An interatrial shunt device (IASD) has demonstrated significant reductions in pulmonary capillary wedge pressure (PCWP) at exercise and a good safety profile in patients with heart failure with preserved ejection fraction (HFpEF). [Circulation 2017, doi: 10.1161/CIRCULATIONAHA.117.032094]

The IASD decompresses the overloaded left atrium (LA) by shunting blood from the LA to the right atrium (RA), especially during exercise. [Circ Heart Fail 2016,  doi: 10.1161/CIRCHEARTFAILURE.116.003025]

In the phase II, randomized, sham-controlled REDUCE LAP-HF I trial in 44 patients, IASD reduced exercise PCWP at 20 W, 40 W and 60 W at 1 month follow-up by 3.2 mm Hg, 1.0 mm Hg and 2.3 mm Hg, respectively. In the sham control group, corresponding changes in exercise PCWP were +0.9 mm Hg, -1.9 mm Hg and -1.3 mm Hg, respectively (p=0.023).

Favourable haemodynamic effects were also observed with legs up at rest (PCWP change, -0.5 mm Hg for IASD vs 0.0 mm Hg for control; p=0.024). Right ventricular output at rest also improved significantly with IASD (+1.6 L/min vs -0.5 L/min for control; p<0.001).

The study was conducted in patients with New York Heart Association class III or ambulatory class IV HFpEF with left ventricular ejection fraction ≥40 percent and a PCWP-RA pressure gradient ≥5 mm Hg.

At 1-month follow-up, no significant differences were found between the IASD and control groups in major adverse cardiac, cerebrovascular embolic or renal events (MACCRE, 0 vs 4.6 percent; p=1.00) or heart failure events requiring intravenous treatment (0 vs 9.1 percent; p=0.49). No death, new-onset atrial fibrillation/flutter, stroke/TIA, systemic embolization, cardiac perforation, device embolization/occlusion or major vascular complication occurred in either group.