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

January 19, 2016 updated by: Peter Giesecke, M.D, Karolinska Institutet

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.

Study Overview

Status

Completed

Conditions

Study Type

Observational

Enrollment (Actual)

327

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Sweden
      • Stockholm, Sweden, 11861
        • Stockholm Arrhythmia Center
      • Stockholm, Sweden, 14147
        • Hjärtkliniken, Karolinska Universitetssjukhuset Huddinge

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

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

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Atrial fibrillation
Patients with atrial fibrillation undergoing ablation
AV-nodal reentry tachycardia
Patients with AV-Nodal Reentry Tachycardia undergoing ablation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Prevalence of subclinical hyperthyroidism in patients undergoing atrial fibrillation ablation
Time Frame: 1 day (Measured upon inclusion)
1 day (Measured upon inclusion)

Secondary Outcome Measures

Outcome Measure
Time Frame
Recurrent atrial fibrillation after ablation
Time Frame: 6 months
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Karolinska Institutet

Investigators

  • Study Chair: Mårten Rosenqvist, Professor, Karolinska Institutet, Institutionen för kliniska vetenskaper vid Danderyds sjukhus

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2013

Primary Completion (Actual)

October 1, 2015

Study Completion (Actual)

November 1, 2015

Study Registration Dates

First Submitted

February 5, 2013

First Submitted That Met QC Criteria

February 11, 2013

First Posted (Estimate)

February 12, 2013

Study Record Updates

Last Update Posted (Estimate)

January 20, 2016

Last Update Submitted That Met QC Criteria

January 19, 2016

Last Verified

January 1, 2016

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 3/9A

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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