Does subclinical atherosclerosis burden identify the increased risk of cardiovascular disease mortality among United Kingdom Indian Asians? A population study

Abstract

Indian Asians living in the United Kingdom have a >50% higher risk of cardiovascular disease (CVD) death compared with native European whites. The mechanisms underlying their excess mortality are not clear, and there are no validated tools capable of identifying this increased risk. The burden of subclinical atherosclerosis detected in the carotid arteries is an established prognosticator for major CVD events. We hypothesized that the increased prevalence of CVD among Indian Asians would be reflected by their having a greater burden of subclinical carotid artery atherosclerosis compared with European whites. We studied 2,288 healthy subjects and 148 patients with known CVD from the London Life Sciences Prospective Population study who underwent carotid ultrasonography for assessment of intima-media thickness (IMT), plaque prevalence, and plaque echogenicity. The prevalence of CVD was significantly higher among Indian Asians compared with European whites (odds ratio 1.72, 95% CI 1.2-2.3). Intima-media thickness was slightly higher in European whites compared with that of Indian Asians (0.66 vs 0.65 mm, P = .06), reflecting their higher Framingham Risk Score. After adjustment for cardiovascular risk factors, there were no significant differences in IMT, plaque prevalence, or plaque echogenicity between the 2 ethnic groups regardless of CVD status. The burden of carotid atherosclerosis does not identify the markedly increased risk of CVD among United Kingdom Indian Asians. Other markers and mechanisms of disease require investigation in this high-risk group.