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

NCT01789541 | Completed

• 1 other identifier: 3/9A
• Study Type: observational
• Target: 327
• Locations: 1 country
• Sites: 2

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

Outcome Measures

Primary Outcomes (1)

• Prevalence of subclinical hyperthyroidism in patients undergoing atrial fibrillation ablation

  1 day (Measured upon inclusion)

Secondary Outcomes (1)

• Recurrent atrial fibrillation after ablation

  6 months

Study Arms (2)

Atrial fibrillation

Patients with atrial fibrillation undergoing ablation

AV-nodal reentry tachycardia

Patients with AV-Nodal Reentry Tachycardia undergoing ablation

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

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

You may qualify if:

• 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)

You may not qualify if:

• Atrial flutter
• Overt hyperthyroidism

Sponsors & Collaborators

• Karolinska Institutet: lead

Study Sites (2)

Stockholm Arrhythmia Center

Stockholm, 11861, Sweden

Location

Hjärtkliniken, Karolinska Universitetssjukhuset Huddinge

Stockholm, 14147, Sweden

Location

MeSH Terms

Conditions

Atrial Fibrillation

Condition Hierarchy (Ancestors)

Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Mårten Rosenqvist, Professor

  Karolinska Institutet, Institutionen för kliniska vetenskaper vid Danderyds sjukhus

  STUDY CHAIR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: M.D.

Study Record Dates

• First Submitted: February 5, 2013
• First Posted: February 12, 2013
• Study Start: February 1, 2013
• Primary Completion: October 1, 2015
• Study Completion: November 1, 2015
• Last Updated: January 20, 2016

Record last verified: 2016-01

Locations

SE (2)