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Published on: August 17, 2022
Attenuated systemic microvascular function in men with coronary artery disease is associated with angina but not
W David Strain1, Alun D Hughes, Jamil Mayet
1Institute of Biomedical and Clinical Science, NIHR Exeter Clinical Research Facility, University of Exeter Medical School, University of Exeter, Exeter, UK.
Insights
Men with coronary artery disease (CAD) show impaired microvascular function. This dysfunction is linked to refractory angina symptoms, not atherosclerosis, suggesting a key role in angina development.
Area of Science:
- Cardiology
- Vascular Biology
- Medical Research
Background:
- Refractory angina presents significant symptoms despite optimal medical treatment.
- Investigating microvascular function and atherosclerosis is crucial for understanding coronary artery disease (CAD).
Purpose of the Study:
- To examine the relationship between microvascular function, atherosclerotic burden, and clinical symptoms in patients with CAD.
- To compare microvascular responses in individuals with and without known CAD.
Main Methods:
- Assessed skin microvascular reactivity using laser Doppler fluximetry in 167 male volunteers (82 with CAD, 85 without).
- Measured coronary artery calcium (CAC) scores and carotid/femoral intima-media thickness (IMT).
- Quantified angina symptoms using the Rose angina questionnaire.
Main Results:
- Patients with CAD exhibited significantly poorer microvascular responses to heating and ischemia compared to controls.
- No correlation was found between markers of atherosclerosis (CAC, IMT) and microvascular function.
- Impaired microvascular function was observed in 42% of CAD patients with refractory angina, distinguishing them from those with high CAC but no symptoms.
Conclusions:
- Symptomatic CAD patients demonstrate reduced microvascular function relative to those without CAD.
- Microvascular dysfunction, rather than atherosclerosis, appears linked to refractory angina symptoms.
- These findings suggest microvascular dysfunction plays a critical role in the symptomatology of angina.
Introduction:
Refractory angina is the occurrence of clinical symptoms despite maximal therapy. We investigated associations between microvascular function, atherosclerotic burden, and clinical symptoms in subjects with CAD.
Methods:
Skin microvascular response to heating and ischemia was assessed in 167 male volunteers by laser Doppler fluximetry; 82 with CAD on maximal therapy and 85 with no known CAD (noCAD). CAC scores, carotid IMT, and femoral IMT were measured and symptoms were scored using the Rose angina questionnaire.
Results:
Patients with CAD had poorer microvascular response to heating (114[95% CI 106-122]au CAD vs. 143[134-153]au no CAD; p < 0.0001) and ischemia (42[38-46]au CAD vs. 53[78-58]au. noCAD; p = 0.001). Thirty-eight percent of the noCAD group had elevated CAC scores. There were no associations between markers of atherosclerosis and microvascular function. Forty-two percent of the CAD group had refractory angina. This was associated with impaired microvascular function compared to those with elevated CAC scores but no symptoms (109 [95-124]au vs. 131[122-140]au; p = 0.008).
Conclusions:
Men with symptomatic CAD have poorer microvascular function compared to individuals without CAD. Microvascular function does not correlate with atherosclerosis, but is impaired in individuals with refractory angina. Microvascular dysfunction may play a role in the symptomatology of angina.
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