DALLAS — Researchers from the Institute for Exercise and Environmental Medicine (IEEM) have developed an exercise regime that stops the progression of what was considered an untreatable type of heart failure and reverses risk factors for the disease in some patients.

Their findings were presented at the 2019 American Heart Association Scientific Sessions in Philadelphia, Pennsylvania, an annual meeting of cardiovascular researchers and clinicians from around the world. In all, researchers from the IEEM, which is a collaboration between Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, made 10 major presentations [need to confirm this number] at the conference. The lectures, the largest number of IEEM projects accepted for presentation at the AHA Scientific Sessions, highlighted the institute’s work to unlock mysteries of some of the most common — and complex — forms of heart disease.

“I think this reflects the quality of the research being done by scientists here at the IEEM and shows what Texas Health and UT Southwestern can achieve when we combine the strengths of our two organizations,” said Dr. Benjamin Levine, director of the IEEM and a professor of internal medicine at UT Southwestern and a cardiologist on the Texas Health Dallas medical staff.

The majority of the IEEM’s presentations centered around the institute’s work to better understand a common cardiac condition called heart failure with preserved ejection fraction (HFpEF). Ejection fraction is a measurement of how much blood the left ventricle — the main pumping chamber of the heart — pushes out with each contraction. In heart failure with preserved ejection fraction, the heart pumps blood adequately throughout the body, but fluid still backs up into the lungs and extremities. In the United States, more than half of all heart failure patients suffer this type.

Once diagnosed the condition is considered untreatable. But IEEM researchers have recently uncovered what causes the disease’s primary symptoms — fatigue and shortness of breath. The research showed that new approaches to exercise and cardiac rehabilitation could provide effective therapy for those with HFpEF and prevent it in patients with risk factors.

In one study, IEEM researchers identified risk factors for HFpEF and then put study participants on a year-long, high-intensity exercise training program. Led by Michinari Hieda, M.D., Ph.D., results showed that the heart function of patients improved and their heart muscle was less stiff — reversing one of the primary risk factors for development of HFpEF in some cases.

“In this paper, we show for the first time, that these patients have already started to develop the precursor of HFpEF, namely a small, stiff heart,” Levine said. “We also show for the first time that a year of exercise training can reverse this stiffening in the high-risk HFpEF population, and thus may be an especially fruitful strategy to preventing this devastating disease.”

Their findings will be published in an upcoming edition of the journal Circulation.

In the other study, patients whose condition had already progressed to heart failure were put on an eight-week specialized exercise program focused on improving skeletal muscle function using isolated leg exercise. It was the first time this kind of exercise regime has been applied to patients with HFpEF, according to the IEEM. Historically, cardiac rehabilitation programs have had these patients doing whole-body workouts that involve major muscle groups, like riding a stationary bike or walking on a treadmill.

“Traditional exercise interventions try to engage a lot of muscles at once such as walking or cycle exercise,” said Christopher Hearon, Ph.D., a researcher at the IEEM who led the project. “The problems is that patients become fatigued and breathless. This approach focuses on one muscle group at a time, limiting the amount of stress placed on the heart.”

Hearon and his team showed that through this new approach, fitness was improved, which led to less fatigue and shortness of breath. “And that translates into a higher quality of life for these patients,” he said.

The two presentations show how scientists can find solutions to complex problems in different ways, Hieda said.

“We looked at the same disease, but really stepped back and thought about how to treat the different stages of the condition in different ways,” Hieda said. “And we’re very excited about the results. Hopefully, it will lead to better treatments for this disease, which is a major health crisis in our country, causing 50 percent of all heart failure cases in the elderly.”

Other presentations by the IEEM discussed the effects of heart failure and the impact of a specialized year-long exercise training program in obese individuals; a new imaging technique to detect heart problems in patients with otherwise normal echocardiograms; and whether exercise training changes how the heart moves as it contracts and relaxes.

About the Institute for Exercise and Environmental Medicine
The Institute for Exercise and Environmental Medicine (IEEM) was founded as a joint program between Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center. Its mission is to promote basic and clinical research, education, and clinical practice in defining the limits to human functional capacity in health and disease, with the objective of improving the quality of life for human beings of all ages. The IEEM includes ten major laboratories tightly integrated and organized intellectually along the “oxygen cascade” — the path that oxygen must follow through the body from the external environment through the lungs, heart, skeletal muscles, and brain to perform cognitive function and physical activity. The IEEM is among the few research centers in the world that fosters the fusion of basic science and clinical medicine in a program designed specifically to study human physiology.