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Predicting AF after Cardiac Surgery - the PARADISE Score. A Clinical Prediction Rule for Post-operative Atrial Fibrillation in Patients Undergoing Cardiac Surgery


Why is this study being done?

Atrial Fibrillation (AF) is a common abnormal heart rhythm. AF causes the heart to beat irregularly and sometimes very rapidly. About 30-50% of patients develop AF after heart surgery. These patients stay longer on the Intensive Care Unit (ICU) after surgery, are more likely to develop complications and have a higher risk of dying. Avoiding AF is important.

Some drugs, including beta blockers and amiodarone may help prevent AF if given after surgery. However, these may also lead to complications (such as lung damage). It is therefore important to identify which patients are most likely to benefit from these treatments (i.e., where the benefits outweigh the risks). There are existing tools designed to predict the risk of suffering AF after heart surgery. However, they are unreliable and therefore not used in clinical practice. A modern, reliable risk prediction tool is needed.

What is the purpose of the study?

We will develop two reliable prediction models to identify which patients are at greatest risk of developing Atrial Fibrillation (AF) following heart surgery. One will predict the risk at assessment prior to surgery, and the second will predict who may develop AF after surgery.  (Two models are needed as changes during surgery may alter the risk of AF).

Whose data is included in this study?

The study will include anonymised data from patients who have undergone heart surgery in the United States and United Kingdom. In the UK, this will include patients whose information is held in the CALIBER database at University College London (, whose surgery took place at Liverpool Heart & Chest Hospital (LHCH) and Barts Heart Centre (BHC), Oxford University Hospital NHS Trust, or who participated in the Tight-K trial (

What if I don’t want my data to be included?

If you decide you do not want your data to be used for this study you can withdraw at any time, without affecting your medical care. There are a couple of ways to do this. You can register with the NHS Opt-out scheme ( ) to ensure your data are not used for research. Data providers use a service provided by NHS Digital to ensure that data of individuals who have indicated that they do not wish their data used for research purposes The data providers will exclude these patients before anonymising patient data and transferring it securely to the study office at the University of Oxford.


You can also contact the study team ( or Chief investigator, Peter Watkinson ( directly to inform us that you do not wish your data to be used. We will ask the individual data providers to contact you. They will ask for your identifiers (e.g., name, NHS number) and your data will be removed from the data set before the anonymised version is transferred to the University of Oxford.

Your personal data is also protected by the General Data Protection Regulation and Data Protection Act 2018. Further details of these protections are given below.

Are there any possible disadvantages or risks from taking part?

This study will analyse anonymised patient data and will not intervene in the care of patients.

What are the possible benefits of taking part?

Including your data in the study will help us design better system to find patients who are most at risk at developing an abnormal heart rhythm after surgery. This will allow us to ensure these patients get appropriate preventative treatments.

Will my taking part in the study be kept confidential?

The study will use anonymised data to construct a research database of patients who have undergone cardiac surgery. This will include information such as blood test results, details of the surgery and participants’ chronic diseases.

All hospitals involved in the study will anonymise participants’ data before transferring it securely to the study office at the University of Oxford. NHS Digital will remove any participants who have indicated that they do not wish their data used for research purposes ( All data will be stored, accessed and analysed within a secure computing system that conforms to UK government Cyber Essentials Plus and NHS Digital Security Toolkit certifications. Responsible members of the University of Oxford and the relevant NHS Trusts]may be given access to data for monitoring and/or audit of the study to ensure that the research is complying with applicable regulations.

As part of creating the research data sets participating hospital may access participants’ personal information (date of birth, NHS number, postcode, and gender – known as direct identifiers) to link data between different hospital systems (e.g., laboratory and theatre management systems). No direct identifiers will be communicated to the study office at any time and will not be retained in the study database While the information received is specific to each study participant, no individual person will be identifiable in any publication arising from this work. Your personal data will not be shared with any third parties and will not be used for any automated decision making or profiling.

What will happen to my data?

Data protection regulation requires that we state the legal basis for processing information about you.  In the case of research, this is ‘a task in the public interest.’ The University of Oxford is the data controller and is responsible for looking after your information and using it properly. 

We will be using information from hospital medical records in order to undertake this study and will use the minimum personally-identifiable information possible. The participating sites will keep identifiable information about you for 12 months after the study has finished. Research documents with anonymised data will be held securely at the University of Oxford for up to five years after the end of the study.

Data protection regulation provides you with control over your personal data and how it is used. If you have not opted-out of your information being used in research, however, some of those rights may be limited in order for the research to be reliable and accurate. Further information about your rights with respect to your personal data is available at

For further information, please see the PARADISE Privacy Notice:

What will happen to the results of this study?

While the information received is specific to each study participant, no individual person will be identifiable in any publication arising from this work.

The key outputs of the study will be two prediction models, PARADISE 1 and PARADISE 2 to identify patients at risk of AF after cardiac surgery. We will publish these models in academic journals and present our results at relevant conferences. and the AF Association and Arrhythmia Alliance, the two largest patient advocacy groups will help us develop and disseminate public and patient information both during and after the project. We will work with these organisations both to publicise study progress and to share our findings.

What if there is a problem?

The University of Oxford, as Sponsor, has appropriate insurance in place in the unlikely event that you suffer any harm as a direct consequence of this study.

If you wish to complain about any aspect of the study, or have further questions on how your information is handled during the course of this study, you should contact Peter Watkinson ( or you may contact the University of Oxford Clinical Research Governance Ethics and Assurance (RGEA) office on 01865 616480, or the head of RGEA, email

How have patients and the public been involved in this study?

Patient and public involvement is integral to our work. We have one patient and one public member on our research team. Both bring experience from our previous database projects. They take part in meetings considering the importance and identification of risk factors and be a key part of our dissemination strategy.

The patient advocacy groups for heart rhythm problems, and the Arrhythmia Alliance and AF Association helped us with this application and will help with dissemination. We will also involve our local NIHR Biomedical Research Centre (BRC) Patient and Public Involvement (PPI) oversight group to help us inform and engage the wider community.

Who is organising and funding the study?

The study is being conducted by researchers at the University of Oxford, which acts as the sponsor for the research.

Who has reviewed the study?

All research in the NHS is looked at by an independent group of people, called a Research Ethics Committee, to protect participants’ interests. This study has been reviewed and given favourable opinion by East of England – Cambridge East Research Ethics Committee.

The study has supported from the Confidentiality Advisory Group, to use patient data without study-specific consent. This permission is given under Section 251 of the National Health Service Act 2006 and its current regulations, the Health Service (Control of Information Regulations 2002) – CAG reference number 20/CAG/0097