A feasibility study has found that coronary artery calcium scanning has the potential to better target patients who truly need statin therapy, reduce unnecessary statin prescriptions, and improve medication adherence than the current standard of using pooled cohort equations to determine atherosclerotic cardiovascular disease risk.

Researchers at the University of Utah, Salt Lake City, and Intermountain Healthcare, a network of 25 hospitals in Utah, reported that the rate of statin usage in patients evaluated with coronary artery calcium (CAC) was 25% lower than in those whose treatment decisions were based on pooled cohort equations (PCE). None of the patients were on statin therapy when they enrolled in the study, published online in JACC: Cardiovascular Imaging.

“This study demonstrates that doing a large outcomes trial is feasible and has a reasonable likelihood of perhaps being a positive trial for the use of CAC,” lead author Joseph B. Muhlestein, MD, said in an interview. Muhlestein is codirector of cardiovascular research at Intermountain Healthcare and a professor at the University of Utah.

The findings address the 2018 American College of Cardiology/American Heart Association guideline that states PCE is the “single most robust tool for estimating 10-year risk in U.S. adults 40-75 years of age”. However, the guideline also bases statin determination on shared decision-making between the patient and physician, and recommends CAC for patients for whom a decision about statin treatment is uncertain and those at intermediate risk to fine-tune the need for statins.

The results also have spurred a larger randomized trial known as CorCal, which aims to enroll 5,500 patients and compare CAC and PCE, Muhlestein said. So far 3,000 patients have been enrolled.

Results of CAC vs. PCE

The feasibility study enrolled 601 patients randomized to CAC (302) or PCE (299), 504 of whom were included in the final analysis. In the CAC group, 35.9% went on statin therapy, compared with 47.9% of the PCE patients (P = .005). Participating physicians accepted the study-dictated recommendation to start a statin in 88.1% of patients in the CAC arm versus 75.0% in the PCE arm.

Muhlestein noted that the feasibility study did not evaluate key outcomes, such as stroke or heart attack, but they will be a key endpoint of the larger randomized trial. “We found in this feasibility study that the recommendations that come from the CAC arm, compared with the PCE arm are significantly different enough that there may be a different outcome,” he said.