Bottom Line Inc

Do You Have a Heart Attack Gene?

0

Finding out could save your life!

Even if you do everything right-you don’t smoke, you’re not overweight and you manage your cholesterol and blood pressure-your odds of having a heart attack might be higher than you think.

An eye-opening case: One of our patients, a 44-year-old executive whom we nicknamed “Superman,” looked very healthy. His Framingham Risk Score—a standard measure of heart disease risk—predicted that he had only a 1% risk of having a heart attack over the next 10 years. That should have been good news—except that other tests we did, which most doctors do not routinely give, showed that his real risk was about 40 times higher.

THE TESTS YOU NEED

Many of the tests that are used to detect heart disease are decades old. Some look for risk factors (such as arterial narrowing) that have less to do with the actual risk of having a heart attack than most people think. Many of the tests that can make a difference still aren’t used by most doctors.

Most cardiologists routinely recommend angiography, an imaging test that looks for large blockages in the coronary arteries. If a blockage of 70% or more is found, a patient might be advised to receive a stent or undergo a bypass, surgical procedures that don’t always help and can have a high rate of complications.

Severely blocked arteries can be a problem, but a more common, and typically overlooked, threat is from small deposits inside artery walls. A patient might have dozens or even hundreds of deposits that are too small to be detected with angiography.

The risk: When these “hidden” deposits are exposed to inflammation—triggered by insulin resistance, smoking, a poor diet or stress, for example—they can rupture, tear the blood vessel lining and trigger a clot, the cause of most heart attacks.

New approaches: Doctors can now predict the risk for a heart attack with far more accuracy than in the past—if you know which tests to ask for. Tests I recommend…

    • Carotid intima-media thickness (CIMT). This is an effective way to measure atherosclerosis inside an artery wall (between the intima and media layers). The FDA-approved test uses an ultrasound wand to look for the thickening of the carotid arteries that occurs when plaque between the two layers accumulates and pushes outward.

An isolated area of thickness measuring 1.3 mm or greater indicates plaque—and an increased risk for a heart attack or stroke.

Most patients who have excessive arterial thickening will be advised to exercise more, eat a healthier diet and take a daily baby aspirin to reduce the risk for clots. A cholesterol-lowering statin drug also may be prescribed.

  • Genetic tests. More than half of all Americans have one or more gene variations that increase the risk for a heart attack and a stroke. According to research published in Circulation, up to 70% of patients who are given the genetic tests described below will be reclassified as having a higher heart attack risk than their doctors originally thought. The cost of testing has dropped to about $100 per gene. Your insurance may cover the cost. Important gene tests…

9P21. If you inherit two copies of this “heart attack gene” (one from each parent), your risk of developing heart disease or having a heart attack at an early age (in men, under age 45…in women, under age 55) is 102% higher than that of someone without the gene. And increased risk continues if you are already past these ages.

You’ll also have a 74% increased risk for an abdominal aortic aneurysm, a dangerous weakening in the heart’s largest blood vessel. If you test positive, your doctor will advise earlier and more frequent abdominal aortic scans. If you smoke, stop now. Most aortic aneurysms occur in smokers.

You should also exercise for at least 22 minutes daily (the amount found in research to be protective) and maintain healthy cholesterol and blood pressure levels.

Important: Patients with the 9P21 gene often are advised to have an ankle-brachial index test, which involves measuring blood pressure in the arms and ankles. It’s used to diagnose peripheral artery disease (PAD), plaque buildups in the legs that quadruple or even quintuple the risk for a heart attack or stroke.

Apo E. This gene affects how your body metabolizes nutrients. There are different types of Apo E. The 3/3 genotype—64% of Americans have it—increases cardiovascular disease, but not as much as the 3/4 or 4/4 types. Those with 3/4 or 4/4 need to eat a very low-fat diet (with no more than 20% of calories from fat). Those with the 3/3 genotype are advised to eat a Mediterranean-style diet—focusing mainly on plant foods…fish…and olive oil.

KIF6. Patients with the so-called arginine gene variant have up to a 55% increased risk for cardiovascular disease. There are no particular lifestyle changes known to be especially helpful for these patients. It’s also useful to know if you’re a noncarrier of KIF6—as such, you won’t receive significant risk reduction if you are prescribed either atorva-statin (Lipitor) or pravastatin (Pravachol), two of the most popular statin drugs. Instead, you’ll need a different statin, such as lovastatin (Mevacor).

ANOTHER CRUCIAL TEST

An oral glucose tolerance test can detect insulin resistance years or even decades before it progresses to diabetes. But many doctors still use the simpler A1C test. It’s more convenient—it doesn’t require fasting—but it often fails to detect insulin resistance, one of the main causes of heart attacks and strokes. Insulin resistance leads to inflammation that can trigger plaques to rupture and form clots.

With an oral glucose tolerance test, your blood sugar is measured. Then you drink a sweet solution, and your blood sugar is measured again two hours later. A level of 100 mg/dL to 139 mg/dL could indicate insulin resistance. Higher levels may indicate prediabetes—or, if they’re high enough, full-blown diabetes.

Next steps: Regular exercise is critical if you have insulin resistance or diabetes. Also helpful: Weight loss, if needed, reduced intake of sugary beverages and foods, and a diet rich in fruits, vegetables and grains.

print
Source: Bradley F. Bale, MD, cofounder of the Heart Attack & Stroke Prevention Center, Nashville, and medical director of the Grace Clinic Heart Health Center, Lubbock, Texas. He is coauthor, with Amy Doneen, ARNP, and Lisa Collier Cool, of Beat the Heart Attack Gene: The Revolutionary Plan to Prevent Heart Disease, Stroke, and Diabetes (Wiley).

Date: January 1, 2014 Publication: Bottom Line Health
Keep Scrolling for related content View Comments