Optimal Maintenance Strategy for Patients with Improved Left Ventricular Function Following Sacubitril/Valsartan Therapy.

: Optimal pharmacological treatment following left ventricular ejection fraction (LVEF) improvement remains largely unknown. This study compared the clinical outcomes of patients with heart failure (HF) with improved EF (HFimpEF) based on the maintenance of sacubitril/valsartan (S/V) or transition to a renin-angiotensin system blocker (RASB). : A total of 354 patients with recovered LVEF of at least 40% after S/V treatment from a single center were retrospectively analyzed. Patients were categorized into three groups: those who continued S/V ( = 294), those who switched to RASB ( = 47), and those who discontinued both S/V and RASB ( = 13). The primary endpoint was HF relapse, defined as a two-fold increase in baseline serum N-terminal-pro hormone B-type natriuretic peptide (NT-proBNP) concentration exceeding 400 pg/dL. Secondary endpoints included the ratio and difference between baseline and peak NT-proBNP levels. : Baseline clinical characteristics were well balanced among groups. Over a median follow-up of 399 (252-589) days, HF relapse occurred more frequently in patients who discontinued both S/V and RASB compared to those who maintained either treatment (53.8% vs. 16.3% vs. 10.6%; = 0.001). NT-proBNP levels also showed a more pronounced increase in this group. However, there were no significant differences in primary or secondary outcomes between the S/V and RASB groups. : Our findings suggest that replacing S/V with another RASB does not worsen outcomes in patients with HFimpEF after S/V treatment, whereas discontinuation of both therapies is associated with a significantly higher risk of HF relapse. A prospective trial is warranted to confirm the safety and effectiveness of this approach in maintaining remission.