MO099: Elastography in the Assessment of Chronic Kidney Disease: A Meta-Analysis

Abstract

Abstract BACKGROUND AND AIMS We require an imagistic quantitative technique for the diagnosis and assessment of chronic kidney disease (CKD). Renal elastography has been widely used in the last years in different studies; however, the results across them are not consistent and, as a result, we conducted a meta-analysis of the published literature on this topic. METHOD The databases of PubMed, Medscape and Medline were searched for all studies published in English from 2010 until November 2021 that evaluated kidney shear wave speed (KSWS) by elastography in patients with CKD. Trial design, methodological information, patient characteristics, interventions, results and outcome data were all collected from each study according to a set protocol. RESULTS We found 33 publications, yet only 18 studies that utilized point shear wave elastography (Virtual Touch Quantification—VTQ system) were compared because the values achieved using different types of elastography are not evaluable. Finally, 1995 attendees (1241 patients with CKD versus 781 healthy subjects as the control group) were included. When comparing mean values of KSWS between studies, we found increased heterogeneity Q = 513.133; DF = 10; P < .001, I2 (inconsistency) = 98.12% (95% CI for I2 97.52–98.57%). With a standardized mean difference of –0.216, patients with CKD have a lower KSWS than healthy controls. A positive association between KSWS and eGFR was also discovered across the presented studies, with a pooled correlation coefficient of 0.38 (Z = 10.3, P < .001), Q = 73.3, DF = 5, P < .001, I2 = 93.18% (95% CI for I2 87.86–96.18). The pooled area under the ROC curve for KSWS to predict mild renal disease was 0.831 (95% CI, P < .001), Q = 28.32, DF = 6, P = .0001, I2 = 78.8% (95% CI for I2 56.37–89.72). In the four articles that used the Elast-PQ method, the data presented were insufficient for statistical analysis: area under the curve values are used to compare distinct characteristics (differentiating KSWS between mildly and moderately impaired kidneys, between non-diabetic, prediabetic and diabetic patients, or KSWS between CKD and control group), therefore not being suitable for further evaluation. CONCLUSION The results show that patients with CKD have a lower KSWS than healthy controls. It remains a viable method for monitoring the progression of CKD but because the number of studies involving renal elastography that have been published is limited and show an increased heterogeneity more research is needed to determine which factors actually influence KSWS in CKD patients and, as a result, to specify the role and indication of renal elastography in clinical practice.