Impact Of Neutrophils To Lymphocytes Ratio In Acute Coronary Syndromes: A Meta-Analysis Of Major Clinical Outcomes

Introduction: The ratio between neutrophils and lymphocytes (NLR) is a potential new biomarker, which can single out individuals at risk for future cardiovascular (CV) events. Among total white blood cell count and its subtypes, NLR seems to have the greatest predictive value for Death and Major Adverse Cardiovascular Events (MACE) in patients with Acute Coronary Syndrome (ACS). To assess the relation between NLR and future CV outcomes, we conducted a meta-analysis of the literature. Methods: MEDLINE and EMBASE databases were searched (1999 to 2017, week 7). Studies were included if they met the following criteria: 1) Patients had a diagnosis of acute myocardial infarction (MI) (STEMI or NSTEMI) or unstable angina (UA) or ACS and/or underwent percutaneous coronary intervention (PCI) because of a STEMI; 2) Diagnosis of cardiovascular disease was objectively confirmed; 3) Information on neutrophils was provided (including NLR); 4) At least one of the following clinical outcomes was evaluated during the acute phase or after a follow-up: death or development of MACE (a new episode or a recurrence of MI, UA, ACS, development or worsening of heart failure, re-hospitalization or stroke); 5) Patients were 18 years or older. Two reviewers selected studies and extracted data. Pooled results are reported as odds ratio and are presented with 95% confidence intervals (CI). Results: Twenty-three studies for a total of more than 16,000 patients were included. High NLR on-admission was associated with a higher overall (OR: 5,08; 95% CI: 3,63-7,12; P Conclusions: In this first large meta-analysis on prognostic significance of NLR in ACS we found that high NLR on-admission in patients with ACS appears to affect clinically important outcomes including both in-hospital and long-term mortality and MACE.