Predictive prognostic value of neutrophil–lymphocytes ratio in acute coronary syndrome

ObjectiveTo evaluate the relations between preprocedural neutrophil/lymphocyte (N/L) ratio and in-hospital outcomes in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI).Data sourcesWe utilize the medical journals, medical text books, and Medline databases (PubMed, Medscape, and Science Direct) which have updated research with keywords 'neutrophil/lymphocyte ratio and acute coronary syndrome' in the title of the paper and all materials available on the Internet from 2013 to 2017.Study selectionThe initial search presented 1270 articles of which 21 met the inclusion criteria. The articles studied the correlation between N/L ratio and the occurrence of no-reflow, along with assessment of the prognostic value of N/L ratio in patients with STEMI.Data extractionIf the studies did not fulfill the inclusion criteria, they were excluded. Study quality assessment included whether ethical approval was gained, eligibility criteria specified, appropriate controls, and adequate information and defined assessment measures were made.Data synthesisComparisons were made by meta-analysis with the results tabulated.FindingsThe levels of inflammatory markers such as the N/L ratio should be routinely checked in all patients presenting with acute STEMI as they may help in the prediction of prognosis; they may guide the emergency physician to provide the best type of therapy in such cases, and they may be useful in the follow-up of patients after reperfusion.ConclusionPreprocedural N/L ratio was an independent prognostic factor for both in-hospital mortality and adverse outcomes among the STEMI patients who underwent primary PCI during the hospital stay. N/L ratio was an independent predictor of no-reflow/reflow and angiographic grade after PCI.