Atrial FibrillationTABLASNCT01789541
Is a Low Thyreotropin Level Predictive of Recurrent Arrhythmia After Catheter Ablative Surgery?
An observational study of Atrial Fibrillation and Subclinical Hyperthyroidism, run by Karolinska Institutet at 2 sites in Sweden.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Atrial Fibrillation, Subclinical Hyperthyroidism
- How many people
- 327 participants
- Where
- 2 sitesSweden
- Study dates
- Feb 2013to Nov 2015
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with atrial fibrillation (cases) or AV-nodal reentry tachycardia (controls)
Who may be able to join
- 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)
Who cannot join
- Atrial flutter
- Overt hyperthyroidism
Trial locations and contacts
2 sites in 1 country.
Sweden2 sites
Stockholm Arrhythmia Center
Stockholm, 11861
Hjärtkliniken, Karolinska Universitetssjukhuset Huddinge
Stockholm, 14147
About this study
Official title: 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.
- Conditions
- Atrial Fibrillation, Subclinical Hyperthyroidism
- Medical subject headings
- Atrial Fibrillation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Atrial fibrillation | Patients with atrial fibrillation undergoing ablation | |
| AV-nodal reentry tachycardia | Patients with AV-Nodal Reentry Tachycardia undergoing ablation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Prevalence of subclinical hyperthyroidism in patients undergoing atrial fibrillation ablation
Measured: 1 day (Measured upon inclusion)
Secondary outcomes (1)
Recurrent atrial fibrillation after ablation
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Feb 2013 (estimated)
- Study startFeb 2013
- Primary completionOct 2015
- Study completionNov 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Atrial FibrillationStudies of the same condition, open and under way.
- More trials run by Karolinska InstitutetThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 327 participants (actual)
Sponsor and investigators
- Lead sponsor
- Karolinska Institutet
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Peter Giesecke, M.D, Karolinska Institutet
- Investigators
- Mårten Rosenqvist, Professor, Study chair, Karolinska Institutet, Institutionen för kliniska vetenskaper vid Danderyds sjukhus
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01789541
- Sponsor's protocol ID
- 3/9A
- Acronym
- TABLAS
- Status last verified
- Jan 2016
- First submitted
- 5 Feb 2013
- Last updated
- 20 Jan 2016
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Jan 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Observational Prospective Case-control Study on Prevalence and Impact of Subclinical Hyperthyroidism in Patients Undergoing Atrial Fibrillation Ablation
- ClinicalTrials.gov ID
- NCT01789541
- Acronym / sponsor ID
- TABLAS / 3/9A
- Conditions
- Atrial Fibrillation, Subclinical Hyperthyroidism
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 327 participants (actual)
- Lead sponsor
- Karolinska InstitutetUniversity, hospital or other
- Study start
- Feb 2013
- Primary completion
- Oct 2015 (actual)
- Study completion
- Nov 2015 (actual)
- First posted
- 12 Feb 2013 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Atrial fibrillation | – | –Patients with atrial fibrillation undergoing ablation |
| AV-nodal reentry tachycardia | – | –Patients with AV-Nodal Reentry Tachycardia undergoing ablation |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with atrial fibrillation (cases) or AV-nodal reentry tachycardia (controls)
Key inclusion criteria (4 listed)
- 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)
Key exclusion criteria (2 listed)
- Atrial flutter
- Overt hyperthyroidism
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Prevalence of subclinical hyperthyroidism in patients undergoing atrial fibrillation ablation
Time frame: 1 day (Measured upon inclusion)
1 secondary outcome
Recurrent atrial fibrillation after ablation
Time frame: 6 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jan 2016.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mårten Rosenqvist, Professor study chair
Karolinska Institutet, Institutionen för kliniska vetenskaper vid Danderyds sjukhus
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Atrial Fibrillation and Subclinical Hyperthyroidism, run by Karolinska Institutet at 2 sites in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 Jan 2016. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Prevalence of subclinical hyperthyroidism in patients undergoing atrial fibrillation ablation (time frame: 1 day (Measured upon inclusion)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jan 2016.