Condition category
Circulatory System
Date applied
04/02/2019
Date assigned
11/02/2019
Last edited
15/02/2019
Prospective/Retrospective
Prospectively registered
Overall trial status
Ongoing
Recruitment status
Recruiting

Plain English Summary

Background and study aims
Atrial fibrillation is a heart problem that causes an irregular heartbeat. It can cause the heart to beat more rapidly and reduce the heart’s ability to pump blood around the body efficiently. It also increases the risk of blood clots forming inside the heart. These clots may then be pumped out of the heart, through the blood vessels, to other parts of the body. This causes strokes if they spread to the brain.

Atrial fibrillation is a common problem in patients outside intensive care units (ICUs). Good, evidence-based, guidelines exist to help doctors treat people who develop this condition.
Around 10% of people treated on an ICU develop atrial fibrillation as a complication of their severe underlying illness. This additional problem makes them more unstable so they stay longer in the ICU and are more likely to die. Atrial fibrillation therefore needs prompt and effective treatment to prevent further harm.

Treatments for atrial fibrillation that work in people who are otherwise well may not work in people who are already very ill before their heart changes rhythm. This means that guidelines for treating atrial fibrillation outside ICU are not helpful for patients treated on an ICU. There is uncertainty about the best treatment, and practices differ between countries and between different ICUs in the same country.

People who have atrial fibrillation outside an ICU are often given medications such as warfarin (commonly referred to as a “blood-thinner”) to reduce their risk of stroke. However these medications can cause bleeding. Risk scoring systems are used to help doctors balance the risk of bleeding against the risk of stroke but these scoring systems may not work for patients admitted to ICUs. This is because their risk of bleeding is higher and their risk of stroke is not well understood.

Our research will bring together the best evidence on which to base improved guidelines for the treatment of patients who develop atrial fibrillation on an ICU. We will start with a review of all published research and expert opinions. This is called a scoping review. It will also suggest the best areas for future research.

Who can participate?
With permission, we will use databases of medical records of patients treated on ICUs to investigate the benefits and harms of existing treatments for atrial fibrillation. Using existing data is a cost-efficient way to work out which treatments need more detailed investigation.

We will use two databases, PICRAM and MIMIC-III, to see which treatments appear to work best for atrial fibrillation. PICRAM is a large detailed research database of patients admitted to three ICUs in the UK. It includes information about 18,000 patients. MIMIC-III holds similar data on 52,000 patients from the ICUs of one large US hospital. Many treatments are different in the two countries, including treatment for atrial fibrillation.

The NIHR HIC critical care database holds some of the clinical details on 40,000 patients from five UK ICUs. We will use this to check some of our findings.

What does the study involve?
To understand how we could improve outcomes for patients who develop atrial fibrillation on an ICU by thinning their blood, we need to know how frequently strokes occur, both in hospital and after they go home. We will use the RISK-II database of over 900,000 patients treated on 200 ICUs in England to estimate how many patients suffered a stroke in hospital and after discharge.

What are the possible benefits and risks of participating?
Not applicable

Where is the study run from?
University of Oxford, Kadoorie Centre for Critical Care Research & Education, Level 3 John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU, UK

When is the study starting and how long is it expected to run for?
February 2019 to August 2020

Who is funding the study?
National Institute for Health Research Health Technology Assessment

Who is the main contact?
Julie Darbyshire, julie.darbyshire@ndcn.ox.ac.uk

Trial website

[under construction]

Contact information

Type

Public

Primary contact

Ms Julie Darbyshire

ORCID ID

http://orcid.org/0000-0002-7655-1963

Contact details

University of Oxford Critical Care Research Group
Nuffield Department for Clinical Neurosciences
Kadoorie Centre for Critical Care Research & Education
Level 3
John Radcliffe Hospital
Headley Way
Headington
Oxford
OX3 9DU
United Kingdom
01865 223101
ccrg@ndcn.ox.ac.uk

