The SPIRO-CKD trial has now closed.  A summary of the trial’s findings will be provided in due course.
Thank you to all of our collaborators for helping us to successfully deliver this important trial. 

SPIRO-CKD is a national clinical trial, funded by the British Heart Foundation, which will randomise 154 patients with early CKD to treatment with Spironolactone or to a different blood pressure lowering drug called Chlortalidone for a 40 week treatment period using a protocol designed to achieve an equal fall in blood pressure.

 SPIRO-CKD Newsletter_Results Issue January 2021 V1.0



SPIRO-CKD is a randomised, multicentre, open-label, blinded endpoint trial to compare the effects of Spironolactone to Chlortalidone on left ventricular mass and arterial stiffness in stage 2 and stage 3 chronic kidney disease

Aim of Study

The primary end points are heart muscle weight measured by magnetic resonance scans and arterial stiffness. The results should show whether or not the effects of spironolactone on the arteries and heart in patients with CKD are due to blood pressure lowering alone or are due to the special effects of spironolactone. If the effects are specific to spironolactone and occur over and above the blood pressure lowering effects, the drug may be a very effective and inexpensive way to prevent death and disability due to heart and artery disease in patients with CKD.


Four secondary care renal and cardiovascular units in England and Scotland.

Target population

Patients aged over 18 years with:

  • Diagnosis of stage 2 or stage 3 CKD (eGFR by 4 variable MDRD of 30-89 ml/min/1.73m2  on 2 occasions, at least 3 months apart)


  • Controlled blood pressure. The local PI must be satisfied that BP control will be clinically satisfactory during the 46 week study period.


  • On established (>6 weeks) treatment with ACE inhibitors or ARBs. 


Participants will be allocated to open-label treatment with either spironolactone 25 mg od. or chlortalidone at a dose of ½ a 50 mg tablet od.  The duration of treatment will be 40 weeks in total.