Asymmetric septal hypertrophy in patients with severe aortic stenosis: the usefulness of associated septal myectomy.

OBJECTIVE: Asymmetric septal hypertrophy frequently coexists with severe aortic stenosis and can be unmasked after successful aortic valve replacement (AVR), jeopardizing the clinical and echocardiographic results. The aim of our study was to investigate, at 5 years postoperatively, the effectiveness of myectomy associated with AVR on left ventricular (LV) mass regression and LV diastolic function.

METHODS: From 1997 and 2004, 86 patients with a diagnosis of severe aortic stenosis and asymmetric septal hypertrophy consecutively underwent AVR (group A) or AVR and concomitant myectomy (group B). To assess the improvement in LV mass and LV diastolic function, we studied the 52 survivors (23 in group A and 29 in group B) who had the same prosthesis type (beleaflet mechanical), the same size (21 mm), and the same follow-up length.

RESULTS: In group A, the LV mass index regressed from 119.2 ± 22.0 to 113.8 ± 21.8, and in group B, it regressed from 121.6 ± 20.8 to 112.7 ± 20.0 (P < .0005). In group A, the E/E' ratio improved from 15.3 ± 3.0 to 11.8 ± 3.0, and in group B, it improved from 16.2 ± 3.2 to 12.1 ± 3.3 (P = .02).

CONCLUSIONS: Surgeons should inspect the LV outflow tract at AVR. Concomitant myectomy at AVR is a safe and effective procedure that improves LV mass regression and LV diastolic function.