The Cardio-ankle Vascular Index Predicts Long-term Kidney Prognosis in Non-diabetic Chronic Kidney Disease Patients Who Underwent Kidney Biopsy.

Background: The cardio-ankle vascular index (CAVI) is a noninvasive index of arterial stiffness that is independent of blood pressure at the time of measurement. Although the role of CAVI as a predictor of cardiovascular events has been reported, few studies have considered kidney prognosis. This study investigated the association between CAVI and long-term kidney prognosis in patients with non-diabetic chronic kidney disease who underwent kidney biopsy.

Methods: This study was a longitudinal, observational, single-center study of patients with chronic kidney disease stages 1-4 and follow-up ≥1 year who had CAVI measured at the time of kidney biopsy. The primary outcome was a 30% decline in the estimated glomerular filtration rate (eGFR) from the baseline or end-stage kidney disease.

Results: Forty-six patients (mean age, 53 years; median eGFR, 61.5 mL/min/1.73 m2; median follow-up period, 98 months) were enrolled. Eighteen patients achieved the primary outcome and a higher CAVI was significantly associated with this outcome. Multivariate analyses consistently identified CAVI as an independent factor associated with the outcome. Using receiver operating characteristic curve analysis, the cutoff value for CAVI was 7.7 (sensitivity, 78%; specificity, 79%). Kaplan-Meier analysis showed significantly lower outcome-free survival in the CAVI ≥7.7 group than in the CAVI <7.7 group. No consistent trend was observed between kidney histopathology and CAVI.

Conclusions: CAVI at the time of kidney biopsy is independently associated with long-term kidney prognosis in patients with non-diabetic chronic kidney disease.