Decreased aortic distensibility and coronary flow velocity reserve in patients with significant aortic valve stenosis with normal epicardial coronary arteries.

摘要

BACKGROUND AND AIM OF THE STUDY: A number of clinical and experimental studies have suggested that aortic valve stenosis (AS) is a manifestation of atherosclerotic process. Previous studies have revealed a decreased coronary flow velocity reserve (CFR) in AS patients in consequence of left ventricular hypertrophy. The hypothesis was tested that the elastic properties of the descending aorta of AS patients might indicate signs of stiffness of the aorta. METHODS: The CFR and indices of aortic distensibility as functional markers of the descending aorta were compared in three different patient populations: (i) control subjects without valvular and coronary artery disease; (ii) patients with AS with normal epicardial coronary arteries; and (iii) patients with significant left anterior descending coronary artery (LAD) stenosis. CFR measurements were carried out according to a standard protocol, using vasodilatory stimulation with dipyridamole (0.56 mg/kg for 4 min), and peak diastolic velocity measurements at 6 min. The elastic properties of the aorta were calculated from echocardiographic parameters and blood pressure data. RESULTS: The CFR in AS patients was decreased to a similar extent as in patients with LAD stenosis. The aortic distensibility indices were similarly significantly increased in patients with AS and normal epicardial coronary arteries and with LAD stenosis, as compared with controls. CONCLUSION: These results indicate that the descending aorta exhibits appreciable increased stiffness in AS patients with normal epicardial coronary arteries.