Plaque Findings in Healthy Relatives of Patients With Early CAD

Study Questions:

Are there differences in plaque burden in healthy individuals who have first-degree relatives with early coronary artery disease (CAD)?

Methods:

This study examined 88 healthy first-degree relatives from 59 families with early-onset CAD in comparison to 88 age- and sex-matched controls with chest pain undergoing coronary computed tomography angiography (CCTA), and compared plaque burden and characteristics between groups using semi-automated plaque quantification software.

Results:

Mean age was 48 ± 8 years and 53% were male in each group. There were no significant differences in rates of tobacco use, diabetes, body mass index, or treatment for hypertension or hyperlipidemia. Relatives had a greater number of coronary segments with plaque than controls (0 segments: 30% vs. 49%; 1-2 segments: 27% vs. 32%; 3-4 segments: 18% vs. 6%; and ≥5 segments: 25% vs. 14%; p = 0.001). In comparison to controls, relatives had increased adjusted median total plaque volume (29 vs. 5 mm3, p < 0001), total plaque length (9 vs. 2 mm, p < 0.001), calcified plaque volume (3 vs. 1 mm3, p < 0.001), noncalcified plaque volume (26 vs. 4 mm3, p < 0.001), and low-density plaque volume (6 vs. 1 mm3, p < 0.001).

Conclusions:

First-degree healthy relatives of individuals with early-onset CAD have increased plaque burden in comparison to age- and gender-matched controls.

Perspective:

This study observes that otherwise healthy first-degree relatives of individuals with early-onset CAD have a markedly increased plaque burden, with an increased number of coronary segments with plaque, and an over five-fold increase in total plaque volume, noncalcified plaque volume, and low-density plaque volume compared to age- and gender-matched controls with chest pain undergoing CCTA. The lack of differences between groups in cardiovascular risk factors (including low-density lipoprotein levels) supports the use of family history as an important and independent risk factor for CAD. A full 70% of the relatives had coronary artery plaque (mostly nonobstructive), which would frequently not be identified by functional testing. It is unclear whether identification of coronary plaque in asymptomatic higher risk groups like this one changes treatment patterns or outcomes.

Keywords: Atherosclerosis, Body Mass Index, Cardiac Imaging Techniques, Chest Pain, Coronary Angiography, Coronary Artery Disease, Diabetes Mellitus, Hyperlipidemias, Hypertension, Lipoproteins, LDL, Myocardial Ischemia, Plaque, Atherosclerotic, Primary Prevention, Risk Factors, Tobacco Use, Tomography, X-Ray Computed


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