Takotsubo Cardiomyopathy Associated with Levothyroxine Over-replacement

Takotsubo Cardiomyopathy and Autoimmune Disorders: A Systematic Scoping Review of Published Cases

Introduction

Takotsubo cardiomyopathy (TCM) features transient left ventricular apical dysfunction or ballooning. The underlying mechanism remains elusive; however, evidence suggests the role of different physical and psychological stressors. We systematically reviewed patients presenting with TCM and autoimmunity to explore the link between the two conditions.

Methods

We applied the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) to report this review. Using keywords related to autoimmune/immune-mediated diseases and TCM, we searched PubMed, Scopus, and WOS in March 2022. The final results were added to a data extraction sheet. Data were analyzed by SPSS version 26.0.

Results

Our search yielded 121 studies, including 155 patients. Females were considerably predominant. Most patients had a history of autoimmune disease, and almost a third had a history of cardiovascular disease. Dyspnea and chest pain were the most common chief complaints. More than 70% of patients had experienced physical stress. Myasthenia gravis, systemic lupus erythematosus, and multiple sclerosis were the most frequently reported autoimmune diseases.

Conclusion

There were similarities in age and sex compared to classic TCM. TCM should be considered as a differential diagnosis for ACS, especially in patients with a positive background of autoimmunity. A precise reporting system is required for further studies.

Pharmacist-Mediated Thyroid-Stimulating Hormone (TSH) Test Guideline Monitoring Program- Outcomes of a Retrospective Study In Patients On Levothyroxine

Thirty to sixty percent of individuals taking levothyroxine were either under or overtreated, which leads to organ damage and excess mortality. This study aims to assess the gaps in the "thyroid-stimulating hormone (TSH) test guideline compliance rate" and validate the scope of ambulatory care pharmacist-mediated practice in patients on levothyroxine. At the study site, pharmacists offered patient-centered telephonic counseling to patients on levothyroxine who had been non-compliant with TSH tests for more than a year. A two-month quantitative retrospective analysis of this practice was conducted to assess its impact on TSH lab test adherence and dose modification outcomes. 415 patients met the study's inclusion criteria who received pharmacist counseling with documented intervention. Pharmacists bridged the significant gap in practice by creating new TSH lab requests with counseling in 81.2% (n = 337) of the study population who did not have TSH lab requests prior to the program. The non-compliance rate population dropped from 79.27% (n = 329) to 17.59% (n = 73) in the study population who had been non-compliant with the TSH test for 13 and 24 months. 74.5% (n = 309) were found to have performed their TSH test after the pharmacist's intervention. Among 100, 66% (n = 66) patients with abnormal TSH values consulted their physician for advice, of which 60.6% (n=40) had their levothyroxine dose adjusted (χ2=82.702, P < 0.01. The study suggests that pharmacists can significantly mediate between patients and physicians to enhance TSH test compliance and essential dose adjustment in patients prescribed levothyroxine.

Autoimmune polyendocrine syndrome II presenting paradoxically as Takotsubo cardiomyopathy: a case report and reappraisal of pathophysiology

BACKGROUND

Takotsubo cardiomyopathy (TCM) is a rare disease entity characterized by acute, non-ischemic, reversible myocardial dysfunction that mimics acute myocardial infarction. Activation and excessive outflow of sympathetic nervous system are believed to be central to the figure in the disease pathogenesis. Adrenocortical hormones potentiate the systemic actions of sympathetic nervous system and accordingly are essential for regulation of myocardial function. We present an unusual case of a middle-aged woman with primary adrenal insufficiency who presented paradoxically with TCM.

CASE PRESENTATION

A 50-year-old woman with past history of hypothyroidism presented to emergency department with history of acute chest pain and syncope. There was no significant drug history or history of an emotional or physical stimulus prior to admission. Prominent pigmentation over the tongue and skin creases of hands were noted. On presentation, she was in shock and had ventricular tachycardia which required electrical cardioversion. The subsequent electrocardiogram demonstrated diffuse T-wave inversions with prolonged QT_C. There was apical hypokinesia on echocardiogram, and cardiac biomarkers were elevated. There was persistent inotropic requirement. She had marked postural symptoms, and a postural blood pressure drop of 50 mm Hg was present. Initial laboratory parameters were significant for hyperkalemia (7.8 mEq/L) and hyponatremia (128 mEq/L). These findings prompted evaluation for adrenal insufficiency which was confirmed with appropriate tests. Autoimmune polyendocrine syndrome II was thus diagnosed based on the above findings. Coronary angiography revealed normal coronaries. The diagnoses of TCM was established in accordance with the International Takotsubo Diagnostic Criteria. She was started on stress dose steroid replacement therapy and improved dramatically. At one month of follow-up, the patient is asymptomatic, and there was normalization of her left ventricular function.

