Prognostic value of neutrophil to lymphocyte ratio in heart failure patients

Background: Neutrophil to lymphocyte ratio (NLR) has been indicated to be an independent predictor for all cause mortality or adverse events in a variety of diseases. However, no consistent conclusions regarding it's relevance to patients with heart failure have been made. This meta-analysis was conducted to assess the significance of NLR in patients with heart failure. Methods: Pubmed and Embase databases were searched for eligible studies that reported the association between NLR and heart failure through September 2017. The overall hazard ratio (HR) and corresponding 95% confidence interval (CI) were used to assess the associations. Results: Ten studies met the eligibility criteria and a total of 5979 heart failure patients were included in the meta-analysis. The overall hazard ratio (HR) for all-cause mortality was 1.28 (95% CI 1.14-1.43) and the HR of renal dysfunction was 1.23 (95% CI 1.07-1.41) comparing the highest with the lowest category of NLR. However, the total pooled adjusted HR for in-hospital mortality (HR = 1.18, 95% CI 0.88-1.59) and rehospitalization (HR = 2.19, 95% CI 0.94-5.09) were not statistically significant. A subgroup analysis showed that sample size with moderate heterogeneity may be the origin of heterogeneity in all-cause mortality. Sensitivity analysis proved the stability of results of our meta-analysis. Conclusions: The meta-analysis demonstrates that NLR is a predictor of all-cause mortality in patients with heart failure. Because the quality of the included studies varies, further well-designed studies are needed to confirm this association.