Neutrophil-to-Lymphocyte Ratio as a Predictor of Mortality and Clinical Outcomes in Heart Failure Patients.

The neutrophil-to-lymphocyte ratio (NLR) is an emerging biomarker reflecting systemic inflammation, playing a critical role in heart failure (HF) prognosis. Elevated NLR, indicative of neutrophilia and lymphocytopenia, correlates with worsened outcomes, including higher mortality and adverse cardiac events. Studies highlight its utility as a robust indicator for risk stratification and management in both acute and chronic HF conditions. This study aims to analyze the correlation of NLR as a predictor of mortality in acute heart failure patients. This systematic review and meta-analysis explored the relationship between the neutrophil-to-lymphocyte ratio (NLR) and clinical outcomes in heart failure (HF) patients, including mortality, rehospitalization, disease progression, and functional capacity. A comprehensive search of PubMed, Scopus, Embase, and Web of Science identified 38 studies meeting the inclusion criteria. Quality and bias were assessed using established tools, and statistical analyses evaluated pooled effect sizes, heterogeneity, and optimal NLR cutoffs, evaluating their prognostic accuracy for HF outcomes. The findings highlight that heart failure (HF) patients who survived had significantly lower neutrophil-to-lymphocyte ratio (NLR) values compared to those who died (pooled standardized mean difference {SMD} = -0.48; 95% confidence interval {CI}: -0.54, -0.43; p < 0.05). Elevated NLR is significantly associated with increased mortality in heart failure patients, with most studies showing strong inverse associations and odds ratios (ORs) below 1. Odds ratios further supported this, with higher NLR linked to increased mortality risk (e.g., OR = 0.38). The area under the curve (AUC) of 0.834 indicates strong predictive accuracy for mortality, with optimal NLR cutoffs of 5.91 and 6.18 balancing sensitivity (84.6%) and specificity (84.6%). High heterogeneity (I² = 90%) shows the variability among studies. The study has concluded that an elevated neutrophil-to-lymphocyte ratio (NLR) is consistently associated with increased mortality in patients with heart failure (HF). Thus, the neutrophil-to-lymphocyte ratio (NLR) can be used as a reliable prognostic marker in patients with heart failure.