Study Evaluates Coronary Artery Calcium Score to Determine Patients Who Will Benefit From Statin

November 5, 2018—The Society of Cardiovascular Computed Tomography announced the publication of a large-scale study that reinforces previous findings that coronary artery calcium (CAC) scoring can identify, with a high degree of accuracy, patients who will or will not benefit from treatment with statins. The study is based on a large number of patients followed for nearly 10 years. The study by Joshua D. Mitchell, MD, et al is available online ahead of print in Journal of the American College of Cardiology.

The CAC score, which measures the amount of calcium in the walls of the arteries that supply the heart muscle, is determined by taking a noninvasive CT scan of the heart. Numerous studies have indicated that 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, noted the investigators.

As summarized by the SCCT, the retrospective study analyzed more than 13,500 patients who underwent CAC scoring at Walter Reed Army Medical Center in Bethesda, Maryland, from 2002 to 2009. Patients were followed for a median of 9.4 years. Comparing patients with and without statin exposure, the investigators found that statin therapy was associated with reduced risk of cardiovascular events (eg, heart attack, stroke, and heart failure) in patients who had CAC but not in patients who did not have CAC.

The study demonstrated that the benefit of statin to a patient is directly proportional to the presence and severity of CAC. The study also showed that a significant proportion of those who had no detectable CAC did not benefit from long-term statin use.

In the SCCT announcement, Harlan Krumholz, MD, stated, “This important study builds on prior literature and makes a strong case for the use of CAC scores to guide decisions about statins. 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.” Dr. Krumholz is a cardiologist and health care researcher at Yale University and Yale-New Haven Hospital in New Haven, Connecticut.

The investigators 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 investigators, these results also support the guidance of the 2017 SCCT consensus statement using a CAC threshold of 100 for treatment, although they recommend further studies to confirm these results. The statement was published by Harvey Hecht, MD, in Journal of Cardiovascular Computed Tomography (2017;11:157–168). Additionally, providers should consider the SCCT statement, along with the overall patient risk profile, in patient shared decision-making.