Quantification of Left Ventricular Trabecular Complexity in Patients With Hypertrophic Cardiomyopathy by Cardiovascular Magnetic Resonance Imaging Fractal Analysis: A Feasibility and Reproducibility Study.

Purpose: To investigate the left ventricular (LV) trabecular complexity and evaluate its relationship with LV cardiac function and especially myocardial strain in patients with hypertrophic cardiomyopathy (HCM).

Materials and methods: A total of 100 patients were retrospectively recruited in the study, including 50 obstructive hypertrophic cardiomyopathy (HOCM) and 50 nonobstructive HCM (NOHCM). Fifty age-matched and sex-matched healthy participants were also enrolled. The global and regional LV fractal dimensions (FDs), the global radial, circumferential, and longitudinal strain (GRS, GCS, and GLS) for LV were measured. FDs and myocardial strain parameters among 3 groups with post hoc paired comparisons. Correlations analysis and receiver operating characteristic analysis were performed.

Results: Mean global FD, max basal FD, and max apical FD were higher in patients with HCM compared with the healthy individuals (1.310 ± 0.046 vs 1.229 ± 0.027, 1.388 ± 0.089 vs 1.313 ± 0.039, 1.393 ± 0.108 vs 1.270 ± 0.041, all P < 0.001). Patients with HOCM showed significantly higher max apical FD than patients with NOHCM (1.432 ± 0.100 vs 1.355 ± 0.102, P < 0.001). The increased global FD was associated with reduced myocardial deformation across all 3 measures of global strain (GCS: r = 0.529, P < 0.001; GLS: r = 0.54, P < 0.001; GRS: r = -0.253, P = 0.002). Max apical FD yielded an area under the curve of 0.73 (95% CI: 0.63-0.83) for discriminating HOCM from NOHCM.

Conclusions: LV trabecular complexity is compensatively increased in patients with HCM and the max apical FD was more pronounced in patients with HOCM. The increased LV global trabecular complexity might be correlated with LV systolic dysfunction.