Triiodothyronine levels for risk stratification of patients with chronic heart failure.
OBJECTIVE
We sought to explore the use of triiodothyronine (T(3)) concentrations as an adjunct to clinical and functional parameters when estimating prognosis in patients with chronic heart failure.


METHODS
We enrolled 281 patients with postischemic (n = 153) or nonischemic (n = 128) dilated cardiomyopathy. Total and free T(3) concentrations, and traditional clinical and functional cardiac parameters, were measured 2 to 5 days after hospital admission. A multivariate model was utilized to predict all-cause and cardiac mortality.


RESULTS
All-cause mortality was 23% (n = 64) after a mean (+/-SD) of 12 +/- 7 months of follow-up; 47 (73%) of the patients died from cardiac causes. The mean ejection fraction was lower in those patients who died than in those who survived (26% +/- 8% vs. 31% +/- 8%, P < 0.001), as were levels of total T(3) (1.0 +/- 0.4 nmol/L vs. 1.3 +/- 0.3 nmol/L, P < 0.001) and free T(3) (3.2 +/- 1.4 pmol/L vs. 3.7 +/- 1.0 pmol/L, P < 0.001). In a multivariate model, ejection fraction (odds ratio [OR] = 2.0 per 10% decrease; 95% confidence interval [CI]: 1.4 to 2.8 per 10% decrease; P < 0.001) and total T(3) level (OR = 0.3 per 1-nmol/L increase; 95% CI: 0.1 to 0.5 per 1-nmol/L increase; P < 0.001) were the only independent predictors of all-cause mortality. In an alternative model using free T(3) levels, ejection fraction (OR = 1.9; 95% CI: 1.4 to 2.7; P < 0.001) and free T(3) level (OR = 0.6 per 1 pmol/L; 95% CI: 0.5 to 0.8 per 1 pmol/L; P <0.02) were associated with all-cause mortality. When we considered cardiac mortality alone, male sex (OR = 3.5; 95% CI: 1.7 to 13; P < 0.04), ejection fraction (OR = 1.7; 95% CI: 1.2 to 2.5; P < 0.006), and total T(3) level (OR = 0.3; 95% CI: 0.2 to 0.7; P < 0.002) were independent predictors with the multivariate model.


CONCLUSIONS
Low T(3) levels are an independent predictor of mortality in patients with chronic heart failure, adding prognostic information to conventional clinical and functional cardiac parameters.
Pingitore
Alessandro
A
Institute of Clinical Physiology, C.N.R., Pisa, Italy. pingi@ifc.cnr.it
Landi
Patrizia
P
Taddei
Maria Chiara
MC
Ripoli
Andrea
A
L'Abbate
Antonio
A
Iervasi
Giorgio
G
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D002908:Chronic Disease; D005260:Female; D006333:Heart Failure / Q000401:mortality* / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017202:Myocardial Ischemia / Q000150:complications; D011379:Prognosis; D018570:Risk Assessment; D013318:Stroke Volume; D016019:Survival Analysis; D014284:Triiodothyronine / Q000097:blood*
D015415:Biomarkers; D014284:Triiodothyronine