A rapid assay for the detection of circulating D-dimer is associated with clinical outcomes among critically ill patients

Abstract

OBJECTIVE: To determine whether the results of a rapid, semiquantitative assay for the detection of circulating D-dimer in whole blood (SRDD assay) are associated with the occurrence of clinical outcomes among critically ill patients. DESIGN: Prospective, blinded, single-center study. SETTING: Medical intensive care unit (ICU) of Barnes-Jewish Hospital, St. Louis, MO, a university-affiliated teaching hospital. PATIENTS: Three hundred twenty-three adult patients admitted to a medical ICU. INTERVENTIONS: Collection of blood samples within 24 hrs of ICU admission. MEASUREMENTS AND MAIN RESULTS: The main outcome measures evaluated included vascular thrombosis, hospital mortality, and the development of multiorgan dysfunction. Fifty (15.5%) patients were found to have increased concentrations of D-dimer as detected by the SRDD assay within 24 hrs of ICU admission. The concentrations of plasma D-dimer simultaneously measured by an enzyme immunoassay based on the same antibody were significantly greater among patients with a positive SRDD assay compared with patients with a negative SRDD assay (1214+/-483 vs. 405+/-407 ng/mL; p< .001). The hospital mortality rate was significantly greater among SRDD-positive patients compared with SRDD-negative patients (32.0% vs. 15.0%; p=.004). SRDD-positive patients also had significantly greater frequencies of acquired multiorgan dysfunction (48.0% vs. 17.6%; p < .001), severe sepsis or septic shock (56.0% vs. 20.9%; p< .001), and vascular thrombosis (14.0% vs. 4.0%; p=.005) compared with SRDD-negative patients. Multiple logistic regression analysis identified the presence of increased concentrations of D-dimer, detected by a positive SRDD assay, as being independently associated with vascular thrombosis (adjusted odds ratio 5.06; 95% confidence interval 2.96 to 8.65; p=.003) and the development of multiorgan dysfunction (adjusted odds ratio 1.51; 95% confidence interval 1.28 to 1.78; p=.012). CONCLUSIONS: Our preliminary investigation suggests that the results from a rapid whole blood assay for the semiquantitative detection of circulating D-dimer are associated with clinical outcomes among patients admitted to a medical ICU. In addition, the use of D-dimer to identify the presence of active intravascular thrombosis may identify patients likely to benefit from antithrombotic therapies in the ICU setting.