Birmingham Clinical Trials Unit will close at 1700 GMT on Monday 20th December 2021 and reopen Tuesday 4th January 2022. Please continue to report Serious Adverse Events as usual. Any urgent queries during this time should be directed to the CI (, copying in the Trial Mailbox (

STOP-ACEi is a national multi-centre randomised controlled trial of Angiotensin Converting Enzyme inhibitor (ACEi) / Angiotensin Receptor Blocker (ARB) withdrawal in advanced renal disease.

Important Message: COVID-19
We are now home-based during the COVID-19 pandemic but available and working. Responses may however take longer than normal as staff may be working altered hours but we are cross covering trials as required and urgent matters will be dealt with promptly. Please do not contact our usual office/landline number and instead email the trial contact and copy in the trial mailbox. If a query requires a prompt response please mark as ‘urgent’ in the email subject header.

Trial details

Full Title: Multi-centre Randomised Controlled Trial of Angiotensin Converting Enzyme inhibitor (ACEi) / Angiotensin Receptor Blocker (ARB) withdrawal in advanced renal disease

Short Title: The STOP-ACEi Trial

Aim of the study: To test the hypothesis that stopping treatment with ACEi, ARB or a combination of both, compared with continuing on these treatments, improves or stabilises renal function in patients with progressive stage 4 or 5 Chronic Kidney Disease (CKD).

Study design: Open-label randomised controlled trial (RCT).

Sample size: 410 patients will be recruited into the study (205 in each arm).

Study Duration: The trial closed to recruitment in June 2018 after reaching the required sample size. All patients in the trial will be followed up for 36 months. 

Timeframes: NIHR/MRC EME programme grant start date: 1st February 2014. Trial set up will take place in 6 months, recruitment will take 24 months, all patients will be followed up for 36 months and 6 months has been allocated for data analysis and report writing. We aim to recruit the first participant in April/May 2014.


Chief Investigator: Prof Sunil Bhandari

Trial Sponsor: Hull University Teaching Hospitals NHS Trust. Ref.: R1578.

Funding: National Institute for Health Research and Medical Research Council Efficacy and Mechanism Evaluation programme (NIHR/MRC EME). Ref: 11/30/07.

EudraCT Number: 2013-003798-82

MHRA CTA: 21411/0242/001-0001 (12th December 2013).

Research Ethics Committee: Yorkshire and The Humber, Leeds East. Ref: 13/YH/0394. (29th January 2014).


NIHR CRN Study ID: 15908

IRAS project ID:138827


STOP-ACEi Protocol v3.0 (14th May 2014)

STOP-ACEi Online Data Entry

Contact the STOP-ACEi trial team