Purpose: Acute pulmonary embolism (PE), frequently seen in the emergency department (ED), is a leading cause of cardiovascular morbidity and mortality. The delta neutrophil index (DNI) reflects the fraction of circulating immature granulocytes as a component of the systemic inflammatory response syndrome criteria. The pathogenesis of acute PE is significantly associated with inflammation. The aim of the study was to investigate the clinical usefulness of the DNI as a marker of severity in patients with acute PE admitted to the ED.
Methods: We retrospectively analyzed the data of patients who were diagnosed with acute PE at a single ED, admitted from January 1, 2011 to June 30, 2017. The diagnosis of acute pulmonary embolism was confirmed using clinical, laboratory, and radiological findings. The DNI was determined at presentation. The clinical outcome was all-cause mortality within 28 days of emergency department admission.
Results: We included 447 patients in this study. The multivariate Cox regression model demonstrated that higher DNI values on ED admission were significantly associated with short-term mortality (hazard ratio, 1.107; 95% confidence interval, 1.042-1.177). The optimal cut-off DNI value, measured on ED admission, was 3.0%; this value was associated with an increased hazard of 28-day mortality following PE (HR, 7.447; 95% CI, 4.183-13.366; P < 0.001) CONCLUSION:: The DNI value, obtained as part of the complete blood count analysis, can be easily determined without additional burdens of cost or time. A high DNI is useful as a marker to predict 28-day mortality in patients with acute PE.