Do Indo-Asians have smaller coronary arteries?

There is a widespread belief that coronary arteries are smaller in Indo-Asi ans. The aim of the present study was to compare the size of atheroma-free proximal and distal epicardial coronary arteries of Indo-Asians and Caucasi ans. We analysed normal coronary angiograms from 77 Caucasians and 39 Indo- Asians. The two groups were comparable for dominance of the coronary arteri es. Indo-Asian patients had generally smaller coronary arteries, with a sta tistically significant difference in the mean diameters of the left main co ronary artery, proximal, mid and left anterior descending, and proximal and distal right coronary artery segments. There was a non-significant trend t owards smaller coronary artery segment diameters for the distal left anteri or descending, proximal and distal circumflex, and obtuse marginal artery s egments. However, after correction for body surface area, none of these dif ferences in size were statistically significant. Thus, the smaller coronary arteries in Indo-Asian patients were explained by body size alone and were not due to ethnic origin per se. This finding nevertheless has important t herapeutic implications, since smaller coronary arteries may give rise to t echnical difficulties during bypass graft and intervention procedures such as percutaneous transluminal coronary angioplasty, stents and atherectomy. On smaller arteries, atheroma may also give an impression of more severe di sease than on larger diameter arteries.