"A Double-blind, Randomized Placebo Procedure-controlled Trial of an Interatrial Shunt in Patients With HFrEF and HFpEF: Principal Results From the?RELIEVE-HF?Trial" presented by Dr Gregg W Stone at the American College of Cardiology Annual Scientific Session (ACC.24), Atlanta, GA, April 6, 2024.

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Heart failure (HF) represents a significant global health challenge, prompting exploration of various treatment options to alleviate symptoms and improve prognosis. The benefits of interatrial shunts (with the Ventura shunt) in HF patients may vary depending on the subtype. This study examined the effects of interatrial shunts in patients with reduced ejection fraction HF (HFrEF) and preserved ejection fraction HF (HFpEF).

The aim of the study was to evaluate the effectiveness and safety of interatrial shunts in patients with symptomatic HF.

A randomized, parallel, blinded, and placebo-controlled study design was employed. Conducted across 94 centers in North America, Europe, Israel, Australia, and New Zealand, the study included a total of 605 participants. Symptomatic HF patients were randomized to receive either an interatrial shunt (n = 250) or placebo procedure (n = 258). The interatrial shunt was implemented using the V-Wave Ventura IAS device. The follow-up period for patients was 22 months, during which primary safety and efficacy outcomes were assessed.

The study findings indicated that, overall, interatrial shunts did not provide significant benefit in HF patients. However, analyses based on left ventricular ejection fraction (LVEF) suggested potential benefits in HFrEF patients but possible worsening outcomes in HFpEF patients. Additionally, improvements in quality of life were observed, partially attributable to the placebo effect. In terms of primary safety outcomes (including all-cause death, stroke, systemic embolism, or need for open cardiac surgery), no events occurred within the interatrial shunt group at 30 days. The primary efficacy outcome (all-cause mortality, heart transplant or LVAD implantation, heart failure-related hospitalization, worsening HF events on outpatient therapy, 5-point change in Kansas City Cardiomyopathy Questionnaire Overall Summary score [KCCQ-OS]), assessed through a win-ratio, was found to be 0.86 (p = 0.20).

According to secondary outcomes stratified by LVEF, among HFrEF patients (LVEF ?40%), event rates in the interatrial shunt group were significantly lower compared to the placebo group (49.0% vs. 88.6%; p < 0.001). Conversely, among HFpEF patients (LVEF >40%), event rates in the interatrial shunt group were significantly higher than the placebo group (60.2% vs. 35.9%; p = 0.001).

This study demonstrated that interatrial shunts were safe but did not reduce symptoms or improve prognosis in symptomatic HF patients. Moreover, it highlighted that the effect of interatrial shunts may vary depending on LVEF.

Interatrial shunts in symptomatic HF patients generally failed to alleviate symptoms or improve prognosis. However, they appeared beneficial in patients with reduced LVEF while potentially harmful in those with preserved LVEF. The reasons for these differential effects across different HF types remain incompletely understood. These findings may guide future research efforts, but further studies are needed to determine whether they apply to other interatrial shunts.