Early characteristics of fulminant myocarditis vs non-fulminant myocarditis: A meta-analysis

BACKGROUND: Fulminant myocarditis (FM) is a sub-category myocarditis. Its primary characteristic is a rapidly progressive clinical course that necessitates hemodynamic support. FM can be difficult to predict at the onset of myocarditis. The aim of this meta-analysis was to identify the early characteristics in FM compared to those of non-fulminant myocarditis (NFM). METHODS: We searched the databases of MEDLINE, EMBASE, CENTRAL, for studies comparing FM with acute NFM from January 1, 2000 to June 1, 2018. The baseline variables were compared in each study. Mean differences (MD) and relative ratios (RR) were calculated. RESULTS: Seven studies (158 FM patients and 388 NFM patients) were included in the analysis. The FM group had significantly lower systolic blood pressure (SBP), higher creatine kinase (CK), wider QRS duration, lower left ventricular ejection fraction (LVEF), thicker left ventricular posterior wall diameter (LVPWd), higher incidence of ST depression, ventricular tachycardia/ventricular fibrillation (Vt/Vf) and syncope, less incidence of chest pain than the NFM groups. There was no difference in terms of heart rate (HR), c-reactive protein (CRP), fever, dyspnea, white blood cells (WBC), atrioventricular block (AVB), Q waves, ST elevation, interventricular septum diameter (IVSd), or end-diastolic left ventricular diameter (LVEDd) between FM and NFM. CONCLUSION: We found that the lower SBP, higher CK, wider QRS duration, lower LVEF, thicker LVPWd, higher incidence of ST depression, Vt/Vf and syncope as well as lower incidence of chest pain were early characteristics of FM.