Accuracy and Prognostic Value of Automated Right Ventricular Strain in Heart Transplantation Patients: Validation Against Cardiac Magnetic Resonance

BACKGROUND: Right ventricular free wall longitudinal strain (RVFWLS) is a sensitive marker of RV dysfunction after heart transplantation (HT), and automated RVFWLS may improve efficiency. This study evaluated the accuracy and prognostic value of automated echocardiographic RVFWLS using cardiac magnetic resonance imaging (CMR) as reference. METHODS: A total of 150 HT recipients undergoing echocardiography and CMR within 3 days were retrospectively analysed. The accuracy and prognostic value of fully and semiautomated RVFWLS were compared with CMR. Image quality was graded as "optimal" or "acceptable" to assess its influence on automated measurements. RESULTS: Both fully and semiautomated methods correlated with CMR (r = 0.727 and 0.863; P < 0.001), with the semiautomated approach showing smaller bias, narrower limits of agreement, and lower coefficient of variation. The subgroup of "acceptable" image quality reduced the accuracy of automated RVFWLS. During a median 37-month follow-up, 29 patients experienced adverse events. In multivariable Cox analysis, semiautomated RVFWLS (hazard ratio HR = 1.499; AIC = 229; C-index = 0.807) showed prognostic performance similar to CMR (HR = 1.570; AIC = 216; C-index = 0.852) and outperformed fully automated RVFWLS (HR = 1.284; AIC = 249; C-index = 0.734). Receiver operating characteristic analysis confirmed the superiority of semiautomated RVFWLS over the fully automated method in predicting adverse events (area under the receiver operating characteristic curve 0.845 vs 0.735; P = 0.002). CONCLUSIONS: Automated RVFWLS showed good accuracy and prognostic value in HT patients as validated by CMR. The semiautomated approach may be preferable for post-HT follow-up owing to its superior performance, whereas the fully automated method may be a potentially acceptable alternative when image quality is adequate.