'Evaluatie van biomarkers in VTE studie met capillair bloed monster; de EVA-II studie'

Rationale: Venous thrombo-embolism (VTE) can be ruled-out in Primary Care in patients with a low score on a clinical decision rule (CDR) and a negative D-dimer test result without the need for referral for imaging. Very recently, new Point-of-Care laboratory devices have been introduced enabling low-volume capillary blood sampling, suitable for rapid exclusion of VTE in primary care.
Objectives: Primary objective of this study is to perform an analytical validation of five novel point-of-care (POC) D-dimer assays compared with a routine lab D-dimer assay. Secondary objectives are a clinical validation according to VTE diagnosis, since a Gold Standard of D-dimer is lacking and testing the additional value of other biomarkers.

Study design and study population: Prospective cohort study in patients suspected of having VTE who are referred to a hospital- or primary care laboratory for a lab D-dimer testing. After written Informed Consent, an additional blood sample will be extracted from the venipuncture that will be used for routine D-dimer testing in order to prepare plasma for a central D-dimer measurement at the Jeroen Bosch Hospital at ‘s-Hertogenbosch. In addition, a POC D-dimer test will be done using a capillary blood sample drawn from a finger prick.
Three months after the blood draw, the GP will be enquired for the diagnosis of the coded patient. The experimental intervention under study is limited to a 11 mL blood draw in addition to the routine-care blood sample drawn from the same venipuncture, and a POC D-dimer test using capillary blood drawn from a finger prick.
For each different POC device, 70 patients will undergo additional testing, which amounts to 5 x 70= 350 patients in total.
Inclusion period will consist of 2 months at 10 puncture posts (2 puncture posts per hospital site) with a follow-up of 3 months.
The additional diagnostic value of four biomarkers (CRP, Procalcitonin, TAT complex and factor VIII) will be evaluated.
Patient burden and safety.
Burden for the patient is limited, for additional blood will be drawn from the same needle as being for the routine D-dimer test. The finger prick for POC testing is complementary and unavoidable, since for safety validation purposes material used for routine tests drawn from a venipuncture has to come from the same origin as the capillary blood used for POC testing. Thus, left over plasma cannot used for this purpose.

Note:This studie is a continuation of the EVA study; Netherlands Trial Register NL5974

N/A

6 months

A single finger prick for capillary whole blood samples (<50 microlitres and for the regular blood sample for the requested D-dimer test, 11 ml of nasal blood is taken from the same needle for the study). So no extra venipuncture takes place.