For Trial Participants

 The STOP-ACEi trial has now closed to recruitment having reached its target number of participants. 


What is STOP-ACEi?

STOP-ACEi is a clinical trial that will test if stopping treatment with drugs that target the Angiotensin system, known as Angiotensin Converting Enzyme inhibitors (ACEi) and Angiotensin Receptor Blockers, is beneficial for patients with advanced Chronic Kidney Disease.

Background and study aims

Chronic kidney disease (CKD) affects 1 in 10 adults in the UK and describes progressive loss of kidney function, regardless of the original kidney disease. CKD can have serious implications for those affected, including a risk of CKD progressing to complete kidney failure so that replacement of kidney function by dialysis or transplantation is required. Kidney disease is expensive, with a high proportion of the health-care budget spent on CKD; the cost of dialysis alone is ~£30,000/year. Dialysis can also have a profound effect on patient quality of life. Treating high blood pressure (BP) is the most important intervention that can slow CKD progression. Some people with CKD gain additional protection from Angiotensin Converting Enzyme inhibitors (ACEi) or Angiotensin Receptor Blockers (ARBs). These drugs treat high BP but also slow CKD progression by other means.

However recent research suggests that in some people with advanced CKD (stages 4 & 5) who are progressing to complete kidney failure and are receiving treatment with an ACEi and/or ARB, stopping these drugs leads to stabilisation and improvement of kidney function and decreases or delays the need for dialysis. This indicates that in some patients the very tablets used to protect the kidneys may be contributing to a harmful decline in their kidney function by a currently unknown mechanism.

To date, research on this is observational and a study to confirm the association between stopping these drugs and stabilisation of kidney function is required. In the STOP-ACEi trial we will randomly allocate suitable participants to either continue or stop their ACEi/ARB treatment and follow-up participants for 3 years. This study is needed before this treatment strategy can be put into routine clinical practice. In addition we will look at other effects of stopping these drugs such as cardiovascular effects and participant quality of life.

Who can participate and what does the study involve?

People under the care of kidney specialists who have stage 4 or 5 Chronic Kidney Disease (CKD) can participate in the study. Participants must be aged 18 years or over and be receiving treatment with either an ACEi or ARB, or combination or both. We are asking 410 patients with advanced kidney disease in hospitals across the UK to take part.

What are the possible benefits and risks of participating?

Participants will either stop their existing ACEi and/or ARB therapy or continue with their current normal treatment. Participants in research studies such as this receive very close monitoring, which will be advantageous to their general health. Although participants may not receive any individual benefit from taking part in the trial, the information we get from the trial may help us to improve the treatment of all people in the UK with stage 4 or 5 CKD in the future.

It is not currently known whether treatment with ACEi and/or ARBs is beneficial for people with stage 4 or 5 CKD. Some recent research suggests that withdrawing ACEi and/or ARB treatment may be beneficial for people with stage 4 or 5 CKD, but more research needs to be done to clarify whether the benefits of withdrawing ACEi and/or ARB treatment outweigh the risks. There is a risk that stopping ACEi and/or ARB treatment may cause a rise in blood pressure, but participants' blood pressure will controlled with other medications during the trial. In a previous small trial, there was no evidence of increased heart problems from stopping ACEi and/or ARB therapy. However the potential risk of increased heart problems for participants will be carefully assessed throughout the trial.

When will the trial take place?

Trial recruitment has now closed. Each participant taking part in the trial will be followed-up in clinic every 3 months over a period of 3 years. There should be no need for additional clinic visits purely for trial purposes as visits will be every 3 months, which is in keeping with routine clinical practice for CKD patients. The trial has been funded for a total of 6 years allowing for 6 months set up, 2 years recruitment, 3 years follow-up and 6 months data analysis and report writing.

Study set-up and contact details

The STOP-ACEi Chief Investigator is Prof Sunil Bhandari who is based at Hull and East Yorkshire Hospitals NHS Trust (

The STOP-ACEi trial is being co-ordinated by the Birmingham Clinical Trials Unit (

STOP-ACEi has been funded by the National Institute for Health Research and Medical Research Council Efficacy and Mechanism Evaluation Programme (NIHR/MRC EME) Ref: 11/30/07.

STOP-ACEi is sponsored by Hull and East Yorkshire Hospitals NHS Trust.

STOP-ACEi has been approved by the Yorkshire and The Humber, Leeds East Research Ethics Committee (REC), Ref. No: 13/YH/0394.

EudraCT Number: 2013-003798-82


Please click here to download the Participant Information Sheet which contains further details on the STOP-ACEi trial. This was given to every patient who was invited to take part in the trial.