Intra-brachial ergonovine, not acetylcholine, is associated with radial artery vasospasm in patients with coronary vasospasm.

BACKGROUND: The intracoronary provocation test is expensive and may cause complications. Therefore, we investigated the sensitivity, specificity and safety of different drug- and dose-peripheral artery provocation tests in the diagnosis of coronary artery spasm (CAS). METHODS: The patients who had repeated chest pain as well as both coronary and radial stenoses <50% were selected. These patients were divided into CAS group (n = 24) and control group (n = 33) after the intracoronary ergonovine provocation test. All patients underwent radial artery provocation tests at different dose-acetylcholine (200 µg, 400 µg and 800 µg) and ergonovine (60 µg, 100 µg and 160 µg). The predictive values of radial provocation tests for CAS diagnosis were analysed using receiver operator characteristic (ROC) curves. RESULTS: In radial acetylcholine provocation tests, 200 µg of acetylcholine failed to induce radial artery spasm, and the radial artery stenosis degree was not significantly different between the CAS group and control group at 400 µg and 800 µg of acetylcholine (all p > 0.05). In the radial artery ergonovine provocation tests, the radial artery stenosis degree was all significantly higher in the CAS group than in the control group at the three different doses (all p < 0.05). The specificity and sensitivity of radial ergonovine provocation tests were 90.91% and 50.00% at 60 µg, 96.97% and 66.67% at 100 µg, and 90.91% and 95.83% at 160 µg. Only the radial 160 µg-ergonovine provocation test caused CAS in one case. CONCLUSION: The radial acetylcholine provocation test has no diagnostic value for CAS. The radial 160 µg-ergonovine provocation test has higher sensitivity and specificity for CAS diagnosis, but its safety should be paid attention to.