Relevance of the perioperative edema index measured by bioelectrical impedance analysis for prediction of cardiovascular disease in living-donor kidney transplantation.

ABSTRACT

OBJECTIVES: Perioperative management of fluid status during kidney transplantation is important, because volume overload can increase the risk of cardiovascular disease in recipients. The edema index calculated by bioelectrical impedance analysis is commonly used to correctly evaluate fluid status. We evaluated the relevance of the edema index for cardiovascular disease in kidney transplant recipients, and searched for predictors of high edema index in the perioperative period during kidney transplantation. METHODS: A total of 88 recipients were included in this study. The group in which the edema index at discharge was >0.40 was termed as the "high edema index group", and that with ≤0.40 was termed as the "low edema index group". We assessed cardiovascular disease-free survival and cardiovascular disease-specific survival in the two groups by using Cox proportional regression analyses adjusted by inverse probability of treatment weighting analysis. The patients' background and conventional cardiovascular disease risk factors were assessed to estimate predictors for a high edema index. RESULTS: A high edema index was significantly associated with short cardiovascular disease-free survival after kidney transplantation (hazard ratio 10.01; P < 0.05) in the inverse probability of treatment weighting model. There were no significant differences in the cardiovascular disease-specific survival. In multivariate logistic regression analyses, non-pre-emptive kidney transplantation and dyslipidemia were significant independent predictors of a high edema index (odds ratio 3.59, P < 0.05 and odds ratio 4.05, P < 0.01, respectively). CONCLUSIONS: A high edema index is associated with the incidence of cardiovascular disease. Overhydration should be especially avoided in recipients with these factors, and their fluid volume should be carefully managed.