Late-breaking data from multiple high-impact clinical trials were presented at the recent 2022 American Society of Nephrology (ASN) Kidney Week (3–6 November, Orlando, USA)—with renal transplant outcomes, hypertension in chronic kidney disease (CKD) patients, and lower-temperature dialysate in haemodialysis treatments, all featuring.
In one trial presented at ASN Kidney Week, investigators analysed data from 807 participants in the BEST-Fluids randomised controlled trial (RCT) who were randomised to receive a balanced low-chloride crystalloid solution (Plasma-Lyte 148), or saline solution, during and after transplant surgery involving a deceased-donor kidney. These analyses were motivated by the fact that saline (0.9% sodium chloride) is the most widely used intravenous fluid in kidney transplantation but may increase the risk of delayed graft function—defined as the need for dialysis within seven days of transplant—due to its high chloride content.
Fewer participants in the balanced crystalloid group needed dialysis after transplant surgery due to poor kidney function compared with those in the saline group (30% vs 39.7%). The effect was consistent across prespecified subgroups of deceased donor type, kidney donor risk index, machine perfusion and ischaemic time. The incidence of hyperkalaemia (high potassium) was similar in both groups, and there were no significant differences in acute rejection, graft failure, or mortality up to 52 weeks. Numbers of serious adverse events were also similar in both groups.
“Reducing dialysis with this simple, low-cost intervention should improve patient recovery after transplant, lower healthcare costs, and may improve long-term outcomes for patients,” said Michael Collins (Royal Adelaide Hospital, Adelaide, Australia), corresponding author of this research. “Based on the results of this trial, we believe that perioperative balanced crystalloid fluid should become the standard of care in deceased donor kidney transplantation.”
High pressures
Black Americans are disproportionately affected by hypertension and CKD, with inequitable access to healthy foods and knowledge gaps about healthy eating playing potential roles. Against this backdrop, a recent trial saw 150 Black adults with hypertension and CKD randomised to one of two groups:
- A Self-shopping dietary approaches to stop hypertension (S-DASH) diet with a US$30 per week grocery allowance for four months, but no guidance on purchases, followed by no grocery allowance for eight months
- A Coaching (C-DASH) diet advice group with a US$30 per week food allowance and assistance in purchasing high-potassium foods for four months, followed by coaching without food allowance for eight months
The C-DASH group had increased dietary potassium and fruit/vegetable consumption compared with the S-DASH group; and the C-DASH group had declines in urine albumin-to-creatinine ratio (UACR)—a marker of kidney damage, with a higher value indicating more damage—that did not differ statistically from the S-DASH group, except among the subgroup with especially high UACR, where the C-DASH group had a 73.3% decrease in UACR and the S-DASH group had a 20.5% increase. There was also a suggestion of benefit for those with diabetes.
“We found several benefits for Black Americans with high blood pressure and early kidney disease who were coached one-on-one on selecting healthy foods that were then delivered to them by a local grocer,” said the study’s corresponding author Deidra Crews (Johns Hopkins University School of Medicine, Baltimore, USA). “People who received the coaching improved the quality of their eating habits compared with those who shopped on their own using gift cards from the same grocer; and we saw some signs of improvements in kidney health, particularly for people who, at the beginning of the study, were losing high amounts of protein in their urine, and for those with diabetes. Our next steps will be to try to expand the programme to support more populations disproportionately affected by kidney disease.”
Low temperatures
Another late-breaker presented at ASN Kidney Week sought to shed new light on the use of cooler dialysate in haemodialysis care across many centres—a practice shift away from the more conventional use of a standard dialysate temperature for all patients receiving maintenance haemodialysis that has occurred in spite of a limited evidence base.
As such, in the open-label MyTEMP trial, 84 of Ontario’s 97 haemodialysis centres were randomised to use cooler temperature dialysate (0.5°C below each patient’s body temperature) or standard temperature dialysate (36.5°C). Over the course of four years, 15,413 patients were treated with haemodialysis. The primary outcome—a composite of cardiovascular-related death, or hospital admission with myocardial infarction, ischaemic stroke or congestive heart failure—occurred in 1,711 of 8,000 patients (21.4%) in the cooler dialysate group versus 1,658 of 7,413 patients (22.4%) in the standard-temperature group, with this difference not being considered statistically significant. Patients in the cooler dialysate group were more likely to report feeling uncomfortably cold during dialysis.
“What is innovative about the MyTEMP trial is the methods we used,” said corresponding author Amit Garg (Western University, London, Canada). “Because we embedded the trial into existing healthcare, we were able to determine whether the intervention would improve outcomes in a real-world setting that included all dialysis patients. Based on the trial’s findings, dialysis centres that are currently providing cooler dialysate as a centre-wide policy should consider using a standard dialysate temperature of 36.5°C for the comfort of their patients, as cooler dialysate did not improve patient outcomes.
“We intend to conduct more large-scale, high-quality clinical trials in this way to efficiently identify those treatments that improve the outcomes and healthcare of patients with kidney disease. We can conduct these trials better, faster and cheaper than traditional trials by integrating them in routine healthcare, and using information from existing data sources to efficiently study patient outcomes.”
Further new data
The remaining high-impact clinical trials presented for the first time at ASN Kidney Week ranged from studies indicating the effectiveness of isuzinaxib and cemdisaran in diabetic kidney disease and IgA nephropathy, respectively, to an RCT assessing how electronic alerts and the discontinuation of certain medications may reduce the development of acute kidney injury (AKI) in hospitalised patients. These studies were contributed from across the globe, spanning South Korea, Canada, the UK and the USA.
And, given the fact that a greater body of evidence is needed regarding the effects of sodium glucose co-transporter-2 (SGLT2) inhibitors on kidney and cardiovascular health in patients with CKD, investigators also recently collated and reanalysed kidney outcome data from all the large, randomised clinical trials that have studied these medications to date. Within a meta-analysis including 13 trials, the team found that SGLT2 inhibitors safely reduced the risk of progression of kidney disease by approximately 40% and AKI by nearly a quarter. “The results were similar in patients with and without diabetes, and across the different kidney disease diagnoses studied in the trials,” said presenting author Natalie Staplin (University of Oxford, Oxford, UK).
