- By Liza Torborg
Tuesday Q and A: Several factors affect long-term DVT treatment plan
DEAR MAYO CLINIC: Eleven years ago I developed deep vein thrombosis, which led to a pulmonary embolism. A vena cava filter was put in place, and I’ve been on warfarin since that time. Will I ever be able to discontinue warfarin and take aspirin instead? Would changing my diet allow me to eventually stop taking warfarin?
ANSWER: This is a very common and important question for people in your situation. How long you need to continue to take warfarin depends on several factors. They include the circumstances surrounding the development of your deep vein thrombosis and whether you have had any recurrences since then. As you and your doctor consider your long-term treatment plan, your medical history and your preferences should be taken into consideration, too.
Deep vein thrombosis, or DVT, happens when a blood clot forms in one or more of the deep veins in your body, usually in your legs. DVT is a serious condition because the blood clot can break loose, travel through your bloodstream and become stuck in your lungs, blocking blood flow. This condition, called a pulmonary embolism, can be life-threatening if it is not treated right away. When a DVT results in pulmonary embolism, it is known as venous thromboembolism.
As in your case, treatment for venous thromboembolism usually involves an anticoagulant medication such as warfarin. Anticoagulants, sometimes referred to as blood thinners, are drugs that decrease your blood’s ability to clot. While they do not break up existing blood clots, they can prevent clots from getting bigger. They also reduce your risk of developing new blood clots.
The duration of anticoagulant treatment depends in large part on when the DVT developed. Certain events and activities can raise your risk for DVT. They include surgery, extended travel, pregnancy, hospitalization, and estrogen exposure such as taking birth control pills. These are considered short-term risks for DVT. When DVT occurs in connection to one of these short-term risks, people usually need to take an anticoagulant for about three to six months.
If your DVT developed without any apparent explanation, then your risk of developing another blood clot may be high enough to require long-term anticoagulant treatment. You may also need long-term anticoagulation if you had another DVT form at some point after the first one resolved. Rarely, presence of certain hereditary or acquired blood conditions may warrant continued anticoagulants.
A vena cava filter can have an impact on your anticoagulant treatment, too. This small, metal device is placed into a large vein that returns blood from your legs to your heart — the vena cava. If a DVT forms, breaks off and travels through your bloodstream, the filter catches it before it reaches your heart, preventing a pulmonary embolism.
It is possible that having a vena cava filter in place may lower your risk of another pulmonary embolism enough that you can stop taking warfarin. But that is not always the case. Some people need both an anticoagulant and a vena cava filter to effectively prevent a pulmonary embolism.
In some cases, lifestyle changes such as exercising regularly, quitting smoking and getting to a healthy weight may reduce the risk of another DVT. But there are no specific dietary recommendations associated with a lower DVT risk.
If you feel strongly that you would like to stop taking warfarin, talk to your doctor. If you still need some anticoagulant, you may be able to switch to aspirin or another medication to prevent blood clots, such as newer blood thinners like rivaroxaban or apixaban. Other treatment alternatives or close, ongoing follow-up care may be options, as well, depending on your medical history and your individual wishes regarding treatment. — Rajiv Pruthi, MBBS, Hematology, Mayo Clinic, Rochester, Minn.