Silent Coronary Atherosclerosis Prevalent on CT Scans in Middle Age

Silent Coronary Atherosclerosis Prevalent on CT in Middle Age

Patrice Wendling

September 28, 2021

Four in 10 middle-aged individuals without a history of heart disease have silent coronary atherosclerosis and 1 in 20 have significant stenosis on coronary CT angiography (CCTA), Swedish researchers report.

“What’s important is that we actually looked at the atherosclerosis of the vessel wall with angiography and now have data on the extent and the severity of atherosclerosis in the general population,” lead author Göran Bergström, MD, PhD, University of Gothenburg, Sweden, told | Medscape Cardiology.

This baseline population-level information is a prerequisite for developing successful screening strategies in high-risk individuals, he said. Recent US guidelines suggest that a coronary artery calcium (CAC) score can be used to improve classification of adults at intermediate risk based on the pooled cohort equation (PCE), with a CAC score of 0 indicating lower risk and not favoring statin therapy.

CAC testing, however, doesn’t provide information on the degree of stenosis or the presence of noncalcified plaques, he noted. Significant atherosclerosis is also possible in the absence of CAC.

Indeed, among the 60% of participants with a 0 CAC score, 5.5% (4.3% of women and 7.3% of men) had CCTA-verified atherosclerosis, according to the study, published September 21 in the journal Circulation.

Defining the true prevalence of atherosclerosis in the general population is an essential first step to guide future prevention strategies, but prior estimates have been based on post-mortem evidence or small, selected populations or relied on CAC, Kuan Ken Lee, MBChB, University of Edinburgh, Scotland, and colleagues observe in an accompanying editorial.

“It is in this context that the findings of the Swedish CArdioPulmonary bioImage Study (SCAPIS) are particularly important,” the editorialists write.

The nationwide, multicenter SCAPIS study recruited 30,154 randomly invited adults aged 50-64 years without known coronary disease who underwent CCTA and CAC imaging based on previously detailed protocols between 2013 and 2018. The present analysis included 25,182 participants (50.6% women). The median age was 57.4, median effective radiation dose was 0.34 mSv from CAC and 1.33 mSv from CCTA imaging, and the median CAC score was 35.

In all, 42.1% of participants had any atherosclerosis on coronary CTA; 5.2% had significant (at least 50%) stenosis; 1.9% had severe disease involving the left main, proximal left anterior descending (LAD) artery, or all three vessels; and 8.3% had noncalcified plaques.