A simple coagulation assay may be useful in identifying patients at risk for recurrent venous thromboembolism (VTE). Researchers in Austria followed 914 patients for an average of 47 months after their first episode of VTE. Thrombin levels were measured after discontinuation of vitamin K antagonist therapy. The study used a level of 400 nM of thrombin generation as the cutoff measurement point for high and low risk. Patients with lower levels of thrombin generation had a 6.5% probability of recurrence, compared with 20% for patients with higher levels.
The authors concluded that thrombin measurement may be a simple way to identify patients with a low level of risk of VTE recurrence. The study, however, excluded any patients with previous or secondary VTE, antithrombin, protein C or S deficiencies, lupus anticoagulant, or cancer, or who were pregnant. Further investigation is needed to establish sensitivity and specificity information for a cutoff level of thrombin.
Dr. Garrett is a clinical pharmacist practitioner at Cornerstone Health Care in High Point, NC.