Prevalent and incident anemia in PARAGON-HF

Abstract Background Anemia is a common comorbidity in patients with heart failure (HF) and is associated with adverse prognosis. Renin-angiotensin system inhibitors (RASi) have been shown to lower hemoglobin levels, potentially related to direct reductions in erythropoetin levels and hematopoiesis. We examined whether sacubitril/valsartan might attenuate this effect of RASi alone on incident anemia in patients with HF with mildly reduced or preserved ejection fraction. Methods PARAGON-HF was a global, multicenter randomized clinical trial of sacubitril/valsartan versus the RASi valsartan in patients with HF and left ventricular ejection fraction≥45%. Anemia was defined as hemoglobin <120 g/L in women and <130 g/L in men. We evaluated changes in hemoglobin, risks of incident anemia and new oral iron initiation during follow-up. We also assessed treatment effects on the primary composite endpoint of total HF hospitalizations (HFH) and cardiovascular (CV) death according to anemia status. Results Among 4,795 participants with a hemoglobin measurement available, 1,111 (23.2%) had anemia at randomization of which 3.5%, 77.7%, and 18.8% were characterized as micro-, normo-, and macrocytic anemia. 5.6% were treated with oral iron at baseline. Over a 2.7-year median follow-up period, patients with anemia were at nearly twice the risk of the primary outcome (21.6 vs. 11.5 per 100py; rate ratio 1.90; 95% CI: 1.62-2.21; P<0.001). Compared with valsartan, sacubitril/valsartan significantly slowed the decline in hemoglobin levels by 1.4 g/L (95% CI: 0.4-2.4 g/L; P = 0.005; Figure 1 Panel A). Participants treated with sacubitril/valsartan were at significantly lower risk of developing anemia (30.3% vs. 37.6%; HR 0.76; 95% CI: 0.68-0.85; P<0.001; Figure 1 Panel B) and starting oral iron therapy (8.1% vs. 10.0%; HR 0.81; 95% CI: 0.67-0.97; P = 0.026; Figure 2). Treatment effects of sacubitril/valsartan vs. valsartan on the primary endpoint were consistent among patients with and without anemia (Pinteraction=1.00). Conclusions Among patients with HF with mildly reduced or preserved ejection fraction, treatment with sacubitril/valsartan resulted in slower declines in hemoglobin, lower rates of incident anemia, and fewer new initiations of iron therapy compared with RASi.