Leicester Clinical Trials Unit



Logo - EASY AS Study


Email: easyas@leicester.ac.uk

Key Information

Trial Title

A Randomised Controlled Trial of Early valve replacement in severe ASYmptomatic Aortic Stenosis (EASY-AS)

Chief Investigators 

Professor Gerry McCann (UK)

Professor Graham Hillis (Australia)


University of Leicester (UK)

University of Western Australia (Australia)

University of Auckland (New Zealand)


British Heart Foundation (UK)

Medical Research Future Fund (Australia)

Heart Foundation (New Zealand)

Trial Registration Number

ClinicalTrials.gov Identifier: NCT04204915


Aortic stenosis (AS) is a common life-threatening condition in which one of the four heart valves becomes narrowed over many years. Symptoms can include shortness of breath and chest pain, but these can take years to develop and some patients never develop symptoms at all. Patients who do have symptoms can have the valve replaced. This works really well, but as with any intervention, there is the chance of complications, and it often takes a long time to recover from.

Heart surgery is a very good treatment for patients with symptoms but can cause complications and is often associated with prolonged recovery. The dilemma is therefore: should we operate in everyone when the AS is severe to avoid the risk of heart failure and death or wait until symptoms develop so that patients are spared unnecessary surgery?

This study is investigating whether it is better for patients in the long run to have the aortic valve replacement (AVR) straight away, or to wait until the symptoms develop before this is done. The results will also tell us which is more cost effective for the health service, both in the UK and internationally, and will therefore directly impact on the management of tens of thousands of patients in the UK and hundreds of thousands worldwide.

Number of Participants

We will randomise 2844 participants with severe asymptomatic AS to either early aortic valve surgery or to continue monitoring with replacement of the narrowed valve only when symptoms develop. 

Trial Design

Pragmatic, multi-centre, prospective, parallel group, open randomised controlled trial.

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