Since 1999, cardiology experts at Johns Hopkins have run a dedicated clinic to manage and treat patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), a leading cause of sudden death among young athletes that also can affect people of all ages and activity levels. The rare inherited disorder impacts about one in 5,000 people and can cause life-threatening irregular heart rhythms. A mainstay of treatment is an implantable cardioverter defibrillator (ICD), a device that detects dangerous heart rhythms and shocks the heart back into a normal pattern.

Precision Medicine at Work

As part of an ongoing precision medicine project, Cindy James, Ph.D., research director for the Johns Hopkins Center for Inherited Heart Diseases; Hugh Calkins, M.D., director of the Electrophysiology Laboratory and Arrhythmia Service at The Johns Hopkins Hospital; and colleagues compiled data from over 500 patients with ARVC around the world to publish a free online calculator in 2019 that helps clinicians determine the risk of their patients developing ongoing dangerous heart rhythms within the next one to five years, based on characteristics including age, gender and whether the patient has fainted due to heart problems. The information can be used to determine which patients are best suited to receive an ICD.

 “With your smartphone, you can put in the different parameters and come up with a five-year risk of an event happening,” Calkins says. “It’s been used all over the world.”

Building on this success, the team has been working to develop a new risk calculator for a subset of ARVC called Desmoplakin cardiomyopathy, which causes inflammation in the heart’s left ventricle (its main pumping chamber) and carries a high risk of sudden cardiac death. They have compiled information from 815 patients with the condition from 26 countries. Information on this will be published in a series of three scientific papers within the next year.