Static intra-access pressure ratio and cardiovascular events in patients undergoing haemodialysis

Static intra-access pressure ratio (SIAPR) measurement, using haemodialysis machine transducers, is the vascular access surveillance method in patients undergoing haemodialysis. However, little is known about the relationship between the SIAPR and arterial stiffness, and the clinical usefulness of the SIAPR in predicting cardiovascular events. A total of 209 patients undergoing maintenance haemodialysis were evaluated. The SIAPRs ranged from 0.01 to 0.52 (median: 0.23). When the patients were divided into two groups according to their median of SIAPR, the incidence of previous cardiovascular disease, E/E' ratio, and brachial-ankle pulse wave velocity were significantly higher in the patients with SIAPRs of <= 0.23 than in those with SIAPRs of >0.23. Conversely, patients with worse comorbid status had a lower SIAPR than patients without it. In the Kaplan-Meier analysis, the cumulative incidence of cardiovascular events was significantly higher in the patients with SIAPRs of <= 0.23 than in those with SIAPRs of >0.23 (P < 0.001). In the multiple Cox regression analysis, an increase in the SIAPR was associated with a reduced risk for cardiovascular events [hazard ratio: 0.36, 95% confidence interval: 0.21-0.60, P = 0.001]. Therefore, a low SIAPR related with arterial stiffness was a predictor for cardiovascular events.