Coronary artery disease has been called “the silent killer.” You even may have known someone who dropped dead out of the blue because of it. Walk-in heart-scan clinics that provide coronary artery calcium (CAC) scores, a highly accurate heart disease assessment that uses computed tomography (CT), have cropped up all over and are advertised on radio and online and in direct-mail brochures —and it’s true that this test can tell you whether you have heart disease and even whether you need to be on a statin drug.
Before you decide to walk in and get a heart scan, be clear about whether you really need one first. How to do this? It helps to know what CAC scores are and why the American Heart Association and American College of Cardiology recommend that only certain people with a specific level of suspected heart disease have the test.
CAC scores, derived from heart scans, show the lifetime accumulation of all your risk factors, explained Matthew Budoff, MD, professor of medicine at UCLA’s Geffen School of Medicine who has extensively studied heart scans. They involve use of a type of X-ray technology called multislice CT, also called helical CT, which can see the calcium buildup in arteries. The more common indicators of potential heart disease, such as measurements of blood pressure and cholesterol, are just that—potential indicators.
In fact, Dr. Budoff pointed out, it’s more common for people with high cholesterol to have a CAC score of zero, which means no heart disease, than the high score that most laypeople (and even some doctors) would expect. “About half of the people with cholesterol levels that are high enough to be prescribed a statin, according to American Heart Association and American College of Cardiology guidelines, actually have a CAC score of zero. This means that they don’t need to be on a statin,” Dr. Budoff told me. “In roughly 50% of patients with high cholesterol, coronary heart disease never develops,” he added.
Heart scans can be revealing. For instance, Dr. Budoff proved the prognostic value of CAC scores in a study of 5,593 people whose average age was 57, each of whom had either no risk factors for heart disease or just one risk factor (high blood pressure, diabetes, high cholesterol, current smoking or a family history of heart disease). More than half of the study population, whether they had risk factors for heart disease or not, had positive CAC scores, indicating that at least some calcium-laden plaque had accumulated in their arteries, and 9.8% of the study participants had scores at the highest end of the spectrum, indicating severe disease.
Over an average of 10.4 years of follow-up, 168 participants died from any cause. After adjusting for age, gender, traditional heart disease risk factors and race, it was found that higher CAC scores were clearly associated with higher mortality. Compared with people with a score of zero who died, a CAC score of 1 to 99 (mild heart disease) was associated with an 88% higher risk of death…a score of 100 to 399 (moderate heart disease) was associated with a more than doubled risk of death…and a score of 400 or more (severe heart disease), with a nearly tripled risk of death.
Although this all sounds very dramatic, when the information is looked at from a different angle related to survival, the news is that 99% of people with a CAC score of zero, 97% with a low score, 94% with an intermediate score and 89% with a high score can be expected to still be alive in 15 years.
It’s been argued in blogs and medical journals that if a heart scan can tell whether you really have heart disease (and by extension whether you really need to be on a statin drug), then the scan should be more widely used to cut back on health-care costs as well as side effects of statin therapy. But even Dr. Budoff says to put the brakes on. He echoed points made by the American Heart Association and American College of Cardiology and what his and others’ studies have shown—CAC scoring is most useful in people at intermediate risk—those who are between 45 and 65 years old, may smoke and have borderline high blood pressure and/or cholesterol and need incentives to stay on or get going with a treatment plan. The vast majority of people who are younger than age 45, don’t smoke and have normal cholesterol and blood pressure levels don’t need a heart scan, because chances are that it won’t tell them or their doctors anything except what already appears to be the case—that they are healthy. On the other end of the spectrum, people who are older than age 65, smoke and/or have high blood pressure and/or cholesterol don’t need a heart scan either because they and their doctors already know that they are at high risk for heart attack.
Dr. Budoff also noted that heart scans involve some radiation exposure…and medical insurers may not necessarily cover heart scans that are done without a prescription from a doctor. What’s the out-of-pocket cost of a heart scan? It can range anywhere from $50 to $350 or more.
If you think you may benefit from a heart scan—whether it is simply for peace of mind or because you really want to know if you can safely ditch a statin prescription or for some other reason—your best strategy is to first visit your primary care doctor and get a full medical workup to assess your coronary artery disease risk. You can even get some insight beforehand about where you stand by calculating your Framingham Risk Score. Then, you and your doctor can evaluate, together, whether to go forward and get a heart scan ordered. (Most insurers do cover heart scans prescribed by physicians, but check with your plan first.)
If your doctor doesn’t think you need a heart scan and isn’t willing to prescribe one…but you still want one, the choice (and possibly the cost), with the availability of walk-in clinics, is still yours.
