A group of scientists in Austria has made significant progress in thrombophilia treatment by establishing clinical parameters that will help physicians better assess the risk of their patients developing recurrent VTE.
Venous thromboembolism (VTE) is a serious condition that can develop when blood improperly clots inside blood vessels. If untreated, the clot can become dislodged, traveling to the brain or other major organs. In some cases, it can be fatal. The standard drug regimen is to treat it with anticoagulants, such as low molecular weight heparin and vitamin K antagonists. However, physicians still need to decide how long to keep their patients on the regimen to prevent the recurrence of VTE. Prolonged anticoagulant therapy can expose patients to an increased risk for other health problems, including severe to fatal hemorrhage. The resulting conundrum has made it difficult to determine the best treatment regimen for patients.
In a report published in the July 26, 2006 issue of the Journal of the American Medical Association (JAMA), the scientists confirmed their hypothesis that an inexpensive blood test that measures thrombin generation may differentiate patients at high or low risk for recurrent VTE. Approximately 5% of patients who previously experienced VTE die from a recurrence. It is important that thrombophilia patients be closely monitored and appropriately cared for after their first episode.
After studying a group of 914 patients from 1992 to 2005, the research team found significant differences in the physiological profile of those who developed recurrent VTE and those who did not. They estimated that patients exhibiting peak thrombin generation less than 400nM (nanomolar) are 60% less likely to develop recurrent VTE than those with higher levels. Thrombin is a coagulation protein in the blood that is important in the clotting process.
By measuring the activity of thrombin in the blood, the Austrian team determined that roughly two out of three participants in their study were at low risk for developing recurrent VTE. Due to the medical complications presented by chronic anticoagulant therapy, the researchers concluded that there is no benefit in keeping low-risk patients on indefinite coagulation therapy. This study is a significant development in thrombophilia treatment using a straightforward, cost-effective blood test.
Source: Hron G, Kollars M, Binder B, et al. Identification of Patients at Low Risk for Recurrent Venous Thromboembolism by Measuring Thrombin Generation. JAMA July 26, 2006; 296: 397-402.