If you have ever had a heart attack, or if your doctor has ever sent you to the "cath lab" (catheterization lab) for an angiogram and found a blockage in an artery, or if you have any of a long list of cardiovascular issues (peripheral artery disease, or the off again on again condition of blindness called amaurosis fugax, or deep venous thrombosis, among them) or cardiovascular risk facts (family history, age, diabetes), chances are you have been put on a statin drug for cholesterol.
Chances also are that you don't actually have "high" cholesterol despite having problems with your arteries. And even if you do, "clogged" arteries are just part of the problem. (I'm not telling you that you don't need your statin drugs if you have good cholesterol levels. Statins also fight inflammation, and sometimes that is what you really need.)
Disaster usually doesn't strike until you develop a blood clot that gets "stuck" in an artery and cuts off circulation. To make sure that doesn't happen, your doctor will put you on anticoagulant drug that you just can't replace with an over the counter blood thinner like aspirin. Managing your clotting factors isn't something you can do on your own, but asking your doctor the right questions can save you a lot of grief.
Who Needs Blood Thinners?
We all know that there are some people who are just a heart attack waiting to happen. They are overweight. They smoke. They drink. They drink 10 cups of coffee a day. They are overweight and angry and turn red in the face a lot. We kind of expect them to have heart attacks.
We don't all know that there are also some people who are at high risk of heart attack even without the obvious risk factors. These are people whose blood readily forms clots. These are people who may have great cholesterol, no weight problems, and lead healthy lives who nonetheless have a heart attack, or a stroke, deep vein thrombosis, ischemic colitis, or eye problems related to occluded arteries. These are people who may need anticoagulant drugs or at least over the counter blood thinners like aspirin.
Which people would be on this list? You might be surprised to learn that those at risk for "idiopathic" (unprovoked) blood clotting events include:
- Women who take oral contraceptives .
- Men and women over the age of 60 .
- Pregnant women .
- Obese people.
- Diabetic people, and especially
- Obese, diabetic people .
- Women on hormone replacement therapy.
- Anyone who is immobile for an extended period (whether confined to bed for illness or even on trans-Pacific and trans-Atlantic flights).
- People who have lupus.
- People who have cancer.
- People who have sickle cell disease.
- People who have any kind of inflammatory condition .
These are people who may develop blood clots in their legs or their lungs or a heart attack or a stroke "out of the blue," never knowing that they needed to be on anticoagulant therapy. There are also people who are at a predictable risk for blood clotting problems, including:
- Antithrombin deficiency, a serious problem that only affects about 10 percent of the general population ,
- Factor V Leiden, which is very rare among people of African and Asian descent but more common (affecting up to 18 percent of people of) European descent ,
- Protein C deficiency, which is relatively common among people of Chinese descent ,
- Protein S deficiency, which occurs in about 1 in 700 people ,
- Prothrombin 20210A, an even rarer condition , and
- MTHFR mutations, which affect about one in three people worldwide .
Far more people are treated for the rare conditions that for the most common condition affecting clotting factors, MTHFR mutations. If you talk with a younger hematologist or vascular surgeon, he or she will probably be dismissive of the idea that MTHFR mutations cause clinically significant clotting disorders. If you talk with a more experienced hematologist or vascular surgeon, he or she will have seen cases in which they clearly do. And if you talk with a doctor who has a holistic orientation, chances are the doctor will bring up the subject with you.
The over the counter "blood thinner" that works for about one in three people is methylfolate. It's an inexpensive vitamin supplement that the body can use more readily than folic acid (and if you have the mutation, your body doesn't use folic acid efficiently). MTHFR testing is getting cheaper all the time, but even if you can't afford the test, or your doctor won't order it, you can simply start taking methylfolate and you will have one of your bases covered. But the better known anticoagulant on the over the counter blood thinners list is aspirin.
Should You Be Taking Aspirin?
Taking a baby aspirin a day without any kind of testing is a shot in the dark for preventing clotting disorders, but it's not a bad investment of about US $0.01 a day. Large-scale studies have found that 32 percent fewer people have first heart attacks and 15 percent fewer people have other blood clotting events when they take an aspirin a day . This means that taking aspirin doesn't guarantee you won't have heart attack, but it does reduce your odds of having a heart attack quite significantly.
There are people, however, for whom taking aspirin is not a good idea. If you're allergic to aspirin, and about one in forty people is , you shouldn't take it, even for cardiovascular health. Aspirin allergies can cause wheezing and sneezing, or you may break out in hives. Some people with peptic ulcer disease likewise should avoid aspirin. There are alternatives to aspirin, such as indobufen, although they aren't cheap. And you should not take aspirin if it interferes with your prescription anticoagulant drugs.
Should You Be Taking One of the New Anticoagulant Drugs?
Blood thinning therapies have come a long way since the early twentieth century. One hundred years ago researchers were trying to extract hirudin from leeches and heparin from dog livers. (No leeches or dog livers are used in modern medicines.) Scientists learned how to synthesize heparin in 1933. It's still something you are very likely to get if you have to go to the hospital with a blood clot.
Coumadin and its related generic medications warfarin, acenocoumarol, and phenprocoumon were used as rat poisons in the 1940's and started being used in appropriate doses for treating blood clots in humans in the 1950's. They are still a mainstay of anticoagulation therapy for many people. Coumadin works by interfering with the body's use of vitamin K to make clotting factors. This gives doctors a way to stop the action of coumadin by giving an injection of vitamin K. Sometimes the ability to "turn off" the anticoagulant is of primary importance. Coumadin itself is very inexpensive, but you will need a blood levels check once a month at your doctor's office.
Clopidogrel, better known as Plavix, has been around since the late 1990's. The advantage of Plavix over Coumadin is that you don't have to limit your consumption of leafy greens and salads, which are high in vitamin K. It's also longer-lasting than Coumadin. A single dose stays in your system for 5 to 15 days. Clopidogrel has been used with low-dose aspirin as a way of preventing second heart attacks and strokes. The problem with clopidogrel is that not everyone responds to it. It has to be activated by an enzyme made by the liver (CYP2A19) that not everyone has in amounts sufficient for an anti-clotting effect. Doctors often just assumed that Plavix worked and never bothered to test for prothromin time (PTT) to see if the patient was getting the needed protection.
You might think that doctors would start testing for CYP2A19 to see if their patients could take Plavix, which is now available for just $4 a month (down from $400 a month twenty years ago), but they usually just prescribe an even new drug that doesn't involve this enzyme. Whether those medications work is a topic I will discuss in a separate article.
Do I Need to Be Looking at Blood Thinners Lists?
Just about everyone would benefit from taking low-dose methylfolate. Many people benefit from taking a baby aspirin every day. And if you have any of the conditions listed above, you really ought to speak with your doctor about appropriate anticoagulant therapy. Lowering your cholesterol, maintaining the right weight, getting enough exercise, and keeping your blood pressure under control just aren't enough if your blood clotting factors aren't in good control.