P5144Nationwide cohort of giant-cell myocarditis fulminant forms on mechanical circulatory support

Abstract

Background: Giant-cell myocarditis (GCM) is a rare aetiology of myocarditis. To date, clinical presentation, treatment and outcome have mainly been reported in case reports and small case series. In addition, clinical course of fulminant forms has not been thoroughly described. Purpose: To assess the clinical course, management and prognosis of acutely ill patients affected with GCM and supported with mechanical circulatory support over the last 15 years. Methods: We created a retrospective nationwide cohort of GCM patients admitted during the last 15 years in French intensive care units (ICU) with mechanical circulatory support (MCS) availability. GCM diagnosis was confirmed for all patients by biopsy, apical sample at ventricular assist device (VAD) implantation, explanted heart histology or autopsy. Criteria for inclusion in this study were 1) positive diagnosis of GCM and 2) mechanical circulatory support (i.e. ECMO or VAD). Demographics, pre-MCS hemodynamic and clinical situation, ECG features, specific treatment and post-MCS outcome were retrospectively collected. Results: Thirteen patients with diagnosis of GCM were included (7 males; mean age at 42±16 years) from 8 French hospitals. Histological samples were obtained by either cardiac biopsy (n=3; 23%), apical sample at VAD implantation (n=2; 15%), explanted heart histology (n=7; 54%) or autopsy (n=1; 8%). Previous autoimmunity medical history was reported in only one patient. Six patients (46%) suffered electrical storm prior to MCS, whereas 10 patients (77%) had some type of arrhythmic disturbance. Eleven patients (84%) were supported with veno-arterial extracorporeal membrane oxygenator for 12±9 days. At MCS implantation, mean lactate was 4,9±3,0 mmol/L, mean left ventricular ejection fraction was 21,7±12,8%, and mean SOFA was 11,8±3,9. Five patients (38%) received immunosuppressive therapy with failure to recovery. Out of the 12 patients (92,3%) who had a non-autopsy diagnosis, 8 (67%) and 3 (25%) patients were initially bridged to transplant or LVAD, respectively. One patient died while waiting for transplantation. None recovered heart function after MCS. Out of 9 patients transplanted, all were alive at one year with no evidence of GCM relapse in the follow-up biopsies. Discussion: Prognosis of fulminant form of GCM is very poor. Transplantation appears as the only option in these extremely severe patients. The benefit of immunosuppressive therapy to allow partial clinical remission, as recommended in less severe forms, appears questionable considering the extreme frailty of these patients in multiorgan failure.