J Vasc Surg Venous Lymphat Disord. 2021 Jun 22:S2213-333X(21)00306-1. doi: 10.1016/j.jvsv.2021.06.011. Online ahead of print.
OBJECTIVE: Plasma D-dimer levels greater than 5,000 ng/ml are encountered in a number of conditions beyond venous thromboembolism (VTE). Recent studies have used plasma D-dimer levels as a prognostic indicator for COVID-19 infection. The implications of abnormal levels are less clear for COVID-positive patients with baseline elevation in plasma D-dimer levels. This study reviews the occurrence of plasma D-dimer levels >5,000 ng/ml and investigates the clinical significance of this finding prior to the onset of the COVID-19 pandemic.
METHODS: Inpatient records over a four-year period were screened for laboratory results of plasma D-dimer levels >5,000 ng/ml. Patient data was reviewed for clinical identifiers commonly associated with elevated plasma D-dimer levels, which included VTE, cancer, sepsis, pneumonia, other infection, bleeding, and trauma. Patients were then categorized into groups by plasma D-dimer level to allow comparison between the various clinical diagnoses.
RESULTS: A total of 671 patients were included in the study. VTE was the most common diagnosis in patients with a plasma D-dimer level >5000 ng/ml followed by cancer and pneumonia. Multiple clinical diagnoses were present in 61% of patients. No clear cause for the ultra-high plasma D-dimer level could be identified in 11.3% of patients. Among the patients lacking a clinical diagnosis at the time of discharge, mortality was 24% in the 5,000-10,000 ng/ml group, 28.6% in the 10,000-15,000 ng/ml group, and 75% in the >15,000 ng/ml group.
CONCLUSIONS: VTE, cancer, and pneumonia are frequently present when ultra-high plasma D-dimer levels are encountered, and mortality is high when levels exceed 15,000 ng/ml. The results of our study from a pre-COVID-19 patient population suggest that ultra-high plasma D-dimer levels indicate the presence of severe underlying disease. This should be considered when using plasma D-dimer as a screening tool or prognostic indicator for COVID-19 infection.