In a groundbreaking study conducted at Washington University School of Medicine in St. Louis, researchers have delved into the effects of low-dose radiation therapy on patients with ventricular tachycardia and mice experiencing heart failure. Contrary to conventional wisdom, the findings challenge preconceived notions, suggesting that low-dose radiation therapy could hold the key to improving heart function.
FROM CANCER TREATMENT TO CARDIOVASCULAR INNOVATION
Originally designed to combat cancer, radiation therapy has been repurposed by innovative cardiologists and radiation oncologists to address ventricular tachycardia—a severe and life-threatening irregular heart rhythm. The targeted therapy, although directed at a specific heart region, has shown unexpected positive outcomes, raising questions about its potential harm.
HUMAN AND MURINE TRIALS: PARALLEL SUCCESS STORIES
The research involved a cohort of nine patients with ventricular tachycardia, meticulously evaluated using cardiac MRI before and after receiving radiation treatment. Encouragingly, the results demonstrated improved heart function, particularly in the left ventricle responsible for circulating blood throughout the body. Similar promising outcomes were witnessed in mice models with heart failure, reinforcing the potential of low-dose radiation therapy.
“The radiation therapy used to treat ventricular tachycardia is targeted to a specific location in the heart; however, a large portion of the rest of the heart gets a low-dose exposure,” said co-senior author and cardiologist Ali Javaheri, MD, PhD, an assistant professor of medicine. “We wanted to understand the effects of that low-dose radiation on these patients’ hearts. There was concern that it could be harmful to overall heart function, even though it treats dangerous arrhythmia. We were surprised to find the opposite: Heart function appeared to be improved after radiation therapy, at least in the short term.”
REDUCED INFLAMMATION AND HEART REMODELING
The unexpected positive impact on heart function challenges existing assumptions about the overall impact of low-dose radiation. The study revealed reduced fibrosis and a decrease in inflammatory immune cells in the irradiated hearts, indicating a potential avenue for heart remodelling. The complexity of these outcomes suggests a multifaceted response to low-dose radiation, revolutionizing our understanding of its role in heart therapy.
IMPLICATIONS FOR HEART FAILURE PATIENTS: A GLIMPSE INTO THE FUTURE
With approximately 6.2 million American adults grappling with heart failure, these findings offer a ray of hope for improved therapies. While acknowledging the need for further research, the study hints at new possibilities in the realm of heart therapy, presenting potential benefits for patients facing this complex and often debilitating condition.
ADVANCING RESEARCH AND EXPLORING HUMAN HEART INFLAMMATION
To deepen the understanding of these unexpected positive outcomes, researchers plan to continue investigations into patients undergoing radiation therapy for ventricular tachycardia. Advanced studies will focus on examining potential reductions in inflammation in human hearts, mirroring the observed effects in murine models. These ongoing efforts seek to unlock the full potential of low-dose radiation therapy in reshaping cardiovascular treatments.