Nakou ES, et al. - In patients with chronic heart failure with reduced ejection fraction (HFrEF), researchers identified factors that might predict sacubitril/ valsartan (LCZ696) treatment response. A total of 48 symptomatic patients with chronic HFrEF (LVEF ≤ 35%) and New York Heart Association (NYHA) class II/III were included and divided into group A (N =23) that received LCZ696 (105 ± 30 mg twice daily), while group B (N = 25) did not. Findings demonstrated a positive correlation of baseline serum troponin-I levels (TnI) and peak oxygen uptake (VO₂max) with the increase in VO₂max following sacubitril/valsartan treatment. A positive correlation of ΔVO₂max with TnI, improvements in the ratio of early diastolic filling to myocardial tissue velocity and the tricuspid annular peak systolic velocity was evident in multiple regression analysis. Overall, in HFrEF, troponin-I levels may be an independent predictive marker of sacubitril/valsartan efficacy.