Myocardial deformation measures by cardiac magnetic resonance tissue tracking in myocarditis: Relationship with systolic function and myocardial damage.

INTRODUCTION AND OBJECTIVES: Cardiac magnetic resonance (CMR)-based tissue tracking (TT) enables quantification of myocardial deformation and may be used as an objective measure of myocardial involvement in myocarditis. The aims of this study were to characterize myocardial deformation alterations in myocarditis and to determine their relationship with the extent of late gadolinium enhancement (LGE), regional wall motion abnormalities (WMA) and left ventricular ejection fraction (LVEF). METHODS: A single-center, retrospective study was conducted by identifying patients with clinically suspected myocarditis who underwent CMR between 2012 and 2016. The myocardial deformation parameters were derived by TT and correlated with LVEF, LGE and WMA, through Spearman's coefficient. RESULTS: A cohort of 78 patients with myocarditis (aged 42.7±17.2 years) were included. CMR characteristics including morphologic parameters (LVEF 52.1±12.8%), extent of WMA (29.3±41.0%) and of LGE (30.5±21.8%) were assessed. Significant correlations were found between all deformation parameters (strain, strain rate, velocity and displacement) and both LVEF and extent of WMA. LGE was significantly correlated with systolic radial strain (r: -0.32, p=0.004), strain rate (r: -0.27, p=0.017) and displacement (r: -0.32, p=0.004) as well as systolic circumferential strain (r: 0.28, p=0.013). CONCLUSION: Deformation parameters are an objective method for quantification of myocardial function in myocarditis. They correlate with LVEF, extent of WMA and degree of myocardial damage. Further studies are needed to assess their incremental beneficial value for the diagnosis and risk stratification of myocarditis.