Nonthyroidal illness syndrome in off-pump coronary artery bypass surgery

Abstract

Objective:It is well known that coronary artery bypass grafting (CABG) is often the cause of non-thyroidal illness syndrome (NTIS). Nonthyroidal illness syndrome (NTIS) is a state characterized by low levels of tri-iodo-thyronine (T3) and high levels of reverse T3 (rT3), with normal or low levels of thyroxin (T4) and normal, low-normal, or low levels of thyroid-stimulating hormone (TSH). Today, there are two main techniques of CABG: CABG with the use of cardiopulmonary bypass (on-pump coronary artery bypass - ONCAB) and CABG without the use of cardiopulmonary bypass (off-pump coronary artery bypass OPCAB), or ’beating-heart surgery.’ The OPCAB technique is considered to be less invasive. We prospectively investigated the influence of these surgical techniques on the occurrence of NTIS.Methods:Serum levels of free fractions of thyroid hormones (FT3 and FT4) and TSH were analyzed in 70 consecutive patients subjected to CABG surgery, using the ONCAB technique in 36 patients and OPCAB technique in 34 patients. The measurements of hormone levels were performed prior to surgery and 12 hours and 14 days after surgery.Results:The basic, the early, and the late postoperative serum levels of FT3 (p=0.458, p=0.632, p=0.869, respectively), FT4 (p=0.664, p=0.301, p=0.417, respectively), and TSH (p=0.249, p=0.058, p=0.324, respectively) were similar in both groups. The levels of FT3 and TSH were significantly lower 12 hours after surgery (p<0.0001, p<0.0001, respectively), and the FT4 levels rose at the same time (p<0.0001). The third measurement showed the return of all investigated parameters back to physiological levels, although they were still not precisely within the initial values.Conclusion:NTIS occurs significantly in patients subjected to CABG. Although the OPCAB technique is considered to be less invasive, its impact on the occurrence of NTIS does not differ significantly from the ONCAB technique.

Predictors for euthyroid sick syndrome and its impact on in-hospital clinical outcomes in high-risk patients undergoing coronary artery bypass grafting

“…In this regard, the impact of CABG-associated ESS on cardiac function is complicated, including upregulating gene expression of cardiac contractile proteins as well as leading to peripheral vasodilation and so as to ultimately decreasing systemic vascular resistance. 2,4,9 Crucial changes in cardiac functions and structure have been found in various original articles involving ESS 3,9 and further confirmed in a meta-analysis regarding 41 studies. 16 It is thus plausible that the decreased T3 in patients with CABG-associated ESS would exacerbate the pathologic cardiac function and thus contribute to increased risk of adverse postoperative outcomes.…”

“…3 CABG is a considerable stress for coronary heart disease (CHD) patients, especially for patients with high-risk cardiac surgery, and can lead to the occurrence of ESS in a huge number of patients undergoing this kind of surgery. 2,4,5 Recent studies further confirmed CABG-associated ESS occurred in two-thirds of CHD patients and off-pump CABG did not improve the postoperative thyroid function. 4,5…”

“…2,4,5 Recent studies further confirmed CABG-associated ESS occurred in two-thirds of CHD patients and off-pump CABG did not improve the postoperative thyroid function. 4,5…”

Non-thyroidal illness syndrome and erectile function in males undergoing coronary artery bypass graft

“…NTIS is a state that is characterized by low triiodothyronine (T3) levels and high reverse T3 levels, with normal or low thyroxine levels and normal, low-normal, or low thyroid-stimulating hormone (TSH) levels. NTIS occurs in a significant number of patients undergoing CABG ( 2 ). The low T3 level is associated with higher marker levels of inflammation and increased endothelial dysfunction.…”

Nonthyroidal illness syndrome in offpump coronary artery bypass surgery

“…We want to congratulate Caluk et al ( 1 ) for their fluent and impressive article “Nonthyroidal illness syndrome in off-pump coronary artery bypass surgery” published in Anatolian Journal of Cardiology 2015: 15: 836-42. As they mentioned, many reasons such as surgical operations, acute and chronic systemic diseases, sepsis, and severe burns may result in nonthyroidal illness syndrome (NTIS).…”