The Effect of Thyroid Stimulating Hormone Level Within the Reference Range on In-Hospital and Short-Term Prognosis in Acute Coronary Syndrome Patients

A Rare Encounter: Unstable Vasospastic Angina Induced by Thyrotoxicosis

Coronary artery vasospasm plays a crucial role in the prevalence of unstable angina. Despite common misdiagnosis, there is limited evidence on this topic. Here, we present a rare case of unstable vasospastic angina in a female with severe thyrotoxicosis. Case Report: A 62-year-old female patient was admitted to the cardiac intensive care unit due to crushing chest pain at rest. The patient exhibited ischemic changes on the ECG with a normal troponin I level. Recurrent chest pain prompted urgent coronary angiography, revealing generalized vasospasm of all coronary artery branches including the left main coronary artery. Intracoronary nitroglycerin injection partially alleviated the vasospasm; however, there was a persistent stenosis in the left main artery. Subsequent intravascular ultrasound demonstrated an anatomically normal left main artery. Post-procedure, laboratory tests revealed undetectable levels of thyroid-stimulating hormone and thyroid hormones above the detectable level. The patient was initiated on methimazole and discharged symptom-free, expecting a good prognosis under conservative management. Conclusions: Clinically significant coronary vasospasm triggered by thyrotoxicosis remains a rarity in clinical practice, often posing diagnostic challenges. This case emphasizes the significance of intracoronary nitroglycerin and intravascular ultrasound in discerning the etiology of coronary lesions seen on angiography. We advocate for these techniques to optimize invasive coronary artery diagnostics, enabling the selection of the appropriate treatment strategies and improving long-term prognosis.

Normal thyroid stimulating hormone is associated with all-cause mortality in patients with acute myocardial infarction after percutaneous coronary intervention

BACKGROUND

Circulating thyroid-stimulating hormone (TSH) levels within the normal reference range can affect the cardiovascular system. The present study investigated the prognostic value of normal TSH levels in patients presenting with acute myocardial infarction (AMI) following percutaneous coronary intervention (PCI).

METHODS

Between January 2013 and July 2019, 1240 patients with AMI and normal thyroid function were enrolled and classified according to TSH tertile. The trial endpoint was all-cause mortality. The integrated discrimination index (IDI) and the net reclassification index (NRI) were used to assess the combined predictive values of the TSH levels and the Global Registry of Acute Coronary Events (GRACE) scores.

RESULTS

After a median 44.25-month follow-up, 195 individuals died. Even after covariate adjustment by multivariate Cox regression (HR: 1.56; 95% CI 1.08-2.25; P = 0.017), the patients in the third TSH tertile were at the highest risk of all-cause mortality. A subgroup analysis revealed significant interactions between the TSH levels and the GRACE scores (high risk vs. low/medium risk) (P = 0.019). The addition of the TSH levels to the GRACE scores substantially improved the prediction of all-cause mortality, especially for high-risk patients (NRI = 0.239; IDI = 0.044; C-statistic value range 0.649-0.691; all significant).

CONCLUSIONS

The third TSH tertile is associated with a higher incidence of all-cause mortality than the first TSH tertile in high-risk patients presenting with AMI after PCI.

Thyroid-stimulating hormone within the normal reference range has a U-shaped association with the severity of coronary artery disease in nondiabetic patients but is diluted in diabetic patients

Too high or too low thyroid-stimulating hormone (TSH) has been associated with the progress and prognosis of coronary artery disease (CAD). However, whether TSH within its normal reference range plays a role in the severity of CAD remains unclear. In this observational study, we explored the potential relationship of hypersensitive TSH (hs-TSH) with the severity of CAD in euthyroid patients with or without diabetes mellitus. A total of 7357 CAD patients with euthyroidism were enrolled in this study. Of those, 1997 had diabetes mellitus. The severity of CAD was evaluated through the presence of myocardial infarction (MI) and the severity of coronary lesions, which was calculated using the Gensini score (GS). Logistic regression models treating hs-TSH as a categorical variable and restricted cubic spline analyses treating it as a continuous variable were used to evaluate the associations of hs-TSH with the severity of CAD. The propensity score matching method was used to further validate the differences between diabetic and nondiabetic patients. CAD patients with diabetes mellitus had lower levels of hs-TSH (1.6 (0.97-2.53) vs 1.67 (1.00-2.64)) in serum compared with CAD patients without diabetes mellitus. Meanwhile, hs-TSH was independently related to the severity of CAD. In CAD patients with vs without diabetes mellitus, the U-shaped relationship between hs-TSH and MI was more prominent in patients without diabetes mellitus, and the significant U-shaped association between higher GS and hs-TSH remained only in nondiabetes. Therefore, hs-TSH within the normal reference range has a U-shaped association with the severity of CAD in nondiabetic patients, which is markedly diluted in diabetic patients.

