Prognostic value of CMR regional longitudinal strain beyond global function and tissue characteristics in patients with suspected myocarditis

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cardiovascular magnetic resonance imaging (CMR) feature tracking (FT) regional longitudinal peak strain (RLS) is a novel method to assess regional myocardial deformation. The aim of this study was to investigate the prognostic value of CMR-FT RLS in patients with suspected myocarditis. Purpose Risk-stratification in patients with myocarditis is challenging. While left ventricular ejection fraction (LVEF) and global longitudinal peak strain (GLS) have shown predictive power in patients with myocarditis, the role of RLS is unknown. Methods Patients meeting clinical criteria for suspected myocarditis who were referred for CMR were included. Global/regional functional and CMR tissue characteristics were analyzed and associated with first major adverse cardiac event (MACE, i.e. heart failure hospitalization, sustained ventricular tachycardia, recurrent myocarditis and all-cause death). RLS was defined as following: anterior-/septal-(inferoseptal-/anteroseptal-))/inferior-/lateral-(anterolateral-/inferolateral). Patients with normal versus impaired function (i.e. according to LVEF and GLS) were selected for further sub-analysis. Results 773 consecutive patients met the inclusion criteria and were included in the final analysis. Mean age was 48.3±16 years, 286 (37%) were female, and at a median follow up of 3.5 years, MACE was present in 131 (17%) of all patients. RLS of all regions were associated with outcome in the univaribale analysis. Lateral-, inferolateral- and anterolateral- RLS remained independent, significant outcome predictors after correcting for cardiovascular risk factors and CMR tissue characteristics/function (HR 1.05–1.08, c-statistics 0.711–0.721). In the 394 (51%) patients with normal LVEF and GLS, septal-, inferoseptal- and inferolateral-RLS were all significant independent predictors for MACE after adjustment for cardiovascular risk factors (HR between 1.11 and 1.13 (95%CI: 1.07–1.17, a c-statistics 0.707–0.721 ). In patients with impaired LVEF/GLS only all but anterior and anterolateral-RLS wereas independently associated with outcome. Conclusion Regional longitudinal strain was independently associated with outcome beyond clinical and CMR tissue characteristsics and might therefore represent a more granular marker to refine risk stratification in suspected myocarditis with impaired- or normal left ventricular function.