CORRELATION BETWEEN TISSUE ABNORMALITIES AND MYOCARDIAL DEFORMATION INDICES IN ARRHYTHMOGENIC CARDIOMYOPATHY: A MULTIMODALITY IMAGING STUDY.

AIMS. Speckle Tracking Echocardiography (STE) and Feature Tracking Cardiac Magnetic Resonance imaging (FT-CMR) are advanced imaging techniques which are increasingly used for the quantification of myocardial deformation indices. We aimed to study the diagnostic performance and correlation of biventricular strain parameters provided by STE and FT-CMR and to evaluate their correlation with tissue abnormalities in patients with definite diagnosis of arrhythmogenic cardiomyopathy (AC). METHODS. 41 AC Patients with available echocardiography (ECHO) and CMR study along with 41 healthy subjects who underwent complete echocardiography and 41 healthy subjects who underwent CMR scan were enrolled. Myocardial deformation indices (i.e. global longitudinal strain -GLS-; global circumferential strain -GCS-; global radial strain -GRS-) for both ventricles were calculated using STE and FT-CMR analysis. Quantification of tissue abnormalities (i.e. fat and late gadolinium enhancement -LGE- extension) was performed. RESULTS. All left and right ventricular (LV and RV) strain parameters were significantly impaired in AC patients compared with healthy subjects for both STE and FT-CMR analysis. There was a good correlation between ECHO LV GLS and both CMR LV 3DGLS and LV 2DGLS (Spearman’s Rho - rs - 0.662, p <0.001 and 0.561, p <0.001 respectively). All myocardial deformation indices, in particular GLS, were moderately associated with LGE extension (ECHO LV GLS rs = 0.461, p = 0.008; ECHO RV GLS 0.506, p = 0.003; CMR LV 3DGLS rs = 0.423, p = 0.016; CMR RV 2DGLS rs = 0.385, p = 0.030). The accuracy in diagnosing AC of both techniques was overall good (area under the receiver-operating characteristics curve -AUC- for ECHO LV GLS = 0.862; ECHO RV GLS AUC = 0.852; CMR LV 2DGLS AUC = 0.844; CMR RV 2DGLS AUC = 0.778). CONCLUSIONS. All myocardial deformation indices are impaired in patients affected by AC compared to healthy subjects and are significantly associated with the extension of tissue abnormalities detected by CMR. Strain analysis by STE and FT-CMR, mostly GLS, show a good diagnostic performance in identifying the disease and might be implemented in diagnostic algorithms.