Drug May Help Those With A Heart Condition Exercise Easier

"By having more oxygen available during exercise, patients with obstructive hypertrophic cardiomyopathy can more easily walk, perform household chores, and do other everyday tasks," said cardiologist Ahmad Masri, M.D., M.S., who co-wrote today's paper and directs the OHSU Knight Cardiovascular Institute's Hypertrophic Cardiomyopathy Center. "Our latest clinical trial results suggest aficamten is a promising treatment for HCM."

1 in 5 people are affected by HCM, and it is one of the most common causes of sudden death for otherwise healthy youths and athletes. HCM is often caused by an inherited gene mutation that thickens heart muscles making it difficult for the heart to function as it normally would. HCM also causes shortness of breath and reduces the ability to exercise and perform certain day-to-day tasks. The obstructive form of HCM also reduces blood flow out of the heart.

There is a surgical option for obstructive HCM to remove excess heart muscle which is not without certain risks, and the drug mavacamten has been approved to target the underlying causes of obstructive HCM. However, mavacamten may increase the risk of heart failure and it interacts with several commonly used medications making those who take it require intensive monitoring. Neither of these options are ideal, thus researchers are looking for better alternatives. 

For this study, about half of the participants were given the experimental drug, and the other half were given a placebo to serve as the control group. Participant oxygen levels were measured while using treadmills or bicycles. According to the researchers, those who took aficamten experienced a significant increase in their maximum oxygen use, 1.7 ml per kg per minute more than those in the control group. 

An increased peak oxygen uptake could help to improve an HCM patient’s ability to be physically active, helping to decrease the risks of reduced oxygen uptake elevating the chances of the patient otherwise experiencing heart failure, needing a heart transplant, and dying. 

"This is an exciting time for treating HCM," Masri said. "While we continue to offer traditional surgical and procedural therapies for HCM, we are now also able to offer patients other treatment options: therapies that were recently approved by the FDA and investigational therapies that are available by participating in clinical trials."