D-dimer PE Exclusion — EECC MCQ

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EasyPulmonary Vascular DiseaseD-dimer PE ExclusionEECC

A 52-year-old man with suspected PE has a pre-test probability calculated as 'PE unlikely' using the Wells score. His D-dimer is negative (<500 ng/mL). What is the next step?

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Correct answer: E — PE can be excluded without further imaging; the combination of a low clinical probability and negative D-dimer has a negative predictive value >99%

The diagnostic strategy for suspected PE follows a sequential approach per the ESC 2019 PE Guidelines: (1) Assess clinical probability using a validated score (Wells or revised Geneva score); (2) In patients with 'PE unlikely' (Wells ≤4 or low/intermediate probability), a negative D-dimer (<500 ng/mL using standard age-adjusted threshold, or <age × 10 for patients >50 years) safely excludes PE without the need for imaging. The negative predictive value of this combination exceeds 99%. (3) CTPA is indicated when: D-dimer is positive, clinical probability is 'PE likely' (Wells >4), or when there is high clinical suspicion regardless of D-dimer. This strategy avoids unnecessary CTPA (with associated radiation, contrast, and incidental findings) in low-risk patients.

Reference: ESC (2019): Guidelines on Acute Pulmonary Embolism