Efficacy and safety of alcohol septal ablation in adolescents and young adults with symptomatic hypertrophic obstructive cardiomyopathy

Abstract

Abstract Background In young patients suffering from hypertrophic obstructive cardiomyopathy (HOCM) surgical myectomy is still considered as the gold standard for septal reduction therapy. Purpose To assess the safety and efficacy of alcohol septal ablation (ASA) for reduction of left ventricular outflow tract gradient (LVOTG) and symptoms in HOCM patients ≤25 years. Methods and results All ASA procedures performed at our institution between 2002 and 2020 were retrospectively allocated to a patient group ≤25 years (group 1) and a reference group >25 years (group 2). Patients were evaluated at baseline and chronic follow-up (FU) after 6 months. 1,264 procedures were analysed in group 2 (58.6±13.5 years) and 41 procedures in group 1 (20.9±3.3 years). Proportion of family history of sudden cardiac death was higher in group 1 (56.1% vs. 24.6% in group 2; p<.0001). We more often found a previously implanted cardiac device in group 1 (31.7% vs. 9.0% in group 2; p<.0001) and the interventricular septal diameter (IVSD) was higher in young patients at baseline (26.0±6.5 mm vs. 21.3±4.4 mm in group 2; p<.0001). LVOTG at baseline did not differ between the groups (54.4±24.4 mmHg in group 1 vs. 52.4±36.6 mmHg in group 2 (p=n.s.). Relief of symptoms was shown for both groups at FU compared to baseline (group 1: mean NYHA class 2.5 at baseline and 1.3 at FU; p<.0001; group 2: mean NYHA class 2.7 at baseline and 1.4 at FU; p<.0001). Compared to baseline IVSD was significantly reduced at FU (20.3±8.2 mm in group 1 at FU; 16.8±5.7 mm in group 2 at FU; p<.0001 for each group compared to baseline). LVOTG improved significantly during FU (25.5±20.0 mmHg in the young patients; 22.1±21.7 mmHg in the reference group; p<.0001 for each group compared to baseline). Mortality was 0.0% in patients ≤25 years and 0.9% in the reference group. Conclusion Our data demonstrate safety and efficacy of ASA to improve LVOT obstruction and symptoms in young adults and adolescents (14–25 years) suffering from symptomatic HOCM. Therefore, ASA may be considered also for this patient population. However, these results may only hold for experienced centres and, thus, invasive procedures in young patients should be reserved to centres with the required expertise. Funding Acknowledgement Type of funding sources: None. Table 1. Baseline characteristics. ASA = alcohol septal ablation. ICD = implantable cardioverter-defibrillator. IVSD= interventricular septum diameter. LA = left atrium. LVOTG = left ventricular outflow tract gradient. n.s. = not significant. PM = pacemaker. SCD = sudden cardiac death. SM = septal myectomy.Figure 1. Echocardiographic parameters in patients ≤25 years at baseline and follow-up (FU) 6 months after alcohol septal ablation. ****p<.0001. A. Interventricular septum diameter (IVSD). B. Left ventricular outflow tract gradient (LVOTG).