For ventricular tachycardia (VT) patients that have not responded to catheter ablation, Stereotactic body radiation therapy (SBRT) seems to be a promising therapy. Therefore, this study was conducted with the goal to check the viability of radioablation to modify an arrhythmogenic substrate.

Methodology:

This study included a total of six men with ischemic cardiomyopathy (left ventricular ejection fraction 20%) with ventricular tachycardia (VT) resistant to antiarrhythmic medicines and catheter ablations. Stereotactic body radiation therapy (SBRT) was applied to the scar substrate in all of them. The average patient age was 72 years. In addition to electroanatomical mapping, MUSIC (Institut Hospitalo-Universitaire l'Institut de Rythmologie et Modélisation Cardiaque, Bordeaux, France) computed tomography segmentation was performed on 5 of the 6 patients. Radioablation at 25 Gy was used to target areas with wall thinning of less than 5 mm, calcification, and intramyocardial fat.

Results:

The average planning target volume was 319 mL (IQR: 280-330). Radioablation had no effect on device-treated or sustained VT episodes (median 42 [IQR: 19-269] to 29 [IQR: 0-81]; P = 0.438). Device shocks, on the other hand, were reduced from 12 (IQR: 3-19) to 0 (IQR: 0-1) (P = 0.046).

Three patients died of end-stage heart failure during a follow-up period of 231 days (IQR: 212-311), while probable adverse events (pneumonia, heart failure exacerbation, and an asymptomatic pericardial effusion) was reported in 3 of the 6 patients.

Conclusion:

In patients with ischemic cardiomyopathy, substrate modification utilizing SBRT with computed tomography segmentation is a viable therapy option for VT. Despite a large reduction in device shocks, this cohort of patients with advanced cardiomyopathy had inadequate VT burden reduction and a high mortality rate, highlighting the need for better mechanistic knowledge of antiarrhythmic effects to guide dose and targeting of scar substrates.

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Keywords

Disease Condition,Investigation Modality,Coronary Artery Disease,Arrhythmias,Myocardial Disease and Cardiomyopathies,Investigation and Imaging,Ischemic Heart Disease,Ventricular Tachycardia,DCMP_others,IIMG_others

Source

https://pubmed.ncbi.nlm.nih.gov/34364832/

Tags

Disease Condition ,Investigation Modality,Coronary Artery Disease,Arrhythmias,Myocardial Disease and Cardiomyopathies,Investigation and Imaging,Ischemic Heart Disease,Ventricular Tachycardia,DCMP_others,IIMG_Others