Contemporary Reviews in Cardiovascular Medicine Cholesterol Embolization Syndrome

Cholesterol embolization syndrome refers to embolization of the contents of an atherosclerotic plaque (primarily cholesterol crystals) from a proximal large-caliber artery to distal small to medium arteries causing end-organ damage by mechanical plugging and an inflammatory response. Synonyms used in the medical literature include atheromatous embolization, cholesterol crystal embolization, and atheroembolism. Cholesterol embolization syndrome should be distinguished from the related and much more common syndrome of arterioarterial thromboembolism in which fragments of a thrombus that forms atop an atheromatous plaque in the aorta or a large artery travel distally and occlude medium to large arteries.1 Cholesterol embolization syndrome is generally characterized by a multitude of small emboli (showers of microemboli) occurring over time. This is in contrast to arterio-arterial thromboembolism, which is usually characterized by an abrupt release of 1 or a few large emboli, leading to severe ischemia of target organs. Cholesterol embolization syndrome has a variety of clinical presentations. Cholesterol emboli originating in the descending thoracic and abdominal aorta may lead to renal failure, gut ischemia, and emboli to the skeletal muscles and the skin. Dermatologic manifestations (most commonly livedo reticularis and blue toe syndrome) are usually confined to the lower extremities but may extend to the abdomen and the chest. Cholesterol emboli originating in the ascending aorta may in addition cause neurological damage that is typically diffuse and due to small infarcts. Cholesterol embolization syndrome is also characterized by a nonspecific acute inflammatory response leading to constitutional symptoms (such as fever and malaise) and abnormalities in laboratory tests (such as hypereosinophilia and elevated erythrocyte sedimentation rate). These manifestations will be discussed in detail later in the text.