Study on non-thyroidal illness syndrome in patients with coronary artery disease

Objective To determine the prognostic significance of non-thyroidal illness syndrome(NTIS)and FT3 on long-term all-cause and cardiovascular mortality in patients with coronary artery disease(CAD). Methods A total of 1 354 patients underwent coronary angiograhy and participated in the study. After screening, 984 patients with CAD were enrolled finally and divided into NTIS group and euthyroid group. The admitted patients were also classified into Tertile 1-3 groups based on FT3 value. The relationship of long-term all-cause and cardiovascular mortality with FT3 was investigated by multivariate Cox regression analysis. Results 129 out of 984 patients had NTIS. As FT3 value decreased, both long-term all-cause mortality(Tertile 1 group 9.6%, Tertile 2 group 11.5%, Tertile 3 group 20.9%, P<0.01)and cardiovascular mortality(Tertile 1 group 4.5%, Tertile 2 group 7.2%, Tertile 3 group 11.0%, P<0.01)gradually increased. After adjusting for all factors, FT3(HR=0.614, 95%CI 0.439-0.859)was independently associated with long-term all-cause mortality. FT3(HR=0.605, 95%CI 0.370-0.986)was also a risk factor for cardiovascular mortality. Conclusion NTIS exists in patients with CAD without myocardial infarction. FT3 reduction is an independent risk factor for long-term all-cause and cardiovascular mortality in patients with CAD. (Chin J Endocrinol Metab, 2015, 31: 47-51) Key words: Non-thyroidal illness syndrome; Coronary artery disease; Long-term mortality