Effect of alcohol septal ablation on exercise hemodynamics, symptoms and quality of life in patients with obstructive hypertrophic cardiomyopathy

Abstract Background The comprehensive impact of septal reduction therapy in patients with obstructive hypertrophic cardiomyopathy (HCM), including exercise hemodynamics and quality of life (QoL), remains poorly understood. Purpose The aim of this study was to evaluate the effect of alcohol septal ablation (ASA) in mitigating left ventricular outflow tract (LVOT) obstruction, reducing filling pressures during exercise, and the effect on QoL in patients with obstructive HCM. Methods This prospective study enrolled 24 patients with obstructive HCM referred for ASA. Evaluations included right-heart catheterization and echocardiography performed at rest and during exercise, before and approximately six months post-ASA. The primary outcome was the difference in filling pressures assessed by pulmonary capillary wedge pressure (PCWP) at 75 Watt (W). Secondary outcome assessed LVOT gradients, New York Heart Association (NYHA) functional class, Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), and exercise capacity. Results ASA significantly reduced PCWP at 75 W (24 ± 10 mmHg vs 33 ± 9 mmHg; P = 0.0001) (Figure 1), decreased LVOT gradients at rest (49 mmHg (24-90) vs 17 mmHg (14-27); P=0.002), at peak exercise (45 mmHg (29-90) vs 32 mmHg (21-61); P = 0.02), and post-exercise (96 mmHg (34-161) vs 28 mmHg (21-62); P=0.004). The KCCQ-OSS score was also significantly reduced (75.6 ± 18.8 vs 64.7 ± 16; P = 0.006), without affecting peak oxygen consumption (19.9 ± 4.8 ml/kg/min vs 18.7 ± 3.6 ml/kg/min; P = 0.26). The improvement in the KCCQ score was confirmed by changes in NYHA functional class. Before ASA treatment, 54% of patients were in NYHA functional class III compared to 13% after ASA (P < 0.0005). Conclusion ASA substantially reduces exercise-induced filling pressures, reduces LVOT obstruction, and improves symptoms and QoL in obstructive HCM, without impacting maximal exercise capacity.