What Is Coronary Artery Calcium (CAC) Scoring?
CAC scoring is a simple computerized tomography (CT) scan that uses a minimal amount of radiation to measure the volume of calcium in your heart’s arteries. “Calcium isn’t the bad stuff that causes a heart attack. But it’s a marker of plaque,” says Erin Michos, MD, a preventive cardiologist with Johns Hopkins Medicine in Baltimore. Heart attacks can happen when plaque — a buildup of fat, cholesterol, and hardened calcium in your heart’s arteries — breaks open inside an artery, causing a clot to form that blocks blood flow to your heart. With CAC scoring, radiologists can see calcium on a CT scan. Unlike plaque, “it shows up bright on X-rays,” Dr. Michos says. Evidence suggests that when a CT scan of the arteries shows calcium, this is a marker that the individual has calcified plaque (atherosclerosis) of the heart arteries. Scoring ranges from 0 to over 400. If your calcium artery score (CAC) is 0, your risk for a heart attack in the next three to five years is very low. Still, your doctor may want to repeat the test in three to five years to reassess. Your risk of heart attack increases significantly when your CAC score is over 100. CAC scoring can help you and your doctor decide if you’re a candidate for statin therapy (cholesterol-lowering drugs).
Should You Ask Your Doctor for CAC Scoring?
It depends. CAC scoring can be useful if you don’t have symptoms of heart disease but do have risk factors. If, for example, you’re over 45, your cholesterol is borderline and you have heart disease in your immediate family, your CAC score can help tip the scale. If calcium is present in your arteries, you and your doctor may decide that taking a statin is a good idea, Michos says. You don’t need CAC scoring if:
You’re at low statistical risk for heart attack. If your 10-year risk of a heart attack is 5 percent or less, you don’t need CAC testing because you’re not a candidate for statin medication, Michos says. (To determine your 10-year heart attack risk, plug in your cholesterol and other health data into the American Heart Association and American College of Cardiology’s heart risk calculator.)You have cardiovascular disease. If you’ve already had a heart attack or stroke, you don’t need CAC scoring because statin therapy is solidly recommended for this risk group, Michos notes.You’re under age 45. CAC scoring isn’t useful until age 45 or older. “I don’t use calcium scoring in women under 45 because if they have plaque in their arteries, it’s not calcified,” Michos says. It takes decades for plaque and calcium deposits to mix and mingle in arteries.You’re at high risk for heart attack. If your 10-year risk of heart attack is 20 percent or greater, don’t waste time getting this test. “You should just start statin therapy,” Michos says.
What a Cardiac CT Scan Can Reveal About Your Heart
Compared with men, women are more likely to be diagnosed with microvascular angina, a type of cardiovascular disease that affects the heart’s smallest blood vessels. Blood is still getting through the arteries, but not enough to give the heart what it needs to pump effectively. “Microvascular angina can be missed,” says Michos, “because it doesn’t show up on an angiogram,” which is a traditional X-ray of the heart. Enter the cardiac CT. This sophisticated test uses computer imaging and contrast dye to create a 3-D image of the whole heart. Cardiac CT helps doctors diagnose blockages in the smaller blood vessels that support the heart, detect coronary artery disease, as well as problems with the aorta (the body’s largest artery) and with heart function. It can also measure plaque in your arteries.
Should You Ask Your Doctor for a Cardiac CT scan?
Yes, you should ask for a cardiac CT if you don’t have symptoms of heart disease but your chances of having a heart attack are 10 percent or more in the next decade, says Jennifer Mieres, MD, professor of cardiology at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell in East Garden City, New York, and coauthor of Heart Smart for Women. Use the American Heart Association and American College of Cardiology’s heart risk calculator to plug in your numbers with your doctor at your next check-up. On the other hand, if you do have symptoms of heart disease, such as tightness in your chest, you’ll need an immediate electrocardiogram (EKG), which provides a one-time snapshot of your heart rhythm. You may also need an imaging exercise stress test, which takes images of your heart while you’re exercising.
How Cardiac Event Monitors Work and What They Can Detect
Atrial fibrillation (afib) — an irregular rhythm that causes one of the heart’s chambers to beat abnormally — is the most common heart arrhythmia, affecting as many as 2.7 million people in the United States. The danger? Because of abnormal blood flow in the heart, a clot can develop, causing a stroke. An EKG in the doctor’s office is the traditional way to diagnose afib. The problem? An EKG can miss afib. “You may not be in afib when you get the EKG,” says Jacqueline Eubany, MD, author of Women and Heart Disease: The Real Story. Fortunately, an event monitor, which looks like a cellphone (you can keep it in your pocket), can give your doctor a more accurate assessment of your heart rhythm. You’ll wear it 24/7 for up to four weeks, except when taking a shower. As you go about your day, you’ll press the device to record your heart’s electrical rhythm when you feel symptoms, such as a rapid heartbeat or light-headedness.
Should You Ask for a Cardiac Event Monitor?
Yes, ask your doctor about an event monitor if you still feel symptoms of an irregular heartbeat, dizziness, or palpitations after having a normal EKG. “Don’t ignore symptoms,” Dr. Eubany says. Afib is a progressive illness. “The longer you have it, the more difficult it can be to get your heart into a normal rhythm,” Eubany says. “The sooner afib is diagnosed and treated, the better,” she says.
