Delta Neutrophil Index as a Promising Prognostic Marker in Out of Hospital Cardiac Arrest

Background The post-resuscitation phase after out-of-hospital cardiac arrest (OHCA) is characterised by a systemic inflammatory response (e.g., severe sepsis), for which the immature granulocyte count is a diagnostic marker. In this study we evaluated the prognostic significance of the delta neutrophil index (DNI), which is the difference in leukocyte subfractions as assessed by an automated blood cell analyser, for early mortality after OHCA. Materials and Methods OHCA records from the emergency department cardiac arrest registry were retrospectively analysed. Patients who survived at least 24 h after return of spontaneous circulation were included in the analysis. We evaluated mortality and cerebral performance category scores at 30 days. Results A total of 83 patients with OHCA were included in the study. Our results showed that DNI >8.4% on day 1 (hazard ratio [HR], 3.227; 95% CI, 1.485-6.967; p = 0.001) and DNI >10.5% on day 2 (HR, 3.292; 95% CI, 1.662-6.519; p<0.001) were associated with increased 30-day mortality in patients with OHCA. Additionally, DNI >8.4% on day 1 (HR, 2.718; 95% CI, 1.508-4.899; p<0.001) and DNI >10.5% on day 2 (HR, 1.709; 95% CI, 1.051-2.778; p = 0.02) were associated with worse neurologic outcomes 30 days after OHCA. Conclusion A higher DNI is a promising prognostic marker for 30-day mortality and neurologic outcomes after OHCA. Our findings indicate that patients with elevated DNI values after OHCA might be closely monitored so that appropriate treatment strategies can be implemented.