A time-dependent analysis of sacubitril/valsartan and gliflozins benefits in patients receiving cardiac resynchronization therapy
Authors: Faccenda D , Pergola V , Salucci A , Marrese A , Comparone G , Cocchiara L , Fonderico C , Ammirati G , Muoio M , Grimaldi A , Liguori V , Rapacciuolo A , Strisciuglio T 
Published: May 2024

Abstract

Background
While sacubitril/valsartan (ARNi), gliflozins (or SGLT2i) and cardiac resynchronization therapy (CRT) are firmly recognized as cornerstones of therapy for heart failure with reduced ejection fraction (HFrEF), robust evidence validating the long-term efficacy of their combination remains elusive. The few data suggesting a synergistic advantage of these drugs alongside CRT have not rigorously considered their time-varying administration, leading to potential selection bias, since only patients with longer initial survival could commence these treatments. As a result, the literature to date lacks a comprehensive and persuasive demonstration of the additional survival benefits conferred by ARNi and gliflozins over CRT alone in HFrEF.

Purpose
To evaluate the impact of ARNi and gliflozins on reducing cardiovascular and overall mortality among HFrEF patients undergoing CRT.

Methods
Patients with heart failure and an ejection fraction ≤ 35%, who were referred for CRT-D implantation from 2015 to 2023, were retrospectively recruited for the study. These patients were grouped into two cohorts: those not receiving drugs (no drugs group) and those treated with ARNi and/or SGLT2i (ARNi/SGLT2i group). Importantly, ARNi and SGLT2i treatments were considered as time-dependent covariates in order to account for patients who initiated or discontinued therapy during follow-up.

Results
The cohort included 183 ischemic and non-ischemic HFrEF patients (148 male [80.9 %], 113 ischemic [61.7 %], median [IQR] age 73 [65-80] years). 117 (74 %) patients started ARNi (61, 52.1 %), gliflozins (7, 6 %) or both drugs (49, 41.9 %) and were assigned to ARNi/SGLT2i group.
During a median follow-up of 5.67 (CI 95 %, 5 – 6.5) years, 63 (34.4 %) patients died, of whom 47 (74.6 %) died of cardiovascular HF-related death. Specifically, 44 (of whom 35 (79 %) due to HF-related death) died in the no drugs group vs 19 (12 (63 %) due to HF-related death) in ARNi/SGLT2i patients. At univariable analysis (Panel A in the Figure), ARNi and/or SGLT2i treatments reduced all-cause (HR 0.59 [0.34-1.02], p = 0.056) and cardiovascular (HR 0.47 [0.24-0.92], p = 0.029) mortality. However, after multivariable adjustment for key covariates (1-year CRT response, age, atrial fibrillation, baseline LVEF, chronic obstructive pulmonary disease, glomerular filtration rate), the survival benefits of ARNi and SGLT2i use diminished, and the only factor strongly associated with reduced mortality risk remained 1-year positive response to CRT (Panel B).

Conclusions
Despite their recognized therapeutic benefits, ARNi and SGLT2i have not demonstrated additional survival benefit compared to CRT alone in patients with HFrEF. A 1-year positive response to CRT remains the most significant prognostic factor. Further studies with larger sample sizes and extended follow-up periods are needed to confirm this hypothesis, also evaluating whether the timing of introduction of these medications may impact survival.