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Updated: Apr 5, 2026
Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Predictive value of factor VIII levels for recurrent venous thrombosis: results from the MEGA follow-up study
J F Timp1, W M Lijfering1,2, L E Flinterman1
1Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
Insights
High levels of coagulation factor VIII (FVIII) predict recurrent venous thrombosis. Elevated FVIII activity, antigen, and von Willebrand factor antigen levels indicate increased risk, improving prediction models.
Area of Science:
- Hematology
- Thrombosis Research
- Clinical Prediction Modeling
Background:
- Predicting recurrent venous thrombosis is clinically challenging.
- Existing risk stratification models have limitations.
Purpose of the Study:
- To evaluate coagulation factor VIII (FVIII) levels as a predictor of recurrent venous thrombosis.
- To assess the role of FVIII activity, FVIII antigen, and VWF antigen in recurrence risk.
Main Methods:
- Prospective follow-up of 2242 patients with a first venous thrombosis after anticoagulant cessation.
- Measurement of FVIII activity, FVIII antigen, and VWF antigen at least 3 months post-treatment.
- Analysis of recurrence rates based on FVIII levels and integration into prediction models.
Main Results:
- Recurrence rates increased with higher FVIII activity levels in a dose-response manner.
- Patients with FVIII > 200 IU/dL had a 3-fold higher recurrence risk than those with FVIII ≤ 100 IU/dL.
- FVIII levels predicted recurrence over time and improved existing prediction models like the DASH score.
Conclusions:
- Coagulation factor VIII is a strong predictor of recurrent venous thrombosis.
- FVIII levels demonstrate a dose-response relationship with recurrence risk.
- FVIII is a valuable component for developing enhanced clinical prediction tools for venous thrombosis recurrence.
Background:
Prediction of recurrent venous thrombosis remains a challenge in the clinic.
Objective:
To investigate the predictive value of coagulation factor VIII (FVIII) levels for recurrent venous thrombosis.
Patients/Methods:
Patients, aged 18-70 years with a first venous thrombosis, were followed from discontinuation of anticoagulant treatment (1999-2010 MEGA follow-up study). The levels of FVIII activity, FVIII antigen and von Willebrand factor (VWF) antigen were measured at least 3 months after cessation of anticoagulant treatment.
Results:
Of 2242 patients followed for a median of 6.9 years, 343 developed recurrent thrombosis (incidence rate 2.7/100 patient-years; 95% confidence interval [CI] 2.5-3.1). Recurrence rates steadily increased with higher FVIII activity levels, from 1.4 (95% CI 1.0-1.9), 2.3 (95% CI 1.8-2.9), 3.0 (95% CI 2.4-3.7), 3.2 (95% CI 2.5-4.1), 3.9 (95% CI 2.8-5.3) to 5.1 (95% CI 3.8-6.8) per 100 patient-years, for levels ranging from < 100 IU dL(-1) to > 200 IU dL(-1) . Patients in the highest category of FVIII (> 200 IU dL(-1) ) had a three-fold higher recurrence rate than patients in the lowest category (≤ 100 IU dL(-1) ) (hazard ratio 3.4; 95% CI 2.2-5.3). Results were similar for FVIII antigen and VWF antigen levels, in several sensitivity analyses, and FVIII predicted recurrence rates over a long time period. Within subgroups of patients currently assumed to have low recurrence risks, a high level of FVIII was still predictive for recurrences. Adding FVIII to an existing prediction model (DASH score) improved its predictive value, and, after replacement of D-dimer with FVIII, the model performed equally well, if not better.
Conclusions:
FVIII predicted recurrence in a dose-response fashion, overall and in several subgroups, and is a strong candidate component of recurrence prediction tools.
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