Effects of Levothyroxine Supplementation in Patients With Systolic Heart Failure and Subclinical Hypothyroidism

Beneficial Effects of Levothyroxine Supplementation in Patients With Systolic Heart Failure and Subclinical Hypothyroidism

The purpose of this study is to determine whether levothyroxine supplementation is beneficial in patients with systolic heart failure and subclinical hypothyroidism on the functional class evaluated with a 6 minute walk test.

Forty patients with systolic heart failure and subclinical hypothyroidism will be include in a open label trial. They will receive levothyroxine supplementation to determine if their functional class will be affect.

Inclusion Criteria:

• Biochemical diagnosis of subclinical hypothyroidism (TSH between 3.5 and 10 with a normal T4)
• Systolic heart failure with New-York Heart Association (NYHA) class II or III
• Left ventricular ejection fraction under 40%
• Stable heart failure for the past 3 months (no IV furosemide or hospital admission)
• Beta-blockers and ACE inhibitors titrated to the maximum tolerated dose

Exclusion Criteria:

• Isolated diastolic heart failure
• Awaiting cardiac resynchronisation therapy
• Impossibility to perform the 6 minutes walk test
• Active cancer / Life expectancy under 18 months
• Treatment with amiodarone