New study shows coronary artery calcium (CAC) scoring identiﬁes patients most likely as well as unlikely to beneﬁt from statins to prevent cardiovascular disease
Vienna, VA (Nov. 5, 2018) — A large-scale study published today in the Journal of the American College of Cardiology shows more clearly than before that coronary artery calcium (CAC) scoring can identify, with a high degree of accuracy, patients who will or will not benefit from statins. The study is based on a large number of patients followed for nearly 10 years.
A CAC score is a measurement of the amount of calcium, or hardening, in the walls of the arteries that supply the heart muscle, caused by atherosclerotic disease. It is measured by taking a noninvasive computed tomography (CT) scan of the heart. Numerous studies have indicated it is a reliable measure of risk for adverse heart events, such as heart attack and stroke. However, there has been previously little data assessing the impact of statins according to the results of CAC scoring.
The retrospective study looked at over 13,500 patients who underwent CAC scoring at Walter Reed Army Medical Center from 2002 to 2009 and followed them for a median of 9.4 years. Comparing patients with and without statin exposure, researchers found that statin therapy was associated with reduced risk of cardiovascular events (e.g., heart attack, stroke and heart failure) in patients who had CAC but not in patients who did not have CAC. It demonstrated that the benefit of statin to a patient is directly proportional to the presence and severity of CAC, a non-invasive measure of coronary atherosclerotic disease burden.
In other words, the presence or absence of CAC clearly identified patients who are most likely to benefit from statins. At the same time, the study showed that a significant proportion of those who had no detectable CAC, more popularly known as “power of zero” did not benefit from long-term statin use.
“This important study builds on prior literature and makes a strong case for the use of coronary artery calcium scores to guide decisions about statins,” said Harlan Krumholz, MD, a cardiologist and health care researcher at Yale University and Yale-New Haven Hospital and author of a regular blog on Forbes.com, who has studied and written about CAC scoring previously. “This simple, inexpensive test seems to identify those who have little to gain from statins. For people contemplating statins, it seems important to know whether you have a zero calcium score.”
The new study is from a multi-center author group, with Joshua D. Mitchell, MD of the Washington University School of Medicine in St. Louis and Todd C. Villines, MD, FACC, FAHA, FSCCT, of Walter Read National Military Medical Center who served as principle investigator, along with colleagues from Baylor College, Emory University Medical Center and others.
The authors concluded “In the absence of a large-scale randomized trial, the last set of cholesterol guidelines released in 2013 by the American College of Cardiology and the American Heart Association lowered the importance of CAC scoring as a decision aid in assessing patients’ risk factors to determine whether they should take statins. We hope these results will elevate CAC scoring as a key factor in risk assessment.”
According to the authors, these results also support the guidance of the recent Society of Cardiovascular Computed Tomography consensus statement using a CAC threshold of 100 for treatment, although they recommend further studies to confirm these results.
Providers should consider the Society of Cardiovascular Computed Tomography statement, along with the overall patient risk proﬁle, in patient shared decision making.