Thyroid hormones were associated with incident heart failure subtypes and changes in cardiac structure and function:...

To evaluate the relationships between serum thyroid hormones and incident HF subtypes and longitudinal changes in cardiac structure and function in adults without prior HF.

In 3508 adults free of HF from the Atherosclerosis Risk in Communities study (Visit 5: 2011-2013), serum total triiodothyronine (T3), free thyroxine (fT4) and thyroid-stimulating hormone (TSH) were measured. Restricted cubic splines and competing risk models estimated associations with incident HF, HF with preserved ejection fraction (HFpEF), and HF with reduced ejection fraction (HFrEF) through 2019. In 1505 participants with echocardiograms at Visits 5 and 7, restricted cubic splines were used to evaluate the links between baseline hormones and echocardiographic changes.

Median age was 74 years; 41.6 % were male. Over a 7.3-year follow-up, 303 patients developed HF (148 HFpEF; 137 HFrEF). Adjusted models showed T3 < 98.8 ng/dl was associated with higher HFpEF risk (subHR = 1.48, 95 % CI: 1.03-2.13, p = 0.034) but not HFrEF. Serum fT4 < 1.09 ng/dl was linked to lower HFrEF risk (subHR = 0.58, 95 %CI: 0.37-0.9, p = 0.016) but not HFpEF. Serum TSH showed no associations. Baseline serum T3 predicted reductions in left ventricular mass index (p = 0.045) and left atrial volume index (p = 0.046). Serum fT4 correlated with changes in global longitudinal strain (p = 0.003), and serum TSH was nonlinearly associated with E/e' (p for overall = 0.049; p for nonlinear = 0.023).

In older adults without HF, thyroid hormones were associated with HF subtypes and cardiac remodeling, highlighting their potential as biomarkers and therapeutic targets in HF subtypes.