European Journal of Cardio-Thoracic Surgery, Vol 5, 230-234, Copyright © 1991 by European Association for Cardio-thoracic Surgery
Coronary artery bypass surgery in patients with angina pectoris and hypothyroidism
M Kawasuji, S Sawa, H Tsujiguchi and T Iwa
Department of Surgery I, Kanazawa University School of Medicine, Japan.
The treatment of hypothyroidism in patients undergoing coronary artery
bypass surgery is a difficult clinical problem. To determine perioperative
thyroid replacement therapy in patients with hypothyroidism, plasma total
thyroxine (T4), total triiodothyroxine (T3), free T4, free T3 and
thyroid-stimulating hormone levels were measured preoperatively and at 1,
2, 3, 7, and 14 days after operation in 9 patients with hypothyroidism and
were compared with levels in 14 patients with normal thyroid function who
underwent coronary bypass surgery. In the normal control group, total T4
decreased to its lowest level on the 1st postoperative day and then
increased gradually to the preoperative level at 7 days. Total T4 remained
within the normal range throughout the entire postoperative course. In 6
patients with hypothyroidism who were treated with thyroid hormone before
surgery, total T4 decreased immediately after operation and only increased
after starting thyroid replacement therapy. In 3 hypothyroid patients
without prior thyroid replacement, total T4 showed a change similar to
patients in the control group but remained below the normal range until
starting thyroid replacement therapy. Coronary bypass surgery was performed
safely in patients with hypothyroidism. Preoperative thyroid replacement
with suboptimal doses was safe in patients with severe hypothyroidism.
Adequate postoperative thyroid replacement was achieved in all patients
without complications.
