STEMI in a 24-year-old man after use of a synephrine-containing dietary supplement: a case report and review of the literature

Abstract

Billions of dollars are spent annually in the United States in the largely unregulated market of dietary supplements. Many of these supplements are marketed as weight-loss and athletic-performance-enhancement products. The association of various ephedra-containing products with adverse cardiovascular events has led to a ban on the sale of these products by the U.S. Food and Drug Administration. The result has been the emergence of new formulations marketed for weight loss and athletic-performance enhancement that are "ephedra-free" but contain other sympathomimetic substances, the safety of which has not been established. We present the case of a previously healthy 24-year-old man who presented with an ST-segment-elevation myocardial infarction (STEMI) within hours of taking the ephedra-free product Nutrex Lipo-6x. Emergent coronary angiography revealed the presence of extensive, diffuse thrombus in the left anterior descending coronary artery. The patient had no risk factors for coronary artery disease or myocardial infarction; this includes the absence of a hypercoagulable state and the absence of a history of illicit drug use. This case of STEMI--associated as it is with the use of a synephrine-containing product by a person without risk factors for coronary artery disease--is to our knowledge the 1st reported in the literature. We discuss the patient's evaluation and clinical course, and we review the literature with respect to synephrine-containing dietary supplements. On the basis of synephrine's chemical composition and mechanism of action, we propose a direct association between this patient's use of Nutrex Lipo-6x and his STEMI.

Keywords: Citrus/adverse effects; United States Food and Drug Administration; coronary vasospasm/complications/etiology; dietary supplements/adverse effects/poisoning; myocardial infarction/chemically induced; plant preparations; synephrine; weight loss/drug effects.

Fig. 1. Patient's electrocardiogram at presentation reveals sinus bradycardia with 3-to 6-mm ST-segment elevations in leads II, III, aVF, and V₃ through V₆.

Fig. 3. Coronary angiogram after percutaneous coronary intervention (right anterior oblique cranial view) reveals resolution of the proximal left anterior descending coronary artery (LAD) thrombus (arrowhead). A persistent total occlusion of the distal LAD with a large residual thrombus burden (arrow) remains.

Fig. 2. Coronary angiogram at presentation (right anterior oblique cranial view) reveals nonocclusive thrombus (arrowhead) in the proximal left anterior descending coronary artery (LAD) and total thrombotic occlusion (arrow) of the distal LAD.

Fig. 4. Molecular structures of ephedrine (left) and synephrine (right).