The Effects of Beta-Blockers on Leukocytes and the Leukocyte Subpopulation in Heart Failure Patients

<b>Background/Objectives:</b> Some specific types of white blood cells (WBCs) and the neutrophil/lymphocyte ratio (NLR) are independent predictors of outcome for heart failure (HF) patients. WBC redistribution is induced by catecholamines, and therefore we evaluate how different types of beta-blockers (BBs) influence it. <b>Methods:</b> The HF patients were clinically evaluated, and blood was drawn to measure N-Terminal pro-B-type natriuretic peptide (NT-proBNP), WBC-differential formula, etc. <b>Results:</b> On admission, 61.16% of patients who used a BB had no significant difference in the number of lymphocytes (Lym) and neutrophils (Neu), but NLR and NT- proBNP were significantly lower compared with those without BB. NT-proBNP correlated with BB dose on admission and was significantly lower in patients treated with Metoprolol (Met) as compared with Carvedilol (Car). The type and dose of BB used was responsible for 6.1% and 5.9% of the variability in the number of Lym and Neu, respectively. Patients treated with ≥100 mg Met/day had a higher Lym number, but not of Neu, with reduced NLR, compared with lower doses. Patients treated with ≥25 mg Car/day had a lower Lym number and a greater Neu number, compared with lower doses, with increased NLR. <b>Conclusions:</b> However, both BBs had the same rehospitalization rate during the 12 month follow-up and had an improved outcome.