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Updated: Mar 7, 2026
Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders
Published on: August 18, 2016
Acetylcholine versus cold pressor testing for evaluation of coronary endothelial function
Ahmed AlBadri1, Janet Wei1, Puja K Mehta1
1Cedars-Sinai Heart Institute, Los Angeles, California, United States of America.
Insights
Cold pressor testing (CPT) shows moderate correlation with intracoronary acetylcholine (IC-Ach) for assessing coronary artery diameter changes in women with suspected coronary microvascular dysfunction (CMD). CPT may aid in evaluating endothelial function but is not a replacement for IC-Ach.
Area of Science:
- Cardiology
- Vascular Biology
- Diagnostic Testing
Background:
- Intracoronary acetylcholine (IC-Ach) assesses coronary endothelial function but is often impractical.
- Cold pressor testing (CPT) is a simpler alternative for endothelial function and perfusion imaging.
- CPT has not been evaluated in symptomatic women with non-obstructive coronary artery disease (CAD) and suspected coronary microvascular dysfunction (CMD).
Purpose of the Study:
- To evaluate the utility of CPT in assessing coronary endothelial function in women with suspected CMD.
- To compare the effects of CPT and IC-Ach on coronary artery diameter and blood flow in this patient group.
Main Methods:
- 163 women with suspected CMD and no obstructive CAD underwent coronary reactivity testing.
- Doppler flow wire assessed coronary artery diameter and coronary blood flow (CBF) in the left anterior descending artery.
- Measurements were taken at baseline, during IC-Ach infusion, and during CPT.
Main Results:
- Coronary artery diameter changes with IC-Ach and CPT were moderately correlated (r=0.59, P<0.001).
- The correlation was stronger in subjects with normal endothelial response to IC-Ach.
- CPT increased rate pressure product, while IC-Ach did not significantly alter it.
Conclusions:
- CPT shows moderate correlation with IC-Ach for coronary diameter changes in women with suspected CMD.
- CPT may be useful, especially in patients with normal endothelial function.
- CPT is not a substitute for IC-Ach in diagnosing coronary endothelial dysfunction.
Background:
Assessment of coronary endothelial function with intracoronary acetylcholine (IC-Ach) provides diagnostic and prognostic data in patients with suspected coronary microvascular dysfunction (CMD), but is often not feasible due in part to the time and expertise needed for pharmacologic mixing. Cold pressor testing (CPT) is a simple and safe stimulus useful for either invasive or non-invasive endothelial function testing and myocardial perfusion imaging but has not been specifically evaluated among symptomatic women with signs of ischemic heart disease (IHD) who have no obstructive coronary artery disease (CAD).
Methods:
163 women with signs and symptoms of IHD and no obstructive CAD from the NHLBI- Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) study underwent coronary reactivity testing with a Doppler flow wire (FloWire® Volcano, San Diego, CA) in the proximal left anterior descending artery. Coronary artery diameter and coronary blood flow (CBF) assessed by core lab using QCA before and after IC-Ach (18.2 μg/ml infused over 3 minutes) and during CPT.
Results:
Mean age was 55 ± 12 years. Rate pressure product (RPP) in response to IC-Ach did not change (baseline to peak, P = 0.26), but increased during CPT (363±1457; P = 0.0028). CBF in response to CPT was poorly correlated to IC-Ach CBF. Change in coronary artery diameter after IC-Ach correlated with change after CPT (r = 0.59, P<0.001). The correlation coefficient was stronger in subjects with coronary dilation to IC-Ach (r = 0.628, P<0.001) versus those without dilation (r = 0.353, P = 0.002), suggesting that other factors may be important to this relationship when endothelium is abnormal.
Conclusions:
In women with no obstructive CAD and suspected CMD, coronary diameter changes with IC-Ach and CPT are moderately-well correlated suggesting that CPT testing may be of some use, particularly among patients with normal endothelial function, however, not an alternative to IC-Ach for diagnosis of coronary endothelial dysfunction.
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