Subclinical Hypothyroidism Increases the Requirement of Renal Replacement Therapy After Cardiac Surgery


  • Naim Boran Tumer University of Health Sciences, Ankara Numune Education and Research Hospital, Department of Cardiovascular Surgery, Ankara, Turkey
  • Atike Tekeli Kunt Kirikkale University, Medical School, Department of Cardiovascular Surgery, Kirikkale, Turkey
  • Hatice Keles Kirikkale University, Medical School, Department of Cardiovascular Surgery, Kirikkale, Turkey
  • Kanat Ozisik University of Health Sciences, Ankara Numune Education and Research Hospital, Department of Cardiovascular Surgery, Ankara, Turkey
  • Serdar Gunaydin University of Health Sciences, Ankara Numune Education and Research Hospital, Department of Cardiovascular Surgery, Ankara, Turkey





Background: Subclinical or biochemically diagnosed hypothyroidism (SCH) is defined as an elevated serum thyroid-stimulating hormone (TSH) with normal free thyroxine (FT4) levels. Thyroid hormones play a major role in the normal function of the heart and vascular physiology. Atherosclerosis, increased systemic vascular resistance, and decreased arterial compliance are common pathophysiological changes that may occur in hypothyroidism. Acute kidney injury (AKI) is one of the devastating complications after cardiac surgery. Age, diabetes mellitus (DM), preexisting renal dysfunction, hypertension, impaired left ventricular function, and severe arteriosclerosis are the major risk factors for the development of AKI. The purpose of the current study was to analyze the influence of SCH on AKI and the requirement of renal replacement therapy (RRT) after isolated coronary artery bypass graft surgery (CABG).

Methods: We retrospectively reviewed the prospectively collected data of 336 adult patients who underwent isolated CABG surgery with normal renal function (baseline serum creatinine value <1.4 mg/dL) from January 2017 to January 2019. The patients were divided into two groups either having the diagnosis of SCH (Group I, N = 47) or not (Group II,
N = 289). SCH was diagnosed based on preoperative serum TSH and FT4 levels. Kidney injury was interpreted, according to RIFLE classification. The effect of SCH on AKI and the need for RRT after CABG was determined using logistic regression analysis and the results were expressed as odds ratio (OR) with a 95% confidence interval (CI). A P value < .05 was considered statistically significant.

Results: Subclinical hypothyroidism was diagnosed in 14% of all patients. Postoperative AKI occurred in 15 patients (31.9%) in Group I, whereas there were 42 patients (14.5%) in Group II. On logistic regression analysis, the presence of SCH was shown to be associated with an increased incidence of postoperative AKI (OR, 0.363; 95% CI, 0.181-0.727;
P = .004). RRT was used in 2.97% of patients (seven patients in Group I and three patients in Group II, P < .001). The 30-day mortality was 2.1%.

Conclusion: The presence of SCH seems to be associated with an increased incidence of AKI and increased requirement for RRT after cardiac surgery.


Bellomo R, Ronco C, Kellum JA, Mehta RL, Palevsky P. 2004. Acute Dialysis Quality Initiative workgroup. Acute renal failure - definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group. Crit Care 8:R204-12.

Bouman CS, Oudemans-Van Straaten HM, Tijssen JG, Zandstra DF, Kesecioğlu J. 2002. Effects of early high-volume continuous venovenous hemofiltration on survival and recovery of renal function in intensive care patients with acute renal failure: a prospective, randomized trial. Crit Care Med 30:2205-11.

Chang YC, Chang CH, Yeh YC, Chuang LM, Tu YK. 2018. Subclinical and overt hypothyroidism is associated with reduced glomerular filtration rate and proteinuria: a large cross-sectional population study. Sci Rep. 8:2031.

Chertow GM, Lazarus JM, Christiansen CL, et al. 1997. Preoperative renal risk stratification. Circulation 95:878-84.

Cikim AS, Oflaz H, Ozbey N, Cikim K, Umman S, Meric M, Sencer E, Molvalilar S. 2004. Evaluation of endothelial function in subclinical hypothyroidism and subclinical hyperthyroidism. Thyroid. 14:605–9.

Cooper DS, Biondi B. 2012. Subclinical thyroid disease. Lancet 379:1142-54.

Cockcroft DW, Gault MH. 1976. Prediction of creatinine clearance from serum creatinine. Nephron 16:31-41.

Demirkılıç U, Kuralay E, Yenicesu M, et al. 2004. Timing of replacement therapy for acute renal failure after cardiac surgery. J Card Surg 19:17-20.

Doddakula K, Al-Sarraf N, Gately K, et al. 2007. Predictors of acute renal failure requiring renal replacement therapy post cardiac surgery in patients with preoperatively normal renal function. Interact Cardiovasc and Thorac Surg 6:314-8.

Garber JR, Cobin RH, Gharib H, et al. 2012. Clinical practice guidelines for hypothyroidism in adults: Cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Endocr Pract 18: 988–1028.

Haase M, Haase-Fielitz A, Bagshaw SM, Ronco C, Bellomo R. 2007. Cardiopulmonary bypass-associated acute kidney injury: a pigment nephropathy? Contrib Nephrol 156:340-353.

