CHICAGO – Coronary artery calcium testing has established itself as a true “game changer” in primary cardiovascular prevention, proponents of the risk-stratification tool said at the American Heart Association scientific sessions.
Knowing a patient’s coronary artery calcium score facilitates a more informed physician-patient discussion and shared decision making regarding whether to go on decades-long statin therapy, according to Dr. Khurram Nasir of the center for prevention and wellness research at Baptist Health Medical Center in Miami Beach.
Dr. Khurram Nasir
“In our view, a much underappreciated value of coronary artery calcium testing lies in the power of zero. Roughly half of adults have a coronary artery calcium score of 0, and this results in a very low cardiovascular event rate,” the cardiologist said.
He presented an analysis of 4,758 nondiabetic participants in the prospective, population-based MESA (Multi-Ethnic Study of Atherosclerosis) in which he examined how they fared in terms of cardiovascular events over a median 10.3 years of follow-up. All were free of known cardiovascular disease at baseline. With the risk estimator included in the 2013 AHA/ACC cholesterol management guidelines, 2,377 subjects would be recommended for high-intensity statin therapy at baseline on the basis of a 10-year atherosclerotic cardiovascular disease risk estimate of at least 7.5%. Another 589 participants were recommended for consideration of a moderate-intensity statin based on an estimated 10-year risk of 5%-7.4%.
Forty-one percent of MESA subjects recommended for a high-intensity statin according to the AHA/ACC risk estimator had a coronary artery calcium (CAC) score of 0, and their 10-year composite rate of MI, stroke, or cardiovascular death was just 4.9% – well below the 7.5% threshold recommended for statin therapy. In contrast, if any CAC was present, the event rate was 10.5%.