Computed tomography angiography planning identifies the target vessel for optimum infarct location and improves clinical outcome in alcohol septal ablation for hypertrophic obstructive cardiomyopathy.

AIMS

Alcohol septal ablation (ASA) is an established treatment option in hypertrophic obstructive cardiomyopathy (HOCM). ASA is ineffective in some: inaccurate infarct and inability to identify a vessel contribute. We aimed to improve accuracy of infarct using CT angiography guidance and provide a more predictable and satisfactory outcome.

METHODS AND RESULTS

Twenty-one successive patients with symptomatic LVOT obstruction refractory to medication underwent CT angiography planning to guide ASA. CT was performed using a dual-source CT system. Alcohol was delivered to the artery identified from CT: in 17/21 this was a sub-branch of a septal artery, in 2/21 the septal vessel was identified from the circumflex artery. Peak gradient improved from 98 (IQR 89.50-111.50) mmHg to 14 (IQR 8.50-22) mmHg (p=0.003). Systolic anterior motion (SAM) improved in 18/20 patients. NYHA class improved by ≥1 in 18/20. Peak VO2 improved from 79.19% of predicted value (±14.01) to 91.62% (±12.02) predicted (p<0.0001). Success at the first procedure is greater with CT guidance, 17/20 vs. 50/75 with traditional methods (pre-CT guidance) (p=0.02); 9/20 had six-month CMR with target septum infarct in all. ASA-related RBBB reduced from 62% to 13% (p=0.0004).

CONCLUSIONS

CT angiography planning improves localisation of infarct and procedural success at the first attempt in ASA when compared to traditional methods. Follow-up to six months suggests a symptomatic, functional and haemodynamic improvement.