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

NCT ID: NCT01789541

Last Updated: 2016-01-20

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 327 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2013-02-28
• Study Completion Date: 2015-11-30

Brief 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. 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

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: PROSPECTIVE

Study Groups

Atrial fibrillation

Patients with atrial fibrillation undergoing ablation

No interventions assigned to this group

AV-nodal reentry tachycardia

Patients with AV-Nodal Reentry Tachycardia undergoing ablation

No interventions assigned to this group

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Karolinska Institutet

OTHER

Sponsor Role: lead

Responsible Party

Peter Giesecke, M.D

M.D.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Mårten Rosenqvist, Professor

Role: STUDY_CHAIR

Karolinska Institutet, Institutionen för kliniska vetenskaper vid Danderyds sjukhus

Locations

Stockholm Arrhythmia Center

Stockholm, , Sweden

Hjärtkliniken, Karolinska Universitetssjukhuset Huddinge

Stockholm, , Sweden

Countries

Sweden

Other Identifiers

3/9A

Identifier Type: -

Identifier Source: org_study_id