Study Finds Cost-effectiveness of Coronary Artery Calcium Screening Highly Dependent on Cost of Statins

Research Triangle Park, N.C. – As long as statins, a class of cholesterol-lowering drugs, remain inexpensive and don’t affect the patient’s quality of life, it is better to simply prescribe the drugs before ordering a heart scan, finds a new study by researchers at University of California at San Francisco; RTI Health Solutions, a business unit of RTI International; University of North Carolina at Chapel Hill; and Northwestern University.

The study, published online this month in Circulation Cardiovascular Quality and Outcomes, emphasizes the importance of considering patient preferences for quality of life and costs when making medical decisions regarding statins and coronary artery calcium (CAC) testing. It also highlights the complications in choosing the best care for patients amongst the proliferation of modern tests and treatments and answers the question relevant to all diseases and specialties: To test or not to test? 

“The results of our research seem to refute conventional wisdom that tests like the CAC scan, which is known to accurately predict heart attacks, will independently yield better outcomes if used,” said Stephanie Earnshaw, Ph.D., a risk management scientist at RTI and co-author of the paper. “Our research showed that the effectiveness of the CAC test is highly dependent on the cost of statins. When statin prices were low (around 13 cents a pill) and did not reduce patients’ quality of life, a CAC test was not cost-effective. However, when the price of the pill was expensive ($1 or more) or if taking the statin reduced quality of life, then CAC testing became cost-effective.”

The researchers created a cost-effectiveness model to predict whether or not it made sense to do a CAC test, a CT scan that measures how much plaque has built up in a patient’s coronary arteries. The model used data from the Multi-Ethnic Study of Atherosclerosis and other sources. 

After modeling the effects of statin treatment in 10,000 55-year-old women with high cholesterol, the results showed that statin therapy alone would prevent 32 heart attacks and add 1,108 years to their cumulative life expectancy.

The researchers found that preceding statin therapy with a CAC test would save money on statin costs and expose fewer women to the side effects of the drug, but it would not prevent as many heart attacks, add only 501 years to their cumulative life expectancy, and bring additional risk to patients, namely exposure to low-dose radiation when compared with just treating all women with statins. 

A parallel analysis for 55-year-old men with coronary heart disease yielded similar results with nearly identical incremental cost-effectiveness ratios. The researchers also tested whether changing several other model inputs would create a difference, but the only critical factors turned out to be the cost of statins and the degree to which they affected the patient’s quality of life.