The Single Best Predictor of a Heart Attack
The calcium score is the single best predictor of a heart attack. Learn about the test, plus eight other risk factors for heart disease you can't ignore.
Each year close to 1.4 million Americans experience a heart attack, and more than 500,000 die from it. Strikingly, according to the Society for Heart Attack Prevention and Eradication, 50 to 70 percent of those who suffered fatal heart attacks were not even aware of their risk. Despite recent scientific advances in heart disease prevention, many high-risk patients are overlooked when conventional risk assessment methods such as cholesterol and blood pressure screenings are used alone.
Here’s what you need to know about the No. 1 predictor of a heart attack, the calcium score, plus eight other risk factors to consider.
The Calcium Score
A calcium score, obtained from a noninvasive computed tomography (CT) scan of your heart, is the measure of the amount of calcium in your coronary arteries. This number reflects the total amount of atherosclerotic plaque. It’s an indication of how all of your risk factors interact with each other to cause heart disease. The higher your calcium score for your age, the greater your risk of a heart attack or stroke. Many preventive cardiologists are recommending that asymptomatic men over age 40 and most postmenopausal women over age 50 have a heart scan to determine their calcium score, unless they have been determined by a doctor to be at very low risk.
A calcium score of zero means you have no calcium deposits and a low risk of heart attack in the next five years. A score of 400 or more puts you at high risk of a heart attack within 10 years; a score of 1,000-plus means you have up to a 25 percent chance of having a heart attack within a year without medical treatment.
The significance of a given score also depends on your age. For instance, if you’re 40 and have a score of 50, it indicates you are at high risk. If an 80-year-old has a score of 50, it indicates low risk because the atherosclerotic process has proceeded very slowly. If your score is high for your age, then your doctor may advise adopting a heart-healthy diet, such as the South Beach Diet, along with other lifestyle changes, and often medications, to improve your risk profile. It may be a statin to lower cholesterol and/or a medication to lower your blood pressure.
You can get a CT scan for coronary calcium at most major medical centers, with the cost ranging from $99 to $399. The test takes about 10 minutes and radiation is minimal, about the same as a mammogram. Check with your insurance carrier to see if this test is covered.
Family History of Heart Disease
If one or both of your parents died prematurely of a heart attack, it puts you at greater risk. Still, there are other factors to consider when it comes to family history. If your father smoked, rarely exercised, and ate a diet high in bad carbs and bad fats, his death could have been hastened by any or all of those factors. You may have been dealt a bad set of genes, but there’s a great deal you can do when it comes to lifestyle to reduce and even eliminate the familial risk. Often, medications are also needed to overcome the effect of bad genes.
While, many people know the cardiovascular health of their parents influences their level of risk, they are unaware that the health of their siblings matters, too. If you have a brother or sister with cardiovascular disease, your own risk is increased by as much as 100 percent. In fact, if you grew up in the same household as your sibling, your sibling’s medical history is likely to be even more informative than your parents’. You and your brothers and sisters not only have similar genes, but you also ate similar food and grew up in the same environment.
Smoking and Heart Disease Risk
At any age, smoking at least doubles your risk of heart disease. In fact, smoking can trigger a heart attack even if your arteries are nearly perfect. Once you light up, smoking narrows your arteries, raises your blood pressure, increases your risk of irregular heartbeat, and makes your blood sticky and more likely to clot. Smoking also lowers your HDL (“good”) cholesterol and increases arterial inflammation. This is the perfect recipe for a heart attack.
If you smoke, and particularly if you have other risk factors for heart disease, each time you light a cigarette, you’re playing Russian roulette with your heart. A smoker who has high blood pressure and high LDL (“bad”) cholesterol has 14 times the normal risk of having cardiovascular disease. A woman who takes birth control pills (which increase the risk of blood clots) and who also smokes has a much greater risk of heart disease than does a woman who takes birth control pills but does not smoke. In young people with heart attacks, smoking is often the biggest culprit.
Diagnosis of Diabetes or Prediabetes
If you are an American age 40 to 70, the odds are about 40 percent that you’ve been diagnosed with diabetes or prediabetes (also known as metabolic syndrome and typically characterized by increased waist circumference, high blood pressure, high triglycerides, low good HDL cholesterol, and a mildly elevated blood sugar). Diabetes is such a strong risk factor for heart disease that medical professionals define it as a “coronary heart disease risk equivalent.” This means that a person with diabetes has the same high risk of a heart attack as someone who has already had one. Up to 70 percent of people in coronary care units have prediabetes or diabetes. Women, take note: If you have diabetes and have suffered a heart attack, you have an even greater risk of having another heart attack or heart failure than a man who has diabetes and has suffered a heart attack.
