Miedema Authors New Paper on CAC Findings in Young Adults

Click on the link below to watch Dr. Miedema’s interview on #JNOLive with JAMA Network Open.

Study Shows Early Coronary Plaque is Common in Certain Young Adults and is Associated with Significantly Elevated Cardiovascular Risk

 Study reinforces the importance of healthy lifestyle habits throughout life and suggests measuring coronary artery calcium may have utility in certain young adults

Minneapolis – July 19th, 2019 – The Minneapolis Heart Institute Foundation® (MHIF) announced today the publication of research findings regarding measuring coronary artery calcium (CAC) in younger adults as a way to assess cardiovascular risk and thereby guide the intensity of preventive therapies. The data came from 22,346 individuals from the CAC Consortium, a multicenter retrospective cohort study of individuals undergoing CAC scores for clinical indications, who were aged 30-49 years at the time of CAC scoring. Surprisingly, approximately 1 in 3 individuals (34.4%) in this younger population was found to have calcified coronary artery plaque. Importantly, during the 12+ years of follow-up, individuals with significant plaque (CAC score > 100) had coronary heart disease death rates 10-times higher than those with zero CAC. Women were less likely to have plaque than men but had similarly elevated rates of cardiovascular death if they were found to have significant plaque. The study was published July 19th, 2019 as an Original Investigation in JAMA Open Network.

“The utility of CAC scoring in middle-aged individuals is relatively well established and is endorsed by the recent national cholesterol guidelines as a method to better assess risk in patients who are uncertain about treatment decisions, but utility of CAC testing in younger adults is much less clear.” said Michael Miedema, MD, MPH, director of Cardiovascular Prevention at the Minneapolis Heart Institute Foundation and first author of the study. “I think most physicians shy away from CAC testing in younger adults because they assume that nearly all young people will have zero CAC, but we found that one-third of our sample had evidence of premature atherosclerosis.”

Miedema clarified the importance of how this sample was identified, “It is really important to understand that this was a sample of individuals with clinical indications for CAC testing, mainly a strong family history of cardiovascular disease or high cholesterol. This was not a sample of the general population; these people were getting a CAC score for a reason, and that is likely why we found a higher prevalence of CAC than we expected.”

Dr. Miedema emphasized two main take-home points that clinicians and patients should understand:

“First and foremost, this data really reinforces the importance of adopting a healthy lifestyle early in life. We know that the process of building up plaque starts early in life. You shouldn’t wait until your 50 to start taking could good care of yourself.”

As for whether or not CAC testing should be used in younger adults, Miedema was less certain. “To take this study and say that we should now be doing CAC testing in all our patients in their 30’s and 40’s would be the wrong conclusion. However, for certain select younger adults who have cardiovascular risk factors and are uncertain if and how aggressively they should be treated, a CAC score may provide useful information.”

Current treatment guidelines are largely based on estimating the risk of future cardiovascular disease and are significantly influenced by older age.  Therefore, younger adults are often estimated to have low 10-year risk even if they have other risk factors and an elevated lifetime risk of cardiovascular disease. A more aggressive preventive treatment approach for these patients might suppress early atherosclerosis (build-up in the arteries) and lower future risk of heart disease. CAC is a direct marker of atherosclerosis and research is now documenting the utility of this testing for early detection of coronary heart disease.   CAC tests typically cost $100 and require a small dose of radiation, similar to a mammogram.