Never ignore extremely elevated D-dimer levels: they are specific for serious illness

Area of Science:

• Clinical diagnostics
• Biomarker research
• Hematology

Background:

• D-dimer (DD) is routinely used in venous thromboembolism (VTE) diagnosis with low cut-offs for high sensitivity but low specificity.
• Dichotomizing test results leads to information loss, particularly concerning extremely elevated D-dimer levels.
• Assessing the differential diagnosis of extremely elevated D-dimer is crucial for understanding its clinical significance.

Purpose of the Study:

• To investigate the differential diagnoses associated with extremely elevated D-dimer levels in a hospital setting.
• To determine the prevalence of severe conditions in patients presenting with significantly high D-dimer values.
• To evaluate the clinical utility of extremely elevated D-dimer as an indicator of severe pathology.

Main Methods:

• Retrospective cohort study including patients over 18 years old with D-dimer results exceeding 5000 μg/l (>10x VTE exclusion cut-off).
• Electronic medical records were reviewed to identify patient diagnoses.
• Exclusion criteria included duplicate results, cardiopulmonary resuscitation, and lack of diagnostic information.

Main Results:

• 581 cases were analyzed from 759 identified extremely elevated D-dimer results.
• The mean D-dimer level was 17,598 μg/l, with a wide range (5030–239,000 μg/l).
• 89% of patients had a diagnosis of VTE, cancer, or sepsis. Specific conditions included pulmonary embolism (32%), cancer (29%), sepsis (24%), trauma/surgery (24%), and deep vein thrombosis (13%).

Conclusions:

• Extremely elevated D-dimer levels are strongly associated with severe diseases, primarily VTE, sepsis, and cancer.
• Despite its reputation for non-specificity, a sharply elevated D-dimer warrants suspicion of severe underlying pathology.
• Clinical vigilance for serious conditions should be maintained even when extremely high D-dimer appears as an isolated finding.