. In EMB the most frequent finding was lymphocytic myocarditis (79.6%). 58 patients received treatment with corticosteroids. 43 patients needed MCS: veno-arterial ECMO (11), Impella (1), left (1) or biventricular Centrimag (14) and Intraortic balloon pump (16). Univariate predictors of MCS were ST segment deviation in ECG, lower LVEF, need for inotropes, positive troponines, need for mechanical ventilation (MV), higher heart rate and lower blood pressure. In the multivariate analysis only ST segment deviation (OR 13.9, p = 0.026) remained significant, but mechanical ventilation (OR 4.488, p = 0.076) and initial LVEF (OR 0.926, p = 0.059) showed a trend to predict MCS. Survival of patients who needed MCS support was worse (with 5 patients needing heart transplant), but those who survived the acute phase showed good recovery of the LVEF at discharge and last follow-up (figure). <h3>Conclusion</h3> In patients with FAM with hemodynamic instability, the presence of ST segment deviation, lower LVEF and MV predict the need to refer to a center with options for MCS