Relationship Between Thoracic Aortic Structure Assessed B PET/CT Scan and Arterial Stiffness in Elderly Patients

Overview

The purpose of this study is to determine the relationship between thoracic aortic inflammation and arterial stiffness in elderly patients. Vascular-aging is accompanied by a gradual remodeling affecting both cardiac and arterial walls. Arterial hypertension, an established cardiovascular risk factor, has been suggested to exert pro-inflammatory actions threw several biological mediators enhancing arterial stiffness. Both effects of aging and hypertension are associated with higher levels of arterial stiffness, but their respective role is not well established in the pathophysiology of arterial stiffening. Few data are available neither on the real anatomic aortic impact of aging and hypertension on aortic compliance and ventricular function and its relationship to arterial stiffness assessed by carotid-femoral pulse wave velocity, nor on the reliability of cine phase contrast magnetic resonance imaging arterial stiffness measurements. Recent studies using positron emission tomography imaging (PET) with 18 F fluorodeoxyglucose (FDG) has been advocated as a means of measuring arterial wall inflammation in various population referred for oncology staging. FDG uptake is correlated with the number of cardiovascular risk factors and even the risk of future cardiovascular events. This method, combined with X-ray computed tomography (CT), has also demonstrated that aortic calcifications quantified by CT and local signs of inflammation detected by FDG uptake contribute to arterial stiffness. A strong relationship between large vessels stiffening assessed by carotid-femoral pulse wave velocity measurement, aortic calcifications quantified by CT and inflammation evaluated by FDG uptake has been demonstrated. Therefore, in the current study, we use FDG PET associated to CT to characterize aortic inflammation and aortic calcifications coupled to pulse wave velocity measurement and cardiac function in elderly individuals. In fact, if vascular aging promoting a local inflammatory process is a risk factor for cardiovascular disease, then vascular changes assessed by non-invasive vascular imaging (MRI,FDG PET) could represent a potential target for treatment and prevention Thirty individuals ≥ 65 years of age were examined, 15 hypertensive subjects and 15 controls. Pulse wave velocity, a surrogate for aortic stiffness, was measured both by cine phase contrast magnetic resonance imaging and applanation tonometry. Brachial pulse pressure, carotid calculated pulse pressure and pulse pressure amplification (brachial to carotid ratio), predictors of cardiovascular mortality were also quantified. Thoracic aorta local inflammation and calcification were measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography imaging. Moreover, biomarkers of low grade inflammation (high-sensitivity C-reactive protein, interleukin 6 were also determined).