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Updated: Jun 30, 2025
Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders
Published on: August 18, 2016
Relation of Vasoreactivity in the Left and Right Coronary Arteries During Acetylcholine Spasm Provocation Testing
Yoshiyuki Okuya1, Yuichi Saito1, Hideki Kitahara1
1Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, Chiba, Japan.
Insights
The diagnosis of vasospastic angina (VSA) may not require acetylcholine provocation in both coronary arteries. Minimal left coronary artery constriction suggests right coronary artery testing might be omitted, aiding VSA diagnosis.
Area of Science:
- Cardiology
- Diagnostic Medicine
- Pharmacology
Background:
- Japanese guidelines recommend acetylcholine (ACh) provocation in both left (LCA) and right coronary arteries (RCA) for vasospastic angina (VSA) diagnosis.
- Global protocol variations often omit RCA testing, risking VSA underdiagnosis.
Purpose of the Study:
- To evaluate the validity of a left coronary artery (LCA)-only ACh provocation approach for VSA diagnosis.
- To determine if LCA vasoreactivity predicts the need for further RCA provocation.
Main Methods:
- 273 patients underwent sequential intracoronary ACh provocation in LCA and RCA.
- Patients with positive LCA ACh tests were excluded.
- Vasoreactivity in the LCA was correlated with RCA ACh test outcomes and adverse events.
Main Results:
- In patients with negative LCA ACh tests, 8.4% had positive RCA tests.
- LCA constriction <25% correlated with a 3.0% positive RCA test rate.
- LCA constriction 25%-90% correlated with a 13.5% positive RCA test rate (p=0.002).
- No major adverse events were observed during RCA ACh testing.
Conclusions:
- Omission of RCA ACh provocation may be acceptable for VSA diagnosis, especially with minimal LCA vasoconstriction.
- Further research is needed to standardize global ACh provocation protocols for VSA.
Abstract:
The diagnosis of vasospastic angina (VSA) according to Japanese guidelines involves an initial intracoronary acetylcholine (ACh) provocation test in the left coronary artery (LCA) followed by testing in the right coronary artery (RCA). However, global variations in test protocols often lead to the omission of ACh provocation in the RCA, potentially resulting in the underdiagnosis of VSA. This study assessed the validity of the LCA-only ACh provocation approach for the VSA diagnosis and whether vasoreactivity in the LCA aids in determining further provocation in the RCA. A total of 273 patients who underwent sequential intracoronary ACh provocation testing in the LCA and RCA were included. Patients with a positive ACh provocation test in the LCA were excluded. Relations between vasoreactivity in the LCA and ACh test outcomes (positivity and adverse events) in the RCA were evaluated. In patients with negative ACh test results in the LCA, subsequent ACh testing was positive in the RCA in 23 of 273 (8.4%) patients. In patients with minimal LCA vasoconstriction (<25%), only 3.0% had a positive ACh test in the RCA, whereas the ACh test in the RCA was positive in 13.5% of those with LCA constriction of 25% to 90% (p = 0.002). No major adverse events occurred during ACh testing in the RCA. In conclusion, for the VSA diagnosis, the omission of ACh provocation in the RCA may be clinically acceptable, particularly when vasoconstriction induced by ACh injection was minimal in the LCA. Further studies are needed to define ACh provocation protocols worldwide.
