Open AccessEffect of Cardiac Resynchronization Therapy on Thyroid Function
Author(s) -
Celikyurt Umut,
Agacdiken Aysen,
Geyik Bilal,
Kozdag Guliz,
Vural Ahmet,
Ural Dilek
Publication year - 2011
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.20952
Subject(s) - medicine , ejection fraction , cardiac resynchronization therapy , triiodothyronine , heart failure , cardiology , thyroid , ventricular remodeling , thyroid function , cardiac function curve , hormone , endocrinology
Background: Heart failure patients frequently have thyroid function abnormalities. Cardiac resynchronization therapy (CRT) is a major treatment for patients with advanced chronic heart failure. We aimed to investigate the effects of CRT on thyroid functions. Hypothesis: CRT improves thyroid functions. Methods: Fifty‐seven patients (42 male, 15 female; mean age 58 ± 13 y) undergoing CRT were included in the study. Serum levels of thyroid hormones and echocardiographic parameters were measured before and 6 months after CRT. A response to CRT was defined as a reverse remodeling detected by a relative increase of ≥15% in left ventricular ejection fraction. Results: The clinical status and functional capacity of the patients in the remodeling group were improved significantly. The mean New York Heart Association class was reduced from 3.2 ± 0.4 to 2.2 ± 0.4 ( P< 0.001). The free triiodothyronine (fT3) level increased from 2.67 pg/mL to 2.97 pg/mL in the reverse remodeling group ( P = 0.005). The fT3/fT4 ratio increased from 1.81 to 2.34 ( P = 0.006). Conclusions: CRT improves fT3 levels and fT3/fT4 ratio, which may play an important role in reverse remodeling. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.