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

This study has been completed.
Information provided by (Responsible Party):
Peter Giesecke, M.D, Karolinska Institutet Identifier:
First received: February 5, 2013
Last updated: January 19, 2016
Last verified: January 2016

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.

Atrial Fibrillation
Subclinical Hyperthyroidism

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Observational Prospective Case-control Study on Prevalence and Impact of Subclinical Hyperthyroidism in Patients Undergoing Atrial Fibrillation Ablation

Resource links provided by NLM:

Further study details as provided by Karolinska Institutet:

Primary Outcome Measures:
  • Prevalence of subclinical hyperthyroidism in patients undergoing atrial fibrillation ablation [ Time Frame: 1 day (Measured upon inclusion) ]

Secondary Outcome Measures:
  • Recurrent atrial fibrillation after ablation [ Time Frame: 6 months ]

Enrollment: 327
Study Start Date: February 2013
Study Completion Date: November 2015
Primary Completion Date: October 2015 (Final data collection date for primary outcome measure)
Atrial fibrillation
Patients with atrial fibrillation undergoing ablation
AV-nodal reentry tachycardia
Patients with AV-Nodal Reentry Tachycardia undergoing ablation


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Patients with atrial fibrillation (cases) or AV-nodal reentry tachycardia (controls)

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
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Please refer to this study by its identifier: NCT01789541

Stockholm Arrhythmia Center
Stockholm, Sweden, 11861
Hjärtkliniken, Karolinska Universitetssjukhuset Huddinge
Stockholm, Sweden, 14147
Sponsors and Collaborators
Karolinska Institutet
Study Chair: Mårten Rosenqvist, Professor Karolinska Institutet, Institutionen för kliniska vetenskaper vid Danderyds sjukhus
  More Information

Responsible Party: Peter Giesecke, M.D, M.D., Karolinska Institutet Identifier: NCT01789541     History of Changes
Other Study ID Numbers: 3/9A
Study First Received: February 5, 2013
Last Updated: January 19, 2016

Additional relevant MeSH terms:
Atrial Fibrillation
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Thyroid Diseases
Endocrine System Diseases processed this record on April 28, 2017