Delayed Initiation of ARNI and SGLT2i in Heart Failure With Corrected Aetiology (DELAY-HF), Pilot Study

In patients with heart failure due to a reversible underlying cause-such as valvular heart disease or coronary artery disease-surgical or procedural correction of the underlying lesion (valve repair/replacement, TAVI, PCI, or CABG) frequently leads to spontaneous recovery of cardiac function, even without neurohormonal modulators. In this clinical setting, a substantial proportion of patients may not require the full set of guideline-directed medical therapies routinely prescribed for chronic HFrEF. The purpose of this study is to determine whether ARNI (angiotensin receptor-neprilysin inhibitor) and SGLT2 inhibitors are truly necessary in patients whose left ventricular function recovers spontaneously after treatment of a correctable cause of heart failure.

The DELAY-HF trial (DELayed initiation of ARNI and SGLT2i in heart failure with corrected aetiologY) is a multi-center, randomized controlled non-inferiority trial evaluating whether a delayed-initiation strategy of ARNI and SGLT2i is non-inferior to immediate initiation in patients with heart failure whose underlying cause has been completely corrected by surgical or procedural intervention.

Adults with a preoperative left ventricular ejection fraction (LVEF) ≤40% who have undergone successful correction of a reversible cause of heart failure-either revascularization (PCI or CABG) for ischemic cardiomyopathy or valvular surgery (including TAVI) for left-sided valvular heart disease causing volume overload-will be randomized 1:1 to (1) delayed initiation, in which ARNI/SGLT2i are withheld for 6 months and started only in patients whose LVEF remains ≤40% at the 6-month assessment, versus (2) immediate guideline-directed medical therapy (GDMT) including ARNI/SGLT2i started shortly after the corrective procedure. All patients are followed for 12 months.

The primary outcome is the absolute change in LVEF from baseline at 12 months. Key secondary outcomes include cardiovascular mortality, heart failure hospitalization, additional echocardiographic indices, NT-proBNP, KCCQ quality-of-life score, 6-minute walk distance, and a cost-effectiveness analysis.

By comparing these two strategies, this trial will clarify the incremental contribution of ARNI and SGLT2i-both to further LVEF recovery and to clinical outcomes-in patients who have already demonstrated spontaneous improvement in cardiac function after correction of the underlying cause, and will thereby help define whether these agents are truly necessary in this population.