Incidence of Subclinical Hypothyroidism in Cardiac Surgery Patients. Comparison of Presentation Characteristics, Hospital and Medium-Term Outcomes with Euthyroid Patients


Subclinical hypothyroidism (SCHT) is common, with an occurrence of up to 10% of the adult population and defined biochemically only by elevated TSH and normal T4. SCHT affects negatively on lipid and carbohydrate metabolism increasing the risk of ischemic heart disease, affects negatively on cardiac performance and have a close correlation with renal function. The aim of this study is to compare presentation characteristics and outcomes between euthyroid pts and pts with SCHT who underwent cardiac surgery. Methods: 474 pts from June 2003 through September 2004 had TSH and T4 measured. 365 pts were euthyroid (Group 1), 41 pts had SCHT (Group 2). Groups were compared by demographics and EuroSCORE (ES) risk profiles. Operative and hospital outcomes were compared as was follow-up mortality up to 96 months. Results: There were more females in Group 2, p = 0.04, more pts with CHF and number of NYHA III-IV pts (p < 0.05). More pts in Group 2 had elevated s-crea (p < 0.0001) and atrial fibrillation (p = 0.007). Comparing the Groups by EuroSCORE (ES) showed higher risk scores in Group 2 pts (Additive ES 6.8 vs 8.5 and Logistic ES 12.3% vs 18.1%, p = 0.01 and 0.03). Hospital mortality was higher in Group 2 (12.2% vs 4.1%, p = 0.04) and the number of pts needing extended care was higher in Group 2 (p = 0.01). Follow up mortality was doubled in Group 2 pts up to 96 months compared to Group 1 (p < 0.0001). Conclusions: Presentation characteristics and risk scores are different and worse in SCHT pts compared with euthyroid pts. Hospital and follow-up mortality are increased in SCHT pts.

