Post-angioplasty changes in venous access pressure ratio is a novel diagnostic tool predicting access failure.
Kumbar L, Zasuwa G, Zaborowicz M, Taylor A, and Yee J. Post-angioplasty changes in venous access pressure ratio is a novel diagnostic tool predicting access failure. Am J Kidney Dis 2017; 69(4):A60.
Am J Kidney Dis
Vascular access pressure ratio (VAPR) test identifies dialysis vascular access (VA) dysfunction in patients when 3 consecutive VAPRs are >0.55. We tested if one week mean post-interventional VAPR decline from mean alert diagnose failing access. Retrospective analysis of all VA procedures from 03/2014 to 06/ 2016. Data included demographics, comorbidities, VA features, %ΔVAPR =Pre-Post/Pre×100%, time-to-next procedure, and patency. Area under curve, receiver operating curve, Kaplan-Meier (KM) arteriovenous graft (AVG) and fistula (AVF) survival curves were compared by the log-rank test. A multivariable Cox-proportional hazard (CP) model was used to determine the association of %Δ VAPR with access survival Analysis of 150 subjects [females 50%; black 85%] included 69 AVF with 114 angioplasties and 81 AVG with 142 angioplasties. Area under the ROC curve (AUC) for fistula failure at 1 year was 0.701, with an optimal cut-off value of 54.7%, sensitivity of 74.3%, and specificity of 40%. AVF with54.7% required earlier subsequent procedure (132 vs 266 d), lower survival on KM analysis (p=0.018) and 2-fold greater risk of failure (p=.006). AUC for AVG failure at 2 weeks was 0.612 with cut-off value of 29.6%, sensitivity of 72.4%, and specificity of 42.6%. AVG with post-intervention VAPR decline <20.6% also required earlier subsequent procedure (129 vs 189d), lower survival on KM (p=0.015) and 72% higher risk for failure. Cut points were significant predictors of overall time to failure in both grafts and fistulas. Post-intervention reduction of VAPR provides a novel diagnostic tool to predict access failure.