title: Impact of Free Thyroxine on the Outcomes of Left Atrial Ablation Procedures.
abstract: The prevalence of atrial fibrillation (AF) is increased in hyperthyroidism. The degree to which thyroid hormones affect the outcomes of left atrial (LA) ablation is still unclear. From September 2010 to September 2013, 1,095 patients who underwent LA ablation (59.7% paroxysmal AF, 32.3% persistent AF, and 8.0% LA tachycardia) had their serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels measured in the 48 hours before the procedure. Patients were followed until they presented the first AF relapse after a blanking period of 3 months. TSH and FT4 were assessed as predictors of arrhythmia relapse and were adjusted for possible confounders. During a mean follow-up of 12.5 ± 7.9 months, 28.9% of patients presented an atrial arrhythmia relapse. TSH was not a predictor of relapse. In contrast, after adjustment, FT4 (median = 11.8 ng/L and interquartile range 10.6 to 14.6 ng/L) remained a predictor of relapse with 15% increase per quartile (hazard ratio 1.15, 95% confidence interval 1.03 to 1.29, p = 0.014). In conclusion, FT4 levels influence the success rate of LA ablation procedures, even when in the normal range.
authors.affiliation: Départment de Rhythmologie, Clinique Pasteur, Toulouse, France. Electronic address: Peter_senado2002@yahoo.com.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Sousa
authors.affiliation: Department of Cardiology, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom.
authors.forename: Rui
authors.initials: R
authors.lastname: Providência
authors.affiliation: Départment de Rhythmologie, Clinique Pasteur, Toulouse, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Albenque
authors.affiliation: Service de Cardiologie, Université Montpellier 1, Université Montpellier 2, Montpellier, France.
authors.forename: Ziad
authors.initials: Z
authors.lastname: Khoueiry
authors.affiliation: Départment de Rhythmologie, Clinique Pasteur, Toulouse, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Combes
authors.affiliation: Départment de Rhythmologie, Clinique Pasteur, Toulouse, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Combes
authors.affiliation: Départment de Rhythmologie, Clinique Pasteur, Toulouse, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Boveda
mesh_terms: D001281:Atrial Fibrillation / Q000453:epidemiology / Q000209:etiology / Q000601:surgery*; D015415:Biomarkers / Q000097:blood; D017115:Catheter Ablation / Q000379:methods*; D055499:Catheter-Related Infections; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000150:complications*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D013614:Tachycardia, Paroxysmal / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D013974:Thyroxine / Q000097:blood*
chemical_list: D015415:Biomarkers; D013974:Thyroxine