Association of aortic stiffness and wave reflections with coronary flow reserve in women without obstructive coronary artery disease: An ancillary study from the National Heart, Lung, and Blood Institute–sponsored Women’s Ischemia Syndrome Evaluation (WISE)

Abstract

Background Increased aortic stiffness and reduced coronary flow reserve (CFR) independently predict adverse outcomes. But information about relationships between arterial properties and CFR in subjects without obstructive coronary artery disease (CAD) is limited. Methods CFR was measured (Doppler flow wire and intracoronary adenosine) in 50 women (age 53±11 years) with symptoms and signs of myocardial ischemia without obstructive CAD. Aortic pulse wave velocity (aPWV), a measure of aortic stiffness, was obtained via catheter pullback; radial artery pressure waves were measured by applanation tonometry and central aortic pressure synthesized. Results Overall, CFR (mean 2.61 ± 0.47) was significantly correlated with aPWV (r = −0.51), pulse wave amplification (r = 0.45), augmented pressure (AP, r = −0.48), augmentation index (AIx, r = −0.44), aortic systolic pressure (r = −0.49), left ventricular wasted energy (LVEw, r = −0.47) (all P < 0.001), systolic pressure time index (r = −0.37, P < 0.008), and rate pressure product (r = −0.29, P < 0.04). In the multiple regression model including aPWV, CFR was still significantly correlated with aPWV (P < 0.008) and aortic systolic pressure (P < 0.01). No other measures contributed significant additional information. Women with CFR ≤2.5 vs. those with CFR >2.5 had greater aPWV (894 ± 117 vs. 747 ± 93 cm/sec, P < 0.001), AP (14 ± 4.9 vs. 11 ± 4.1 mmHg, P < 0.008), AIx (32 ± 6.6 vs. 27 ± 6.6%, P < 0.003), LVEw (30 ± 12 vs. 21 ± 10 dyne-sec/cm2 × 102, P < 0.02) and reduced pulse pressure amplification (1.20 ± .07 vs. 1.26 ± .10, P < 0.008) and pressure wave travel time (133 ± 7.3 vs. 138 ± 6.9 msec, P < 0.04). Conclusions Among symptomatic women without obstructive CAD, CFR was inversely related to aortic systolic pressure and indices of aortic stiffness. These changes in arterial properties increase LV afterload requiring the ventricle to generate additional, but wasted, energy that increases indices of myocardial oxygen demand, reduces CFR and increases vulnerability to ischemia.

Effects of statin therapy on augmentation index as a measure of arterial stiffness: A systematic review and meta-analysis

“…Augmentation index is commonly accepted as a measure of the enhancement of central aortic pressure by a reflected pulse wave. AIx was identified as a risk factor for all-cause mortality and cardiovascular disease in recently published papers referring to the different risk factor groups and examined populations (like obese children [47]; elderly [48]; women [49]; metabolic syndrome and its components [50,51] respectively). There are several potential reasons why our meta-analysis showed a significant reduction in aortic AIx following statin therapy which was not so clearly proven in some other studies.…”

Ischemia and No Obstructive Coronary Artery Disease (INOCA)

“…60 Arterial stiffness is known to predict cardiovascular events beyond traditional risk factors. When arterial stiffness indices were assessed by magnetic resonance imaging (MRI), ultrasound, and tonometry in asymptomatic subjects from the community, 61 peripheral and central pulse pressure, augmentation index, carotid-femoral PWV, and aortic arch PWV all increased with age, but ascending aortic strain and distensibility decreased with age.…”

Coronary Microvascular Function and Cardiovascular Risk Factors in Women With Angina Pectoris and No Obstructive Coronary Artery Disease: The iPOWER Study

“…Studies that include factors of vessel stiffness such as brachial-ankle pulse-wave velocity, augmentation index, and aortic pulse-wave velocity achieve a greater explanatory effect of the CFVR variation with r 2 values ranging from 0.36 to 0.52. 30,31 A full invasive assessment including both endothelial and nonendothelial mechanisms is regarded as the "gold standard" for assessing CMD. However, given that only a minority of patients with angina will ultimately need revascularization; noninvasive methods for assessment of CMD deserve wider application.…”