Quantitative Assessment of Three-Dimensional Aorto-Mitral Angle in Hypertrophic Cardiomyopathy

Background This study explored the correlation between the 3-dimensional aorto-mitral angle and pressure gradients in patients with obstructive hypertrophic cardiomyopathy (HCM) undergoing septal myectomy, with or without aortic shortening. Methods A single-site, retrospective observational study was conducted at a tertiary-level hospital; 67 patients underwent septal myectomy for obstructive HCM. Preoperative and postoperative transesophageal images were analyzed offline to measure the end-systolic 3-dimensional aorto-mitral angle with Mitral Valve Quantification software and Doppler-derived pressure gradients. The angle's impact on pressure gradients after myectomy, with or without aortic shortening, was evaluated by linear regression. Results Regression analysis found no significant relationship between aorto-mitral angle changes and postmyectomy pressure gradients (r = 0.03; 95% CI, −0.22 to 0.28; P = .81), regardless of aortic shortening. No major angle differences were observed between myectomy-only patients and those with additional aortic shortening (97.0° ± 8.4° vs 100.4° ± 8.7°; P = .78). Conclusions The reduced angle seen in patients with obstructive HCM did not return to normal values after septal myectomy, even with normalized pressure gradients. Aortic shortening did not significantly influence the aorto-mitral angle after myectomy either.