NPPB and ischemia: Biomarkers whose increased plasma concentration was evidenced as significant and an independent risk factor for prediction of ischemia in HFrEF patients were as follows: BNP (OR = 1.14, 95% CI = 1.057–1.235, p = 0.001), renalase (OR = 1.32; 95% 1.152–1.517, p < 0.001), sST2 (OR = 1.19, 95% CI = 1.057–1.341, p = 0.004), galectin-3 (OR = 1.06, 95% CI = 1.021–1.103, p = 0.003), GDF-15 (OR = 1.00, 95% CI = 1.001–1.004, p = 0.001), syndecan-1 (OR = 1.09, 95% CI = 1.046–1.136, p < 0.001), and presence of chronic CAD (OR = 3.69, 95% CI = 1.349–10.121, p = 0.011).