BACKGROUND: It has been suggested that low thyroid hormones levels may be 
associated with increased mortality in patients with cardiovascular disease.
AIM: To evaluate the prognostic role of thyroid function deficiency in patients 
with chronic heart failure (CHF).
METHODS: We evaluated 338 consecutive outpatients with stable CHF receiving 
conventional therapy, all of whom underwent a physical examination, 
electrocardiography and echocardiography. Blood samples were drawn to assess 
renal function, and Na+, hemoglobin, NT-proBNPs, fT3, fT4 and TSH levels. 
Patients with hyperthyroidism were excluded.
RESULTS: During the follow-up (15+/-8 months), heart failure progression was 
observed in 79 patients (including 18 who died of heart failure after 
hospitalisation and six who underwent transplantation). Univariate regression 
analysis showed that TSH (p<0.0001), fT3 (p<0.0001), fT4 (p=0.016) and fT3/fT4 
(p<0.0001) were associated with heart failure progression but multivariate 
analysis showed that only TSH considered as a continuous variable (p = 0.001) as 
well as subclinical hypothyroidism (TSH &gt 5.5 mUI/l; p=0.014) remained 
significantly associated with the events.
CONCLUSIONS: In CHF patients TSH levels even slightly above normal range are 
independently associated with a greater likelihood of heart failure progression. 
This supports the need for prospective studies aimed at clarifying the most 
appropriate therapeutic approach to sub-clinical hypothyroidism in such 
patients.