ORLANDO, Florida — Treatment with a renin-angiotensin system (RAS) inhibitor is widely accepted as standard practice for slowing progression of chronic kidney disease (CKD), but data have been inconsistent as to whether there is benefit to continuing RAS inhibition when patients develop advanced CKD, defined as an estimated glomerular filtration rate (eGFR) of less than 30 mL/min/1.73m2.
Now, in STOP ACEi, a new multicenter, randomized trial of 411 patients, maintaining treatment with a RAS inhibitor in adults with advanced and progressive CKD did not cause a clinically relevant change in kidney function, or in the long-term rate of decline in kidney function, compared with stopping treatment, for 3 years.
People who continued RAS inhibitor treatment did not develop a significant or clinically relevant decrease in eGFR, the study's primary outcome, both overall as well as in several prespecified subgroups compared with those who discontinued treatment, said Sunil Bhandari, MBChB, PhD, and associates, who presented the research in a poster at Kidney Week 2022, organized by the American Society of Nephrology.
I hope these results will reassure clinicians to continue ACE inhibitors or ARBs" in patients with advanced CKD, "with their known beneficial cardiovascular effects," Bhandari told Medscape Medical News.
The results were simultaneously published in the New England Journal of Medicine.
Asked to comment, Janani Rangaswami, MD, who was not involved with the study, said: "The message from STOP ACEi is that there is no harm continuing RAS inhibitor treatment, so when feasible continue treatment" even when a patient's eGFR drops below 30 mL/min/1.73m2.
"There has been a perception among nephrologists of harm from RAS inhibitors in these patients because they can cause hyperkalemia and may not help with CKD progression once eGFR is less than 30 mL/min/1.73m2," she noted in an interview.
However, "there was no eGFR benefit from stopping treatment, and numerically fewer patients progressed to end-stage kidney disease or renal replacement therapy" when treatment continued, although this was not a significant difference, observed Rangaswami, a nephrologist and professor of medicine at George Washington University School of Medicine and Health Sciences in Washington, DC.
Plus, "overall, the RAS inhibitor treatment was well tolerated," she added.
Similar eGFR Levels After 3 Years
While it's clear that in patients with mild or moderate CKD, treatment with a RAS inhibitor, which includes angiotensin-converting–enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs), reduces blood pressure, slows decline in eGFR, reduces proteinuria, and delays progression to advanced CKD, there has been little evidence that the use of RAS inhibitors benefits patients with advanced CKD.
Data from previous trials have been inconsistent regarding whether the use of RAS inhibitors is nephroprotective in patients with advanced CKD, say Bhandari, a nephrologist and professor at Hull York Medical School, Hull, UK, and colleagues.
"Current guidelines do not provide specific advice on whether to continue or stop ACE inhibitors or ARBs for advanced chronic kidney disease," they also note.
And so they decided to assess whether discontinuation of ACE inhibitors/ARBs could slow progression of CKD in patients with advanced CKD.
Three years after 206 study participants stopped RAS inhibitor treatment, the least-squares mean eGFR was 12.6 mL/min/1.73m2 in the discontinuation group and 13.3 mL/min/1.73m2 in the 205 patients in the continuation group, a difference that was not significant.
In addition to the primary outcome, 62% of patients who stopped RAS inhibitor treatment and 56% of those who continued developed end-stage kidney disease or required renal-replacement therapy, which translated into an adjusted hazard ratio of 1.28 for this outcome among those who discontinued compared with those who continued, which was just short of significance (95% CI, 0.99 - 1.65).
The two study groups also showed no significant differences in the 3-year incidence of hospitalization for any reason, cardiovascular events, or deaths. The two groups also showed no meaningful differences in various domains of quality of life and no differences in serious adverse effects.
Participants Had an eGFR Less Than 30 mL/min/1.73m2
The study ran at 39 UK centers in 2014-2019. Investigators enrolled adults with an eGFR of less than 30 mL/min/1.73m2 who were not on dialysis and had not received a kidney transplant. In addition, all enrolled patients had to have an annual drop in eGFR of more than 2 mL/min/1.73m2 during the prior 2 years and had to have been on treatment with at least one RAS inhibitor for more than 6 months.
The randomization protocol insured balanced distribution of subjects between the two study arms by age, eGFR, presence of diabetes, and level of proteinuria, among other factors. The study design also mandated that participants maintain a blood pressure of no more than 140/85 mmHg.
Those who discontinued RAS-inhibitor treatment could receive any guideline-recommended antihypertensive agent that was not a RAS inhibitor, although adding a RAS inhibitor was permitted as a last treatment resort.
People in the maintenance group could receive whichever additional antihypertensive agents their treating clinicians deemed necessary for maintaining the target blood pressure.
The enrolled population was a median age of 63 years old and 68% were men. Their average eGFR at baseline was 18 mL/min/1.73 m2, and 118 (29%) had an eGFR of less than 15 mL/min/1.73 m2. Their median level of proteinuria was 115 mg/mmol (about 1018 mg/g). Diabetes was prevalent in 37%, and 58% of participants were taking at least three antihypertensive medications at entry.
Among the study's limitations, the researchers cited the open-label design, which may have affected clinical care and the tally of subjective endpoints, including quality of life and exercise capacity. Also, because the study enrolled people who were on a RAS inhibitor at the time of randomization it did not include anyone who had already discontinued these agents.
Continue RAS Inhibitors in Advanced CKD for Best Outcomes
Bhandari and colleagues note that in a large observational trial published in January 2021, Swedish researchers found an increase in the incidence of major cardiovascular events and death among patients with advanced CKD who had discontinued RAS inhibitors, as reported by Medscape Medical News.
But they observe, "Our trial did not have sufficient power to investigate the effect of the discontinuation of RAS inhibitors on cardiovascular events or mortality. However, because our findings are consistent with a lack of advantage for such discontinuation with respect to kidney function, there is little rationale to conduct a larger randomized trial to investigate cardiovascular safety."
"Our findings do not support the hypothesis that the discontinuation of RAS inhibitors in patients with advanced and progressive chronic kidney disease would improve kidney function, quality of life, or exercise capacity."
"The results of this trial will inform future clinical practice worldwide and guideline recommendations," they conclude.
STOP ACEi received no commercial funding. Bhandari has reported no relevant financial relationships.
N Engl J Med. Published online November 3, 2022. Abstract
Kidney Week 2022. Abstract TH-PO966. Presented November 3, 2022.
Mitchel L. Zoler is a reporter for Medscape and MDedge based in the Philadelphia area. @mitchelzoler
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Cite this: Study Sheds New Light on RAS Inhibitors' Role for Advanced CKD - Medscape - Nov 05, 2022.