Efficacy and Mechanism Evaluation (Mar 2024)
Withdrawal of renin-angiotensin system inhibitors’ effect on estimated glomerular filtration rate in adults with advanced kidney disease: the STOP-ACEi RCT
Abstract
Background Renin–angiotensin system inhibitors, both angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, slow progression of mild and moderate chronic kidney disease. However, some evidence suggests that discontinuation of renin–angiotensin system inhibitors in patients with advanced chronic kidney disease might increase estimated glomerular filtration rate or slow its decline. Objective To test the hypothesis that stopping angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, or a combination of both, compared with continuing these treatments, improves or stabilises kidney function in patients with progressive stages 4 or 5 chronic kidney disease based on assessment of kidney function using the modification of diet in renal disease four-variable estimated glomerular filtration rate at 3 years, follow-up. Setting Thirty-seven UK hospitals with kidney services. Design An investigator-led multicentre open-label, randomised controlled trial of 411 participants with advanced (stage 4 or 5) progressive chronic kidney disease. Participants Adult patients with advanced (estimated glomerular filtration rate 50% decline in estimated glomerular filtration rate or commencement of kidney replacement therapy (including end-stage kidney disease), cystatin C, hospitalisations, blood pressure, exercise capacity and quality of life. Cardiovascular events, death and safety were recorded. Results At 3 years, the least-squares mean (± standard error) estimated glomerular filtration rate was 12.6 ± 0.7 ml/minute/1.73 m2 in the discontinuation group and 13.3 ± 0.6 ml/minute/1.73 m2 in the continuation group [difference −0.7, 95% confidence interval (−2.5 to 1.0; p = 0.42)] with a negative value favouring the continuation group. The treatment effect did not differ (heterogeneity) when data were analysed by the pre-specified subgroups. End-stage kidney disease or kidney replacement therapy occurred in 128 (62%) and 115 (56%) participants randomised to the discontinue and continue renin–angiotensin system inhibitor groups, respectively (hazard ratio 1.28, 95% confidence interval 0.99 to 1.65). The numbers of cardiovascular events and deaths observed were similar for those randomised to discontinue (108 events and 20 deaths) or continue (88 events and 22 deaths) renin–angiotensin system inhibitors. Limitations Non-white ethnic backgrounds were poorly represented, limiting the generalisability of our findings. The open-label nature of the trial may have affected clinical care and subjective end points, such as quality of life and exercise capacity. We only included patients who were receiving renin–angiotensin system inhibitors at the time of randomisation, thus excluding those who had already discontinued these agents. Conclusions Discontinuing renin–angiotensin system inhibitors in advanced and progressive chronic kidney disease does not cause a clinically relevant change in estimated glomerular filtration rate or difference in its long-term decline. Future work Future work should focus on updating clinical guidelines. Further analyses, in addition to the prespecified analyses, may be undertaken if new estimated glomerular filtration rate equations are introduced into clinical practice. Subgroup analysis by kidney disease aetiology and gender may be undertaken to look for potential differences in outcome in specific groups. Trial registration This trial is registered as STOP ACEi EudraCT Number, 2013-003798-82; ISRCTN62869767. Funding This award was funded by the Efficacy and Mechanism Evaluation (EME) programme (NIHR award ref: 11/30/07), a Medical Research Council (MRC) and National Institute for Health and Care Research (NIHR) partnership. This is published in full in Efficacy and Mechanism Evaluation; Vol. 11, No. 5. See the NIHR Funding and Awards website for further award information. Plain language summary Drugs called angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, together known as renin–angiotensin system inhibitors, are used to treat high blood pressure, slow worsening kidney function and lower the risk of kidney failure (known as end-stage kidney disease which requires treatment with dialysis or kidney transplantation) in patients with early chronic kidney disease. However, we did not know if patients treated with renin–angiotensin system inhibitors and who have progressed to more advanced chronic kidney disease (stage 4 or 5) should stop or continue renin–angiotensin system inhibitors. To determine whether stopping renin–angiotensin system inhibitors in people with advanced chronic kidney disease leads to an improvement or stabilisation of kidney function required a study comparing the outcomes of people who had had these drugs stopped with a group who continued these drugs (the STOP-angiotensin-converting enzyme inhibitors trial). We recruited 411 participants with advanced chronic kidney disease who were receiving renin–angiotensin system inhibitors from 37 kidney units in the UK, and randomly (like flipping a coin) allocated them to either stop or continue renin–angiotensin system inhibitors. We then compared kidney function between the two groups at 3 years. We also assessed whether stopping or continuing renin–angiotensin system inhibitors had an influence on the development of end-stage kidney disease or need for kidney replacement therapy, the number of hospitalisations, blood pressure, quality of life and physical function. We collected data on safety outcomes