CONCLUSIONS

Intricate relationship and interplay exist between the steroid hormones and catecholamines in the pathogenesis of TCM. Steroid hormones not only potentiate the actions of catecholamines, but they also regulate and channelize catecholaminergic actions preventing their deleterious effects on the cardiac tissue. Hence, both steroid deficiency and exogenous steroid replacement may precipitate TCM. Evidence from more such cases and larger perspective studies in future will further improve our understanding of this complex disease process and its myriad associations.

Abnormal thyroid function is common in takotsubo syndrome and depends on two distinct mechanisms: results of a multicentre observational study

BACKGROUND

Several reports have described Takotsubo syndrome (TTS) secondary to thyrotoxicosis. A complex interaction of central and peripheral catecholamines with thyroid homeostasis has been suggested. In this study, we analysed sequential thyroid hormone profiles during the acute phase of TTS.

METHODS

Thyrotropin (TSH), free T4 (FT4) and free T3 (FT3) concentrations were analysed at predefined time points in 32 patients presenting with TTS or acute coronary syndrome (ACS, n = 16 in each group) in a 2-year period in two German university hospitals. Data were compared to age- and sex-matched controls (10 samples, each of 16 subjects), and an unsupervised machine learning (ML) algorithm identified patterns in the hormone signature. Subjects with thyroid disease and patients receiving amiodarone were excluded from follow-up.

RESULTS

Among patients with TTS, FT4 concentrations were significantly higher when compared to controls or ACS. Four subjects (25%) suffered from subclinical or overt thyrotoxicosis. Two additional patients developed subclinical or overt thyrotoxicosis during stay in hospital. In four subjects (25%), FT4 concentrations were increased, despite nonsuppressed TSH concentration, representing an elevated set point of thyroid homeostasis. The thyroid hormone profile was normal in only six patients (38%) presenting with TTS.

CONCLUSION

Abnormal thyroid function is frequent in patients with TTS. Primary hyperthyroidism and an elevated set point of thyroid homeostasis are common in TTS, suggesting a stress-dependent endocrine response or type 2 thyroid allostasis. Thyroid function may be a worthwhile target in treating or preventing TTS.

Development and Prospective Validation of the Levothyroxine Dose Prediction Model in Primary Hypothyroidism

Multiple visits are needed to achieve euthyroidism on levothyroxine in newly detected primary hypothyroidism. We aimed to develop a levothyroxine dose estimation algorithm for primary hypothyroidism. Adults with newly diagnosed hypothyroidism were enrolled prospectively, first in the training cohort, followed by the validation cohort separated by time and person. We developed a predictive algorithm from Training Cohort and validated the model in Validation Cohort. Training Cohort: In this cohort, 358 subjects (259 women and 99 men) were enrolled. The median duration needed to achieve euthyroidism was 4±0.5 months. The mean levothyroxine daily dose was 60.5±34.1 μg. Data of euthyroid subjects within 6 months of treatment initiation and age range 18-65 years were used for algorithm development. In the multivariable linear regression algorithm, pretreatment serum thyrotropin level, and sex formed the best-fit predictive model (adjusted R² 0.73, p-value <0.001). Validation Cohort: Eighty-four subjects (61 women and 23 men) were enrolled and started on an estimated levothyroxine dose derived from the developed prediction model. On the first follow-up on treatment, 34/50 participants achieved euthyroidism (68%) at 1.5 months. In conclusion, the proposed prediction model for levothyroxine dose estimation effectively achieves early euthyroidism in two-third subjects in the age range of 18-65 years.

Levothyroxine Dose Adjustment to Optimise Therapy Throughout a Patient's Lifetime

Levothyroxine is the standard therapy for patients with hypothyroidism, a condition that affects up to 5% of people worldwide. While levothyroxine therapy has substantially improved the lives of millions of hypothyroid patients since its introduction in 1949, the complexity of maintaining biochemical and clinical euthyroidism in patients undergoing treatment with levothyroxine cannot be underestimated. Initial dosing of levothyroxine can vary greatly and may be based on the amount of residual thyroid function retained by the patient, the body weight or lean body mass of the patient, and thyroid-stimulating hormone levels. As levothyroxine is usually administered over a patient's lifetime, physiological changes throughout life will affect the dose of levothyroxine required to maintain euthyroidism. Furthermore, dose adjustments may need to be made in patients with concomitant medical conditions, in patients taking certain medications, as well as in elderly patients. Patients who have undergone any weight or hormonal changes may require dose adjustments, and the majority of pregnant women require increased doses of levothyroxine. Optimal treatment of hypothyroidism requires a partnership between patient and physician. The physician is tasked with vigilant appraisal of the patient's status based on a thorough clinical and laboratory assessment and appropriate adjustment of their levothyroxine therapy. The patient in turn is tasked with medication adherence and reporting of symptomatology and any changes in their medical situation. The goal is consistent maintenance of euthyroidism, without the patient experiencing the adverse events and negative health consequences of under- or overtreatment.Funding Merck.Plain Language Summary Plain language summary available for this article.