Abstract
BackgroundThis study aims to investigate the role of free triiodothyronine (fT3) in predicting poor prognosis of adult patients with acute myocarditis.MethodsA total of 173 consecutive adult patients with acute myocarditis completed thyroid function evaluations. They were divided into two groups according to fT3 levels: low fT3 group (n = 54, fT3 < 3.54 pmol/liter) and normal fT3 group (n = 119, fT3 ≥ 3.54 pmol/liter). The primary endpoint was major adverse cardiac events (MACE).ResultsDuring the 3.5 ± 2.8 years follow-up, the rate of MACE was 29.6% versus 3.5% in low fT3 group versus normal fT3 group, respectively (P < 0.0001). Long-term at 8 years MACE-free survival were lower in low fT3 group versus normal fT3 group (52.9% versus 92.3%, log-rank P < 0.0001), respectively. Univariate Cox analysis showed that left ventricular ejection fraction (LVEF) < 50% [hazard ratio (HR) 10.231, 95% confidence interval (CI): 3.418–30.624, P < 0.0001) and low fT3 level (HR 0.360, 95% CI: 0.223–0.582, P < 0.0001) were strongest two predictors of MACE. After adjustment for traditional risk predictors, the prognostic value of fT3 status was still significant (HR 0.540, 95% CI: 0.316–0.922, P = 0.024). Compared with normal fT3 group, those in low fT3 group were at a much higher risk of MACE (HR 5.074, 95% CI: 1.518–16.964, P = 0.008).ConclusionsLow T3 syndrome was a strong predictor of poor prognosis in adult patients with acute myocarditis. These findings suggest that fT3 level could serve as a biomarker for risk stratification in acute myocarditis patients.
Highlights
The cardiovascular system is a major target on which thyroid hormone act
10 Patients without available thyroid hormone tests were excluded from the analysis. 5 patients were excluded from the study because of overt primary hypothyroidism in 1 patient and hyperthyroidism in 4 patients by thyroid hormone evaluation after admission
The diagnosis of acute myocarditis was based on the European Society of Cardiology expert consensus on diagnosis and management of myocarditis [8]: 1) Clinical presentation: acute chest pain, dyspnea, fatigue, palpitation, syncope, heart failure signs and/or aborted sudden cardiac death, unexplained cardiogenic shock; 2) electrocardiography (ECG)/Holter/stress test features; 3) Myocardium injured markers: elevated troponin I/T; 4) Functional and structural abnormalities on echocardiography; 5) Edema and/or late gadolinium enhancement on cardiovascular magnetic resonance imaging, and in the absence of coronary stenosis ≥50%, valvular heart disease, hypertensive heart disease or cardiomyopathy
Summary
The cardiovascular system is a major target on which thyroid hormone act. The heart relies mainly on the biologically active hormone triiodothyronine (T3) [1]. Clinical and experimental evidence has shown that T3 plays an important role in maintaining cardiovascular homeostasis and low T3 status can adversely influence cardiovascular outcomes [2, 3]. Accumulating evidence suggests that low T3 status was a strong predictor of death in cardiac patients [5, 6]. Acute myocarditis is an inflammatory disease of myocardium with variable clinical presentations and prognosis according to distinct etiology [7, 8]. Cohort studies showed that patients presenting with complicated myocarditis might progress quickly and suffered a greater death risk than those with uncomplicated myocarditis [9, 10]. This study aims to investigate the role of free triiodothyronine (fT3) in predicting poor prognosis of adult patients with acute myocarditis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