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A. Jyrala, N. Gatto and G. Kay, "Incidence of Subclinical Hypothyroidism in Cardiac Surgery Patients. Comparison of Presentation Characteristics, Hospital and Medium-Term Outcomes with Euthyroid Patients," World Journal of Cardiovascular Surgery, Vol. 2 No. 3, 2012, pp. 54-59. doi: 10.4236/wjcs.2012.23012.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] B. Biondi and D. S. Cooper, “The Clinical Significance of Subclinical Thyroid Dysfunction,” Endocrine Reviews, Vol. 29, No. 1, 2008, pp. 76-131, doi:10.1210/er.2006-0043
[2] F. Monzani, V. Di Bello, N. Caraccio, A. Bertini, D. Giorgi, C. Giusti and E. Ferrannini, “Effect of Levothyroxine on Cardiac Function and Structure in Subclinical Hypothyroidism: A Double-Blind, Placebo-Controlled Study,” The Journal of Clinical Endocrinology & Metabolism, Vol. 86, No. 3, 2001, pp. 1110-1115 doi:10.1210/jc.86.3.1110
[3] N. Rodondi, A. B. Newman, E. Vittinghoff, N. de Rekeneire, S. Satterfield, T. B. Harris and D. C. Bauer, “Subclinical Hypothyroidism and the Risk of Heart Failure, Other Cardiovascular Events, and Death,” Archives of Internal Medicine, Vol. 165, No. 21, 2005, pp. 2460-2466. doi:10.1001/archinte.165.21.2460
[4] J. P. Walsh, A. P. Bremner, M. K. Bulsara, P. O’Leary, P. J. Leedman, P. Feddema and V. Michelangeli, “Subclinical Thyroid Dysfunction as a Risk Factor for Cardiovascular Disease,” Archives of Internal Medicine, Vol. 165, No. 21, 2005, pp. 2467-2472. doi:10.1001/archinte.165.21.2467
[5] G. Iervasi, S. Molinaro, P. Landi, M. C. Taddei, E. Galli, F. Mariani, A. L’Abbate and A. Pingitore, “Association between Increased Mortality and Mild Thyroid Dysfunction in Cardiac Patients,” Archives of Internal Medicine, Vol. 167, No. 14, 2007, pp. 1526-1532. doi:10.1001/archinte.167.14.1526
[6] M. Chonchol, G. Lippi, G. Salvagno, G. Zoppini, M. Muggeo and G. Targher, “Prevalence of Subclinical Hypothyroidism in Patients with Chronic Kidney Disease,” Clinical Journal of the American Society of Nephrology, Vol. 3, No. 5, 2008, pp. 1296-1300. doi:102215/CJN.00800208
[7] P. Iglesias and J. J. diez, “Thyroid dysfunction and kidney disease,” European Journal of Endocrinology, Vol. 160, No. 4, 2008, pp. 503-515. doi:101530/EJE-08-0837
[8] B. O. ?svold, T. Bj?ro and L. J. Vatten, “Association of Thyroid Function with Estimated Glomerular Filtration Rate in a Population-Based Study: The HUNT Study,” European Journal of Endocrinology, Vol. 164, No. 1, 2011, pp. 101-105. doi:101530/EJE-10-0705
[9] J. C. Lo, G. M. Chertow, A. S. Go and C.-Y. Hsu, “Increased Prevalence of Subclinical and Clinical Hypothyroidism in Persons with Chronic Kidney Disease,” Kidney International, Vol.67, No. 6, 2005, pp. 1047-1052, doi:10.1111/j.1523-1755.2005.00169.x
[10] M. Hage, M. S. Zantout and S. T. Azar, “Thyroid Disorders and Diabetes Mellitus,” Journal of Thyroid Research, Vol. 2011, 2011, pp. 1-7. doi:10.4061/2011/4393463
[11] EuroSCORE, “NEW! EuroSCORE II,” 2011.
[12] Social Security Death Master File, “Important Notice: Change in Public Death Master File Records,” 2011.
[13] E. N. Pearce, “In People with Subclinical Hypothyroidism, TSH > 10 mIU/l May Predict Increased Risk of Coronary Heart Disease and Related Mortality,” Evidence-Based Medicine, Vol. 16, No. 1, 2011, pp. 31-32.
[14] M. I. Surks, E. Ortiz, G. H. Daniels, C. T. Sawin, N. F. Col, R. H. Cobin, J. A. Franklyn, J. M. Hershman, K. D. Burman, M. A. Denke, C. Gorman, R. S. Cooper and N. J. Weissman, “Subclinical Thyroid Disease: Scientific Review and Guidelines for Diagnosis and Management,” The Journal of American Medical Association, Vol. 291, No. 2, 2004, pp. 228-238. doi:10.1001/jama.291.2.228
[15] M. T. McDermott and E. C. Ridgway, “Subclinical Hypothyroidism Is Mild Thyroid Failure and Should Be Treated,” The Journal of Clinical Endocrinology & Metabolism, Vol. 86, No. 10, 2001, pp. 4585-4590. doi:101210/jc86.10.4585
[16] N. Rodondi, D. C. Bauer, A. R. Cappola, J. Cornuz, J. Robbins, L. P. Fried, et al., “Subclinical Thyroid Dysfunction, Cardiac Function and the Risk of Heart Failure: The Cardiovascular Health Study,” Journal of the American College of Cardiology, Vol. 52, No. 14, 2008, pp. 1152-1159. doi:10.1016/j.jacc.2008.07.009
[17] M. Yazici, S. Gorgulu, Y. Sertbas, E. Erbilen, S. Albayark, O. Yidiz and C. Uyan, “Effects of Thyroxin Therapy on Cardiac Function in Patients with Subclinical Hypothyroidism: Index of Myocardial Performance in the Evaluation of Left Ventricular Function,” International Journal of Cardiology, Vol. 95, No 2, 2004, pp. 135-143. doi:10.1016/j.ijcard.2003.05.015
[18] K. Ashizawa, M. Imaizumi, T. Usa, T. Tominaga, N. Sera, A. Hida, et al., “Metabolic Cardiovascular Disease Risk Factors and Their Clustering in Subclinical Hypothyroidism,” Clinical Endocrinology, Vol. 72, No. 5, 2010, pp. 689-695. doi:10111/j.1365-2265.2009.03697.x
[19] R. Kadiyala, R. Peter and O. E. Okosieme, “Thyroid Dysfunction in Patients with Diabetes: Clinical Implications and Screening Strategies,” International Journal of Clinical Practice, Vol. 64, No. 8, 2010, pp. 1130-1139. doi:10.1111/j.1742-1241.2010.02376.x
[20] J. Y. Park, J. W. Yoon, K. I. Kim, Y. J. Lee, K. W. Kim, S. H. Choi, S. Lim, D. J. Choi, K.-H. Park, J. H. Choh, H. C. Jang, S. Y. Kim, B. Y. Cho and C. Lim, “Subclinical Hypothyroidism May Increase the Risk of Transient Atrial Fibrillation after Coronary Artery Bypass Grafting,” The Annals of Thoracic Surgery, Vol. 87, No. 6, 2009, pp. 1846-1852. doi:10.1016/j.athoracsurg.2009.03.032
[21] N. Rodondi, W. P. den Elzen, D. C. Bauer, A. R. Cappola, S. Razvi, J. P. Walsh, B. O. Asvold, G. Iervasi, M. Imaizumi, T. H. Collet, A. Bremner, P. Maisonneuve, J. A. Sgarbi, K. T. Khaw, M. P. Vanderpump, A. B. Newman, J. Cornuz, J. A. Franklyn, R. G. Westendorp, E. Vittinghoff, J. Gussekloo and Thyroid Studies Collaboration, “Subclinical Hypothyroidism and the Risk of Coronary Heart Disease and Mortality,” The Journal of American Medical Association, Vol. 304, No. 12, 2010, pp. 13651374. doi:101001/jama.20
[22] N. Ochs, R. Auer, D. C. Bauer, D. Nanchen, J. Gusselkoo, J. Cornuz and N. Rodondi, “Meta-Analysis: Subclinical Thyroid Dysfunction and the Risk for Coronary Heart Disease and Mortality,” Annals of Internal Medicine, Vol. 148, No. 11, 2008, pp. 832-845.
[23] S. Razvi, A. Shakoor, M. Vanderpump, J. U. Weaver and S. H. S. Pearce, “The Influence of Age on the Relationship between Subclinical Hypothyroidism and Ischemic Heart Disease: A Meta-Analysis,” The Journal of Clinical Endocrinology & Metabolism, Vol. 93, No. 8, 2008, pp. 2998-3007. doi:10.1210/jc.2008-0167
[24] I. A. Weiss, N. Bloomgarden and W. H. Frishman, “Subclinical Hypothyroidism and Cardiovascular Risk: Recommendations for Treatment,” Cardiology in Review, Vol. 19, No. 6, 2011, pp. 291-299. doi:10.1097/CRD.0b013e318227df87

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