Extended septal myectomy versus Alcohol septal ablation. Clinical results in a national referral center.

OBJECTIVES: Extended septal myectomy and alcohol septal ablation are two invasive treatments for hypertrophic obstructive cardiomyopathy. We aim to compare which of these techniques achieves a higher reduction in gradients, improvement in NYHA class and reduction in medical treatment.

METHODS: This is a single-center observational and retrospective analysis. This is a single-center observational and retrospective analysis. We have used multivariable regression analyses to assess the association of ablation/myectomy with different outcomes. Odds ratio or coefficient along with the 95% confidence interval were estimated according to the group, and adjusting for the corresponding pre procedural variables and Euroscore II.

RESULTS: 78 patients underwent septal myectomy and 25 patients underwent alcohol septal ablation. Basal and Valsalva gradients after myectomy were reduced in a higher degree in comparison to ablation, 21.0 mmHg (p < 0.001, 95%CI -30.7; -11.3), and 34.3 mmHg (p < 0.001, -49.1; -19.5) respectively. Those patients who received myectomy had lower probability of presenting moderate mitral regurgitation (OR = 0.18, p = 0.054). Patients after septal myectomy were more likely to be in NYHA I (80.4%); whilst patients after ablation were more likely to be NYHA III (48%). Both groups continued with betablocker therapy, but disopyramide could be discontinued after myectomy in more cases (20% - 36% vs. 59% - 1.3%; p < 0.001) and there is a tendency in the discontinuation of calcium channel blockers (48% - 16% vs. 15.4-3.8%; p = 0.054).

CONCLUSIONS: After adjustment by pre procedural gradients and Euroscore II, myectomy achieves greater reduction in left ventricular outflow tract gradients compared to septal ablation.