including death and heart-related events (such as heart attacks). The results of the trial showed no difference in kidney function at 3 years. The number of participants requiring dialysis, or a kidney transplant was also similar, as was the quality of life and physical function between the groups. Deaths and the number of heart events were similar in both groups. This research suggests that there is no benefit in stopping renin–angiotensin system inhibitors in patients with advanced chronic kidney disease. Scientific summary Background Renin–angiotensin system (RAS) inhibitors, both angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB), slow the progression of mild and moderate chronic kidney disease (CKD). However, some evidence suggests that discontinuation of RAS inhibitors in patients with advanced CKD might increase estimated glomerular filtration rate (eGFR) or slow its decline. Primary objective To test the hypothesis that discontinuing ACEi or ARB treatment, or a combination of both, compared with continuing on these treatments, improves or stabilises kidney function in patients with progressive stage 4 or stage 5 CKD based on assessment of kidney function using the modification of diet in renal disease (MDRD) four-variable eGFR at 3 years follow-up. Secondary objectives To test whether in each of the randomised groups. Clinical outcomes The number of participants starting kidney replacement therapy (KRT) (dialysis or transplantation) or sustaining a > 50% decline in eGFR differs. There is a difference in the time taken to reach end-stage kidney disease (ESKD) or need for KRT. Hospitalisation rates from any cause are different. Participant quality of life and well-being [measured using the kidney disease quality of life (KDQoL)-SF™ v1.3 questionnaire] differs. Participant physical function (measured using the 6-minute walk test) differs. Withdrawal of these treatments does not cause excess harm [e.g. increased cardiovascular (CV) events such as heart failure, hypertension, myocardial infarction, stroke] and is not associated with an increase in adverse effects. Participant survival in each group is similar. Blood pressure (BP) control is the same. Cystatin-C levels differ. Mechanistic outcomes There is a change in urine protein excretion [urinary protein-to-creatinine ratio (uPCR)]. Discontinuation of ACEi/ARB affects haemoglobin concentration. Discontinuation of ACEi/ARB affects the requirement for erythropoietin stimulating agents. Methods An investigator-initiated, multicentre, open-label randomised trial where people with advanced and progressive CKD (eGFR 50% decline in eGFR or need to start KRT (including ESKD) was 140/206 (68%) in the discontinue RAS inhibitor group compared to 127/202 (63%) in the continue RAS inhibitor group; RR 1.07, 95% CI 0.94 to 1.22. The number of hospitalisations were similar between the groups; 414 in the stop RAS inhibitor group versus 413 in the continue RAS inhibitor group. The difference in LS-Mean at 3 years for systolic BP was 0 mmHg, 95% CI −4 to 5 mmHg. The results were similar for diastolic BP; 0 mmHg, 95% CI −2 to 3 mmHg. Adverse events were similar in both the discontinuation group and continuation group with respect to CV events (108 vs. 88) and deaths (20 vs. 22). Conclusions Our STOP-ACEi trial showed that discontinuing RAS inhibitors for patients with advanced and progressive CKD does not lead to a clinically relevant change in eGFR or difference in the rate of long-term decline in eGFR, overall or in pre-specified subgroups by age, severity of CKD, diabetes, proteinuria or BP. Numerically more patients who discontinued RAS inhibitors had progression to ESKD or need for KRT, so a larger trial might have shown an advantage to continuing with RAS inhibition. The rate of CV events and death was similar. Systolic and diastolic BP and proteinuria were greater over the first year of follow-up in those randomised to discontinue RAS inhibitors but there was little difference, thereafter, reflecting initiation of antihypertensive agents other than RAS inhibitors. No differences in quality of life or exercise capacity were observed for those who discontinued or continued RAS inhibitors. Our trial lacked sufficient power to investigate the effect of withdrawing RAS inhibitors on CV events or mortality. However, because our trial suggests that there is no advantage in discontinuing RAS inhibitors from the perspective of kidney function, there is little rationale to conduct a larger randomised trial to investigate CV safety. Future work Future work should initially focus on updating clinical guidelines in the UK and potentially worldwide. Further analyses, in addition to the prespecified analyses, may be undertaken if new eGFR equations are introduced into routine clinical practice such as the National Institute for Health and Care Excellence recommended removal of black ethnicity correction factor from the eGFR equation. Consideration of subgroup analysis by aetiology of kidney disease and gender will be considered to look for any potential differences in outcome in specific groups which might warrant future studies. Trial registration This trial is registered as STOP ACEi EudraCT Number, 2013-003798-82; ISTRCTN62869767. Funding This award was funded by the Efficacy and Mechanism Evaluation (EME) programme (NIHR award ref: 11/30/07), a Medical Research Council (MRC) and National Institute for Health and Care Research (NIHR) partnership. This is published in full in Efficacy and Mechanism Evaluation; Vol. 11, No. 5. See the NIHR Funding and Awards website for further award information.
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