Background: High aortic stiffness may reduce myocardial perfusion pressure and contribute to development of myocardial ischemia. Whether high aortic stiffness is associated with myocardial ischemia in patients with stable angina and non-obstructive coronary artery disease (CAD) is less explored.
Purpose: Assess if high aortic stiffness is associated with myocardial ischemia in patients with stable angina and non-obstructive CAD.
Methods: We assessed aortic stiffness as carotid-femoral pulse wave velocity (PWV) by applanation tonometry in 125 patients (62±8 years, 58% women) with stable angina and non-obstructive CAD participating in the Myocardial Ischemia in Non-obstructive CAD (MicroCAD) project. Non-obstructive CAD and coronary calcium score were assessed by coronary computer tomography angiography. Patients were grouped in PWV tertiles, and the highest tertile (>8.7 m/s) was taken as high aortic stiffness. Stress induced myocardial ischemia was detected as delayed contrast replenishment by myocardial contrast stress echocardiography. The number of left ventricular (LV) segments with delayed contrast replenishment was regarded as the extent of ischemia.
Results: Patients with high aortic stiffness were older with higher LV mass index and lower prevalence of obesity (all p<0.05), while there were no difference in symptoms, sex, prevalence of hypertension, diabetes, smoking, lipid profile, LV ejection fraction or coronary artery calcium score. Stress induced myocardial ischemia was more common (46% vs. 19%, p=0.001) and the extent of ischemia was larger (4±3 vs. 2±3 LV segments, p=0.005) in patients with high aortic stiffness. In multivariable logistic regression analysis, high aortic stiffness was associated with stress induced myocardial ischemia independent of age, LV mass index and obesity (Table).
Conclusions: In patients with stable angina and non-obstructive CAD, high aortic stiffness was associated with stress induced myocardial ischemia. This suggests that assessment of aortic stiffness may add to the diagnostic evaluation in patients with non-obstructive CAD.