Prognostic Value of Right Ventricular Function in Patients With Suspected Myocarditis Undergoing Cardiac Magnetic Resonance.

Background: Risk-stratification of myocarditis is based on functional parameters and tissue characterization of the left ventricle (LV), whereas right ventricular (RV) involvement remains mostly unrecognized.
Objectives: In this study, the authors sought to analyze the prognostic value of RV involvement in myocarditis by cardiac magnetic resonance (CMR).
Methods: Patients meeting the recommended clinical criteria for suspected myocarditis were enrolled at 2 centers. Exclusion criteria were the evidence of coronary artery disease, pulmonary artery hypertension or structural cardiomyopathy. Biventricular ejection fraction, edema according to T2-weighted images, and late gadolinium enhancement (LGE) were linked to a composite end point of major adverse cardiovascular events (MACE), including heart failure hospitalization, ventricular arrhythmia, recurrent myocarditis, and death.
Results: Among 1,125 consecutive patients, 736 (mean age: 47.8 ± 16.1 years) met the clinical diagnosis of suspected myocarditis and were followed for 3.7 years. Signs of RV involvement (abnormal right ventricular ejection fraction [RVEF], RV edema, and RV-LGE) were present in 188 (25.6%), 158 (21.5%), and 92 (12.5%) patients, respectively. MACE occurred in 122 patients (16.6%) and was univariably associated with left ventricular ejection fraction (LVEF), LV edema, LV-LGE, RV-LGE, RV edema, and RVEF. In a series of nesting multivariable Cox regression models, the addition of RVEF (HR _adj : 0.974 [95% CI: 0.956-0.993]; P = 0.006) improved prognostication (chi-square test = 89.5; P = 0.001 vs model 1; P = 0.006 vs model 2) compared with model 1 including only clinical variables (chi-square test = 28.54) and model 2 based on clinical parameters, LVEF, and LV-LGE extent (chi-square test = 78.93).
Conclusions: This study emphasizes the role of RV involvement in myocarditis and demonstrates the independent and incremental prognostic value of RVEF beyond clinical variables, CMR tissue characterization, and LV function. (Inflammatory Cardiomyopathy Bern Registry [FlamBER]; NCT04774549; CMR Features in Patients With Suspected Myocarditis [CMRMyo]; NCT03470571).
Competing Interests: Funding Support and Author Disclosures Dr Bernhard has received career development grants from the Swiss National Science Foundation. Dr Safarkhanlo has received research funding from the Center for Artificial Intelligence in Medicine Research Project Fund, University Bern, outside of the submitted work. Dr Benz has received career development grants from the Swiss National Science Foundation and reimbursement of travel expenses by Philips Healthcare and Amgen. Dr Gräni has received research funding from the Swiss National Science Foundation and Innosuisse, the Center for Artificial Intelligence in Medicine Research Project Fund University Bern, and the GAMBIT foundation, outside of the submitted work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)