[Surgical treatment of ischemic heart disease combined with hypothyroidism].

Treatment for patients with ischemic heart disease and hypothyroidism contains many difficulties, such as a dilemma that thyroid hormone to hypothyroid patients may worsen angina. The purpose of this study is to propose an appropriate control of thyroid function in these patients before coronary artery bypass grafting (CABG), and to clarify the change of thyroid function during postoperative period. Because of progressive angina pectoris, five hypothyroidism patients underwent CABG. Preoperatively, minimal dose of L-Thyroxine (0-75 micrograms, daily) was administered orally to keep thyroid function at slightly low level before CABG. Ten consecutive CABG patients with normal thyroid function were selected as control group. Between both groups, there was no significant difference in age, coronary artery disease, and the number of bypass grafts. Serum T4, free-T4, T3, free-T3, and TSH were measured at 1st, 2nd, 3rd, and 7th P.O.D. In control group, pituitary-thyroid function was suppressed transiently. In hypothyroid group, T4 revealed no change and was kept at slightly low level during observed period. There was no significant difference in postoperative hemodynamics between both groups. Postoperatively all of hypothyroid patients got free from angina and received an adequate thyroid hormone replacement therapy without complications. It is concluded that CABG for patients with angina and hypothyroidism can be performed safely by keeping preoperative thyroid function at slightly low level.