Background: The association between thyroid-stimulating-hormone (TSH) and prognosis of nonischemic dilated cardiomyopathy (NIDCM) in patients with normal thyroid function remains unclear.
Hypothesis: Our aim was to investigate the association between TSH and major adverse cardiovascular events in euthyroid NIDCM patients.
Methods: The original cohort consisted of 216 consecutive euthyroid NIDCM patients, with left ventricular ejection fraction (LVEF) ≤35%, who were observed from 2010 to 2013. Patients with persistent ventricular arrhythmia (VA) histories, amiodarone taken for VA prevention, or on heart transplant list within 1 year were excluded. A follow-up evaluation was performed, and VA events, heart failure (HF) exacerbation/heart transplant, cardiac death, or death from any cause were separately evaluated.
Results: A total of 184 patients were enrolled, and 97.8% (180/184) ultimately received follow-up evaluations. During the median 4.6-year follow-up, 24 VA events, 28 cardiac deaths, 30 all-cause deaths, 40 HF exacerbations, and 11 heart transplant events occurred. Serum TSH levels showed good predictive efficacies for VA events (area under the curve [AUC] = 0.702, 95% confidence interval [CI]: 0.629-0.767), and the risk of VA events increased, according to serum TSH quarters, as determined by Kaplan-Meier analysis (2.2% vs 13.4% vs 21.0% vs 30.0%, Q1-Q4, P = 0.011). Multivariable Cox analysis showed that patients at the Q4 level of serum TSH (>2.67 mIU/L) suffered an increased risk of VA events, compared with those at the Q1 level of TSH (hazard ratio [HR] = 15.88, 95% CI: 2.01-65.15) or those at the other three quarters (HR = 3.17, 95% CI: 1.38-7.26). However, the Q4 TSH level was not associated with other adverse cardiac events.
Conclusion: An association between TSH levels and the risk of VA events may exist in euthyroid NIDCM patients.
Keywords: euthyroid; nonischemic dilated cardiomyopathy; thyroid-stimulating hormone; ventricular arrhythmias.
© 2018 Wiley Periodicals, Inc.