P452Prognostic performance of clinical presentation and cardiac magnetic resonance ejection fraction and late enhancement pattern at basal examination in acute myocarditis

Abstract

BACKGROUND: The presence of late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) in the setting of acute myocarditis (AM) has a diagnostic and prognostic value. There is conflicting evidence on the association between the presence of septal LGE, compared to other LGE localizations, and the occurrence of major cardiac events (MCE) at follow up (fu). We aimed to clarify the prognostic performance of LGE localization in AM patients (pts) from a multicenter registry. METHODS: In a retrospective registry including 443 AM pts (onset of symptoms <30 days) diagnosed either by endomyocardial biopsy (EMB) or increased troponin plus edema and LGE (non-ischemic pattern) at 1.5 T CMR. CMR scans with LGE localization were available in 175 patients (39.5%). Median age was 34 years and female were 13.1%. Basal CMR was performed after a median of 5 days from admission. Using the area under the receiver operating characteristic curve (AUROC), we assessed the prognostic performance for the prediction of MCE (cardiac death, heart transplant, aborted ventricular arrhythmias, sustained ventricular tachycardia [SVT] or hospitalization due to heart failure [HF]) of the following parameters: presence of septal LGE, evidence of left ventricular ejection fraction (LVEF)<50% at basal CMR, complicated (presence of sustained ventricular arrhythmias or a low cardiac output state at admission or the evidence of LVEF <50% at first echocardiogram performed after hospitalization) clinical presentation (CCP). RESULTS: Median LVEF was 61% (Q1-Q3, 55-66%) with median indexed LV end diastolic volume of 79 mL/m2 (Q1-Q3, 70-89 mL/m2). After a median fu of 44 months, 8 pts (4.6%) experienced a MCE: 5 episodes of HF, 1 aborted sudden cardiac death and 2 SVT. Among these 8 pts, 5 had septal LGE, 5 had a LVEF < 50% at basal CMR and all of them had a CCP. Pts with septal LGE had a significantly higher number of MCE during fu compared with those with other LGE localizations (5/41 [12.2%] vs. 3/134 [2.2%]; p = 0.02). The AUROC for septal LGE was 0.71 (p = 0.051). Similarly, pts with LVEF <50% at basal CMR had a significantly higher incidence of MCE at fu compared with those with LVEF≥50% (5/20 [25%] vs. 3/155 [1.9%]; p = 0.0005). The AUROC for LVEF < 50% at CMR was 0.77 (p = 0.01). Finally, pts with CCP had a significantly higher likelihood to experience a MCE compared with those with uncomplicated presentation (8/48 [16.6%] vs. 0/127 [0%]; p < 0.0001). The AUROC for CCP was 0.88 (p < 0.0001, see Figure). Among the 5 pts with septal LGE experiencing a MCE, 2 had cardiac sarcoidosis, 1 had eosinophilic myocarditis in Churg-Strauss syndrome, and 1 giant cell myocarditis. CONCLUSIONS: The prognostic performance of septal LGE for the prediction of MCE in AM seems inferior to LVEF < 50% at basal CMR or a CCP, the latter having the best accuracy. Septal LGE in pts who had subsequent MCE was related to specific histologies, suggesting the performance of EMB in this group of pts.