Noninvasive assessment of endothelial function and ST segment changes during exercise testing in coronary artery
G Chequer1, T P Navarro, B R Nascimento
1Serviço de Cardiologia e Cirurgica Cardiovascular, Hospital das Clínicas, Universidade Federal de Minas Gerais. grazichequerr@hotmail.com
Insights
Endothelial dysfunction is present in coronary artery disease (CAD) patients, regardless of lesion severity. Exercise ECG also showed differences, suggesting both endothelial function and exercise tests aid CAD assessment.
Area of Science:
- Cardiovascular Medicine
- Vascular Biology
- Diagnostic Cardiology
Background:
- Endothelial function (EF) is crucial in atherosclerosis development and progression.
- The precise relationship between EF and the presence/extent of coronary artery disease (CAD) requires further definition.
Purpose of the Study:
- To evaluate endothelial function and ST segment response during exercise testing in patients with varying degrees of CAD.
- To determine if EF and exercise test results correlate with CAD severity.
Main Methods:
- Sixty-two patients undergoing coronary angiography were categorized into three groups based on atherosclerotic lesion (AL) severity.
- Endothelial function was assessed using flow-mediated dilation (%FMD) of the brachial artery.
- Fifty-four patients underwent exercise electrocardiogram (ECG) testing.
Main Results:
- Endothelial dysfunction (%FMD reduction) was evident in CAD patients across all severity groups compared to controls.
- A higher incidence of ischemic ST segment alterations on exercise ECG was noted in patients with obstructive CAD (AL ≥70%).
- Both EF and exercise ECG results showed significant differences among the study groups.
Conclusions:
- Endothelial dysfunction is a common finding in patients with CAD, irrespective of lesion severity.
- Exercise ECG can identify ischemic changes, particularly in obstructive CAD.
- Combined assessment of EF and exercise ECG may offer complementary insights for CAD evaluation.
Abstract:
Endothelial function (EF) plays an important role in the onset and clinical course of atherosclerosis, although its relationship with the presence and extent of coronary artery disease (CAD) has not been well defined. We evaluated EF and the ST segment response to an exercise test in patients with a broad spectrum of CAD defined by coronary angiography. Sixty-two patients submitted to diagnostic catheterization for the evaluation of chest pain or ischemia in a provocative test were divided into three groups according to the presence and severity of atherosclerotic lesions (AL): group 1: normal coronaries (N = 19); group 2: CAD with AL <70% (N = 17); group 3: CAD with AL > or = 70% (N = 26). EF was evaluated by the percentage of flow-mediated dilatation (%FMD) in the brachial artery during reactive hyperemia induced by occlusion of the forearm with a pneumatic cuff for 5 min. Fifty-four patients were subjected to an exercise test. Gender and age were not significantly correlated with %FMD. EF was markedly reduced in both groups with CAD (76.5 and 73.1% vs 31.6% in group 1) and a higher frequency of ischemic alterations in the ST segment (70.8%) was observed in the group with obstructive CAD with AL > or = 70% during the exercise test. Endothelial dysfunction was observed in patients with CAD, irrespective of the severity of injury. A significantly higher frequency of ischemic alterations in the ST segment was observed in the group with obstructive CAD. EF and exercise ECG differed among the three groups and may provide complementary information for the assessment of CAD.
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