A team of physicians at Allegheny General Hospital (AGH), part of Allegheny Health Network (AHN), are among the first in the country to use a novel form of radiation therapy to treat a life-threatening heart rhythm disorder known as ventricular tachycardia (VT). Led by AHN cardiac electrophysiologist Emerson Liu, MD, and radiation oncologist Mark Trombetta, MD, the treatment, called stereotactic arrhythmia radioablation (STAR), was first performed at the hospital late last year and is now being offered as part of a clinical trial at the hospital.
VT is a type of abnormal heart rhythm, or arrhythmia, which takes place when the lower chamber of the heart beats too fast to pump adequately. The accelerated rhythm disrupts the body’s oxygenated blood flow and can cause sudden cardiac death. According to the Centers for Disease Control, VT is one of the leading causes of sudden cardiac-related mortality which claims the lives of roughly 300,000 people across the country each year.
“The first line of treatment for patients with ventricular tachycardia will typically involve a course of medical therapies and in some cases, an ablation procedure,” explained Dr. Liu, one of the principal investigators in the trial. “During an ablation procedure, we thread a catheter through the blood vessels to the lower chambers of the heart using an extremely precise, three-dimensional mapping process. Once we reach the target areas where the arrhythmia originates, we deliver radiofrequency energy to selectively ablate that tissue.”
Catheter ablation is designed to permanently cure arrhythmias. According to recent studies, however, first time success rates for ablating VT in structural heart disease stand at roughly 50 to 65 percent in many cases. Failure of almost half of initial attempts to treat the condition are often caused by difficult anatomy, such as scar tissue or thick areas of heart muscle, that prevents effective application of energy to cauterize all of the necessary areas.
“STAR allows us to help a patient population that historically didn’t have many viable alternatives when conventional methods proved unsuccessful,” said Dr. Liu. “This technique allows us to better access areas of the heart that are difficult to reach with catheters, and more directly target the primary tissue for a patient’s unstable heart rhythms.”
STAR therapy manages VT by delivering convergent radiation beams to precisely-targeted locations within the heart. The treatment takes place in a linear accelerator, the same machine used to treat cancer patients, and takes roughly 15 to 20 minutes to perform.
“In oncology, it’s routine to use advanced radiation therapy to shrink or eradicate solid cancerous tumors,” said Dr. Trombetta, who serves as co-investigator in the trial. “This new application allows us to leverage the same essential process to ablate tissue causing the misfire of cardiac electrical impulses. Radiation beams can better penetrate areas that may prove too challenging to access during conventional ablation techniques.”
In an early analysis of STAR, published as a preprint in medRxiv (doi.org/10.1101/2020.05.09.20094763), researchers looked at the effectiveness and safety of STAR for VT therapy in 39 patients across four observational studies. It was concluded that VT burden reduction at six months was close to 91 percent and the need for anti-arrhythmia drugs declined by more than 80 percent within the same time frame.
Under Dr. Liu’s and Dr. Trombetta’s direction, AGH will serve as the country’s primary investigative lead site on a global MRI-Linear Acceleration Consortium initiative further assessing the efficacy of STAR for VT. It’s estimated that approximately 100 patients worldwide have been treated with this approach.
“We’re thrilled to be leading this global effort to better understand the potential of STAR for managing a complex cardiovascular disease like VT. Our goal is to establish this therapy through a broader experience as an innovation that will ultimately result in better long-term outcomes, lower hospitalization rates and an improved quality of life for patients,” concluded Dr. Trombetta.
To learn more information on the procedure, please call 412-359-3400.
About the Allegheny Health Network
Allegheny Health Network (AHN.org), a Highmark Health company, is an integrated healthcare delivery system serving the greater Western Pennsylvania region. The Network is composed of 13 hospitals, ambulatory surgery centers, Health + Wellness Pavilions, an employed physician organization, home and community-based health services, a research institute, and a group purchasing organization. The Network provides patients with access to a complete spectrum of advanced medical services, including nationally recognized programs for primary and emergency care, trauma care, cardiovascular disease, organ transplantation, cancer care, orthopedic surgery, neurology and neurosurgery, women’s health, diabetes, autoimmune disease and more. AHN employs approximately 21,000 people, has more than 2,500 physicians on its medical staff and serves as a clinical campus for Drexel University College of Medicine and the Lake Erie College of Osteopathic Medicine.