Social differences in subclinical coronary artery atherosclerosis in Sweden

Abstract Most data indicate an inverse relation between socioeconomic status and clinically manifest coronary heart disease that is only partly explained by modifiable cardiovascular risk factors. Few population-based studies have investigated social factors with respect to differences in subclinical coronary atherosclerosis in a healthy population without prior manifest coronary disease. Purpose To examine socioeconomic differences in imaging-detected coronary atherosclerosis, and to which extent potential differences could be explained by modifiable risk factors. Methods The Swedish CArdioPulmonary bioImage Study (SCAPIS) randomly invited individuals aged 50 to 64 years from the general population. Out of 30,154 participants, we defined a population of healthy participants without prior myocardial infarction or coronary procedures, with technically satisfactory results from coronary computed tomography angiography (CCTA) and coronary artery calcification scoring (CACs). CCTA outcomes were recorded as 1. any coronary atherosclerosis, 2. coronary stenosis ≥50%, 3. segment involvement score (SIS) ≥4, and 4. coronary artery calcium score (CACs) ≥100. Results Among 24,616 participants (49.2% women, mean age 57.4 (SD 4.2) years), those with ≤9 compared to ≥12 years of education were heavier, with mean (SD) BMI 28.0 (4.5) compared to 26.1 (4.0) kg/m2, with more hypertension (23.3% vs 15.0%), and diabetes (9.6% vs 4.6%), and with more active smokers (17.4% vs 3.8%). The prevalence of plaque/significant stenosis is shown in the Figure. Findings with respect to low vs high education and odds ratios (ORs) adjusted for age and sex were: 48.8% vs 35.3% for any coronary atherosclerosis, OR 1.31; 95%CI 1.19-14.4; 6.8% vs 4.4% for coronary stenosis ≥50%, OR 1.21; 95%CI 0.99-1.47; 15.7% vs 9.8% for SIS≥4, OR 1.21; 95% CI 0.99-1.47; and 10.1% vs 7.1% for CACS≥100, 1.29; 95%CI 1.12-1.48 (Table). However, after adjustment for coronary risk factors no significant associations with subclinical coronary atherosclerosis persisted. Conclusions After adjustment for conventional modifiable risk factors there was no convincing evidence of any independent association between low education and subclinical coronary atherosclerosis. Further studies are needed to explore which other mechanisms could potentially explain an independent link between low socioeconomic status and clinically manifest coronary heart disease.Figure