# A Clinical Study of Precision Chemoablation for Hypertrophic Obstructive Cardiomyopathy Without Large Interventricular Septal Branches

## TL;DR

This study shows that a new ultrasound-guided chemical ablation method safely reduces heart obstruction in patients with a specific heart condition.

## Contribution

The study introduces a precision chemical ablation technique for HOCM patients without large septal branches.

## Key findings

- Ultrasound-guided ablation significantly reduced left ventricular outflow tract gradient in HOCM patients.
- Patients showed improved quality of life and heart function one year after the procedure.
- No significant change in septal thickness or ejection fraction was observed post-treatment.

## Abstract

This study aims to evaluate the clinical efficacy and safety of ultrasound‐guided percutaneous septal precision chemical ablation in the treatment of hypertrophic obstructive cardiomyopathy (HOCM).

From December 2020 to July 2024, 27 patients with HOCM without large target septal branches (diffuse multiple branches, all less than 1 mm in diameter) were enrolled and underwent ultrasound‐guided percutaneous septal chemical ablation. Intraoperative left ventricular outflow tract gradient (LVOTG), postoperative cardiac troponin I (cTnI), complications, and changes in the 36‐Item Short Form Survey (SF‐36) score, New York Heart Association (NYHA) functional classification and echocardiography parameters in 1 year post‐PTSMA were monitored and analyzed.

Immediate postoperative LVOTG values monitored by catheter and echocardiography were both significantly decreased (both p < 0.05) in the 27 patients, whereas the cTnI level was increased after PTSMA treatment (p < 0.05). One patient developed transient complete right bundle branch block during the procedure. At the 1‐year follow‐up, these patients showed significantly increased scores in all the eight domains of the SF‐36 scale, and markedly improvement in echocardiography‐based LVOTG value (p < 0.05) and NYHA functional classification (p < 0.05). However, no significant change were observed in the mean interventricular septal thickness (IVSTh) and left ventricular ejection fraction (LVEF) before and after operation (p > 0.05).

Ultrasound‐guided precision PTSMA with gelatin sponge is a safe and effective treatment approach for HOCM patients, which can reduce the left ventricular outflow tract obstruction and greatly improve the life quality of the patients.

For HOCM patients without large target septal coronary arteries, we identify target septal coronary artery supplying the most hypertrophied septum, and make sure the guide‐wire can access this target vessel. We perform precise ablation of the most hypertrophied septum using gelatin sponge as an embolic medium.