Patients with chronic kidney disease (CKD) stage 4 are as likely to progress to end-stage renal disease (ESRD) as they are to die prior to ESRD, and certain variables could help to distinguish between the two, researchers reported.
The equal likelihood of ESRD and death prior to ESRD is particularly problematic for decisions on the optimal time to begin preparation for renal replacement therapy (RRT), according to investigators led by Maneesh Sud, MD, and David M. Naimark ,MD, MSc, of the University of Toronto.
The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines recommend starting RRT education and planning when patients’ glomerular filtration rate decreases to below 30 mL/min/1.73 m2, the researchers noted in a paper published in the American Journal of Kidney Diseases (2014;63:928-936).
“Our work suggests that if the latter guidelines were applied to all stage 4 patients, the inconvenience, risk, and cost of RRT preparations would not benefit a substantial proportion of that group,” they wrote.
If RRT planning were started only when patients reached CKD stage 5, many patients would not be adequately prepared, Dr. Sud’s group observed. For patients who choose a hemodialysis-based modality, Dr. Naimark and his colleagues pointed out, many would initiate dialysis without a functioning arteriovenous access.
“Thus, identification of patients with CKD stage 4 at higher risk of progression to ESRD would allow for earlier preparation for RRT and prevention of unplanned initiation of RRT and its associated risks, whereas for patients at higher risk of death prior to ESRD, measures focused on risk reductions, particularly for cardiovascular events, could the main focus of care,” the authors wrote.
The researchers studied 3,273 patients with CKD stages 3-5. ESRD developed in 459 patients (14%), and 540 (16%) died over a median follow-up of 2.98 years. The rates of ESRD and death prior to ESRD, per 100 patient-years, were 7.7 and 8.0 for CKD stage 4, a difference that was not statistically significant.
The differences in the rates of ESRD and death prior to ESRD were significantly different in other CKD stages. The rates, respectively, were 0.6 versus 2.2 for stage 3A, 1.4 versus 4.4 for stage 3B, and 41.4 versus 9.4 for stage 5.
On multivariable analysis, age, diabetes, heart failure, and serum phosphate level were among 19 variables found to be associated with progression to ESRD or death prior to ESRD in patients with CKD stage 4. Each 10-year increment in age was associated with a 22% decreased risk of ESRD and a nearly twofold increased risk of death prior to ESRD.
Patients with diabetes had a 59% increased risk of ESRD and a 21% decreased risk of death prior to ESRD. Those with heart failure had a 32% decreased risk of ESRD and a 2.2 times increased risk of death prior to ESRD. Each 1 mg/dL increment in serum phosphate was associated with a 16% increased risk of ESRD and a 17% decreased risk of death.