Ultrafiltration intensification in hemodialysis patients improves hypertension but increases AV fistula complications and cardiovascular events

Introduction: Hypertension remains a major problem in hemodialysis (HD) patients. Methods: We performed a pragmatic trial (Pragmatic Clinical Intervention on Blood Pressure Driven by Audit [CLINIDEA]) testing the effectiveness and safety of a 6-month multimodal intervention in hypertensive HD patients regarding the application of higher ultrafiltration (UF) rates or longer or more frequent dialyses in UF-intolerant patients, and an educational intervention to encourage patients to lower their salt and fluid intake. Results: Blood pressure (BP) in hypertensive patients (n=32) fell from 156.8 +/- 13.3 / 81.1 +/- 8.9 mm Hg to 147.9 +/- 18.8 / 77.5 +/- 11.1 mm Hg. UF intensification was well tolerated, and the BP goal was achieved without resorting to longer or more frequent dialyses. BP changes were paralleled by a consistent (p<0.01) fall in dry body weight. The trial largely failed at increasing compliance with salt prescription (salt intake: baseline: 156.9 +/- 64 mEq/day, 6-month: 150.7 +/- 60.3 mEq/day). During the 12 months preceding the trial, the hospitalization rates for arteriovenous (AV) fistula complications and cardiovascular (CV) events were identical in hypertensive and in normotensive patients. However, these complications selectively increased (AV complications: relative risk [RR] = 7.6; CV complication: RR=8.4) in hypertensive patients coinciding with UF intensification during the trial. Increasing the UF rate is an effective BP-lowering intervention in HD patients. However, this intervention is associated with a higher risk for AV complications and CV events. Conclusion: Longer and/or more frequent dialyses and better efforts to increase compliance to low salt diets than those put in place in this study are needed to reduce the high prevalence of hypertension in the HD population.