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Large artery stiffness predicts ischemic threshold in patients with coronary artery disease
Bronwyn A Kingwell1, Tamara K Waddell, Tanya L Medley
1Alfred and Baker Medical Unit, Baker Medical Research Institute, Prahran, Victoria, Australia. b.kingwell@alfred.org.au
Insights
Large artery stiffness significantly impacts exercise-induced myocardial ischemia in coronary artery disease (CAD) patients. Stiffer arteries lower the threshold for ischemia, highlighting their clinical relevance in managing CAD.
Area of Science:
- Cardiovascular Physiology
- Clinical Cardiology
- Biomedical Engineering
Background:
- Large artery stiffness is a key predictor of cardiovascular mortality.
- It influences pulse pressure, cardiac afterload, and coronary perfusion.
- The clinical relevance of arterial stiffening on myocardial ischemia was previously undemonstrated.
Purpose of the Study:
- To investigate if large artery stiffness contributes to exercise-induced myocardial ischemia in patients with coronary artery disease (CAD).
- To determine the relationship between arterial stiffness and the myocardial ischemic threshold.
Main Methods:
- Ninety-six patients with angiographically confirmed CAD underwent treadmill exercise testing.
- Arterial stiffness and compliance were measured at rest using carotid applanation tonometry and Doppler velocimetry.
- Myocardial ischemia was assessed by time to 0.15 mV ST-segment depression.
Main Results:
- All measured large artery stiffness and compliance indexes correlated with time to ischemia.
- Carotid and brachial pulse pressures inversely correlated with time to ischemia.
- Arterial stiffness indexes were independent predictors of ischemic threshold in multivariate analysis.
Conclusions:
- Large artery stiffness is a significant determinant of myocardial ischemic threshold in patients with moderate CAD.
- These findings underscore the importance of assessing arterial stiffness in CAD management.
Objectives:
The goal of this study was to determine whether large artery stiffness contributes to exercise-induced myocardial ischemia in patients with coronary artery disease (CAD).
Background:
Large artery stiffness is an independent predictor of cardiovascular mortality and a major determinant of pulse pressure and, thus, cardiac afterload and coronary perfusion. Clinical relevance of the hemodynamic consequences of large artery stiffening has not previously been demonstrated in relation to myocardial ischemia.
Methods:
We hypothesized that stiffer large arteries would reduce myocardial ischemic threshold as assessed by time to ST-segment depression of 0.15 mV during a treadmill exercise test in patients with CAD. Ninety-six patients with CAD (78 men) age 62 +/- 9 years (mean +/- SD) were classified as having single (52 patients), double (31 patients), or triple (13 patients) coronary vessel disease, based on angiographically confirmed stenoses >50%. Systemic arterial compliance, distensibility index, aortic pulse wave velocity, and carotid augmentation index were measured using carotid applanation tonometry and Doppler velocimetry of the ascending aorta, at rest.
Results:
In univariate analysis, all large artery stiffness/compliance indexes correlated with time to ischemia (p = 0.01 to 0.009). Both carotid (p = 0.007) and brachial (p = 0.001) pulse pressure also correlated inversely with time to ischemia. In multivariate analysis including other major risk factors plus severity of coronary stenosis, indexes of arterial stiffness were significant independent predictors of ischemic threshold.
Conclusions:
Within a patient group with moderate CAD, large artery stiffness was a major determinant of myocardial ischemic threshold.