Vasospastic myocardial infarction complicated with ventricular tachycardia in a patient with hyperthyroidism

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.

Cardiothyreosis: Epidemiological, clinical and therapeutic approach

Introduction

Cardiothyreosis corresponds to the cellular effects of free thyroid hormones on the vascular wall and the myocardium. We aim to describe the clinical, para-clinical and therapeutic aspects of cardiothyreosis and to detail prognostic factors.

Methods

We conducted a descriptive retrospective study at the Endocrinology-Diabetology Department of the Hedi Chaker University Hospital in Sfax-Tunisia. We collected medical records of 100 patients with cardiothyreosis between January 1999 and December 2019. We included patients with cardiothyreosis who underwent adequate cardiac evaluation. We excluded patients with cardiac abnormalities related to conditions other than hyperthyroidism, patients who died and patients without cardiothyreosis.

Results

We included 100 adult patients (43 men and 57 women). The mean age was 49.3 ±12.9 years (20-79 years). The diagnosis of cardiothyreosis was concomitant with that of hyperthyroidism in 72% of cases. Weight loss and palpitations were the two most frequently reported signs in 91% of cases each. Hypertension was systolic in 15 patients. The average heart rate was 103.1 beats/min (52-182 bpm). The mean TSH and FT4 levels were 0.042 μIU/ml and 59.6 pmol/l, respectively. Rhythm disorders and heart failure were the most common cardiac complications with 81 and 56 cases, respectively. Cardiac ultrasound showed dilatation of the left atrium in 28.3% of patients. Pulmonary arterial hypertension was present in 43% of cases. 57 patients had been treated with benzylthiouracil at a mean dose of 157.45 mg/day. Radical treatment with radioactive iodine was indicated in 81 patients. The evolution of cardiothyreosis was favourable in 58 patients.

Conclusion

Cardiothyreosis is a serious complication of hyperthyroidism. Future prospective studies will be of great help to better characterise and manage cardiothyreosis.

The Impact of Subclinical Hyperthyroidism on Cardiovascular Prognosis in Patients Undergoing Percutaneous Coronary Intervention

CONTEXT

Limited studies have focused on the impact of subclinical hyperthyroidism (SHyper) on poor prognosis in patients with known coronary artery disease (CAD).

OBJECTIVE

We implemented the present study to explore the association between SHyper and adverse cardiovascular events in CAD patients who underwent drug-eluting stent implantation.

METHODS

We consecutively recruited 8283 CAD patients undergoing percutaneous coronary intervention (PCI). All subjects were divided into 2 groups according to their thyroid function: group 1 (euthyroidism group, n = 7942) and group 2 (SHyper group, n = 341). After 1:4 propensity score (PS) matching, 1603 patients (332 SHyper group and 1271 euthyroidism group) were selected. The primary endpoint was major adverse cardiovascular events (MACEs), a composite of cardiac mortality, nonfatal myocardial infarction (MI), and target vessel revascularization (TVR).

RESULTS

Kaplan-Meier (K-M) survival analyses suggested that there was no significant difference in the primary endpoint and secondary endpoints (MACE: 11.4% vs 8.8%, log-rank P = .124; cardiac death: 1.2% vs 0.9%, log-rank P = .540; nonfatal MI: 5.7% vs 4%, log-rank P = .177; and TVR: 6% vs 4.7%, log-rank P = .303) in the PS-matched population. Cox regression analysis indicated that SHyper was not an independent risk factor for MACEs (HR 1.33, 95% CI 0.92-1.92, P = .127).

CONCLUSION

SHyper is not independently associated with adverse cardiovascular events in CAD patients undergoing PCI. More studies should be implemented in the future to assess the long-term predictive value of SHyper with thyrotropin levels <0.1 mIU/L for CAD patients undergoing PCI.

A silent myocardial infarction with normal coronary arteries associated with Graves' disease

Acute myocardial infarction (AMI) is a scarce but fatal complication in Graves' disease (GD). Silent myocardial infarction (MI) associated with GD has never been reported. A 37-year-old male patient was admitted due to poorly controlled hyperthyroidism and persistent fever. But the patient did not complain of chest pain on admission. The electrocardiogram (ECG) showed Q waves and ST-segment elevations. Cardiac troponin I (cTnI) was sharply increased. He was qualified to an emergency coronary angiography which showed normal coronary arteries without any stenosis. The potential mechanisms for AMI with angiographically normal coronary arteries in the setting of hyperthyroidism may be attributed to the hyper-metabolic state due to thyrotoxicosis, severe vasospasm in coronary artery, coagulation abnormalities, and the inflammatory/autoimmune milieu. In conclusion, patients with GD-associated silent MI are unusual. Early recognition and diagnosis by clinicians provide a better prognosis. This case demonstrates the importance of ECG and cTnI screening among GD patients.