Table 3.

Serum Thyroid Hormone Levels in the “Conclusion” Blood Sample According to the Site Where Blood Was Collected and Type of Surgical Procedure

Conclusion sample	Aortic root	Coronary venous sinus	p
Valve replacement
T3 (ng/mL)	0.75 ± 0.14	0.74 ± 0.13	0.335
rT3 (ng/mL)	0.18 ± 0.05	0.18 ± 0.04	0.421
T3/rT3	4.62 ± 1.96	4.44 ± 1.70	0.277
T4 (ng/mL)	77.0 ± 13.6	78.9 ± 11.7	0.048
TSH (μU/mL)	2.09 ± 1.85	2.08 ± 1.96	0.432
CABG off-pump
T3 (ng/mL)	0.75 ± 0.29	0.83 ± 0.30	0,021
rT3 (ng/mL)	0.20 ± 0.11	0.23 ± 0.12	0,084
T3/rT3	4.31 ± 2.24	4.43 ± 2.25	0.088
T4 (ng/mL)	80.9 ± 28.3	92.6 ± 38.0	0,010
TSH (μU/mL)	1.94 ± 3.09	1.68 ± 2.73	0,168
CABG CPB
T3 (ng/mL)	0.67 ± 0.22	0.68 ± 0.24	0.342
rT3 (ng/mL)	0.15 ± 0.03	0.15 ± 0.03	0.074
T3/rT3	4.60 ± 1.99	4.86 ± 2.14	0.103
T4 (ng/mL)	64.2 ± 13.8	65.3 ± 13.6	0.093
TSH (μU/mL)	1.29 ± 0.65	1.27 ± 0.58	0.213

Values are the mean ± SD.

Reference ranges for peripheral blood are: T3 (0.7–1.8 ng/mL); rT3 (0.10–0.24 ng/mL); T4 (45–120 ng/mL); TSH (0.45–4.5 μU/mL).

Statistical analysis was by paired Student's t-test.

CABG, coronary artery bypass grafting; CPB, cardiopulmonary bypass.