Study Reveals Response to Exercise is Key to Device Therapy for Patients with HFpEF
March 24, 2022 | 3 min. to read
A Northwestern Medicine-led study published in The Lancet suggests that some patients with the most common form of heart failure may benefit from a minimally invasive cardiac implant device called an atrial shunt. The study also offers new insight into the role that exercise plays in understanding, diagnosing and treating this type of heart failure.
Heart failure with preserved ejection fraction (HFpEF), also called diastolic heart failure, affects 3 million Americans. Despite being the most common type of heart failure in the United States, effective treatments remain elusive, leading to high morbidity and mortality.
“HFpEF makes up half of all heart failure cases, yet we have very limited treatment options,” says Sanjiv J. Shah, MD, the Neil J. Stone, MD, Professor of Medicine in the Division of Cardiology and lead author of the study. Dr. Shah is also the director of research at Bluhm Cardiovascular Institute and director of the Northwestern Medicine HFpEF Program.
“Most standard therapies for heart failure are ineffective for this condition, leaving a major unmet need for a large patient population,” says Dr. Shah.
This type of heart failure occurs when the left ventricle is unable to relax. This limits the amount of blood filling the heart, leading to build-up in the lungs and the body. The build-up in a patient’s lungs and body causes symptoms including shortness of breath, irregular heartbeat and exercise intolerance.
“While the overall trial was neutral, in our subgroup analyses we found that what happens in the heart and lungs during exercise is of prime importance in this type of heart failure,” says Dr. Shah, who served as the international principal investigator of the trial. “The normal response to exercise is relaxation of the blood vessels in the lungs. Patients with HFpEF who are able to relax the blood vessels in their lungs appear to do well with the device, whereas those whose blood vessels can’t relax appear to do worse when an atrial shunt is implanted.”
An atrial shunt is placed through a catheter, creating a small hole between the left and right atria and allowing blood to flow from the stiff left atrium to the normal right atrium, potentially lowering pressure in the left atrium and reducing the symptoms of HFpEF. The procedure is minimally invasive, low-risk and patients are able to go home the next day.
“What we saw in this study is encouraging and suggests that future clinical trials should specifically investigate the subgroup of patients with HFpEF whose pulmonary blood vessels respond normally to exercise,” says Dr. Shah. “If future trials validate what we found, the potential is enormous. This subgroup comprises two-thirds of people with this type of heart failure — that is 2 million people who could benefit from this innovative therapy. This simple, one-time procedure could reduce hospitalizations and significantly improve quality of life.”
While cardiovascular conditions such as coronary artery disease are routinely diagnosed with exercise testing, clinical assessment for HFpEF is done at rest — something that Dr. Shah hopes will change following this trial.
“This has potential to change the way we evaluate patients with this condition and should guide how future clinical trials are conducted and the criteria for enrollment,” says Dr. Shah.