Type

Scientific

Additional contact

Dr Peter Watkinson

ORCID ID

Contact details

University of Oxford Critical Care Research Group
Nuffield Department for Clinical Neurosciences
Kadoorie Centre for Critical Care Research & Education
Level 3
John Radcliffe Hospital
Headley Way
Headington
Oxford
OX3 9DU
United Kingdom

Additional identifiers

EudraCT number

Nil known

ClinicalTrials.gov number

Nil known

Protocol/serial number

Nil known

Study information

Scientific title

Critical Care Atrial Fibrillation Evaluation: a scoping review and data base analysis

Acronym

CAFE

Study hypothesis

Scoping review
1. To evaluate the evidence for the effectiveness and safety of:
a. pharmacological and non-pharmacological (electrical, electrolyte, fluid) New-onset atrial fibrillation (NOAF) treatments; and
b. acute anticoagulation.

2. To provide guidance for the database analysis on:
a. NOAF definitions used in patients on an ICU;
b. patient subgroups who develop NOAF on an ICU; and
c. inclusion/exclusion of specific treatments and potential confounders.

3. To determine barriers to future research.

Database analysis
1. To compare the use and effectiveness of pharmacological and non-pharmacological NOAF treatments with respect to heart rate and rhythm control.
2. To assess anticoagulation use, effect on thromboembolic complications and safety.
3. To determine the incidence of short and long-term complications of NOAF and identified treatments.

Ethics approval

Approved 17/07/2019, Committee on Clinical Investigations (Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215, USA; +1 617-975-8511, alisbon@bidmc.harvard.edu), ref: 2001P001699

Study design

Two phase project. Phase 1: scoping review; Phase 2: retrospective database analysis

Primary study design

Other

Secondary study design

Trial setting

Hospitals

Trial type

Other

Patient information sheet

N/A

Condition

Patients who experience new onset atrial fibrillation (NOAF) during their admission for intensive care

Intervention

None - retrospective data analysis & review of literature only

Intervention type

Other

Phase

Drug names

Primary outcome measure

To evaluate the evidence for the effectiveness and safety of treatment for new onset atrial fibrillation (NOAF) in the intensive care unit

Secondary outcome measures

1. To assess anticoagulation use and their effect on thromboembolic complications and safety
2. To determine the incidence of short and long-term complications of NOAF and identified treatments
3. To determine barriers to future research in the field

Overall trial start date

30/11/2017

Overall trial end date

31/07/2019

Reason abandoned (if study stopped)

Eligibility

Participant inclusion criteria

To be included in the retrospective data analysis phase of the project patients must have been admitted to one of the intensive care units included in the PICRAM & MIMIC-III datasets

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

~1,000,000 across all datasets

Participant exclusion criteria

1. Patients with known prior AF
2. Patients (and studies for the scoping review) with evidence of NOAF outside of the intensive care unit

Recruitment start date

01/04/2019

Recruitment end date

31/05/2020

Locations

Countries of recruitment

United Kingdom, United States of America

Trial participating centre

University of Oxford
Kadoorie Centre for Critical Care Research & Education, Level 3 John Radcliffe Hospital, Headley Way, Headington
Oxford
OX3 9DU
United Kingdom

Trial participating centre

ICNARC
Napier House, 24 High Holborn
London
WC1V 6AZ
United Kingdom

Trial participating centre

University of York
Centre for Reviews and Dissemination, University of York
York
YO10 5DD
United Kingdom

Sponsor information

Organisation

University of Oxford

Sponsor details

Joint Research Office
1st Floor
Boundary Brook House
Churchill Drive
Headington
Oxford
OX3 7GB
United Kingdom

Sponsor type

University/education

Website

https://researchsupport.admin.ox.ac.uk/ctrg

Funders

Funder type

Government

Funder name

National Institute for Health Research

Alternative name(s)

NIHR

Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government

Location

United Kingdom

Results and Publications

Publication and dissemination plan

Planned publication in a high-impact peer-reviewed journal

IPD sharing statement:
The datasets generated during and/or analysed during the current study are available from the corresponding author (ccrg@ndcn.ox.ac.uk) on reasonable request

Intention to publish date

31/12/2020

Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

15/02/2019: Internal review.