From the Guidelines
A D-dimer level of 1.27 μg/mL is elevated and requires further evaluation to rule out conditions involving abnormal blood clotting, such as deep vein thrombosis or pulmonary embolism, particularly in the context of clinical presentation and risk factors 1. Given the high sensitivity but low specificity of the D-dimer test for blood clots, a negative result can help rule out clotting disorders, but a positive result like this one necessitates additional testing for definitive diagnosis. The clinical probability of pulmonary embolism (PE) should be assessed, and if low, a highly sensitive D-dimer assay can safely exclude PE, but if the clinical probability is moderate, further diagnostic testing such as compression ultrasonography or computed tomographic venography may be necessary 1. It's also important to consider that D-dimer levels can be elevated in non-thrombotic conditions, including pregnancy, inflammation, recent surgery, cancer, or infection, which should be taken into account when interpreting the results 1. The next steps should include consulting a healthcare provider for proper interpretation and management, and potentially undergoing imaging studies such as ultrasound for suspected DVT or CT pulmonary angiography for suspected pulmonary embolism, based on clinical presentation and risk factors 1. Key considerations in the interpretation of D-dimer results include the type of assay used, the analytical performance of the assay, and the reporting of results in a consistent and clear manner to avoid confusion and errors 1. Given the potential for D-dimer to be elevated in various conditions, a comprehensive clinical evaluation is essential to determine the underlying cause of the elevated D-dimer level and to guide appropriate management.
From the Research
D-Dimer Levels and Deep Vein Thrombosis
- A D-dimer level of 1.27 is considered elevated, as most studies use a cutoff value of 0.5 mg/L or 500 ng/mL to exclude deep vein thrombosis (DVT) 2.
- Elevated D-dimer levels are associated with an increased risk of thrombosis, and a level of 1.27 may indicate the presence of DVT or other thrombotic conditions 3, 4.
- However, D-dimer levels can also be elevated in other conditions, such as inflammation, infection, or cancer, and therefore, a single elevated D-dimer level should not be used as the sole diagnostic criterion for DVT 5, 6.
Diagnostic Approach
- The diagnostic approach for DVT typically involves a combination of clinical assessment, D-dimer testing, and imaging studies such as ultrasound or computed tomography (CT) scans 3, 4.
- A clinical decision rule, such as the Wells score, can be used to stratify patients into low-, moderate-, or high-risk categories for DVT, and guide further diagnostic testing 3, 4.
- In patients with a low pre-test probability of DVT, a negative D-dimer test can be used to exclude DVT, while a positive D-dimer test may indicate the need for further imaging studies 2.
Management and Outcome
- If DVT is confirmed, anticoagulation therapy is typically initiated to prevent progression and reduce the risk of post-thrombotic syndrome and pulmonary embolism 4.
- Elevated D-dimer levels have been associated with a poor outcome in critically ill patients, and may be used as a prognostic marker in certain clinical contexts 5.
- However, the management and outcome of patients with elevated D-dimer levels and suspected DVT should be individualized based on clinical presentation, medical history, and other diagnostic findings 4, 6.