Reduction of left ventricular mass, left atrial size, and N-terminal pro–B-type natriuretic peptide level following alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy

Abstract

Background: Alcohol septal ablation (ASA) is an alternative to surgical treatment in patients with hypertrophic obstructive cardiomyopathy (HOCM). Through alcohol-induced necrosis, ASA leads to an increase in left ventricular outflow tract (LVOT) diameter and a decrease in LVOT pressure gradient.

Aims: We sought to assess the effect of ASA on left ventricular (LV) wall thickness and mass, left atrial (LA) size, and N-terminal pro–B-type natriuretic peptide (NT-proBNP) level.

Methods: The study cohort consisted of 50 patients with HOCM (30 in the ASA group, 20 in the optimal pharmacotherapy group [OPG]). Transthoracic echocardiography (TTE), cardiac magnetic resonance (CMR), and NT-proBNP level analysis were performed at baseline and at six months.

Results: All parameters are presented as means. In the ASA group, the maximal LVOT pressure gradient decreased from 122.7 to 54.8 mmHg directly after ASA and to 37.2 mmHg after a further six months (p < 0.0001). The NT-proBNP level decreased from 2174.4 to 1103.4 pg/mL (p < 0.001). On TTE, the interventricular septum (IVS) thickness decreased to from 23.6 to 19.4 mm (p < 0.0001) and the lateral wall (LW) thickness decreased from 15.9 to 14.2 mm (p < 0.007). On CMR, basal IVS thickness decreased from 23.7 to 18.0 mm (p < 0.0001) and the LW thickness decreased from 13.2 to 12.2 mm (p = 0.02). IVS mass reduced from 108.9 to 91.5 g (–16%; p < 0.001). All of the above parameters remained unchanged in the OPG.

Conclusions: Successful ASA reduces LV hypertrophy and improves parameters of the LV overload, resulting in LV wall hy­pertrophy regression, and LA size and NT-proBNP level reduction. The above parameters may be as useful in assessing the efficacy of ASA as the LVOT gradient itself.