Abstract 18476: Are Cardiac Magnetic Resonance Patterns Associated with Adverse 18-Month Outcome in Patients with Acute Myocarditis?

Abstract

Introduction: Cardiac Magnetic Resonance (CMR) is a fundamental tool in the diagnosis of Acute Myocarditis (AM). However, its prognostic value is not well established. Hypothesis: CMR findings in patients with AM may predict functional/clinical outcome. Methods: We studied consecutive pts diagnosed with AM by CMR between 2008 and 2011. All pts underwent initial clinical assessment and CMR was performed at a mean of 11±12 days after acute clinical presentation. Black-blood T2-CMR was used for myocardial edema assessment and contrast-enhanced CMR was performed 3 (early gadolinium enhancement, EGE) and 10 (late gadolinium enhancement, LGE) min after gadolinium chelates. Images were analysed dividing the myocardium into 17 segments and 3 myocardial sectors (subepicardium, midwall, and subendocardium), allowing quantification of lesions extent as percent of LV myocardium. Presence of pericardial effusion and LV segmental wall motion was assessed. Adverse cardiac events including recurrence of symptoms, congestive heart failure, ventricular arrhythmias, heart transplantation, or death, were carefully recorded at clinical follow-up (FU) performed 19±8 months after indexed CMR. Results: The patient population comprised 203 pts (43±17 year-old, 76% males) with AM. A total of 22/203 patients (10.8% of the whole population) experienced adverse cardiac events. By univariate analysis, the extent of EGE was inversely correlated with the presence of clinical events at FU (2.2±4.1 vs. 5.1±6.0% of LV myocardial mass, for pts with and without adverse cardiac events, respectively, p=0.005). Additionally, pts with altered EF on initial CMR examination had worse myocardial function at FU. In contrast, presence of hyper-T2 signal (p=0.68), extent (p=0.72) and distribution (p=0.09) of LGE, presence of pericardial effusion p=0.18), were not associated with adverse clinical outcome. Multivariate analysis showed no CMR predictors of adverse clinical outcome. Conclusions: In this large cohort of patients with AM, there were no CMR predictors of adverse clinical outcome. A significant association was found between initial LV function and impaired LVEF at FU, as well as between EGE and adverse clinical events.