Reactivity of proximal and distal angiographically normal and stenotic coronary segments in chronic stable angina pectoris

Abstract

To assess whether vasoreactivity of significant coronary stenosis (>5O% intraluminal diameter reduction) and that of angiographically normal coronary segments differs in proximal and distal locations, S3 patients (40 men, 13 women, mean ± standard deviation age SS ± 11 years) with chronic stable angina and angiographically documented coronary artery disease were studied. While abstaining from antianginal therapy, all 53 patients underwent coronary arteriography before and after 1 mg of intracoronary isosorbide dinitrate and 21 of the S3 also before and after 20 to 30 μg intracoronary ergonovine. Computerized quantitative angiography was used to assess changes in the intraluminal diameter of 126 normal coronary segments (63 proximal, 63 distal) and 43 significant coronary stenoses. Nitrates dilated proximal normal coronary segments by 7.4 ± 1.2% and distal normal coronary segments by IS ± 1.7% (p < 0.01). Significant proximal coronary stenoses dilated by 11 ± 2.S% and distal stenoses by 23 ± 2.8% (p < 0.01) after nitrates. Ergonovine reduced the diameter of proximal normal coronary segments by 9.3 ± 1.7% and that of normal distal segments by 15.5 ± 1.4% (p < 0.01). Proximal stenoses constricted by 11 ± 2.2% and distal stenoses by 18.4 ± 2.8% (p = 0.06). Analysis of segments showed that nitrates dilated 19 of 63 (30%) proximal normal segments (by ≥ 10%), 31 of 63 (49%) distal (p <O.O5) and 21 of 43 (49%) stenoses. Ergonovine constricted (by ≥10%) IS of 37 (41%) proximal normal segments, 27 of 37 (73%) distal (p < 0.01) and 13 of 22 (5g9%) significant stenoses. These findings indicate that distal normal coronary segments have greater reactivity to nitrates and to ergonovine than proximal segments. Stenosis reactivity parallels that of angiographically normal segments.