Regional Left Ventricular Reverse Remodeling After Myectomy in Hypertrophic Cardiomyopathy.

BACKGROUND

Surgical extended septal myectomy is appropriate treatment for obstructive hypertrophic cardiomyopathy (HCM) with refractory symptoms. Using 3-layer speckle tracking imaging, we aimed to evaluate the effects of myectomy on left ventricular (LV) regions and the potential factors associated with LV reverse remodeling.

METHODS

In 71 patients (mean age, 41.0 ± 15.0 years) undergoing septal myectomy, 3-layer speckle tracking was performed before myectomy and latest review. We evaluated the myectomy site (target anteroseptum) and LV free wall longitudinal strain (LS) and circumferential strain (CS) in endocardial, midmyocardial, and epicardial layers. The thickness of each free wall segment was calculated and totaled for the free wall thickness score.

RESULTS

Compared with before myectomy, LS increased; however, CS decreased at the myectomy site after myectomy. For the free wall, LS and CS improved in all 3 layers after the procedure (all p < 0.05). Factors independently associated with latest-review free wall strain were free wall thickness score (LS, β = -0.150; p < 0.001; CS, β = -0.090; p < 0.001), age (LS, β = 0.118; p < 0.001), and ΔLV outflow tract gradient (CS, β = 0.039; p = 0.002). Factors independently associated with myectomy site strain were resected thickness (LS, β = -0.439; p = 0.001; CS, β = -0.736; p = 0.001), and age (LS, β = 0.178; p < 0.001).

CONCLUSIONS

Sufficient relief of obstruction and lower resected thickness in the target anteroseptum lead to more favorable remodeling. Free wall thickness score and age are important factors associated with reverse remodeling.