Hall RI, Smith MS, Rocker G. 1997. The systemic inflammatory response to cardiopulmonary bypass: pathophysiological, therapeutic, and pharmacological considerations. Anesth Analg 85:766-82.

Iglesias P, Olea T, Vega-Cabrera C, Heras M, Bajo MA, del Peso G, et al. 2013. Thyroid function tests in acute kidney injury. J Nephrol. 1:164–72.

Kahaly GJ, Dillmann WH. 2005. Thyroid hormone action in the heart. Endocr Rev 26:704-28.

Kim EO, Lee IS, Choi YA, et al. 2014. Unresolved subclinical hypothyroidism is independently associated with progression of chronic kidney disease. Int J Med Sci 11: 52-9.

Kim YA, Park YJ. 2014. Prevalence and risk factors of subclinical thyroid disease. Endocrinol Metab 29:20–9.

Klein I, Ojamaa K. 2001. Thyroid hormone and the cardiovascular system. N Engl J Med. 7:501–9.

Kunt AT, Akgün S, Atalan S, Bitir N, Arsan S. 2009. Furosemide infusion prevents the requirement of renal replacement therapy after cardiac surgery. Anadolu Kardiyol Derg 9:499-504.

Lassnigg A, Donner E, Grubhofer G, Presterl E, Druml W, Hiesmayr M. 2000. Lack of renoprotective effects of dopamine and furosemide during cardiac surgery. J Am Soc Nephrol 11:97-104.

Liu KL, Lo M, Canaple L, Gauthier K, Del Carmine P, Beylot M. 2014. Vascular function of the mesenteric artery isolated from thyroid hormone receptor-α knockout mice. J Vasc Res. 51:350–9.

Marfella R, Ferraraccio F, Rizzo MR, Portoghese M, Barbieri M, Basilio C, Nersita R, et al. 2011. Innate immune activity in plaque of patients with untreated and L-thyroxine- treated subclinical hypothyroidism. J Clin Endocrinol Metab 96:1015–1020.

Michael UF, Barenberg RL, Chavez R, Vaamonde CA, Papper S. 1972. Renal handling of sodium and water in the hypothyroid rat. Clearance and micropuncture studies. J Clin Invest. 51:1405–12.

Mousa S, Hemeda A, Ghorab H, Abdelhamid A, Saif A. 2020. Arterial wall stiffness and the risk of atherosclerosis in Egyptian patients with overt and subcliınical hypothyroidism. Endocr Pract 26:161-6.

Saif A, Mousa S, Assem M, Tharwat N, Abdelhamid A. 2018. Endothelial dysfunction and the risk of atherosclerosis in overt and subclinical hypothyroidism. Endocr Connect 7:1075-80.

Song RH, Wang B, Yao QM, Li Q, Jia X, Zhang JA. 2019. The Impact of Obesity on Thyroid Autoimmunity and Dysfunction: A Systematic Review and Meta-Analysis. Front Immunol. 10:2349.

Suen WS, Mok CK, Chiu SW, et al. 1998. Risk factors for development of acute renal failure (ARF) requiring dialysis in patients undergoing cardiac surgery. Angiology 49:789-90.

Suher M, Koc E, Ata N, Ensari C. 2005. Relation of thyroid disfunction, thyroid autoantibodies, and renal function. Ren Fail 27 (6): 739-42.

Tekeli Kunt A, Parlar H, Findik O, Duzyol C, Baris O, Balci C. 2016. The Influence of Metabolic Syndrome on Acute Kidney Injury Occurrence after Coronary Artery Bypass. Heart Surg Forum. May 18;19:E099-103.

Uchino S, Kellum JA, Belloma R, et al. 2005. Acute renal failure in critically ill patients; a multinational, multicenter study. JAMA 294:813-8.

Weerasinghe A, Hornick P, Smith P, Taylor K, Ratnatunga C. 2001. Coronary artery bypass grafting in non-dialysis-dependent mild-to-moderate renal dysfunction J Thorac Cardiovasc Surg 121:1083-9.

Wikström L1, Johansson C, Saltó C, Barlow C, Campos Barros A, Baas F, Forrest D, Thorén P, Vennström B. 1998. Abnormal heart rate and body temperature in mice lacking thyroid hormone receptor alpha 1. EMBO J. 17:455–61.

Yang L, Lv X, Yue F, et al. 2016. Subclinical hypothyroidism and the risk of metabolic syndrome: A meta-analysis of observational studies. Endocr Res 41:158–65.

Zahler D, Izkhakov E, Rozenfeld KL, Ravid D, Banai S, Topilsky Y, Shacham Y. 2019. Relation of subclinical hypothyroidism to acute kidney injury among ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention. IMAJ 21: 692–5.

Zhang L, Yang G, Su Z, Yang J. 2017. Correlation between subclinical hypothyroidism and renal function in patients with diabetes mellitus. Nephrology (Carlton) 22 (10): 790-5.



How to Cite

Tumer, N. B., Tekeli Kunt, A., Keles, H., Ozisik, K., & Gunaydin, S. (2020). Subclinical Hypothyroidism Increases the Requirement of Renal Replacement Therapy After Cardiac Surgery. The Heart Surgery Forum, 23(4), E482-E487.