Evaluation of Wells score and repeated D-dimer in diagnosing venous thromboembolism

Patients presenting with symptoms suggestive of venous thromboembolism (VTE), i.e., deep vein thrombosis (DVT) and pulmonary embolism (PE), are common at the emergency departments. However, of those, only 15-25% actually have the disease. The aims of this study were to determine (1) if low pre-test probability (PTP) using the Wells score, together with a normal D-dimer, safely excludes VTE in outpatients and (2) if a follow-up D-dimer adds extra information.

Patients (n=151, 68% women) with suspected VTE, a PTP below 1.5, and a D-dimer test (TinaQuant) below 0.5 mg/L were included in the study and underwent no further diagnostic investigations. Patients (n=177, 54% women) with D-dimer levels of 0.5 mg/L or higher or a PTP of 1.5 or higher were excluded. A follow-up D-dimer test was conducted 3-7 days after the initial hospital visit and further diagnostic investigations were made if test results were abnormal. Patients were studied for 3 months.

A follow-up D-dimer test was conducted in 101/151 cases (67%), 13/101 of which revealed elevated D-dimer levels. None of these 13 patients had persistent symptoms or was diagnosed with VTE. All 151 patients were contacted after 3 months; none of them had clinical signs of VTE. Of the 177 patients excluded, 45 (25%) were diagnosed with VTE. Of the 176/328 (151+177) patients with normal D-dimer levels, only 1 had VTE (<0.01%).

A normal PTP using the Wells score and a normal D-dimer safely excludes VTE at the emergency department. A follow-up D-dimer test adds no further information.