Thyroid hormone is a critical determinant of myocardial performance in patients with heart failure: potential therapeutic implications.
OBJECTIVE
Previous experimental studies have provided evidence showing that changes in thyroid hormone signaling correspond to alterations in myocardial function in animal models of heart failure. The present study further explores whether thyroid hormone alterations are correlated with the functional status of the myocardium in patients with heart failure.


METHODS
In this study, 37 patients with mean ejection fraction (EF%) of 26.2 (8.2) were included. Myocardial performance was assessed by echocardiography and cardiopulmonary exercise testing. Total tri-iodothyronine (T3), thyroxine, and TSH levels were measured in plasma.


RESULTS
Total T3 was strongly correlated with VO2max (r = 0.78, P = 2 x 10(-8)). Furthermore, multivariate analysis revealed that total T3 was an independent predictor of VO2max (P = 0.000 005). A weaker but significant correlation was also found between total T3 and EF% (r = 0.56, P = 0.0004), systolic (r = 0.43, P = 0.009) and diastolic (r = 0.46, P = 0.004) blood pressure.


CONCLUSIONS
changes in thyroid hormone were closely correlated to myocardial functional status in patients with heart failure. These data probably indicate a possible role of thyroid hormone in the pathophysiology of heart failure and confirm previous experimental reports.
Pantos
Constantinos
C
Department of Pharmacology, University of Athens, 75 Mikras Asias Avenue, 11527 Goudi, Athens, Greece. cpantos@cc.uoa.gr
Dritsas
Athanasios
A
Mourouzis
Iordanis
I
Dimopoulos
Antonios
A
Karatasakis
Georgios
G
Athanassopoulos
Georgios
G
Mavrogeni
Sofia
S
Manginas
Athanasios
A
Cokkinos
Dennis V
DV
D000328:Adult; D000638:Amiodarone / Q000494:pharmacology; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology / Q000627:therapeutic use; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume; D006321:Heart / Q000503:physiopathology*; D006333:Heart Failure / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013963:Thyroid Hormones / Q000097:blood / Q000502:physiology*; D013972:Thyrotropin / Q000097:blood; D016277:Ventricular Function, Left
D000889:Anti-Arrhythmia Agents; D013963:Thyroid Hormones; D013972:Thyrotropin; D000638:Amiodarone