Research in context
Evidence before this study
We searched PubMed for papers published between Jan 1, 2015, and Nov 20, 2021, using the search terms “heart failure”, “shunt device”, “randomised”, and “sham”, and various combinations of these words with no language restrictions. We aimed to identify randomised clinical trials of interatrial shunt devices and procedures to decompress the left atrium in patients with heart failure. We identified only one previous randomised trial of an interatrial shunt therapy (the Corvia Atrial Shunt Device) in 44 patients with heart failure (REDUCE LAP-HF I; all with ejection fraction ≥40%), which showed a reduction in exercise pulmonary capillary wedge pressure at 1 month (p=0·028) and numerically lower rate of heart failure-related admissions to hospital at 1 year (0·22 vs 0·63 in the sham procedure group, p=0·06), but no effect was seen on health status or exercise capacity.
Added value of this study
REDUCE LAP-HF II was an adequately powered, phase 3 pivotal trial of the Corvia Atrial Shunt in patients with heart failure and ejection fraction of at least 40%. It showed no difference between the active treatment and control groups for the hierarchical composite endpoint of cardiovascular death, non-fatal ischaemic stroke, first and recurrent heart failure events, and health status (Kansas City Cardiomyopathy Questionnaire). In prespecified subgroup analyses, individuals with the following had more frequent heart failure events when treated with the atrial shunt device: pulmonary artery systolic pressure greater than 70 mm Hg at 20W bicycle exercise, right atrial volume index greater than 29·7 mL/m2, and male sex.
Implications of all the available evidence
REDUCE LAP-HF II is the first phase 3, randomised clinical trial to evaluate an interatrial shunt device in patients with heart failure, with the goal of evaluating the efficacy of shunt-induced lowering of left atrial pressure on cardiovascular death, total heart failure events, and patient-reported outcomes. Despite the reduction of exercise pulmonary capillary wedge pressure in the previously completed REDUCE LAP-HF I trial, there was no improvement in clinical outcomes in this study after atrial shunt device placement compared with sham procedure. However, prespecified analyses showed divergent results in select subgroups.