Abstract 11063: Impaired Coronary Artery Distensibility is an Endothelium-Dependent Process, and Associated with Vulnerable Plaque Composition
Background: Coronary endothelial-dependent microvascular dysfunction is an early reversible stage of coronary artery disease(CAD), associated with poor clinical outcome. The current study investigated whether coronary artery distensibility index(CDI) is associated with: 1)coronary endothelial dependent microvascular function and 2)vulnerable plaque composition among subjects with non-obstructive CAD.
Methods: This matched case-control study consists of 20 subjects with and without coronary endothelial-dependent microvascular dysfunction who underwent coronary angiography. Coronary flow reserve(CFR) of left anterior descending coronary artery(LAD) during intra-coronary(IC) infusion of Acetylcholine(Ach), and adenosine were measured. CDI in LAD was defined as:[(Early diastolic LAD cross sectional area(CSA) - End diastolic LAD CSA)/ (end-diastolic LAD CSA x coronary pulse pressure) x1000]. In sub-study, plaque compositions of 154 coronary segments assessed by intravascular ultrasound(IVUS) were analyzed.
Results: CDI was significantly lower in subjects with endothelial dysfunction as compared to normal cohort (p=0.005). After adjustment for risk factors, the risk of impaired CDI was 151% higher in subjects with endothelial-dependent microvascular dysfunction as compared to normal cohort (p<0.05). (Figure) A strong agreement between CDI and CFR Ach (r2=0.85, p=0.0001) was observed. Multivariable regression analysis showed that CDI was an independent predictor of the vulnerable plaque characteristics. After adjustment for risk factors, the risk of impaired CDI was 125% higher in segments with necrotic core and 60% higher in segments with fibro-fatty components as compared to normal segments (p=0.001)
Conclusions: The current study reveals that impaired CDI is an endothelial dependent process and is associated with vulnerable plaque composition.
- Endothelial function
- Intravascular ultrasound/Doppler
- Coronary circulation
- Subclinical atherosclerosis
- Vulnerable plaque
- © 2011 by American Heart Association, Inc.