Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure

In the REDUCE LAP-HF II trial, implantation of an atrial shunt device did not provide, overall, a clinical benefit for patients with heart failure and preserved or mildly reduced ejection fraction (HFpEF/HFmrEF). However, pre-specified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial (RA) volume, and sex. Shunt implantation reduces left atrial (LA) pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). Based on these results, the study hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance (PVR) during exercise, might be harmed by shunt implantation. Conversely, patients without PVD might benefit. Furthermore, in patients with HFpEF/HFmrEF, latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.