The Neutrophil-to-Lymphocyte Ratio’s Predictive Utility in Acute Pulmonary Embolism: Systematic Review

Abstract Acute pulmonary embolism is a cardiovascular emergency with a significant morbidity and mortality. In the last decade, attempts have been made to find prognostic markers for pulmonary embolism. We conducted a systematic review of the literature for studies that assess the relationship between the neutrophil-to-lymphocyte ratio (NLR) and disease progression in patients with pulmonary embolism. We included a total of seven studies published between 2016 and 2021, reporting on a total of 4,272 patients. The mean NLR observed in these studies was 5.93, with values ranging from 5.12 to 7.3. Elevated NLR was significantly associated with an increased rate of mortality in all studies. Furthermore, the collected data revealed a 2-to-15 times higher mortality rate in the group with NLR values higher than the mean. Due to its accessibility and the simplicity with which it can be calculated, as well as the outcomes revealed in this review, we strongly emphasize that NLR should be used more in medical practice.