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19/132 A clinical prediction rule for post-operative atrial fibrillation in patients undergoing cardiac surgery




The aim of the HTA Programme is to ensure that high quality research information on the effectiveness, costs and broader impact of health technology is produced in the most efficient way for those who use, manage, provide care in or develop policy for the NHS. Topics for research are identified and prioritised to meet the needs of the NHS. Health technology assessment forms a substantial portfolio of work within the National Institute for Health Research and each year about fifty new studies are commissioned to help answer questions of direct importance to the NHS. The studies include both primary research and evidence synthesis.

Research Question:

Can a clinical prediction rule be refined/developed and validated that allows patients undergoing cardiac surgery to be identified as being at 'normal' or 'elevated' risk of developing post-operative atrial fibrillation, in order to guide prophylactic treatment?

  1. Technology: A clinical prediction rule for the development of post-operative atrial fibrillation to stratify patients undergoing cardiac surgical procedures.
  2. Patient group: Adult patients undergoing cardiac surgery. The research should include any type of cardiac surgery as appropriate; applicants should specify and justify their choice of procedures they wish to include.
  3. Setting: Secondary and tertiary care.    
  4. Study design:
    • Refinement/development of a clinical prediction rule, using routine data and data sets as appropriate (applicants to specify and justify). The tool should be able to stratify patients by risk group, taking into account the relative weight of individual risk factors and their cumulative risk.
    • A prospective study to evaluate the predictive performance of the tool – design to be defined and justified by applicants. Applicants should explain how they will overcome challenges arising from the use of treatments during the study.
  5. Outcomes and outputs: A clinical prediction rule; measures of predictive performance; how the results might affect medication choice; trade-off between under- and over-stratification.  


Postoperative atrial fibrillation is the most common side effect of heart surgery. It may occur during or shortly after any type of procedure but appears to be most common in coronary artery bypass graft surgery, valve replacement or repair, and in combined bypass/valve surgery. Patients who develop postoperative atrial fibrillation usually require a longer intensive care or hospital stay compared to those without the complication, and they are at increased risk of experiencing a stroke or other serious long-term conditions.

The NICE guideline on atrial fibrillation (CG180) and other expert guidance recommend preventative treatment prior to, during, and after surgery, in order to reduce the risk of developing postoperative atrial fibrillation. Different drugs are available for this purpose, and experts suggest the choice of medication should be based on the patient's individual risk of developing postoperative atrial fibrillation.

Several tools have been developed in the past that identify risk factors of postoperative atrial fibrillation. However, most of these do not show sufficient predictive performance, and many did not undergo independent validation. None of the existing tools is currently able to estimate the relative weight of individual risk factors, to identify patients' cumulative risk, and to stratify patients by risk group.  

The HTA programme therefore wishes to commission a study to refine (or develop) and validate a clinical prediction rule to assess the risk of postoperative atrial fibrillation. If successful, the tool would guide clinicians to provide risk-based prophylactic treatment. This could reduce the number of people who experience post-operative atrial fibrillation and its long-term implications on patients' health and healthcare needs. 

Additional commissioning brief background information

A background document is available that provides further information to support applicants for this call. It is intended to summarise what prompted the call and the existing evidence base, including relevant work from the HTA and wider NIHR research portfolio. It was researched and written on the basis of information from a search of relevant sources and databases, and in consultation with a number of experts in the field. If you would like a copy please email

Making an application

If you wish to submit a Stage 1 application for this call, the online application form can be found on the Funding opportunities page.  To select this call, use the filters on the right of the screen or search using the call name and/or number.

Your application must be submitted on-line no later than 1pm on the 29th January 2020. Applications will be considered by the HTA Funding Committee at its meeting in March 2020.

Guidance notes and supporting information for HTA Programme applications are available by clicking the links.

IMPORTANT: Shortlisted Stage 1 applicants will be given eight weeks to submit a Stage 2 application. The Stage 2 application will be considered at the Funding Committee in July 2020.

Applications received electronically after 1300 hours on the due date will not be considered.

Should you have any queries please contact us:


General Funding Committee 02380 595630