New Use of Aspirin May Save Lives
In the U.S, there are approximately one million cases of venous thromboembolism (VTE)—many of which are recurrent and is the focus of a new study that found that aspirin maintenance therapy after treatment of VTE may save lives by preventing recurrence of venous thromboembolism.
Venous thromboembolism is a lethal disorder that affects hospitalized and non-hospitalized patients and includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). Pulmonary embolism is the third most common cause of hospital-related death and is believed in many cases to be preventable if monitored closely and treated appropriately.
The lethal factor of VTE is the venous thrombi (blood clots) that consist of red blood cells, platelets and leukocytes that are bound together by fibrin—an important protein involved in wound healing. These venous thrombi often form in areas of vessel damage and stagnant blood flow such as the valve pockets of the deep veins of the calf or thigh. Sometimes the thrombi break free and travel like a loose clog in a drain only to later block a small blood vessel in the heart, brain or lungs and result in cardiac arrest, stroke or hypoxemia respectively.
The risk factors of developing VTE include both hereditary and acquired risk factors such as hypertension, diabetes mellitus, cigarette smoking and high cholesterol levels. Furthermore, it can occur spontaneously during pregnancy or surgery, from trauma, and from sitting for prolonged periods during air travel.
One of the problems with having developed VTE is that it can reoccur years later following successful treatment of the disease. According to a new study published in the New England Journal of Medicine, about 20% of patients with unprovoked venous thromboembolism have a recurrence within 2 years after the withdrawal of oral anticoagulant therapies.
Long term treatment of VTE is typically through the use of the blood clot busting/blood thinning drug warfarin. However, long term use of warfarin sometimes results in internal bleeding leaving physicians and patients with the task of balancing the risk factors of potential clotting against excessive thinning.
The good news is that researchers from the study published in the New England Journal of Medicine may have found an easy solution to the problem—aspirin.
In the study, the researchers gave either aspirin or an inactive placebo for a two-year period to 402 patients who had developed first-ever unprovoked venous thromboembolism. Previous to the aspirin/placebo control treatment, the patients had received other anticoagulant treatment for an initial six- to 18-month period following the onset of their venous thromboembolism.
The results of the study revealed that taking aspirin reduced the risk of developing recurring VTE. Of the 205 patients who took aspirin, only 28 had recurring VTE. This is in comparison to 43 out of 197 patients with recurring VTE while on the placebo. The researchers also found that there was no apparent increased risk of internal bleeding by the patients during the study.
While aspirin appears to show promise in preventing recurring VTE, it may be a while before it will become standard treatment. Currently, two larger studies are underway to determine if the results are repeatable and whether aspirin may be an option for patients who are particularly susceptible to an increased risk of bleeding while on warfarin.
Image Source: Courtesy of Wikipedia
Reference: “Aspirin for Preventing the Recurrence of Venous Thromboembolism” New England Journal of Medicine 2012; 366:1959-1967; Cecilia Becattini, M.D. et al.