Relation between free triiodothyronine/free thyroxine ratio, echocardiographic parameters and mortality in dilated cardiomyopathy.
BACKGROUND
Abnormalities in thyroid function are frequent in patients with heart failure and are associated with increased mortality. However, the relation between thyroid hormone levels and echocardiographic parameters has not been investigated sufficiently.


OBJECTIVE
The aims of this study were to investigate the correlations of thyroid hormone levels with echocardiographic parameters and to evaluate their associations with subsequent mortality in a group of patients with dilated cardiomyopathy (DCMP).


METHODS
Serum levels of thyroid hormones were measured in 111 consecutive patients with DCMP (35 female, 76 male, mean age: 62+/-12 years). All patients underwent echocardiographic examination and were followed-up for a period of 12+/-8 months.


RESULTS
Twenty-three patients (21%) had abnormalities in thyroid function tests. Free triiodothyronine (fT3)/free thyroxine (fT4) ratio was significantly correlated with most of echocardiographic parameters, such as chamber diameters and ejection fraction. Sixteen patients (14%) died during the follow-up period; their fT3/fT4 ratio was significantly lower than the patients who survived (1.31+/-0.37 vs. 2.01+/-0.72, p<0.001). A fT3/fT4 ratio of <or=1.7 was associated with an increased risk of mortality (p<0.001), independent of other prognostic markers. Sensitivity, specificity, positive and negative predictivity of fT3/fT4 ratio <or=1.7 for cardiac mortality were 100%, 71%, 36% and 100%, respectively.


CONCLUSIONS
Determination of FT3/FT4 ratio may be a valuable and simple predictor for identification of patients with DCMP who are at high risk of subsequent mortality.
Kozdag
Guliz
G
Department of Cardiology, Kocaeli University, Yahyakaptan Mah. A4 Blok Daire:3, Kocaeli 41050, Turkey. gkozdag@superonline.com
Ural
Dilek
D
Vural
Ahmet
A
Agacdiken
Aysen
A
Kahraman
Goksel
G
Sahin
Tayfun
T
Ural
Ertan
E
Komsuoglu
Baki
B
D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000097:blood* / Q000000981:diagnostic imaging* / Q000401:mortality; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012720:Severity of Illness Index; D013318:Stroke Volume; D015996:Survival Rate; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000031:analogs & derivatives* / Q000097:blood*; D014463:Ultrasonography
D014284:Triiodothyronine; C040407:3,3',5-triiodothyronamine; D013974:Thyroxine