Atrial Shunt Placement Shows No Improvement in Health Status in HFpEF Patients

Sanjiv J Shah, MD

Findings from a recent study observed the placement of an atrial shunt device did not reduce the total rate of heart failure events or improve health status of patients with heart failure and preserved or or mildly reduced ejection fraction.

Led by study author Sanjiv J Shah, MD, Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, a team investigated whether an interatrial shunt can reduce heart failure events or improve health status.

The REDUCE LAP-HF II was a randomized, international, blinded, sham-controlled trial performed at 89 health centers. It included patients (aged ≥40 years) with symptomatic heart failure, an ejection fraction of ≥40%, and pulmonary capillary wedge pressure during exercise of >25mm while exceeding right atrial pressure by >5 mm Hg.

Those included were randomized 1:1 to receive either a shunt device or sham procedure, while patients and outcome assessors were masked to randomization. Primary endpoint was a hierarchical composite of cardiovascular death or non-fatal ischemic stroke at 12 months, rate of total heart failure events at 24 months, and change in overall summary score at 12 months. 

Then, analysis of the primary endpoint, all other efficacy endpoints, and safety endpoints was conducted in the modified intention-to-treat population, defined as all patients allocated to treatment.

In the study period between May 2017 - July 2020, a total of 1072 participants were enrolled. From that total, 626 were randomly assigned to either the atrial shunt device (n = 314) or sham procedure (n = 312).

No difference was observed between groups in the primary composite endpoint (Win ratio 1.0; 95% CI, 0.8 - 1.2, P = .85) or in the individual components of the primary endpoint.

Investigators observed the prespecified subgroups demonstrating a differential effect of atrial shunt device treatment on heart failure were pulmonary artery systolic pressure at 20W of exercise (P for interaction = .002; >70 mm Hg associated with worse outcomes), right atrial volume index (P for interaction = .012; ≥29.7 ml/m2, worse outcomes), and sex (P for interaction = .02; men, worse outcomes.

Lastly, no differences in the composite safety endpoint between the two groups were observed (n = 116, 38% for shunt device versus n = 97, 31% for sham procedure; P = .11).

In a statement, Shah suggested that some patients may end up benefiting from the implant of the shunt device.

“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,” Shah said. “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.”

The study, “Atrial shunt device for heart failure with preserved and mildly reduced ejection fraction (REDUCE LAP-HF II): a randomised, multicentre, blinded, sham-controlled trial,” was published in The Lancet.