Can A New Atrial Shunt Device Help Heart Failure Patients?

REDUCE LAP-HF II trial suggest more research is needed

Results have been announced for a new clinical trial exploring the safety and efficacy of an atrial shunt device in heart failure patients with preserved (HFpEF) or mildly reduced (HFmrEF) ejection fraction. Led by Principal Investigators Sanjiv J Shah, MD, of Northwestern University and Martin Leon, MD, director of the Interventional Cardiovascular Care program at Columbia University, the randomized, blinded, and sham-controlled REDUCE LAP-HF II trial included 89 sites and 626 participants.

The study results were presented at the Technology and Heart Failure Therapeutics (THT) 2022 conference. Results were published online in the Lancet.

An Unmet Clinical Need

Heart failure (HF) is a chronic, progressive condition where the heart cannot pump enough blood to meet the body's needs. For patients with HFpEF or HFmrEF, the heart experiences increased pressure—especially with exertion. “If you think of the heart as being like a balloon, it fills up with blood,” says Dr. Leon. “In HFpEF patients, the elasticity of the heart—to be able to enlarge and fill with blood—is impaired.”

Because the heart can’t expand enough as it fills up with blood, pressure can back up to the lungs. HFpEF patients experience symptoms like shortness of breath with exertion, fatigue, chest pain, and swelling in the lower extremities.

Current treatment options for HFpEF are limited to medications like diuretics—and typically aren’t very effective. “It's very difficult to treat HFpEF,” says Dr. Leon. “It tends to defy current treatment options—these patients don't have as many medical therapies available to them.”

Testing an Interatrial Shunt Device for HFpEF

The REDUCE LAP-HF II trial was designed to explore a new therapy using a device called an interatrial shunt. The device, made by Corvia Medical, Inc., is the first of its kind to undergo this degree of study in a rigorous clinical trial.

During a transcatheter procedure, the device is implanted between the left and the right atrium. “During exercise or exertion, pressure builds in the heart,” explains Dr. Leon. “The device allows blood to move from the left side to the right to relieve that pressure, rather than be reflected in the lungs—allowing it to decompress the heart internally.”

The study used supine bicycle exercise testing to assess participant eligibility, with eligible patients randomized to either the treatment or control group. Participants in both groups were sedated and underwent a transcatheter procedure to either measure pressure in the heart or to have the device implanted. “The patient doesn't know if they've had the true device or if they've had simply pressure recordings,” notes Dr. Leon. “The patient is blinded to the device therapy.” Trials with this kind of study design are also known as sham-controlled.

“It's unusual to do sham-controlled studies—it's difficult to do,” says Dr. Leon, director of Columbia Interventional Cardiovascular Care. “It's the highest order of rigor in a clinical trial.”

Patients were then followed to carefully monitor results. “The main endpoints we looked at are death or stroke,” says Dr. Leon. “We also look at recurrent heart failure hospitalizations and quality of life assessments using something called the Kansas City Cardiomyopathy Questionnaire (KCCQ)—a self-administered questionnaire used to measure a patient's perception of their health.

Study Results

The REDUCE LAP-HF II study proved to have a neutral outcome—meaning that it did not demonstrate that the device was successful in improving clinical outcomes for the entire population. But the study also proved valuable for directing future research.

“The overall outcome is that it did not fulfill the primary endpoint,” notes Dr. Leon. “But with further post-hoc analyses, we did uncover what we believe is a relevant, significant subgroup of patients that we think have the potential to benefit. That will need to be validated in future trials.

“We believe now we're much smarter about which patients we can select for this kind of therapy, with a better expectation of success,” says Dr. Leon. “We can direct future efforts accordingly—and aim to generate a prospective trial that would look at just the patients from this study that would benefit most, and to see if we can replicate that finding in a different smaller study.

“If that's the case, it would provide justification for potential use of this device in the right patients with heart failure. And that would have major clinical implications for patients.”