Outcomes of Mechanical Circulatory Support after Giant Cell Myocarditis: A Systematic Review

Abstract

Giant cell myocarditis (GCM) is a rare, serious form of myocarditis that can require bridging to orthotopic heart transplant (OHT) with mechanical circulatory support (MCS). Given that the roles of MCS and immunosuppressive therapy have not been well defined in this patient population, we sought to analyze the outcomes of patients with GCM who required MCS. A systematic search was performed in June 2019 to identify all studies of biopsy-proven GCM requiring MCS in the English literature after 2009. 27 studies were identified consisting of 43 patients. Patient-level data were extracted for statistical analysis. Median patient age was 45 [IQR: 32 - 57] years, and 42.1% (16/38) of patients were female. 34.9% (15/43) of patients presented with symptoms of acute heart failure, and 20.9% (9/43) presented in cardiogenic shock. Biventricular (BiVAD) MCS was required in 76.7% (33/43) of cases. The final diagnosis of GCM was made using endomyocardial biopsy in 72.1% (31/43) of cases, left ventricular apical core biopsy in 23.3% (10/43) of cases, and biopsy of the explanted heart in 2.3% (1/43) of cases. An immunosuppressive regimen was used in 62.8% (27/43) of cases. Of these patients, 81.5% (22/27) received steroids in combination with at least one other immunosuppressant, of which cyclosporine was the most common, administered to 40.7% (11/27) of patients. Immunosuppression was initiated before MCS in 59.3% (16/27) of cases, after MCS in 29.6% (8/27) of cases, and not specified in 11.1% (3/27) of cases. Survival stratified by immunosuppression (Panel A) and mode of MCS (Panel B) is shown. 58.5% (24/41) underwent OHT with a median time to transplant of 104 [58 - 255] days from diagnosis, and 46 [18 - 201] days from the initiation of MCS. Recurrence of GCM after OHT was reported in 8.3% (2/24) of cases. Non-dischargeable BiVAD predominates in mechanically supported patients with GCM. Survival appears to be better in patients on immunosuppression, especially if initiated before MCS.