Atrial shunt therapy for heart failure: an update review

Interatrial shunt devices (IASDs) and implant-free strategies have emerged as novel approaches for heart failure (HF) management by mechanically unloading the left atrium (LA) to reduce left atrial pressure (LAP), a key driver of pulmonary congestion and exercise intolerance. However, evidence from pivotal randomized trials remains mixed, and optimal patient selection is evolving. To provide an updated and balanced review of IASDs and implant-free atrial shunting therapies, integrating recent data from major clinical trials and exploring their current role, limitations, and future perspectives in HF. A comprehensive literature search was conducted using PubMed, Embase, and ClinicalTrials.gov up to August 2025. We summarized available evidence on device designs, procedural approaches, pivotal trials, patient selection, contraindications, and safety considerations. Early feasibility studies demonstrated improvements in hemodynamics, functional capacity, and quality of life. However, REDUCE LAP-HF II failed to show an overall clinical benefit, with potential harm signals in patients with elevated pulmonary vascular resistance. RELIEVE-HF similarly reported no significant improvement in the composite endpoint; however, the HFpEF subgroups showed favorable signals. RESPONDER-HF demonstrated modest but significant quality-of-life improvements in carefully selected HFpEF patients without pulmonary vascular disease. Implant-free strategies, such as Alleviant and InterShunt, aim to minimize device-related risks but remain in early investigation. Interatrial shunt therapy holds promise for a subset of HF patients but is not universally beneficial. Precision-based patient selection, integration with guideline-directed therapy, and validation through ongoing sham-controlled trials are critical before broader clinical adoption.