When radiation meets the heart: Future of stereotactic body radiation therapy for hypertrophic obstructive cardiomyopathy.

Abstract

Hypertrophic obstructive cardiomyopathy (HOCM) is a hereditary cardiac disorder characterized primarily by septal hypertrophy and left ventricular outflow tract obstruction. Traditional therapeutic modalities, such as medications and surgeries, do not yield satisfactory outcomes in a subset of patients. The advancements have been made in novel treatments, including new drugs and percutaneous intramyocardial septal radiofrequency ablation (PIMSRA), still need further observation to obtain long-term efficacy and safety. In recent years, stereotactic body radiation therapy (SBRT) has emerged as an innovative non-invasive approach for treating HOCM. Studies indicate that SBRT allows for precise targeting of the hypertrophied septal region, causing both direct and indirect damage to targeted myocardial cells. This can alleviate left ventricular outflow tract obstruction and myocardial ischemia, fulfilling the therapeutic objective. For those with HOCM who neither respond well to medications nor are surgical candidates, SBRT offers a potential new therapeutic alternative. However, the latent risks of radiation therapy persist, such as the onset of radiation-induced heart disease (RIHD). The preliminary investigations guarantee the safety and feasibility of SBRT in HOCM management, an increased volume of clinical studies and prolonged follow-up data are essential to evaluate its real efficacy and potential hazards. In addition, research regarding the therapeutic mechanisms of SBRT for HOCM, optimal dosages and treatment durations, indications and contraindications, prevention of complications, and enhancing the precision of radiation therapy, still needs to be further exploration, to determine the best therapeutic strategies.