Effects of Triiodothyronine Treatment in an Animal Model of Heart Failure with Preserved Ejection Fraction.

Treatment with T3 was shown to improve metabolic profile, myocardial calcium handling, and cardiac function. While the low-dose was well-tolerated and safe, the replacement dose was associated with increased heart rate, and increased risk of arrhythmias and sudden death. Modulation of thyroid hormones may be a potential therapeutic target in HFpEF; however, it is important to take into account the narrow therapeutic window of T3 in this condition.