<qa>  What is the main outcome of the RCT?Methods: The investigators will conduct a RCT in 185 patients with subclinical hypothyroidism who will be randomly assigned to thyroxine or placebo with an average follow-up of 24 months from baseline 4 death and 17 withdrawal. The main outcome will be CV imaging modalities measured by carotid ultrasound at the close-out visit. Ultrasound of carotid intima media thickness CIMT will be used to assess subclinical atherosclerosis and plaque burden. All images will be centralized at the core lab for a blinded and standardized interpretation. 