ENDOTHELIAL DYSFUNCTION OF THE NONINFARCT RELATED, ANGIOGRAPHICALLY NORMAL, CORONARY-ARTERY IN PATIENTS WITH AN ACUTE MYOCARDIAL-INFARCTION

Background Patients with acute myocardial infarction and single-vessel disease may have early atherosclerosis in other angiographically norm al coronary arteries. Methods Coronary endothelial responses were anal ysed in 20 non-diabetic patients with an acute myocardial infarction a nd one-vessel disease. In an angiographically normal, non-infarct rela ted, coronary artery serial acetylcholine doses of 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M and nitroglycerin 40 mu g were infused over 3 m in. The responses of the coronary vessel were measured with quantitati ve angiography. Coronary blood flow was also measured with a Doppler c atheter in 11 of the 20 patients. Results Four patients showed a trend towards vasodilation during acetylcholine infusion in the proximal an d distal segments: from 2.49 +/- 0.23 mm to 2.95 +/- 0.42 mm and 2.43 +/- 0.56 mm to 2.81 +/- 0.66 mm, respectively. Coronary vascular resis tance decreased to 57 +/- 4% (P=0.03). The other 16 patients presented vasoconstriction in the proximal and distal segments: 2.61 +/- 0.75 m m to 2.03 +/- 0.65 mm (P=0.0001), and 2.40 +/- 0.58 to 1.81 +/- 0.56 m m (P=0.0036), respectively. Nitroglycerin caused vasodilation in the p roximal (2.69 +/- 0.61mm, P=0.017, ANOVA) and distal segments (2.48 +/ - 0.45 mm, P=0.009, ANOVA). Coronary vascular resistance increased to 141 +/- 43% (P=0.03) over the basal value in this group of patients. C onclusion Endothelial dysfunction of the epicardial and resistance ves sels was found in angiographically normal coronary arteries of patient s with one-vessel disease in 75% of this population.