From the Guidelines
A D-dimer level of 0.59 is considered normal, as most laboratories set the normal cutoff value at less than 0.50 μg/mL. The interpretation of D-dimer results always depends on the clinical context and why the test was ordered, as it is a protein fragment produced when blood clots break down, so elevated levels can indicate conditions like deep vein thrombosis, pulmonary embolism, or disseminated intravascular coagulation 1. According to the American College of Physicians, a normal plasma d-dimer level, ideally age-adjusted (age × 10 ng/mL) but otherwise <500 ng/mL, provides sufficient negative predictive value for PE; no imaging studies are indicated 1.
Key Points to Consider
- The D-dimer test is used to help diagnose or rule out thrombotic disorders, such as deep vein thrombosis or pulmonary embolism.
- A result of 0.59 μg/mL is only marginally elevated and may not be clinically significant in many cases.
- The clinical context, including symptoms and risk factors, is crucial in interpreting D-dimer results.
- If symptoms such as leg pain, swelling, chest pain, or shortness of breath are present, discussing the borderline result with a healthcare provider is recommended, as they may suggest additional testing based on individual circumstances 1.
Clinical Decision Making
In patients with low pretest probability of PE, the PERC criteria should be applied, and if all criteria are met, the risk for PE is lower than the risks of testing; thus, no plasma d-dimer test is needed 1. For those with intermediate or high pretest probability, d-dimer testing is warranted, with a normal level indicating no need for imaging studies, and an elevated level prompting further investigation 1.
Next Steps
Given the borderline D-dimer result of 0.59, it is essential to consider the patient's clinical presentation, risk factors, and the reason for the test. Discussing the result with a healthcare provider to determine the need for additional testing or evaluation is recommended, as they can provide personalized guidance based on the individual's specific situation 1.
From the Research
D-Dimer Levels
- A D-dimer level of 0.59 is considered low, but the normal range may vary depending on the assay used and individual patient characteristics 2.
- D-dimer levels are used to exclude venous thromboembolism (VTE) in patients with low or intermediate pretest probability, but a level above the suggested threshold may indicate the need for further imaging tests 2, 3.
- The diagnostic accuracy of D-dimer levels can be improved by adjusting the cutoffs according to patient characteristics, such as age, pretest probability, pregnancy, renal function, or cancer 2.
Interpretation of D-Dimer Results
- A low D-dimer level, such as 0.59, may indicate a low risk of VTE, but it is essential to consider the patient's clinical presentation and other diagnostic factors 4, 5.
- D-dimer levels can be elevated in various conditions other than thrombosis, and therefore, a high level does not necessarily confirm the presence of VTE 2, 5.
- The use of D-dimer testing in conjunction with clinical pretest probability assessment can help reduce the need for unnecessary imaging tests and improve diagnostic accuracy 2, 3.