The aim of this study was to investigate the short and long-term efficiency of alcohol septal ablation (ASA) in different groups of obstructive hypertrophic cardiomyopathy (oHCM) patients with severe and non-severe gradients in the left ventricle outflow tract (LVOT) and those with severe and non-severe basal septal hypertrophy. Material and methods. In this study, 212 oHCM patients were included. The mean age was 52+15. Female patients were 50.7% (107 patients). Patients were divided into 4 groups, according to the septal hypertrophy pattern and the severity of LVOT gradient at rest: group 0 - patients without severe LVOT gradient (<50 mmHg at rest) or severe basal hypertrophy (<20 mm); group 1 - patients with severe LVOT gradient (≥50 mmHg at rest), but without severe basal hypertrophy (<20 mm); group 2 - patients without severe LVOT gradient (<50 mmHg at rest), but with severe basal hypertrophy (≥20 mm); group 3 - patients with severe LVOT gradient (>50 mmHg at rest) and with severe basal hypertrophy (≥20 mm).
Results. The median follow-up was 74 (38-127) months. The long-term survival rates in entire cohort were as follows 98.1 (95% CI 96.2-100.0)%, 92.3 (95% CI 88.5-96.3)%, 77.2 (95% CI 70.1-85.0)%, at 1-, 5-, 10-years of follow-up. The cumulative incidence of mortality cases in the longterm was 41 patients (19.3%). The difference in survival rates between groups in this study did not reach the statistical significance (p=0.16), but comparing a group 3 (PG >50 mmHg and IVS >20 mm) with the rest of patients (PG <50 mmHg and/or IVS <20 mm) the statistically significant difference between survival rates was identified (p=0.029) with a hazard ratio (HR) = 1.98 (95% CI 1.06-3.72). The mean functional class of chronic heart failure improved from 2.5+0.6 to 1.5+0.6. In the follow-up, the LVOT gradient decreased from 60 (40-89) mmHg to 15 (9-124) mmHg at rest and from 108 (80-135) mmHg to 26 (16-49) mmHg after provocation. The mean IVS reduction was 5+3 mm in the follow-up. Residual obstruction was observed in 42 cases (20%) in the whole cohort. Comparing patients with PG ≥50 mmHg with those with PG <50 mmHg the higher reoperation rates were observed in patients with the severe LVOT gradient at baseline [p=0.046, HR = 2.12 (95% CI 1.00-4.49)].
Conclusion. Alcohol septal ablation showed higher reintervention rates in cases with severe resting left ventricle outflow gradient at baseline. Patients with severe resting gradient and severe basal hypertrophy at baseline had higher long-term mortality rates despite the septal reduction.