0083 : Hyperhemia on the first-pass MRI perfusion for the diagnosis of acute myocarditis

Abstract

MRI is the current way for the diagnosis of acute myocarditis, based on the Lake Louise criteria (presence of at least two of the three following criteria: myocardial edema, hyperaemia and/or a late Gadolinium enhancement). The first-pass perfusion sequence, used for detecting myocardial ischemia, may also be used to highlight a myocardial hyperemia in acute myocarditis. The aim of our study was to assess subepicardial hyperemia, seen on the first pass perfusion sequence by MRI, as a new method for the diagnosis of acute myocarditis. 47 patients (mean age = 42.4±15,6 years; 35 men) with acute myocarditis were included and compared to 16 healthy controls (without heart disease). The first-pass perfusion was evaluated by two blinded observers and compared to myocardial late Gadolinium enhancement, considered the reference method for the diagnosis of acute myocarditis, using both a qualitative (visual analysis) and a semi-quantitative method (ratio of the signals: infarction hyperaemia / healthy myocardium). 24 (51.1%) patients with myocarditis exhibited detectable hyperemia. Qualitative analysis showed good inter-observer variability (kappa = 0.75). There was an increase of the signal intensity in the myocardium with hyperhemia as compared to the adjacent normal myocardium (myocarditis vs controls: 1.08±0.03 vs 0.95±0.05, p=0.03; myocarditis with hyperhemia vs myocarditis non hyperhemia: 1.22±0.04 vs 0.94 ±0.04, p<0.0001). The correlation between the first-pass perfusion and late Gadolinium enhancement was good (kappa = 0,70). Considering the late Gadolinium enhancement as gold standard, the calculated values of sensitivity and specificity were 85% and 94%, respectively. Hyperhemia on the First-pass perfusion sequence, is a valuable and reproducible tool for the diagnosis of acute myocarditis. The author hereby declares no conflict of interest