Efficacy, safety, and clinical outcomes of interatrial shunt devices in heart failure with preserved and mildly reduced ejection fraction: A systematic review

Heart failure with preserved or mildly reduced ejection fraction (HFpEF/HFmrEF) accounts for over half of all heart failure cases. It has a progressive clinical course, decreased functional capacity, and poor prognosis. Despite its increasing prevalence, evidence-based treatment options remain limited, resulting in recurrent heart failure related hospitalizations, a lower quality of life, and higher healthcare costs. The interatrial shunt device (IASD), a new intervention, is inserted via a catheter to create a controlled connection between the left and right atria, aiming to lower left atrial pressure, reduce pulmonary congestion, and possibly enhance exercise capacity. This systematic review followed the PRISMA 2020 guidelines and, analyzed three randomized controlled trials (REDUCE LAP-HF I, REDUCE LAP-HF II, and RELIEVE-HF) covering a total of 1,178 patients with HFpEF or HFmrEF. Eligible studies included adults with LVEF >40%, NYHA class II–IV symptoms, and those diagnosed with ambulatory heart failure. The data sources included PubMed, EMBASE, ClinicalTrials.gov, and the Cochrane Library. The primary outcomes were hemodynamic changes, functional capacity, quality of life (QoL), and heart failure related hospitalizations. The studies showed that IASDs reliably lowered exercise pulmonary capillary wedge pressure in patients with high baseline values. However, improvements in functional capacity, measured by six-minute walk distance or exercise duration, and QoL, evaluated using the Kansas City Cardiomyopathy Questionnaire, have shown mixed results and often do not reach the minimum clinically important difference (MCID). Although some subgroups gained symptomatic and clinical benefits, others, specifically the HFpEF subgroup in RELIEVE-HF, faced an increased risk of hospitalization. IASDs could be a promising treatment for carefully selected patients with HFpEF/HFmrEF with elevated filling pressures and preserved right ventricular function. However, widespread adoption is premature until better patient selection criteria are established, long-term safety is confirmed, and direct comparisons between devices are available. These findings emphasize the heterogeneity of HFpEF/HFmrEF and highlight the need for phenotype-specific therapy in this diverse patient group.