Distinct Myocardial Deformation Patterns Across Various Subtypes of Hypertrophic Cardiomyopathy

Background Previous investigation into hypertrophic cardiomyopathy (HCM) have uncovered diminished myocardial contractility and heterogeneous left ventricular (LV) regional deformation. Furthermore, the distribution and extent of LV hypertrophy vary across different types of HCM. Despite these observations, there remains a need to comprehensively explore potential distinctions in myocardial deformation among distinct forms of HCM. Methods A cohort comprising 45 patients with septal HCM (SeHCM), 10 with apical HCM (AHCM), and 7 with symmetric HCM (SyHCM) patients undergoing cardiovascular magnetic resonance (CMR) were investigated. Various clinical and echocardiographic measures were systematically collected. Strain (ε), strain rate (SR), and displacement, derived through CMR-feature tracking (CMR-FT) were quantified. Comparative analyses of CMR-FT results were conducted among the three HCM groups. Multiple linear regression models were employed to identify potential factors correlating to regional ε alterations. Results While all three HCM groups exhibited a reduction in global deformation, but the differences were not statistically significant difference ( Ps > 0.05). However, distinct regional patterns in ε, SR, displacement were observed, particularly at basal and apical levels. SeHCM demonstrated lower basal ε parameters, while AHCM exhibited lower apical parameters, both with statistical significance ( Ps < 0.05). Intriguingly, AHCM displayed lower apical deformation parameters compared to middle and basal indices, while SeHCM exhibited consistently lower basal deformation across all regions ( Ps < 0.05). Consequently, base-to-apex global longitudinal strain (GLS) and global circumferential strain (GCS) gradients were diminished in SeHCM and reversed in AHCM (GLS gradient: 2.29 ± 7.29 vs -12.81 ± 7.47, P < 0.001, GCS gradient: 2.81 ± 4.79 vs -5.04 ± 5.58, P < 0.001). SyHCM did not exhibit such regularities. Stepwise regression analysis demonstrated a direct relationship between HCM types and reduced regional ε. Conclusion Our findings illuminate specific regional deformation changes and the loss of the base-to-apex ε gradient in different types of HCM. This observations could serve as early markers of cardiac involvement in HCM, offering independent and incremental diagnostic significance and distinctive patterns across various HCM subtypes. Trial registration NCT 04830787