Association of Increased Cardio-Ankle Vascular Index (CAVI) with Echocardiographically Impaired Diastolic Dysfunction and Low Klotho Levels in Kidney Transplant Patients

Abstract

Background and Objectives: Cardiovascular disease is the leading cause of mortality after kidney transplantation. Cardio-ankle vascular index (CAVI), a recently devised technique whose utility for evaluation of cardiac risk in kidney transplantation is not well known. We investigated the associations of CAVI with echocardiographic assessment of cardiac functions and atherosclerotic parameters including FGF-23 and klotho. Materials and Methods: Two age- and gender-matched groups were subjects in the study. Group 1 included 75 KT patients with kidney transplant durations of at least 2 years; group 2 included 55 non-uremic controls. All participants underwent CAVI measurement and echocardiographic assessment. Atherosclerosis-associated parameters were determined using standard methods. Results: CAVI levels were similar between transplant patients and controls (7.26 +/- 1.68 vs. 7.02 +/- 1.3 m/sec); however, the percentage of subjects with pathological CAVI score (>8) was higher in transplant group (p = 0.077). Echocardiographic parameters displayed a significant increase in KT patients with higher CAVI scores. Low klotho levels were found to be significantly correlated to increased CAVI scores. Independent predictors of CAVI levels, as revealed by stepwise regression analysis, included high E/e' (p = 0.012) and low klotho (p = 0.001). Conclusions: Our findings showed that higher CAVI scores still persist to some extent even after successful kidney transplantation and are independently linked to impaired E/e' levels, which is an indicator of impaired diastolic dysfunction and low klotho levels. These findings underscore the importance of cardiovascular risk control in KT patients and suggest a possible role for klotho-mediated mechanisms in the development of arterial stiffness.