Thyrotoxicosis and acute coronary syndrome: a „deadly” association

Introduction: Coronary vasospasm associated with untreated hyperthyroidism may raise the risk of myocardial injury and sudden cardiac death.
Case presentation: We report the case of a 47 years old female patient with documented and neglected hyperthyroidism, admitted in the Cardiology Department of the University Emergency Hospital of Bucharest describing recurrent episodes of angina pectoris in the last month. The ongoing episode at presentation debuted on the morning of admission accompanied by nausea, vomiting and hypotension. The electrocardiogram (ECG) performed in emergency emphasized anterior and lateral ST segment depression associated with elevated troponin I suggestive for acute coronary syndrome without ST segment elevation. The emergency angiography showed 70% subocclusive ostial stenosis (type B2 lesion) of the left main coronary artery, without any significant lesions on other territories. Primary percutaneous coronary intervention (PCI) with implantation of a 3.0 x 11 mm drug eluting stent was performed, with optimal result and no complications. The transthoracic echocardiography (TEE) emphasized hypokinesia in the apical third of the anterior wall and interventricular septum, mild regurgitation and an ejection fraction of 57% of the left ventricle (modified Simpson). Standard treatment with dual anti-platelet therapy with ticagrelor and acetylsalicylic acid, along with beta-blockers, statin and enzyme conversion inhibitors was initiated. Forty-eight hours post procedural the patient complained of thoracic pain and paresthesia in the left arm, but without significant changes on the ECG and TEE, followed by repeated bradyasystolic cardiac arrests, rapidly resuscitated. Suspicion of intra-stent restenosis was raised and, as a consequence, an emergency angi-ography was repeated and showed permeable stent and no significant lesions on other arteries, but with generalized coronary spasm especially in the right coronary artery. The ECG showed transient anterior ST segment elevation and inferior ST segment depression, with trifascicular block completely reversed in minutes, but with a series of conduction and rhythm abnormalities that determined an emergency temporary pacing.
Particularity of the case: The presence of vasospasm during angiography as a possible cause of cardiac arrests determined the introduction of calcium channel blockers and isosorbide mononitrate therapy along with the treatment of hyperthyroidism. Furthermore, due to the age of the patient and the intense and pro-longed vasospasm associated with cardiac arrest, we decided the implantation of a cardiac defibrillator.
Conclusions: The presence of untreated hyperthyroidism in a female patient with standard medical and interventional treatment for acute coronary syndrome ca-used by critical lesion of left main coronary artery may determine prolonged and diffuse coronary vasospasm and sudden cardiac death. The subsequent therapy and the decision of implantable cardiac defibrillator represent a medical problem of great importance.

ISSN – online: 2734 – 6382
ISSN-L 1220-658X
ISSN – print: 1220-658X
The Romanian Journal of Cardiology is indexed by:
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CODE: 379
CME Credits: 10 (Romanian College of Physicians)