Negative D-Dimer Can Safely Rule Out DVT as Standalone Test
Standalone D-dimer testing followed by whole-leg compression US in positive patients rules out DVT
FRIDAY, Oct. 16, 2020 (HealthDay News) -- Initial standalone D-dimer testing followed by whole-leg compression ultrasonography (CUS) in patients with positive D-dimer can safely rule out deep vein thrombosis (DVT), according to a study published online Oct. 15 in Blood Advances.
Synne G. Fronas, M.D., from Østfold Hospital Trust in Norway, and colleagues conducted a prospective management outcome study to examine the safety of referring only patients with positive D-dimer for whole-leg CUS irrespective of pretest probability. Consecutive outpatients referred to the emergency department with suspected DVT between February 2015 and November 2018 were included; data were analyzed for 1,397 patients.
The researchers found that 29.7 and 70.3 percent of patients were negative and positive for D-dimer, respectively. DVT was diagnosed in 19.8 percent of patients (277 patients). Within three months of follow-up, six patients in whom DVT was ruled out at baseline (negative D-dimer and/or normal CUS) were diagnosed with DVT (thromboembolic rate, 0.5 percent; 95 percent confidence interval, 0.2 to 1.2).
"To our knowledge, this is the first large prospective study to assess the clinical outcomes of a diagnostic strategy using standalone D-dimer," Fronas said in a statement. "This method could result in fewer unnecessary ultrasound examinations because not all high-risk patients are referred -- only the ones with positive D-dimer."
Several authors disclosed ties to the pharmaceutical industry, including Bayer, which partially funded the study.