Impact of centre experience on complete clinical and haemodynamic response after alcohol septal ablation for hypertrophic obstructive cardiomyopathy.

BACKGROUND

Alcohol septal ablation (ASA) is an established therapy for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) in patients unresponsive to medical treatment. However, comprehensive assessment of ASA outcomes remains challenging. This study aimed to evaluate the impact of institutional experience and patient characteristics on achieving complete clinical and haemodynamic response (CCHR), a novel composite outcome integrating long-term symptomatic, haemodynamic, safety, and major clinical endpoints, including survival and resuscitation.

METHODS

We retrospectively analysed 1206 symptomatic HOCM patients undergoing first-time ASA between 1996 and 2023 in seven European centres. CCHR was defined as residual left ventricular outflow tract (LVOT) gradient <30 mmHg, NYHA class I/II, absence of new permanent pacemaker implantation, and absence of major adverse cardiovascular events at last follow-up.

RESULTS

After a median follow-up of 4.9 (IQR 2.0-7.0) years, CCHR was achieved in 59 % of patients, with inter-centre variability ranging from 21.4 % to 69.3 %. Centres with higher procedural volumes showed significantly better outcomes. Patients treated within the first 50 procedures at a centre had significantly lower odds of achieving CCHR (OR 0.49; 95 % CI 0.34-0.71; p < 0.001). Younger age, lower baseline LVOT gradient, and higher baseline ejection fraction were independent predictors of success.

CONCLUSIONS

CCHR, integrating both haemodynamic and hard clinical outcomes, was achieved in the majority of ASA-treated HOCM patients. Institutional experience and patient selection emerged as key determinants of success. These findings support centralisation of ASA in high-volume centres and may inform patient-tailored therapeutic strategies.