Induction of coronary artery spasm by two pharmacological agents: comparison between intracoronary injection of acetylcholine and ergonovine

Background and objectives There have been few studies comparing the clinical usefulness for the induction of coronary artery spasm (CAS) between acetylcholine (ACh) and ergonovine (ER). This study is designed: (1) to examine the duration of effect after intracoronary injection of ACh on the responsible vessels using a 0.014 inch, 15 MHz Doppler guide wire, and (2) to evaluate the efficacy of two pharmacological agents, ACh and ER, for the induction of CAS in patients with < 50% stenosis in the cardiac laboratory. Methods Phasic coronary flow velocity patterns were recorded at rest and during ACh tests in 22 patients with normal or near-normal coronary arteries. The tip of the guide wire was placed on the proximal right coronary artery (RCA) and mid-left anterior descending artery. We measured the time required to baseline level of average peak velocity after intracoronary injection of ACh. We performed selective intracoronary administration of both ER and ACh in the same 171 patients (106 men, 65 women, mean age of 62 +/- 10 years) with < 50% stenosis. Under no medication, ACh was injected first in incremental doses of 20, 50, and 80 mug into the RCA and of 20, 50, and 100 mug into the left coronary artery (LCA). Ten minutes later, ER was administered at 10 mug/min for four minutes for a maximal dose of 40 mug on the RCA and at 16 mug/min over four minutes for a total dose of 64 mug on the LCA. Positive spasm was defined as greater than or equal to 99% luminal narrowing. Results The time-averaged peak velocity returned to baseline after intracoronary injection of ACh within 10 minutes in all 120 procedures, consisted of 19 with positive spasm (RCA (n = 10): 245 +/- 33 s; LCA (n = 9): 351 +/- 187 s) and 101 with negative spasm (RCA (n = 48): 155 +/- 62 s, LCA (n = 53): 248 +/- 106 s). In the overall results, there was no difference concerning the incidence of provoked spasm between the two pharmacological agents (ACh: 33% versus ER: 32%, NS). Coronary spasms were induced by either pharmacological agent in 134 vessels. Concordance in this study was 94% in all vessels, whereas the remaining 6% of vessels were different from each other. The non-concordance rate of the right coronary artery was significantly higher than that of the left coronary artery (10% versus 4%, p < 0.01). However, ER provoked more focal spasms, whereas ACh provoked more diffuse and distal spasms, compared with each other. Seventy-four (55%) of the 134 vessels had coronary spasms in the same coronary arteries. Concordance of both provoked spasm sites and spasm configurations in the same coronary artery was observed in only 18 (13%) vessels. No serious or irreversible complications were observed during the two sequential tests. Conclusions As a spasm provocation test, there were no differences between ACh and ER. We recommend the supplementary use of these two pharmacological agents for the induction of CAS in the cardiac laboratory, if available. (C) 2003 Lippincott Williams & Wilkins.