South Asian men have different patterns of coronary artery disease when compared with European men Therese Tillin a, ⁎ , Harshil Dhutia a , John Chambers a , Iqbal Malik a , Emma Coady a , Jamil Mayet a , Andrew R. Wright a , Jaspal Kooner a , Angela Shore b , Simon Thom a , Nish Chaturvedi a , Alun Hughes a a International Centre for Circulatory Health, St Mary's Hospital, Hammersmith Hospital and Imperial College, 59 North Wharf Road, London W2 1LA, UK b Institute of Biomedical & Clinical Science, Peninsula Medical School, Exeter, UK Received 28 March 2007; received in revised form 6 June 2007; accepted 7 July 2007 Available online 26 November 2007 Abstract Background: To compare patterns of coronary artery disease in British South Asian and White European men. Methods: 41 South Asian and 42 European men (mean age 64 ± 9 years) with coronary artery disease were studied. All had similar symptoms. Vessel reference diameter and degree of stenosis were calculated using quantitative coronary angiography. Extent of atherosclerotic disease in the LAD was assessed using calcification scores (CAC) measured by multislice Computed Tomography. Fasting bloods and blood pressure were measured. The LAD was subdivided into four 2.5 cm segments for analysis. Results: Most atherosclerosis occurred in the proximal LAD segment, South Asian men had more proximal LAD stenosis than European men (50% vs. 37%, p =0.036), but CAC scores were similar. South Asians with CAC scores in the lowest tertile (0–22 HU), had significantly narrower LAD diameters than Europeans (2.8 mm vs. 3.8 mm, p = 0.004, adjusted for body surface area and age). This ethnic difference was not explained by measured risk factors, including diabetes. In contrast, ethnic differences in LAD diameter were abolished in the upper tertiles of CAC scores (23–2416 HU) (South Asians: 3.0 mm, Europeans: 3.1 mm, p = 0.6). Calcification scores were negatively correlated with LAD diameter in Europeans (rho = - 0.38, p = 0.016) but not in South Asians (rho = - 0.06, p = 0.72). Conclusions: Increased LAD stenosis, despite equivalent levels of calcified disease, in South Asians is attributable to narrower arteries. Reduced LAD diameter is associated with advanced disease in Europeans but not in South Asians, indicative of ethnic differences in vascular remodelling. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: South Asian; Atherosclerosis; Coronary artery disease; Coronary calcification; Vascular remodelling 1. Introduction People of South Asian descent worldwide have markedly elevated rates of coronary artery disease (CAD) compared with European origin populations [1–5]. Unfavourable risk factors, such as diabetes and dyslipidaemia, may account for only part of this elevated risk. In addition, although in- hospital death rates may be declining in parallel with those of European origin populations [6], risk of subsequent death and re-infarction remains greater in British South Asians post infarct [7,8], and South Asians have higher risk of mortality following coronary artery bypass grafting [9,10]. These observations are unexplained but may be due to adverse local patterns of atherosclerosis itself, or vessel responses to atheroma. In support of this hypothesis, South Asians in the UK have been reported to have a more proximal distribution of angiographic CAD in association with longer lesions than Caucasians [11]. In addition, a number of studies suggest that South Asians have smaller coronary arteries than Europeans, although some, but not all, report that the difference is explained by smaller body size [12–16]. However, it is not International Journal of Cardiology 129 (2008) 406 – 413 www.elsevier.com/locate/ijcard ⁎ Corresponding author. Tel.: +44 20 75943396; fax: +44 20 7594 3392. E-mail address: t.tillin@imperial.ac.uk (T. Tillin). 0167-5273/$ - see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.07.129