Coronary flow reserve in angiographically normal coronary arteries with one-vessel coronary artery disease without traditional risk factors

Abstract

Aims: Reduced coronary flow reserve has been reported in patients with traditional risk factors, in particular hyperlipidaemia, despite angiographically normal coronary arteries. However, it is recognized that traditional risk factors do not explain the presence of coronary atherosclerosis in a large proportion of patients. The aim of this study was to assess whether coronary flow reserve is preserved in the myocardium supplied by normal coronary arteries in patients with one-vessel coronary artery disease without traditional risk factors. Methods and Results: Positron emission tomography using [13N]ammonia was performed at baseline and after intravenous dipyridamole administration (0.56 mg . dl-1 over 4 min) in 30 subjects: six patients with ischaemia on effort, no myocardial infarction, and isolated left anterior descending coronary artery stenosis without traditional risk factors (coronary artery disease patients without risk factors, aged 59 ± 13), five patients with ischaemia on effort, no myocardial infarction, and isolated left anterior descending coronary artery stenosis with multiple risk factors (coronary artery disease patients with risk factors, aged 69 ± 7), 11 age-matched controls (aged 58 ± 6). and eight healthy young volunteers (aged 34 ± 4). Myocardial blood flow calculated in the myocardium supplied by normal coronary arteries in the coronary artery disease patients was compared with those of the two control groups. Coronary flow reserve was defined as the ratio of hyperaemic blood flow after dipyridamole infusion to baseline blood flow. Although coronary flow reserve in the coronary artery disease patients with risk factors was significantly lower than that in the age-matched controls (1.62 ± 0.37, 2.58 ± 0.71, P=0.0428), coronary flow reserve in the coronary artery disease patients without risk factors was similar to that in the age-matched controls (2.54 ± 0.17 vs 2.58 ± 0.71, P=ns). Conclusion: Coronary flow reserve is preserved in regions supplied by angiographically normal coronary arteries with one-vessel coronary artery disease without traditional risk factors. © 2001 The European Society of Cardiology.