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A CALIBER Study: Risk Factors for Stroke, Heart Failure, and Myocardial Infarction in Atrial Fibrillation

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01944397
Recruitment Status : Unknown
Verified September 2013 by University College, London.
Recruitment status was:  Active, not recruiting
First Posted : September 17, 2013
Last Update Posted : September 17, 2013
London School of Hygiene and Tropical Medicine
St Bartholomews and The Royal London Hospital
Information provided by (Responsible Party):
University College, London

Brief Summary:
We aim to investigate the prognosis of patients diagnosed with AF, particularly in relation to the development of subsequent stroke, heart failure, and myocardial infarction. We will explore the relationship between these outcomes and a range of risk factors.

Condition or disease
Atrial Fibrillation Heart Failure Stroke Myocardial Infarction

Detailed Description:

The development of stroke in AF patients continues to be an area of substantial research focus. However, comparatively little research has investigated the extent to which HF and MI also make a substantial contribution to morbidity and mortality in this patient group, and whether there is overlap in the prognostic factors associated development of stroke, HF, and MI.

Conen et al. demonstrated that mortality risk in AF patients is partly mediated by the development of non-fatal stroke, HF, and MI. However, they did not investigate differences in the cumulative incidence of these conditions between different patient groups (e.g. men and women), or the relationship between potential prognostic factors and the development of these conditions. Sets of prognostic factors for stroke and HF in AF patients have been defined through the development of prognostic models, but these models were developed specifically for each condition so it is unclear whether these prognostic factors are associated with increased risk of a particular condition, or simply any major adverse cardiovascular event. Additionally, some potentially important prognostic factors were not evaluated in these studies (e.g. anaemia and kidney failure).

Thus we chose to conduct an exploratory study of prognostic factors for HF, MI, and stroke in patients diagnosed with AF. We selected our candidate factors from those that have previously been associated with stroke, HF, or MI (in AF patients or the general population). Identification of prognostic factors for stroke, HF, and MI in those diagnosed with AF is a first step toward understanding both the development of these conditions, and the scope for targeting preventive treatments to improve prognosis.

This study will be undertaken using linked electronic health record data for primary and secondary care from CALIBER. This data set contains a broad range of clinically relevant, clinically conducted measurements of potential prognostic factors, and also provides a very large baseline sample from which we can draw a sufficient number of incident AF cases to investigate our three endpoints.

The study has two aims. First, to determine the cumulative incidence of fatal and non-fatal heart failure (HF), myocardial infarction (MI) and stroke (ischaemic, haemorrhagic, and NOS) in patients diagnosed with atrial fibrillation (AF). Differences between clinically relevant groups (e.g. men and women) will be explored. Second, to compare the direction and magnitude of associations between prognostic factors and the development of these conditions (HF, stroke, MI) in patients with AF. The following panels of prognostic factors will be investigated: sociodemographic; anthropomorphic and haemodynamic; behavioural; co-existing conditions (cardiovascular and non-cardiovascular); blood biomarkers; secondary preventive drugs.

This study is part of the CALIBER (Cardiovascular disease research using linked bespoke studies and electronic records) programme funded over 5 years from the NIHR and Wellcome Trust. The central theme of the CALIBER research is linkage of the Myocardial Ischaemia National Audit Project (MINAP) with primary care (GPRD) and other resources. The overarching aim of CALIBER is to better understand the aetiology and prognosis of specific coronary phenotypes across a range of causal domains, particularly where electronic records provide a contribution beyond traditional studies. CALIBER has received both Ethics approval (ref 09/H0810/16) and ECC approval (ref ECC 2-06(b)/2009 CALIBER dataset).

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Study Type : Observational
Estimated Enrollment : 125000 participants
Observational Model: Cohort
Time Perspective: Retrospective
Official Title: Risk Factors for the Development of Stroke, Heart Failure, and Myocardial Infarction in Patients Diagnosed With Atrial Fibrillation: a CALIBER Study
Study Start Date : December 2011
Estimated Primary Completion Date : December 2013
Estimated Study Completion Date : December 2014

Resource links provided by the National Library of Medicine

Atrial fibrillation
Patients with a diagnosis of atrial fibrillation recorded in primary or secondary care during the study period.

Primary Outcome Measures :
  1. Stroke (ischaemic, haemorrhagic, and NOS) [ Time Frame: Throughout follow-up (maximum 12 years) ]
  2. Myocardial infarction [ Time Frame: Throughout follow-up (maximum 12 years) ]
  3. Heart failure [ Time Frame: Throughout follow-up (maximum 12 years) ]

Secondary Outcome Measures :
  1. Non-cardiovascular mortality [ Time Frame: Throughout follow-up (maximum 12 years) ]
  2. Cardiovascular mortality [ Time Frame: Throughout follow-up (maximum 12 years) ]
    Excluding heart failure, myocardial infarction, stroke

Information from the National Library of Medicine

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Ages Eligible for Study:   30 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
Adults aged 30 years and over, registered with a CPRD practice that is up-to-standard, and having a minimum of one year of validated follow-up data. The index date is 1st January 1998 with follow-up ending on 26th March 2010, which corresponds to the administrative censoring date of the CPRD component of the CALIBER dataset.

Inclusion Criteria:

  • Patients with a coded diagnosis for atrial fibrillation in their primary or secondary care record.
  • Patients in GPRD practices which are deemed "up to standard" by GPRD criteria
  • Patients whose records are deemed "acceptable" by GPRD criteria and contain at least one year of data
  • Patients whose age and sex, as recorded in GPRD is the same as that recorded in HES.

Exclusion Criteria:

  • A diagnosis of heart failure, stroke, or myocardial infarction occurring before diagnosis of atrial fibrillation

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01944397

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United Kingdom
University College London
London, United Kingdom, WC1E 7H
Sponsors and Collaborators
University College, London
London School of Hygiene and Tropical Medicine
St Bartholomews and The Royal London Hospital
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Study Director: Harry Hemingway, FRCP University College, London
Principal Investigator: Katherine I Morley, PhD University College, London

Additional Information:
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Responsible Party: University College, London Identifier: NCT01944397     History of Changes
Other Study ID Numbers: CALIBER-12-03-PROG-18
086091/Z/08/Z ( Other Grant/Funding Number: Wellcome Trust )
RP-PG-0407-10314 ( Other Grant/Funding Number: NIHR )
G0902393 ( Other Grant/Funding Number: Medical Research Council (UK) )
First Posted: September 17, 2013    Key Record Dates
Last Update Posted: September 17, 2013
Last Verified: September 2013

Keywords provided by University College, London:
Atrial fibrillation
Heart failure
Myocardial infarction

Additional relevant MeSH terms:
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Heart Failure
Atrial Fibrillation
Myocardial Infarction
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vascular Diseases
Cardiovascular Diseases
Heart Diseases
Arrhythmias, Cardiac
Pathologic Processes
Myocardial Ischemia