Waist Circumference and Your Heart
The circumference of your waist is an indicator of your odds of having a heart attack or stroke. If you have an apple-shaped body and carry much of your weight around your middle, you are at greater risk for cardiovascular disease than if you have a pear-shaped body and store fat mainly in your buttocks and thighs, or evenly over your entire body. Studies have found that waist circumference is an excellent predictor of who will develop diabetes and heart disease. A waist circumference of more than 35 inches if you’re a women (and 40 inches if you’re a man) puts you at risk. Get rid of that extra belly fat through diet and exercise.
High Blood Pressure
About one in three American adults has high blood pressure, also called hypertension. High blood pressure is currently defined as a reading of 140/90 mm Hg or higher, but guidelines regarding what constitutes “high” versus “normal” keep changing. Right now, blood pressure anywhere between 120/80 (normal) and 139/89 are labeled prehypertension. The American Heart Association estimates that 65 million Americans are in this category. It also estimates that people with prehypertension may be three times as likely to have a heart attack as those with normal blood pressure. Although blood pressure can vary from minute to minute with exercise, stress, sleep, and even changes in posture when at rest and relaxed, it should normally be less than 120/80 mm Hg for both men and women age 20 and older.
Cholesterol and Your Heart
Total cholesterol, when considered alone, is a poor predictor of heart disease and heart attack. Studies show that total cholesterol levels among people who’ve had heart attacks are almost the same as those of people who haven’t, and that roughly half of heart attacks occur in people without high cholesterol.
If you have other risk factors for heart disease, particularly a family history, having your HDL and LDL particle size measured with an advanced blood test will give you a far clearer picture of your heart risk than the conventional lipid panel. Having a lot of large particles cuts your risk for a heart attack, while having a lot of small ones raises it. You do not want more than 15 percent of your particles to be the small, dense type.
Triglycerides and Your Heart
Triglycerides are the form in which fat is stored in your body’s fat cells. Your triglyceride level is almost always strongly influenced by lifestyle. If you have high triglycerides (over 150 mg/dL is borderline high) and low HDL (less than 40 mg/dL if you’re a man and less than 50 mg/dL if you’re a woman), your risk of heart disease is compounded. To find out if you have this added risk, divide your triglyceride count by your HDL count. Ideally, the resulting number will be 2 or lower. For example, if your triglyceride level is 200 and your HDL is 40, divide 200 by 40 and you get 5. This is much higher than the desirable ratio, and it tells you that you have a heightened risk of a heart attack that will need to be addressed.
Your triglyceride level can also offer insight into your LDL particle size. In general, the higher your triglycerides and the lower your HDL, the smaller and denser your LDL and the greater your risk of heart disease. If your triglycerides are higher than 200 and your HDL is lower than 45, it is likely that you have too many small, dense LDL particles.
A Sedentary Lifestyle and Your Heart
A life with little to no physical activity leads to a number of undesirable body changes. Your blood pressure goes up, your triglycerides increase, your level of good HDL falls (this is why triglycerides and HDL are often called the “lifestyle” numbers), and you are more likely to gain weight, especially around your midsection. This is a picture of a heart attack in the making. No wonder the AARP recently called sitting the new smoking. The sad news is that two-thirds of American adults report that they are physically inactive — that is, they are sedentary most of the time. It’s time to get up and get moving.
What You Can Do to Improve Your Heart Disease Risk Factors
Beyond understanding your risk factors, getting the correct tests, and taking medications as prescribed, the most important step you can take to minimize your risk of heart attack and sudden death is to engage in a healthy lifestyle. That means shedding any extra pounds by adopting a heart-healthy diet, like the South Beach Diet, that focuses on nutrient-dense, fiber-rich fruits, vegetables, and whole grains, in addition to good fats and lean protein. It means making time for at least 20 minutes of aerobic or core-strengthening exercise most days of the week. And it means getting plenty of restorative sleep. Not only will these three steps help you lose weight and keep it off (yes, lack of sleep promotes weight gain), they will also help lower your blood pressure, improve insulin resistance in those with prediabetes and diabetes, and counter most of the other risk factors you’ve just read about.
It’s an encouraging fact: The earlier you start making these healthy lifestyle changes, the better your chances of avoiding a heart attack down the road.