3.2: Spectral Analysis of Carotid Distension Rate and R—R Interval (Spontaneous Baroreflex Activity) Predicts Coronary Heart Disease Risk in Patients with Moderate Chronic Kidney Disease and in Those with Normal Renal Function: The EPP3 Study

The classic technique to evaluate the spontaneous baroreflex is the spectral analysis of finger blood pressure and heart rate. However, baroreceptors respond to deformation and not to pressure per se and the results obtained with this technique can be influenced by the vascular component of the baroreflex. Recently, the spectral analysis of carotid distension rate has been used to study the neural baroreflex. The aim of this study is to test this new technique to predict the coronary heart disease (CHD) risk in patients with moderate chronic kidney disease (CKD) and in those with normal renal function. Methods From the cohort of EPP3 study, 2211 patients were included in this report (age 59±6 years). The baroreceptor sensitivity (BRS) was defined as the ratio between variations in the carotid distension rate and variations in R-R interval in the low-frequency range (0.04–0.15Hz). The CHD risk was estimated according to the Framingham risk score. Results We studied 2088 patients with GFR>60ml/min/1.73m 2 and 123 patients with CKD (GFR 45–60ml/min/1.73m 2 ). The prevalence of 10 years CHD risk≥20% was significantly higher in patients with CKD than in those with normal renal function (30% and 14%, respectively). In fully adjusted model, in the total population, the increase of BSA, IMT and carotid PP, the reduction of carotid strain and BRS, and the presence of CKD were independently associated with 10 years CHD risk≥20% (Table 1). Conclusions The spontaneous BRS is a predictor of CHD risk in patients with moderate CKD and in those with normal renal function. Predictors of 10 years CHD risk ≥ 20% OR 95%CI P value Body surface area, m 2 × 10 −1 1.20 1.13–1.27