Intracoronary ergonovine caused localized coronary spasm with an 87.8% diameter reduction in patients with variant angina, compared to a 16.2% reduction in patients with atypical chest pain.
Does intracoronary ergonovine induce coronary artery spasm by a direct local action in patients with variant angina?
Intracoronary ergonovine induces coronary artery spasm through a direct local effect caused by localized arterial hyperreactivity, suggesting it may be a safe and effective diagnostic tool for variant angina.
Absolute Event Rate: 87.8% vs 16.2%
To investigate whether ergonovine acts directly on coronary arteries or via remote neurohumoral reflexes, we administered small titrated increments of intracoronary ergonovine up to a maximum cumulative dose of 50 micrograms to 15 patients. In six patients with variant angina (group 1), ischemic electrocardiographic ST changes, angina, and localized coronary spasm (local coronary diameter reduction of 87.8 +/- 18.9% mean +/- SD) followed after 6 to 50 micrograms (mean 20.7) cumulative intracoronary ergonovine. In nine patients with atypical chest pain, normal baseline coronary arteriograms, and no evidence of variant angina (group 2), there was no ischemic ST segment change or localized coronary spasm after 6 to 50 micrograms (mean 31.6) intracoronary ergonovine. Coronary diameter of proximal vessels of patients in group 2 was reduced by 16.2 +/- 6.5% and did not differ from the response of nonspastic vessels of comparable size of group 1 (20.5 +/- 13.8%; p = .7). There was no significant difference in the median effective dose values in the dose-response curves of the spastic and nonspastic segments between groups 1 and 2. Ergonovine causes coronary spasm by a direct local effect, which seems to be caused by localized arterial hyperreactivity rather than supersensitivity. Intracoronary delivery may be safer than intravenous administration because negligible drug recirculation may prevent perpetuation of spasm and selective coronary administration can avoid branches with critical stenoses.
Hackett et al. (Sun,) conducted a other in Variant angina and atypical chest pain (n=15). Intracoronary ergonovine vs. Patients with atypical chest pain (Group 2) was evaluated on Coronary diameter reduction. Intracoronary ergonovine caused localized coronary spasm with an 87.8% diameter reduction in patients with variant angina, compared to a 16.2% reduction in patients with atypical chest pain.