(RxWiki News) Heart scans are often ordered before doctors prescribe statin medications to reduce cholesterol. Those heart scans may not be routinely necessary, a new study suggests.
Heart scans known as coronary artery calcium tests (CAC) can help doctors decide how to treat patients at risk for heart disease, including whether they should treat patients with statin medications. But CAC tests are costly and can expose patients to potentially harmful radiation.
The researchers behind this new study concluded that as long as statins remain inexpensive and don’t cause problems for patients, doctors should freely prescribe these pills without feeling they need to run a CAC test.
"Ask your physician if you need a heart scan before you start taking statins."
This research was led by Mark J. Pletcher, MD, MPH, Associate Professor in the Divisions of Epidemiology & Biostatistics and Medicine at the University of California, San Francisco.
The CAC test, which uses computed tomography (CT) scan technology, costs $200 to $400 per person. The test looks at calcifications (build-up of calcium that can block blood flow) along the arteries leading to the heart, and can predict if someone is likely to develop coronary heart disease. This test is sometimes used to see if a person should take statins or not.
Dr. Pletcher and colleagues created a statistical model (analysis applied to data used to verify assumptions) to predict if it made sense to do the scans on patients who need statins because their cholesterol is high.
These researchers used data from the Multi-Ethnic Study of Atherosclerosis and other sources. They modeled the effect of statin treatment on a baseline scenario of 10,000 55-year-old women with high cholesterol (total cholesterol 221 mg/dl and high-density lipoprotein 40 mg/dl) and no other coronary heart disease risk factors such as diabetes or smoking.
The researchers determined that if all the women took statins, the 10-year risk for a heart attack was 7.5 percent. That is, 32 heart attacks would be prevented if these women took statins. Taking statins would add 1,108 years to the cumulative life expectancy. However, 70 women would have statin-induced muscle disease.
Statins cost 13 cents a pill if patients fill their prescription at a large-scale discount retailer for $4 per month.
Since CAC is expensive, and there is a small risk of radiation-induced cancer associated with the procedure, the researchers determined it was not cost-effective to perform CAC on the average person. If taking statins cost $1 per pill or more, and if it reduced the patient’s quality of life, then routinely ordering CAC would make sense, they concluded.
Their findings are consistent with other studies that have come to the same conclusion.
The researchers noted limitations to their analysis, such as that the patients had moderately high cholesterol, and not low or very high cholesterol. “The decision to use a statin, however, is often difficult for clinicians and patients,” the study's authors wrote. “In these settings, the additional information about coronary heart disease risk that CAC testing provides can be worth the additional expense and radiation exposure that comes with the test.”
In an editorial in the same publication, Mark Hlatky, MD, Professor of Health Research & Policy at Stanford University in California, wrote that for someone who is low-risk for heart disease, neither statins nor CAC may be necessary. For someone who is high-risk, statins are probably a good idea, he wrote, and a CAC may be advisable if the patient is reluctant to take statins. It is the patient at intermediate risk who causes physicians to pause, wondering what is best.
Dr. Hlatky came to a similar conclusion as Dr. Pletcher and colleagues: “Whenever there is a treatment threshold, patient near that boundary might benefit from testing to guide choice of treatment," he wrote.
The study by Dr. Pletcher and team appeared online March 11 in Circulation: Cardiovascular Quality and Outcomes.
No conflicts of interest were declared.