Abstract 16820: Clinical Outcomes of Patients Presenting With Acute Heart Failure and Biopsy-Proven Myocarditis at a Major Academic Center

Abstract

Introduction: Myocarditis is an inflammatory disease of myocardium with heterogeneous clinical presentation. There is limited data on short and long term outcomes of patients with biopsy-proven myocarditis. Methods: We conducted a retrospective study of patients with biopsy-proven myocarditis treated at our institution from 2004-2015 and retrieved demographic, echocardiographic, and outcome data. The primary outcomes were need for mechanical circulatory support (MCS), transplant, or death at 1 year. The cohort was limited to viral or idiopathic myocarditis to exclude clinical variability resulting from other etiologies. Results: In total, 39 patients were identified with a clinical presentation of myocarditis who had a biopsy consistent with this diagnosis. Mean age was 40 ± 15 years and 15 (38.5%) were women. Mean LVEF was 32 ± 17%. Median INTERMACS score was 2 (IQR 1-4). Predominant histologic subtypes were 39% lymphocytic, 21% mixed infiltrate, 8% lymphohistiocytic, 8% mononuclear, 5% eosinophilic, 5% giant cell, 5% histiocytic/eosinophilic and 9% undesignated. Medical treatment included inotropes (64.1%), vasopressors (46.2%), intravenous immunoglobulin (2.6%), steroids (30.8%) or other immunosuppression (15.4%). Twenty (51.3%) patients were treated with MCS which included intra-aortic balloon pump (n=13, 33.3%), percutaneous ventricular assist device (n=2, 5.1%), short term ventricular assist device (n=11, 28.2%, average duration 18 ± 11 days), and veno-arterial extracorporeal membrane oxygenation (n=1, 2.6%); 1 (2.6%) patient required a durable ventricular assist device and was explanted for recovery after 38 days. No patients were transplanted; 6 (15.4%) died, all of whom were treated with MCS and died within 1 month of presentation. Histologic subtypes of those that died were: giant cell (2), lymphocytic (2), mononuclear (1), and mixed infiltrate (1). Cohort survival at 1 year was 84.6% (70% in MCS vs 100% in non-MCS subgroup, p = 0.009). Conclusions: Acute myocarditis is highly variable with regards to clinical presentation and infiltrate cell pattern. Early recognition and appropriate utilization of MCS could improve outcomes. The observed increased mortality with MCS likely reflects sicker substrates needing MCS.