Abstract 9270: Left Ventricular Diastolic Dysfunction is Associated with Increased Vascular Resistance and Reduced VO2max in Patients Awaiting Kidney Transplantation

Abstract

Hypothesis: Chronic heart failure (CHF) is a major contributor to high mortality in chronic kidney disease (CKD) patients. We hypothesize that LV diastolic stiffness, in part caused by loss of large artery elasticity in CKD, promotes reduction in cardiovascular reserve. Methods: 68 CKD patients (age, 46 ± 13 years; male, 61%) waitlisted for kidney transplantation were prospectively recruited in 2010. TD echocardiography, arterial pulse wave velocity (PWV) and symptom-limited cardiopulmonary exercise testing were performed to determine the relationship between LV diastolic function, arterial stiffness and cardiovascular reserve. Patients were evaluated and categorised into quartile groups according to the level of maximal exercise oxygen capacity (VO2max). Results: Reduced VO2max was significantly associated with higher E/E∋ (p= 0.002). E/E∋ was calculated using the averaged of septal and lateral mitral annular lengthening velocities. A high E/E∋ was also associated with a worse anaerobic threshold (AT) (p<0.001). These patients (with low VO2max and high E/E∋) also demonstrated a significantly greater aortic stiffness (p= 0.026). VO2max was inversely correlated with both E/E∋ (r= -0.413, p= 0.001) and PWV (r= -0.355, p= 0.003). Distribution of gender and history of coronary artery disease were no different between the groups. Conclusions: Evidence for diastolic dysfunction with increased LV filling pressure and diastolic stiffness by the measure of E/E∋ was strongly associated with poor functional cardiovascular reserve. The importance of ventriculo-arterial coupling in the complex mechanism of CKD mediated CHF is evidenced by the significant association between high E/E∋ and increased aortic stiffness.