D-dimer, factor VIII coagulant activity, low-intensity warfarin and the risk of recurrent venous thromboembolism.

Abstract

BACKGROUND:

Elevated plasma D-dimer and factor VIII coagulant activity (FVIIIc) may be associated with the risk of recurrent venous thromboembolism (VTE).

OBJECTIVES:

To evaluate D-dimer and FVIIIc as risk factors for recurrent VTE and assess the efficacy of extended low-intensity warfarin (target International Normalized Ratio 1.5-2.0) in preventing recurrence by biomarker level.

PATIENTS AND METHODS:

In the Prevention of Recurrent Venous Thromboembolism trial, 508 idiopathic VTE patients treated for > or = 3 months with full-intensity warfarin, and who had stopped warfarin for 7 weeks on average, were randomized to low-intensity warfarin or placebo and followed for 2.1 years for recurrent VTE. Prerandomization blood samples were analysed for D-dimer and FVIIIc.

RESULTS:

One-third of participants had elevated baseline D-dimer (> or = 500 ng mL(-1)) and one-fourth, elevated FVIIIc (> or = 150 IU dL(-1)). Adjusting for other risk factors, the hazard ratios (HRs) for recurrent VTE with elevated D-dimer or FVIIIc were 2.0 [95% confidence interval (CI) 1.2-3.4] and 1.5 (95% CI 0.8-2.8), respectively. The association of elevated D-dimer with recurrence was larger among patients with one prior VTE (HR 3.2, 95% CI 1.3-8.0) than in patients with more than one event (HR 1.4, 95% CI 0.7-2.2). For patients with one prior VTE on placebo, the annual recurrence incidence was 10.9% with elevated D-dimer and 2.9% with normal values. Low-intensity warfarin was equally effective in recurrence risk reduction in those with normal or elevated biomarkers.

CONCLUSIONS:

Among patients with idiopathic VTE, measurement of D-dimer, but not FVIIIc, might be useful for risk stratification. The efficacy of extended low-intensity warfarin therapy did not vary by biomarker level.

• Authors: S Shrivastava, P M Ridker, R J Glynn, S Z Goldhaber, S Moll, H Bounameaux, K A Bauer, C M Kessler, M Cushman
• Journal: Journal of thrombosis and haemostasis : JTH (J Thromb Haemost) Vol. 4 Issue 6 Pg. 1208-14 (Jun 2006) ISSN: 1538-7933 [Print] England
• PMID: 16706961 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Anticoagulants
• Biomarkers
• Fibrin Fibrinogen Degradation Products
• fibrin fragment D
• Warfarin
• F8 protein, human
• Factor VIII

Topics

• Adult
• Aged
• Anticoagulants (administration & dosage, therapeutic use)
• Biomarkers (blood)
• Double-Blind Method
• Drug Administration Schedule
• Factor VIII (metabolism)
• Female
• Fibrin Fibrinogen Degradation Products (metabolism)
• Humans
• Male
• Middle Aged
• Risk Factors
• Secondary Prevention
• Thromboembolism (blood, drug therapy, prevention & control)
• Venous Thrombosis (blood, drug therapy, prevention & control)
• Warfarin (administration & dosage, therapeutic use)