More Frequent Dialysis Increases Risk for Complications

Damian McNamara

February 13, 2013

Previously reported benefits of hemodialysis performed 6 times per week compared with the conventional 3-day regimen include gains in physiology and health-related quality of life. However, a new study suggests these benefits come at a price.

That cost could be significantly higher rates of vascular complications, according to the study by Rita S. Suri, MD, from the Division of Nephrology, University of Western Ontario, London, Canada, and colleagues, published online February 7 in the Journal of the American Society of Nephrology.

The researchers found that 48 of 125 patients receiving hemodialysis 6 days per week (the "daily" strategy) experienced a composite primary endpoint event of vascular repair, loss, or related hospitalization. In contrast, only 29 of 120 patients receiving conventional treatment experienced a similar event. These numbers translated to a rate of 40 vs 23 events per 100 patient-years.

"We found that daily hemodialysis significantly increased the risk of vascular access complications, as measured by time to first access repair, loss, or access-related hospitalization [(hazard ratio), 1.76; 95% (confidence interval), 1.11–2.79; P=0.017]," the authors write.

"[W]e hypothesize that more frequent use of the arteriovenous access itself causes vascular access dysfunction."

The investigators also compared these outcomes between nocturnal hemodialysis (6 nights per week) and conventional regimens. They found that 23 of 45 patients receiving nocturnal therapy experienced a vascular complication event compared with 15 of 42 patients receiving conventional therapy. The event per 100 patient-years rate was 58 in the nocturnal group vs 32 in the conventional cohort. A vascular access event was more likely with nocturnal hemodialysis (hazard ratio, 1.81; 95% confidence interval, 0. 94 - 3.48; P = .076).

More Frequent, More Problems

"The authors found that more frequent hemodialysis, long proposed as more physiologic, led to more problems with the access for dialysis. This risk must be considered when making a decision about moving to more frequent hemodialysis vs the standard 3 times per week hemodialysis," Beth Piraino, MD, president of the National Kidney Foundation and professor of medicine at the University of Pittsburgh in Pennsylvania, told Medscape Medical News. "The former results in better self-reported quality of life and less hypertrophy of the heart, but this must be balanced against a higher risk of requiring further procedures on the hemodialysis access."

The increased risk for access complications with frequent hemodialysis "may have significant clinical impact," the authors note. For example, permanent arteriovenous access could be lost in settings in which vascular repair procedures are not readily available, patients might end up with a tunneled catheter borne out of frustration by patients and providers from frequent repairs, and clinical costs to maintain functional vascular access could be higher with more frequent hemodialysis.

The evaluation of prospective, detailed vascular access data in the largest, randomized trials to date is a strength of the study. Potential limitations included a relatively short duration of follow-up (1 year), a lack of explanations for why patients received different repair procedures, and an inability to rule out a role that heightened surveillance may have played in the patients receiving hemodialysis more frequently.

The National Institute of Diabetes and Digestive and Kidney Diseases, the Centers for Medicare & Medicaid Services, and the National Institutes of Health Research Foundation supported the study. The National Institutes of Health Foundation is supported Amgen, Baxter, Dialysis Clinics, and Fresenius Medical Care. Dr. Suri received funding via a Canadian Institutes of Health Randomized Trials Mentorship Award and, along with a coauthors, received unrestricted research grants from Fresenius Medical Care Canada and Baxter Inc. One coauthor is a consultant for Amgen and DaVita, and one coauthor sits on the Machine Medical Advisory Board for Fresenius Medical Care North America (Sorbent Machine).

J Am Soc Nephrol. Published online February 7, 2013. Abstract