Transaortic septal myectomy provided similar postoperative gradient relief across septal thickness groups (<18 mm, 18-21 mm, >21 mm; median reduction 51, 54, and 50 mmHg, P=0.11).
Cohort (n=1,486)
Does septal thickness influence the outcome and adequacy of transaortic septal myectomy in patients with hypertrophic obstructive cardiomyopathy?
Transaortic septal myectomy provides adequate relief of left ventricular outflow tract obstruction with minimal risk of ventricular septal defect even in patients with basal septal thickness <18 mm, challenging the notion that these patients require mitral valve replacement.
p-value: p=0.11
Patients with hypertrophic obstructive cardiomyopathy and basal septal thickness 21 mm, n = 505), were performed with the Kruskal-Wallis and the Pearson χ2 tests and semiparametric analysis of covariance.Median group ages were 57, 57 and 54 years (P = 0.007); men comprised 50.4%, 56.7% and 62.0%, respectively (P = 0.003). Intrinsic MV disease was present in 5.9%, 5.2% and 4.6%, respectively (P = 0.80). All patients underwent transaortic septal myectomy. Additional mitral procedures were performed in 7.6%, 7.8% and 8.1%, respectively (P = 0.90). Reasons for MV surgery included intrinsic MV disease (66.7%), residual mitral regurgitation (30.8%) and residual gradient (2.6%). All groups had postoperative gradient relief (median reduction: 51, 54 and 50 mmHg; P = 0.11). Ventricular septal defect occurred in 4 patients (0.3%), and risk did not differ by group (P = 0.24).Adequate relief of left ventricular outflow tract obstruction can be achieved via transaortic septal myectomy without concomitant MV procedures when septal thickness is < 18 mm, and the risk of ventricular septal defect is minimal. Concomitant MV repair/replacement should be reserved for patients with intrinsic MV disease or inadequate relief of mitral regurgitation/left ventricular outflow tract obstruction following adequate extended septal myectomy.
Nguyen et al. (Mon,) conducted a cohort in Hypertrophic obstructive cardiomyopathy (n=1,486). Transaortic septal myectomy vs. Septal thickness groups (<18 mm, 18-21 mm, >21 mm) was evaluated on Postoperative gradient relief (p=0.11). Transaortic septal myectomy provided similar postoperative gradient relief across septal thickness groups (<18 mm, 18-21 mm, >21 mm; median reduction 51, 54, and 50 mmHg, P=0.11).