Is a Low Thyreotropin Level Predictive of Recurrent Arrhythmia After Catheter Ablative Surgery? (TABLAS)

This study is currently recruiting participants. (see Contacts and Locations)
Verified September 2015 by Karolinska Institutet
Information provided by (Responsible Party):
Peter Giesecke, M.D, Karolinska Institutet Identifier:
First received: February 5, 2013
Last updated: September 9, 2015
Last verified: September 2015

February 5, 2013
September 9, 2015
February 2013
October 2015   (final data collection date for primary outcome measure)
Prevalence of subclinical hyperthyroidism in patients undergoing atrial fibrillation ablation [ Time Frame: 1 day (Measured upon inclusion) ] [ Designated as safety issue: No ]
Same as current
Complete list of historical versions of study NCT01789541 on Archive Site
Recurrent atrial fibrillation after ablation [ Time Frame: 6 months ] [ Designated as safety issue: No ]
Same as current
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Is a Low Thyreotropin Level Predictive of Recurrent Arrhythmia After Catheter Ablative Surgery?
Observational Prospective Case-control Study on Prevalence and Impact of Subclinical Hyperthyroidism in Patients Undergoing Atrial Fibrillation Ablation

Overt hyperthyroidism (so-called "goiter" in lay language) is a hormonal disturbance that is known to increase the risk of atrial fibrillation (a common heart arrhythmia with potentially severe consequences) in some patients. Previous research has indicated that even slight elevations in thyroid hormone levels - so called subclinical hyperthyroidism - may increase this risk. When atrial fibrillation and overt hyperthyroidism are found simultaneously in a patient, the hormonal imbalance must be treated first in order to later resolve the arrhythmia. It is unclear whether this strategy holds true for subclinical hyperthyroidism. Our two hypotheses are: 1) Subclinical hyperthyroidism is more prevalent in patients admitted for atrial fibrillation ablation than in the population as a whole, and 2) Patients with subclinical hyperthyroidism and atrial fibrillation benefit less from ablation than others.

As a control group, we have chosen patients admitted for ablation of AV-nodal Reentry Tachycardia at the same clinics as the cases. No correlation has ever been shown between AV-nodal Reentry Tachycardia and hyperthyroidism.

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Observational Model: Case Control
Time Perspective: Prospective
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Probability Sample

Patients with atrial fibrillation (cases) or AV-nodal reentry tachycardia (controls)

  • Atrial Fibrillation
  • Subclinical Hyperthyroidism
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  • Atrial fibrillation
    Patients with atrial fibrillation undergoing ablation
  • AV-nodal reentry tachycardia
    Patients with AV-Nodal Reentry Tachycardia undergoing ablation
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*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
November 2015
October 2015   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • Atrial fibrillation or AV-nodal reentry tachycardia
  • Fulfills criteria for ablation (severe arrhythmia symptoms; for atrial fibrillation patients, having tried at least one antiarrhythmic agent with poor effect)
  • Admitted for ablation for the first time
  • Has left blood samples for thyroid status (TSH, free T4, free T3)

Exclusion Criteria:

  • Atrial flutter
  • Overt hyperthyroidism
18 Years and older
Contact: Peter Giesecke, M.D. +46 70 768 43 88
Peter Giesecke, M.D, Karolinska Institutet
Karolinska Institutet
Not Provided
Study Chair: Mårten Rosenqvist, Professor Karolinska Institutet, Institutionen för kliniska vetenskaper vid Danderyds sjukhus
Karolinska Institutet
September 2015

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP