['The low lymphocyte counts and high neutrophil leucocyte fractions have been associated with poor prognosis in chronic heart failure. We hypothesized that the baseline ratio of the neutrophil leucocytes to the lymphocytes (NL ratio) would predict the outcome of chronic heart failure patients undergoing cardiac resynchronization therapy (CRT).', 'The qualitative blood counts and the serum levels of N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) of 122 chronic heart failure patients and 122 healthy controls were analysed prospectively in this observational study. The 2-year mortality was considered as primary endpoint and the 6-month reverse remodelling (≥15% decrease in the end-systolic volume) as secondary endpoint. Multivariable regression analyses were applied and net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were calculated. The NL ratio was elevated in chronic heart failure patients when compared with the healthy controls [2.93 (2.12-4.05) vs. 2.21 (1.64-2.81), P < 0.0001]. The baseline NL ratio exceeding 2.95 predicted the lack of the 6-month reverse remodelling [n = 63, odds ratio = 0.38 (0.17-0.85), P = 0.01; NRI = 0.49 (0.14-0.83), P = 0.005; IDI = 0.04 (0.00-0.07), P = 0.02] and the 2-year mortality [n = 29, hazard ratio = 2.44 (1.04-5.71), P = 0.03; NRI = 0.63 (0.24-1.01), P = 0.001; IDI = 0.04 (0.00-0.08), P = 0.02] independently of the NT-proBNP levels or other factors.'] Does the ratio of the neutrophil leucocytes to the lymphocytes predict the outcome after cardiac resynchronization therapy?