Coronary artery bypass grafting in patients with both coronary artery disease and hypothyroidism / 中华胸心血管外科杂志

ABSTRACT

Objective Hypothyroidism may have adverse effects on the post-operative outcomes. We evaluated the outcomes of coronary artery bypass grafting (CABG) in patients who had both coronary artery disease (CAD) and hypothyroidism.Methods Among 1347 patients undergoing CABG between September 2002 and June 2009, hypothyroidism was diagnosed in 21 patients (Group A, with 6 men and 15 women) and treated with thyroxin replacement therapy. The average age of patients in group A was(60.4 ± 10.2). Hypothyroidism was identified with tests for thyroid functions. CABG in 4 patients was performed with extracorporeal circulation, three of them received on-pump beating heart CABG, and in 17 patients was performed with off pump CABG( OPCAB). CABG was performed following the improvement of FT3, FT4 and TSH with the use of levothyroxine for all patients in group A Twenty patients with CAD in the absence of hypothyroidism ( group B) served as control, 4 of these patients underwent CABG with extracorporeal circulation. Data of thyroid function and hemodynamics pre-, post- and during operation were analyzed. Results Serum thyroid hormones, such as FT3, were measured with sensitive and specific radioimmunoassays peri-operatively. In the patients receiving CABG without extraorporeal circulation, the mean serum FT3 concentrations were ( 1. 39 ± 0. 36 ) pg/ml pre-operatively and ( 1.29 ± 0. 32 ) pg/ml post-operatively ( P = 0.18 ) for 17 cases in group A, and were (2.28 ±0.36)pg/ml and (2.19 ±0.34) pg/ml respectively (P =0.24)for 16 cases in Group B. In the patients receiving CABG with extracorporeal circulation, the mean serum FT3 concentrations were( 1.53 ±0.51 )pg/ml pre-operatively and (0.85 ± 0.40) pg/ml post-operatively ( P = 0. 04 ) for 4 cases in group A, and were ( 2.08 ± 0.24) pg/ml vs. ( 1.96 ±0. 26) pg/ml ( P = 0. 26 ) for 4 cases in group B. The CIs of patients in group A and group B were ( 2.7 ± 1.4)L · min-1 · m-2 vs. (2.8 ±1.5) L · min-1 · m-2, P=0.53). One patients with severe hypothyroidism and underwent CABG with extracorporeal circulation in Group A died of refractory bradycardia after failure in heart resuscitation. Twenty survivors in group A underwent coronary artery bypass on-beating heart. All survivors had improvement in cardiac function during 2to 30 months of follow-up, their preoperative ejection fraction (EF) was 0.48 ± 0.17 and follow-up EF was 0.55 ± 0. 21. All 20 patients in group B were alive. There was no significant difference between group A and B in hemodynamics, prognosis, duration of hospitalization [( 12.2 ±4.7 ) day vs. ( 10. 1 ± 3.9 ) day, P = 0.17], time to extubation [( 17.6 ± 9. 1 ) h vs.(15.1 ± 13.7) h, P =0.12]. Conclusion CABG in patients with both CAD and hypothyroidism is relatively safe. Proper peri-operative nanagement, combined with on-beating heart techniques of CABG, may decrease the operation risks. Off pump CABG had little effect on serum concentrations of FT3. Peri-operative thyroid replacement therapy was critical for patients with hypothyroidism. Patients with severe hypothyroidism who underwent CABG with extracorporeal circulation were at high risk.