Left ventricular ejection fraction recovery under contemporary quadruple guideline-directed therapy and the need for ICD/CRT-D implantation in HFrEF: a retrospective single-center cohort study

BACKGROUND: Guidelines advise deferring primary-prevention implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy-defibrillator (CRT-D) implantation until left ventricular ejection fraction (LVEF) is reassessed after at least three months of medical therapy in heart failure with reduced ejection fraction (HFrEF). Real-world data under contemporary quadruple therapy are limited. RESEARCH DESIGN AND METHODS: Retrospective single-center cohort of 65 HFrEF patients (Coburg Hospital, Germany; October 2023-December 2024), prescribed beta-blocker, angiotensin receptor-neprilysin inhibitor, mineralocorticoid receptor antagonist and SGLT2 inhibitor (all four in 92%; doses not recorded). LVEF was measured by echocardiography (TTE) and cardiac magnetic resonance (CMR) at baseline and ~3 months; reader blinding was not documented. Device implantation followed guideline criteria. Patients with severe arrhythmic events were excluded. RESULTS: Twenty-nine patients (44.6%) received a device. LVEF rose on TTE (28.0→36.0%) and CMR (26.3→38.5%) (both p < 0.001), mainly without device implantation (TTE +13.0 vs + 1.5 points). Larger baseline left ventricular end-diastolic diameter was associated with smaller recovery (β = -0.41, p = 0.006) and device implantation (odds ratio 1.11/mm, 95% CI 1.01-1.22). Adverse events were not recorded. CONCLUSIONS: LVEF recovery was common, and associations are consistent with disease severity. Findings are hypothesis-generating; absent dose, arrhythmic-outcome and wearable-defibrillator data and the selected cohort limit generalizability.