From the Guidelines
The patient's D-Dimer test result of 0.27 mcg/mL FEU is below the cutoff level of 0.49 mcg/mL, indicating a low likelihood of deep vein thrombosis (DVT) or pulmonary embolism (PE) in patients with low or moderate pre-test probability. Given this result, the negative predictive value for DVT is 100% and for PE is 99.7% in patients with low or moderate pre-test probability, as indicated by the performed test 1. The American College of Physicians recommends using validated clinical prediction rules to estimate pretest probability in patients suspected of having acute PE, and not obtaining d-dimer measurements or imaging studies in patients with low pretest probability of PE who meet all Pulmonary Embolism Rule-Out Criteria 1. Key considerations include:
- Clinical correlation is essential in interpreting D-Dimer test results
- The D-Dimer test has excellent negative predictive value when normal, but a positive result indicates active clotting that requires prompt medical attention
- Patients should be assessed for clinical symptoms, risk factors for thrombosis, and potentially started on anticoagulation therapy depending on the clinical scenario and confirmation of thrombosis
- Age-adjusted d-dimer thresholds should be used in patients older than 50 years to determine whether imaging is warranted 1. Therefore, based on the low D-Dimer level and the guidelines, no further diagnostic evaluation for DVT or PE is immediately necessary, unless clinical symptoms or risk factors suggest otherwise.
From the Research
D-Dimer Test Results and Clinical Implications
- The D-Dimer test result is <0.50 mcg/mL FEU, which is below the cutoff level of 0.49 ug/ml (FEU) 2.
- At this cutoff level, the negative predictive value for deep vein thrombosis (DVT) is 100% for patients with a low or moderate pre-test probability 3.
- The negative predictive value for pulmonary embolism (PE) is 99.7% for patients with a low or moderate pre-test probability 4.
- Clinical correlation is essential to interpret the test results, as D-Dimer levels can be elevated in several other conditions than thrombosis 2.
Diagnostic Strategies for DVT and PE
- The diagnostic work-up of suspected DVT or PE includes the sequential application of a clinical decision rule and D-Dimer testing 5.
- Imaging and anticoagulation can be safely withheld in patients who are unlikely to have venous thromboembolism and have a normal D-Dimer 5.
- The combination of clinical assessment, D-Dimer testing, and non-invasive diagnostic tools can safely reduce the need for imaging tests 6.
Clinical Decision Rules and D-Dimer Testing
- Clinical decision rules, such as the Wells score, can be used to estimate the pre-test probability of DVT or PE 3.
- D-Dimer testing can be used to rule out DVT or PE in patients with a low or moderate pre-test probability 4.
- The sequential use of clinical score assessment and D-Dimer testing can safely reduce the need for imaging tests 6.