The answer is yes.
Thyroid disease is a broad term. In general there are diseases when the thyroid gland is more active than normal, and diseases with less active gland.
Both can badly affect the heart and lead to heart disease which can be fatal if not well treated.
A third group of thyroid disease are cancers of the thyroid gland . Some of them are aggressive and cause significant mortality.
A person with thyroid disease (whatever) , usually lives a normal life if he/she follows doctor's instructions and advises, and gets regular checks.