Assessment of agreement of left ventricular myocardial strain derived from cardiac computed tomography with cardiac magnetic resonance.

To assess differences and correlations between left ventricular myocardial strain measurements derived from cardiac CT (CCT) and cardiac MR (CMR) in patients with ischemic (IHD) and non-ischemic heart disease (NIHD). This single-center retrospective study included patients who underwent both full cardiac cycle CCT and CMR within 3 months. Global longitudinal (GLS), radial (GRS), and circumferential strain (GCS) were measured for both CCT and CMR. The mean difference with limits of agreement (LOA) and Pearson's correlation coefficient (r) with 95% confidence intervals (CI) were calculated. A prespecified margin of ± 1.5%, based on clinically acceptable differences, was used as a reference for assessing agreement. Sixty-three patients (mean age 68 ± 14 years; 70% male; 48% NIHD) were included. GLS and GCS from CCT showed minimal bias and good correlation with CMR (GLS, difference, -1.1% [LOA, -4.6%-2.4%]; r = 0.89 [95% CI 0.83-0.93]; GCS, difference, -1.2% [LOA, -7.4%-4.9%]; r = 0.78 [95% CI 0.66-0.86]). GRS from CCT showed slight overestimation compared to CMR (difference, 2.8% [LOA, -12.7%-18.3%]; r = 0.70 [95% CI 0.55-0.81]). The small bias in GLS was consistent between IHD and NIHD subgroups (-2.8% vs. 0.5%, p = 0.694), while GRS and GCS differences were more pronounced in the IHD subgroup (GRS, 5.2% vs. 0.1%, p = 0.014; GCS, -2.8% vs. 0.5%, p < 0.001). GLS and GCS from CCT showed good agreement with CMR, supporting their clinical feasibility. However, GRS and GCS measurements may be influenced by imaging protocols and disease backgrounds, necessitating standardized protocols for clinical application.