Yang M, Li X, Morris JC, et al. - To gain clarity regarding the link between hypothyroidism and results of cardiac resynchronization therapy (CRT) among patients suffering from severe heart failure, researchers performed this study with 1,316 patients who underwent cardiac resynchronization therapy between 2002 and 2015. They found no link between hypothyroidism and a higher risk of all-cause mortality in patients treated with CRT for heart failure. In the entire cohort as well as in the hypothyroid group, increased baseline thyroid-stimulating hormone level was shown to be associated with a significantly increased risk of appropriate implantable cardioverter-defibrillator therapy. After receiving CRT, hypothyroid patients experienced improvement of their cardiac function. A correlation was identified between ventricular arrhythmic events requiring implantable cardioverter-defibrillator therapies and baseline thyroid-stimulating hormone concentration, which might be regarded as a crucial biomarker to stratify the risk of sudden death for patients experiencing heart failure and hypothyroidism.