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Effect of basal epicardial tone on endothelium-independent coronary flow reserve measurement
D Hasdai1, D R Holmes, S T Higano
1Division of Internal Medicine and Cardiovascular Diseases, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
Insights
Basal epicardial tone does not influence coronary flow reserve (CFR) measurements in patients with nonobstructive coronary disease. This study found no significant impact of epicardial tone on endothelium-independent CFR assessments.
Area of Science:
- Cardiology
- Vascular Physiology
Background:
- Increased basal epicardial tone may potentially affect coronary flow reserve (CFR) by influencing resistance vessels.
- Understanding factors influencing CFR is crucial for diagnosing and managing coronary artery disease.
Purpose of the Study:
- To investigate the impact of basal epicardial tone on endothelium-independent CFR measurements.
- To determine if basal epicardial tone affects CFR assessments in patients with nonobstructive coronary artery disease.
Main Methods:
- Patients with nonobstructive coronary disease underwent CFR evaluation using intracoronary adenosine.
- CFR was measured at baseline and after administration of intracoronary nitroglycerin to assess epicardial tone.
- Coronary artery diameter and vascular resistance were analyzed post-nitroglycerin.
Main Results:
- Nitroglycerin administration significantly increased coronary artery diameter and decreased coronary vascular resistance.
- The CFR response to adenosine was similar at baseline and after nitroglycerin administration.
- No correlation was found between the effect of nitroglycerin on CFR and coronary endothelial function.
Conclusions:
- Basal epicardial tone does not significantly affect endothelium-independent CFR measurements in patients with angina and nonobstructive coronary disease.
- These findings suggest that CFR assessments using adenosine are reliable in this patient population, irrespective of basal epicardial tone.
Abstract:
Increased basal epicardial tone may attenuate the coronary flow reserve (CFR) by causing vasodilatation of resistance vessels. We examined the effect of basal epicardial tone on the endothelium-independent CFR measurements in subjects with nonobstructive coronary disease. Patients underwent evaluation of endothelium-independent CFR using adenosine (18-36 microg) and endothelium-dependent CFR using acetylcholine (10(-6) M-10(-4) M), both administered intracoronary. CFR to adenosine, presented as the ratio of Doppler flow velocities post- and pre-adenosine, was measured at baseline and after intracoronary nitroglycerin (200 microg). Nitroglycerin increased the coronary artery diameter by 19.7 +/- 2.5%, and decreased the coronary vascular resistance from 3.0 +/- 0.2 mm Hg/ml/min to 1.8 +/- 0.1 mm Hg/ml/min (p < 0.0001). The response to adenosine at baseline and after nitroglycerin was similar (CFR ratio of 2.52 +/- 0.09 and 2.57 +/- 0.10, respectively, p = NS). The effect of nitroglycerin on the response to adenosine did not correlate with coronary endothelial function (r2 = 0.06, p = 0.13). The basal epicardial tone does not affect CFR measurements in patients with angina and nonobstructive coronary disease.