Prognostic Value of Normal Thyroid Stimulating Hormone in Long-Term Mortality in Patients With STEMI

BACKGROUND

Although within the normal range, thyroid stimulating hormone (TSH) levels are associated with cardio-metabolic disorders and have an effect on the cardiovascular system. The aim of our study was to assess the prognostic value of normal TSH on long-term mortality in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

Consecutive STEMI patients who had a TSH level within the normal range (0.55-4.78 μIU/ml) were enrolled from November 2013 to December 2018. Patients were stratified into three groups depending on the tertile of TSH level, and all-cause mortality and cardiac death were compared. TSH concentrations associated with risk of all-cause mortality were evaluated in a continuous scale (restricted cubic splines) and the Cox proportional hazards regression model.

RESULTS

A total of 1,203 patients with STEMI were eligible for analysis. During a median follow-up of 39 months, patients in the 3rd tertile group had higher all-cause mortality (20.1% vs. 12.2% and 14.3%, p = 0.006) and cardiac death (15.4% vs. 7.7% and 12.3%, p = 0.001) as compared to the 1st and 2nd tertile groups. The Cox proportional hazards model showed that TSH was an independent predictor on long-term all-cause mortality (HR: 1.248, 95% CI: 1.046-1.490, p = 0.014). However, subgroup analysis indicated that TSH (HR: 1.313, 95% CI: 1.063-1.623, p = 0.012) was only significantly associated with long-term all-cause mortality in the patients without emergency reperfusion therapy. Restricted cubic spline analyses showed a linear relationship between TSH concentrations and all-cause mortality (P for non-linearity = 0.659).

CONCLUSIONS

A Higher TSH level - even in a normal range is associated with long-term mortality in patients with STEMI, proposing an additional indication to identify STEMI patients with poor prognosis.

Altered methylarginine levels after surgery in subjects with multinodular goiter

OBJECTIVES

Thyroid disorders are important risk factor for cardiovascular diseases. Levels of methylarginines such as asymmetric dimethyl arginine (ADMA), L-monomethyl arginine (L-NMMA), symmetric dimethyl arginine (SDMA) are increase in cardiovascular diseases. Multinodular goiter (MNG) is the most common type of goiter in adults. To date, no study has been conducted to determine the levels of methylarginine in euthyroid MNG patients. Our aim in this study is to compare levels of methylarginines and related metabolites in the preoperative, postoperative MNG patients and controls.

METHODS

Serum ADMA, SDMA, L-NMMA, homoarginine (hArg), arginine and citrulline concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

RESULTS

ADMA (p<0.001), L-NMMA (p=0.002), l-arginine (p=0.006) and citrulline (p<0.001) levels were statistically significantly higher in preop group than postop group. ADMA (p=0.003), L-NMMA (p=0.003) levels were statistically significantly higher and SDMA/ADMA (p<0.001), hArg/ADMA (p<0.001) levels were statistically significantly lower in preop group than control group.

CONCLUSIONS

The levels of methylarginines and related metabolites altered in the euthyroid MNG patients compared to the control group, and more importantly, there were significant differences between the preop and postop groups. Therefore, these metabolites can be useful in the diagnosis and prognosis of thyroid disorders, even if thyroid hormone levels are normal.

Prognostic implications of thyroid hormone alterations in acute coronary syndrome-A systematic review

There is considerable association of thyroid function and the cardiovascular system during various acute systemic illnesses. It is well established that the normal thyroid homeostasis is known to alter in disease states including the acute coronary syndromes (ACS). Abnormal thyroid hormonal status has been shown to be related to worse outcomes and prognosis. This review focuses on the relationship of alterations in thyroid function and its influence on the pathophysiological mechanisms and cardiovascular hemodynamics in ACS and based upon the literature, summarises all the existing evidence to this date on this subject. The data largely points out that low levels of triiodothyronine (T3) levels seen in ACS might be useful in prognosticating the outcomes of ACS.