Comparative Performance of Speckle Tracking Echocardiography and CMR Feature Tracking for Right Ventricular Myocardial Fibrosis in advanced heart failure.
BACKGROUND Right ventricular free wall longitudinal strain (RVFWLS) assessed by three-dimensional speckle-tracking echocardiography (3D-STE), two-dimensional (2D) STE and cardiac magnetic resonance feature tracking (CMR-FT) has been reported to correlate with the degree of right ventricular myocardial fibrosis (RVMF), but the value of 3D-STE in evaluating RVMF compared with CMR-FT has not been investigated in patients with advanced heart failure. AIMS This study aimed to determine which RVFWLS obtained by 2D-STE, 3D-STE, and CMR-FT, is the most robust noninvasive imaging marker for evaluating RVMF in patients with advanced heart failure using histopathological RVMF as the gold standard. METHODS 151 patients (118 male; mean age, 40±18 years) with advanced heart failure who underwent CMR, 2D and 3D echocardiographic examinations before heart transplantation were recruited in this study. RVFWLS was obtained from 2D-STE, 3D-STE and CMR-FT. The degree of RVMF was evaluated using late gadolinium enhancement (LGE) of CMR and Masson's staining in right ventricular myocardial samples, and patients were divided into three groups according to tertiles of histopathological RVMF. RESULTS Patients with severe RVMF had lower 3D-RVFWLS, 2D-RVFWLS and CMR-derived RVFWLS, and higher CMR-LGE compared with those with mild and moderate RVMF. RVMF was strongly correlated with CMR-derived RVFWLS (r = 0.73, p < 0.001), 3D-RVFWLS (r = 0.72, p < 0.001) and CMR-LGE (r = 0.71, p < 0.001), and moderately correlated with 2D-RVFWLS (r = 0.56, p < 0.001). The correlations of CMR-derived RVFWLS and 3D-RVFWLS with RVMF were not different from correlation of CMR-LGE with RVMF (p > 0.05). CMR-LGE, CMR-derived RVFWLS and 3D-RVFWLS had similar performance in identifying severe RVMF (AUC: 0.90 vs 0.87 vs 0.85, all p > 0.05). The model with CMR-derived RVFWLS (R2 = 0.515, p < 0.001) had a similar ability to assess RVMF as the model with 3D-RVFWLS (R2 = 0.499, p < 0.001), but better than the model with 2D-RVFWLS (R2 = 0.340, p < 0.001). CONCLUSIONS 3D-RVFWLS and CMR-derived RVFWLS are strongly correlated with RVMF in patients with advanced heart failure. 3D-STE may be a promising technique that correlates with RVMF, providing a similar accuracy as CMR-FT in assessing RVMF.