Does increased aortic stiffness predict reduced coronary flow velocity reserve in patients with suspected coronary artery disease?

Purpose: In recent studies, reduction in coronary flow velocity reserve (CFR) has been demonstrated in patients with increased aortic stiffness. Stress transoesophageal echocardiography (TEE) is a suitable method for the simultaneous evaluation of CFR and aortic stiffness parameters. The present study was designed to test whether increased echocardiography-derived aortic elastic modulus [E(p)] predicts impaired CFR in patients with suspected coronary artery disease (CAD). Results: The present study comprised 158 patients with suspected CAD. A CFR value < 2 was considered abnormal. Both mean grade of aortic atherosclerosis (AA) (as a morphologic characteristic) (1.31 ± 0.68 vs. 1.02 ± 0.89, p < 0.05) and aortic distensibility (E(p) as a functional characteristic) (892 ± 584 mmHg vs. 723 ± 495 mmHg, p < 0.05) were increased in subjects with CFR < 2. In ROC analysis, the cut-off value for E(p) to predict impaired CFR was ≥ 670 mmHg, with 61% sensitivity and 61% specificity (ROC area 0.60, p = 0.026). The logistic regression model identified higher AA grade (hazard ratio (HR) 2.01, p < 0.05) and increased E(p) as independent predictors of reduced CFR (HR 1.10, p < 0.05). Conclusion: Increased aortic stiffness predicts impaired CFR in patients with suspected CAD