Adding access blood flow surveillance reduces thrombosis and improves arteriovenous fistula patency: a randomized controlled trial.

PURPOSE: Stenosis is the main cause of arteriovenous fistula (AVF) failure. It is still unclear whether surveillance based on vascular access blood flow (QA) enhances AVF function and longevity. METHODS: We conducted a three-year follow-up randomized, controlled, multicenter, open-label trial to compare QA-based surveillance and pre-emptive repair of subclinical stenosis with standard monitoring/surveillance techniques in prevalent mature AVFs. AVFs were randomized to either the control group (surveillance based on classic alarm criteria; n = 104) or to the QA group (QA measured quarterly using Doppler ultrasound [M-Turbo®] and ultrasound dilution [Transonic®] added to classic surveillance; n = 103).The criteria for intervention in the QA group were: 25% reduction in QA, QA<500 mL/min or significant stenosis with hemodynamic repercussion (peak systolic velocity [PSV] more than 400 cm/sc or PSV pre-stenosis/stenosis higher than 3). RESULTS: At the end of follow-up we observed a significant reduction in the thrombosis rate in the QA group (0.025 thrombosis/patient/year in the QA group vs. 0.086 thrombosis/patient/year in the control group [p = 0.007]). There was a significant improvement in the thrombosis-free patency rate (HR, 0.30; 95% CI, 0.11-0.82; p = 0.011) and in the secondary patency rate in the QA group (HR, 0.49; 95% CI, 0.26-0.93; p = 0.030), with no differences in the primary patency rate between the groups (HR, 0.98; 95% CI, 0.57-1.61; p = 0.935).There was greater need for a central venous catheter and more hospitalizations associated with vascular access in the control group (p = 0.034/p = 0.029).Total vascular access-related costs were higher in the control group (€227.194 vs. €133.807; p = 0.029). CONCLUSIONS: QA-based surveillance combining Doppler ultrasound and ultrasound dilution reduces the frequency of thrombosis, is cost effective, and improves thrombosis free and secondary patency in autologous AVF.

Irbesartan is projected to be cost and life saving in a Spanish setting for treatment of patients with type 2 diabetes, hypertension, and microalbuminuria.

OBJECTIVES: The purpose of this study was to project the cumulative incidence of end-stage renal disease (ESRD), life expectancy, and costs in a Spanish setting of treating patients with diabetes, hypertension, and microalbuminuria with either standard hypertension treatment alone or standard hypertension treatment plus irbesartan 300 mg daily. METHODS: A peer-reviewed, published Markov model that simulated progression from microalbuminuria to nephropathy, doubling of serum creatinine, ESRD, and all-cause mortality in patients with hypertension, type 2 diabetes, and microalbuminuria was adapted to a Spanish setting. Two strategies were compared: (1) irbesartan versus (2) standard hypertension care with comparable blood pressure control; both began in diabetic hypertensive subjects with microalbuminuria. Cumulative incidence of ESRD, costs, and life expectancy were projected for a hypothetical cohort of 1000 subjects. Future costs and life expectancy were discounted at 3% yearly. A 25-year time horizon and third party payer perspective were used. RESULTS: When compared to standard blood pressure control, irbesartan was projected to reduce the cumulative incidence of ESRD from (mean +/- standard deviation) 24 +/- 1% to 9 +/- 2%, save 11,082 +/- 2,996 euro, and add 1.40 +/- 0.27 life years per treated patient. The superiority of irbesartan over standard care was robust under a wide range of plausible assumptions. CONCLUSION: Treating patients with hypertension, microalbuminuria, and type 2 diabetes with irbesartan was projected to reduce the incidence of ESRD, extend life, and reduce costs.