Search

Background: Similar to overt hypothyroidism, subclinical hypothyroidism (SCH) has been reported to increase the risk of cardiovascular disease. However, the influence of SCH on clinical outcomes following percutaneous coronary intervention (PCI) remains unclear., Methods: We performed a prospective cohort study. SCH was defined as a thyroid-stimulating hormone (TSH) level ≥4.5mIU/l and a normal level of free thyroxine (FT4). A composite event was defined as the combination of cardiac death, non-fatal myocardial infarction (MI) and repeat revascularization., Results: Of 936 patients, who were observed for 3.1years, 100 patients (10.7%) were diagnosed with SCH. Repeat revascularization, cardiac death and a composite event occurred more frequently in the SCH group than in the euthyroidism group, while the incidence of non-fatal MI was similar between the two groups. Multiple Cox regression analysis showed that SCH was associated with the risk of a composite event (hazard ratio, 1.52; 95% confidence interval, 1.04-2.22) after adjustment for age, sex, current smoking, ST-segment elevation MI, prior PCI, diabetes, hypertension, renal function, left ventricular ejection fraction, B-type natriuretic peptide, stent numbers, total stent length, stent types, obesity and lipid profiles. Serum TSH levels were also significantly associated with the risk of a composite event. SCH was not associated with repeat PCIs for de novo stenotic lesions but was associated with repeated PCIs for in-stent restenotic lesions., Conclusions: SCH negatively impacted clinical outcomes following PCIs. Therefore, patients with SCH should be carefully observed after undergoing a PCI., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Plasma triiodothyronine (fT3) is a strong predictor of adverse clinical outcomes in various clinical conditions. Since fT3 in patients with end-stage renal diseases (ESRD) is frequently reduced and is associated with inflammation and cardiovascular damage, we prospectively tested the hypothesis that it predicts death in a cohort of 200 hemodialysis patients. Plasma fT3 was lower in ESRD patients (P<0.001) than in healthy subjects and in clinically euthyroid patients with normal renal function. During the follow-up 102 patients died. Patients who died had significantly lower plasma fT3 than those who survived (P<0.001) and in a Kaplan-Meyer analysis plasma fT3 was associated with death (P<0.001). On multivariate Cox's regression analyses, adjusting for a series of traditional and emerging risk factors including inflammation markers, patients with relatively higher plasma fT3 (hazard ratio (HR) (1 pg/ml increase in fT3)) had a 50% reduction in the risk of death (HR=0.50, 95% CI: 0.35-0.72) as compared to those having relatively lower fT3 levels. Of note, plasma fT3 captured most of the predictive power of interleukin-6 (IL-6) because this latter variable emerged as a significant predictor of death only in a model excluding fT3. Low fT3 is an independent predictor of death in hemodialysis patients. These data lend support to the hypothesis that thyroid dysfunction is implicated in the high risk of the ESRD population.

A longitudinal study among the population of Busselton, Western Australia, has identified individuals with persistent and transient thyroid microsomal antibodies (TMA). 59 (72%) of 82 subjects with persistent TMA, 18 (72%) of 25 with recently developed TMA, and 12 (23%) of 53 with transient antibody were found to have subclinical hypothyroidism, as indicated by high serum thyroid stimulating hormone concentrations. This study reveals the high specificity, sensitivity, and predictive value of persistent or recently required TMA.