A 62-year-old obese woman with type 2 diabetes, hypertension, and a pack-a-day smoking habit presents to the emergency department for acute onset of left-side arm and leg weakness and sensory loss on awakening.
She reports taking a baby aspirin daily to “prevent heart attacks.” Her electrocardiogram demonstrates a left bundle branch block and frequent premature atrial contractions. She recovers partially but has residual mild hemiparesis. A duplex carotid ultrasound shows 80% stenosis of the right internal carotid artery.
In the United States each year approximately 700,000 cerebrovascular accidents (CVA) constitute the largest cause of age-adjusted morbidity of any illness.1 About 200,000 of these strokes are recurrent events.
CVA is the third-leading cause of death. Hospitalists increasingly are responsible for the inpatient care of patients with acute CVA. Atheroembolism from carotid atherosclerosis is the suspected cause for about one in five ischemic strokes.2
The link between carotid stenosis and stroke has been recognized for many years. The first carotid endarterectomy (CEA) was reported more than 50 years ago.3
This targeted review covers the natural history of symptomatic carotid stenosis, the key efficacy trials of CEA and carotid angioplasty and stenting (CAS) among symptomatic patients, and pitfalls for properly diagnosing the severity of carotid stenosis. The medical therapy of carotid stenosis and the secondary prevention of CVA were recently reviewed in The Hospitalist (October 2007, p. 34).
The presence or absence of referable neurological symptoms is pivotal to understanding the near-term risk for recurrent CVA related to carotid stenosis. In the absence of symptoms, the risk for future CVA is essentially constant over years.
However, once symptoms occur, the risk for a second event accelerates substantially. Among patients with newly symptomatic carotid stenosis, the risk for another transient ischemic attack (TIA) or stroke within the following 24 months is 26%.4 This risk peaks within the first month or two following the index event, underscoring the time-dependent nature of carotid evaluation and intervention.
Guidelines from the American Heart Association and the American College of Cardiology on the management of ischemic stroke assign early carotid intervention, defined as within two weeks from the index event, a Class 2 indication.5 Hospitalists must rapidly identify the severity of carotid stenosis and make timely referrals to meet this recommended therapeutic window.