Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio as Biomarkers for Risk Stratification and Predictors of 90-day Mortality in Acute Pulmonary Embolism

Abstract

Background: Acute Pulmonary Embolism (APE) is a critical cardiovascular emergency requiring timely risk stratification. Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) are emerging inflammatory biomarkers that may enhance existing risk models, such as the European Society of Cardiology (ESC) guidelines.
Objectives: To assess the prognostic value of NLR and PLR in predicting 90-day mortality in APE patients and their potential role in improving ESC risk stratification.
Methods: A retrospective cohort study of 42 APE patients at Chettinad Hospital (2021-2024) was conducted. Clinical, laboratory, and radiological data were analyzed. Statistical tests, including logistic regression, were used to evaluate associations between NLR, PLR, and 90-day mortality.
Results: The study included 42 patients (57.1% male, mean age 54.19 ± 15.98 years). Dyspnea (85.7%) and palpitations (54.8%) were the most common symptoms. Elevated NLR and PLR were significantly associated with higher mortality risk. Malignancy (p < 0.001) and right ventricular dysfunction (p < 0.001) were independent mortality predictors. Integrating NLR and PLR into the ESC model improved predictive accuracy with AUC of 0.848 as compared to only ESC stratification with AUC of 0.771.
Conclusion: NLR and PLR are valuable biomarkers for APE risk stratification and mortality prediction. Their inclusion in ESC guidelines may refine prognostication, facilitating timely interventions. Prospective multicenter studies are needed for validation.