There are few reports regarding the concordance of coronary arterial response between acetylcholine (ACh) and ergonovine (ER) spasm provocation tests.
We attempted to perform selective spasm provocation tests to examine the incidence of provoked spasm in patients who had undergone first coronary angiography as much as possible and we compared the coronary arterial response and clinical usefulness between selective intracoronary injection of ACh and intracoronary administration of ER.
We performed 1508 selective spasm provocation tests, consisting of 873 ACh tests and 635 ER tests, from 1991 to 2002. We examined the frequency of provoked spasms of each agent retrospectively. ACh was injected in incremental doses of 20, 50 and 80 μg into the right coronary artery and 20, 50 and 100 μg into the left coronary artery. ER was administered as 10 μg/min over 4 min for a maximal dose of 40 μg in the right coronary artery and as 16 μg/min over 4 min for a total dose of 64 μg in the left coronary artery. Coronary spasm was defined as transient >99% luminal narrowing.
Intracoronary ACh provoked spasms in 36.0% of patients and intracoronary ER induced spasms in 29.8% of patients. In patients with ischemic heart disease, the incidence of provoked spasms was not different between ACh tests (50.9%) and ER tests (43.8%). In contrast, the frequency of provoked spasms with ACh tests was significantly higher than that with ER tests (11.0% compared with 6.4%, P<0.05) in patients without ischemic heart disease. Moreover, ACh provoked more spasms in patients without fixed stenosis than ER (36.2% compared with 25.5%, P<0.01) and multiple spasms were frequently observed when performing ACh tests (40.0% compared with 27.0%, P<0.01). Major complications were observed in 1.4% of patients with ACh tests and in 0.2% of patients with ER tests. The need for intracoronary administration of isosorbide dinitrate to relieve coronary spasms during ER testing before performing another coronary artery test was more frequently observed in ACh tests (5.04% compared with 1.49%, P<0.01). However, no serious irreversible complications, such as death or acute myocardial infarction, were observed in this study. There was a significant difference in sex, history of smoking and hyperlipidemia between patients with and without spasms for both tests, whereas no difference in age or hypertension was observed in either test.
Thus, both selective ACh and ER tests were useful as spasm provocation tests.