D-dimer Levels in Acute, Medically Ill, Hospitalized Patients: A Large, Prospective, Multicenter Study in the United States.

Abstract

Background: The study's main aim was to determine the prevalence of elevated D-dimer levels in adult patients hospitalized for acute medical illnesses not suspected to have venous thromboembolism (VTE). The secondary aims were to determine VTE prophylaxis rates and VTE events.

Methods: This multicenter, prospective, observational study included patients who were admitted across nine US hospitals. Patients who were ≥60 years of age, admitted for an acute medical illness (nonsurgical/nontraumatic), and not suspected to have VTE (deep vein thrombosis [DVT]/pulmonary embolism [PE]) were enrolled. Current use of anticoagulation and recent major surgery were exclusion criteria. D-dimers were measured at hospital admission, and the analysis was performed at a central laboratory using the STA-Liatest D-Di test kit (Diagnostica Stago, Asnières sur Seine, France). The upper limit of normal (ULN) for D-dimer was defined as ≥500 ng/mL. Age-adjusted thresholds were calculated as age × 10 ng/mL. VTE events included symptomatic DVT (distal or proximal) or PE occurring during admission.

Results: Among 995 patients (50.7% female; mean age, 70 ± 8 years), 74.4% (n = 740) had a D-dimer ≥ ULN, 62.2% (n = 619) had elevated age-adjusted levels, and 48.8% (n = 486) had D-dimers at least two times the ULN. The rate of VTE prophylaxis was 66.5% (n = 662); in this cohort, 1.8% (n = 18) developed a VTE.

Conclusion: Most hospitalized acute medically ill patients ≥60 years of age had elevated D-dimer levels on admission. Although an elevated D-dimer may be associated with VTE risk, its poor specificity indicates that it should not guide prophylaxis management without a multifactor risk assessment.