Kidney function decline slows with AVF creation, which may delay dialysis
Researchers from Canada found placement of an arteriovenous fistula slowed decline in kidney function for patients with advanced chronic kidney disease who were not yet on hemodialysis.
The same was not true for a matched cohort of patients oriented toward peritoneal dialysis who had a catheter placed during follow-up.
“Recent studies suggested AVF creation could slow eGFR decline,” Marie-Eve Dupuis, MD, of Maisonneuve-Rosemont Hospital in Montreal, and colleague wrote. “The major limitation of these studies was the absence of a control group (or one that was poorly comparable to the AVF group), and the inability to adjust for confounding factors. Thus, it remains unclear if the attenuation in eGFR slope is due to the beneficial effect of AVF, the natural history of late CKD, or an artifact caused by the equations used to evaluate eGFR that performs less well at a low kidney function level.”
To investigate further, the researchers assessed eGFR changes in patients who were receiving pre-dialysis care at a single center and matched those who had an AV fistula placed with a control group of individuals who would go on to receive PD if necessary (61 total pairs; mean age of those in the PD group was 61 years vs. 64 years for those in the AV fistula group). Researchers noted patients in the PD group had a lower BMI than those in the AVF group, as well as a trend toward less cardiovascular disease. No differences were found between groups regarding the use of RAAS inhibitors.
Patients in the AVF group were followed for a median of 11 months before AVF creation (crude annual eGFR decline was -4.1 mL/min/m2 per year) and 10 months after fistula creation, while patients in the PD group were followed for 9 months before match (decline of -5.3 mL/min/m2 per year) and 11 months after fistula creation.
After AVF creation, researchers observed an annual eGFR decline of -2.5 mL/min/m2 (for patients in the PD group this decline was -4.5 mL/min/m2 after matching).
Further results showed the predicted annual decline decreased from -5.1 mL/min/m2 per year before AVF creation to -2.8 mL/min/m2 per year after creation. There was no difference in predicted eGFR decline for those in the PD group (-5.5 mL/min/m2 vs. -5.1 mL/min/m2 per year).
In a related editorial, Thomas A. Golper, MD, of Vanderbilt Medical Center in Nashville, contended that these results (coupled with his own observations of more than 35 years) suggest the slowing of kidney function decline following AVF creation “appears to be real” and additional research must be conducted to determine the underlying mechanisms.
“The discovery of specific substances that may be associated with the slowing could be applied in many CKD settings and might delay or obviate hemodialysis,” Golper wrote. “The consequence of that on the quality of life of our patients is immeasurable. Financial implications can be measured. There would be a reduction in the financial burden in all components of late-stage CKD.”
According to Golper, the notion that AVF creation could delay hemodialysis may persuade “reluctant” patients to undergo the procedure.