Reassessing D-dimer Cut-offs for Pulmonary Embolism: A Path Toward Safer and More Cost-effective Diagnosis

Pulmonary embolism (PE) is a life-threatening condition requiring early and accurate diagnosis. The Wells and Geneva scores, along with D-dimer testing, are key tools in assessment. However, the standard D-dimer cut-off of 0.5 mg/mL, while highly sensitive, has low specificity, leading to excessive imaging. This study examines whether modifying the D-dimer threshold can improve diagnostic efficiency and reduce unnecessary testing.

This retrospective study analyzed 878 patients who underwent computed tomography pulmonary angiography (CTPA) at Monmouth Medical Center from January 2022 to December 2023. Statistical analysis, including ROC curve assessment, was conducted using IBM SPSS, with significance set at p < 0.05.

The study cohort had a mean age of 57.2 years (±18.3), with 61.4 % female patients. PE was diagnosed in 7.7 % (n = 68) via CTPA, while 92.3 % had negative results. Dyspnea (59 %) and chest pain (33.9 %) were the most common symptoms. Patients with PE had significantly higher mean D-dimer levels (4.77 mg/mL) than those without PE (1.45 mg/mL, p < 0.001). Raising the D-dimer cut-off from 0.5 mg/mL to 0.65 mg/mL improved specificity from 12 % to 37 % while maintaining 100 % sensitivity.

This study highlights the potential to improve the diagnosis of pulmonary embolism (PE) by adjusting the D-dimer cut-off. By increasing the cut-off, we were able to enhance specificity while maintaining sensitivity, leading to fewer unnecessary imaging tests. These results suggest that refining diagnostic thresholds can improve the accuracy of PE detection, reduce patient exposure to unnecessary procedures, and better allocate healthcare resources.