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Updated: Sep 9, 2025

Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders
06:39

Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders

Published on: August 18, 2016

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Clinical Characteristics and Outcomes of Patients with a Positive Finding for the Coronary Spasm Provocation Test at

Hiroki Kuji1,2, Yuichi Saito1, Shota Kuranaga3

  • 1Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, Japan.

Internal Medicine (Tokyo, Japan)
|September 3, 2025
PubMed

Insights

The intracoronary acetylcholine (ACh) provocation test diagnoses coronary spastic angina (CSA). A low-dose positive response may indicate distinct mechanisms and outcomes compared to high-dose responses in CSA patients.

Area of Science:

  • Cardiology
  • Diagnostic Testing
  • Vascular Medicine

Background:

  • The intracoronary acetylcholine (ACh) provocation test is the standard invasive method for diagnosing coronary spastic angina (CSA).
  • Current guidelines recommend incremental ACh doses, but the clinical significance of positive responses at lower doses remains unclear.

Purpose of the Study:

  • To investigate the clinical relevance and outcomes of low-dose versus high-dose positive results in the intracoronary ACh provocation test for diagnosing CSA.
  • To compare intraprocedural adverse events and long-term clinical outcomes between patients with low-dose and high-dose positive ACh test results.

Main Methods:

  • A retrospective analysis of 636 patients with suspected CSA undergoing intracoronary ACh provocation testing.
  • Patients with positive ACh tests were categorized into 'low-dose positive' (positive at initial dose) and 'high-dose positive' (requiring higher doses).
  • Comparison of baseline characteristics, procedural events, and long-term outcomes between the two positive groups.

Main Results:

  • Out of 636 patients, 4.1% were low-dose positive and 47.8% were high-dose positive for CSA.
  • The low-dose positive group showed a higher incidence of ST-segment elevation during testing and unstable angina during follow-up compared to the high-dose positive group.
  • Despite differing event frequencies, overall long-term clinical outcomes were similar between the low-dose and high-dose positive groups.

Conclusions:

  • Approximately 10% of CSA diagnoses via ACh testing occur at low doses, suggesting a potential subgroup with unique characteristics.
  • The dose-dependent response in ACh testing may reflect distinct underlying pathophysiological mechanisms in CSA.
  • Further research is warranted to elucidate the specific mechanisms and refine management strategies for low-dose positive CSA patients.

Keywords:
acetylcholine provocationoutcomevasospastic angina

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