Evaluation of the Relationship between FeNO and Clinical Risk Stratification for Early Mortality in Pulmonary Embolism.

Background: Pulmonary embolism (PE) is a common complication of deep vein thrombosis that causes high mor-tality and morbidity. This study aimed to determine the relationship between clinical risk scoring for early mor-tality and fractional exhaled nitric oxide (FeNO) in PE patients.Methods: The study included a total of 98 subjects, 68 patients diagnosed with PE in the emergency department, and 30 healthy controls. Patients with PE were grouped according to clinical scoring of early mortality risk as low (n = 20), moderate-low (n = 24), and moderate-high (n = 24) risk. FeNO levels were measured after diagnosis.Results: FeNO levels were significantly higher in patients with moderate-high risk PE compared to the other three groups and in those with moderate-low risk PE compared to the control group (p < 0.001 for all). Moderate to strong positive correlations were observed between FeNO level and mean pulmonary artery pressure (r = 0.818, p = 0.01), troponin-I (r = 0.67, p = 0.01), pro-BNP (r = 0.762, p = 0.01), and D-dimer levels (r = 0.652, p = 0.01). A FeNO cutoff value of 7.5 ppb had 84% sensitivity and 78% specificity in differentiating moderate-high risk PE from moderate-low risk PE.Conclusions: FeNO may be as reliable, noninvasive, and easily accessible as cardiac biomarkers in clinical risk scoring for early mortality in PE patients.