It is a dilemma that asymptomatic carotid disease can cause a stroke when untreated, and yet,carotid artery surgery which is the treatment can also cause the stroke. UT Southwestern Medical Center researchers have now developed a clinical risk prediction rule using factors such as sex, race and health history to assess the danger the surgery poses, while a modified version will help patients make a more fully informed choice about whether to have the procedure.
"It may take a thief to catch a thief, but physicians don't want to cause stroke while trying to prevent stroke, so being able to carefully weigh an individual's benefits and risk from carotid surgery is critically important," said Dr. Ethan Halm, chief of the William T. and Gay Solomon Division of General Internal Medicine and senior author of the study published in the journal Stroke.
Researchers drew on factors that increase the risk for postsurgical death or stroke for people with silent, or asymptomatic, carotid disease to predict which patients were at highest risk for complications. Those most at risk were female, non-white and had certain neurologic and heart diseases.
The carotid arteries, which run on the sides of the neck, are main blood vessels that supply oxygen to the brain. These arteries can become narrowed by fatty cholesterol deposits called plaque. If pieces of plaque break free, they can lodge in the brain, causing stroke.
In carotid endarterectomy (CEA), one of the most common types of vascular surgery performed in the U.S., surgeons open the artery and remove the plaque. Silent, or symptom-free, carotid artery disease usually is found by chance during unrelated medical tests.
"Asymptomatic patients achieve only a modest benefit from surgery – their chance of stroke decreases from 2 percent annually to 1 percent annually – because they have a lower chance of having a stroke in the first place," Dr. Halm said. "For patients with several other medical risk factors, the upfront risk of surgery can outweigh any potential long-term benefits."
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The UT Southwestern researchers found that eight factors were independent predictors of death or stroke – being female, a minority, or severely disabled, or having a history of stroke, having arteries narrowed more than 50 percent, coronary artery disease, congestive heart failure or valvular heart disease.
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They then created the CEA-7, a patient-friendly model, that eliminates non-operative stenosis. Patients can also determine their own risk, even if they don't know whether their arteries are more than 50 percent blocked.
"These models are the first for asymptomatic patients and are a practical and easy-to-use tool for doctors and patients to evaluate what is best for them in the long term," Dr. Halm said. "These aren't the only factors a patient should consider – individual health and experience of the surgeon and hospital team count, too – but hopefully with these models, patients and doctors can more accurately individualize the risk of complications."
The authors are now developing an interactive educational program that helps patients better understand the different risks and benefits of surgical versus medical management of asymptomatic carotid disease.
Source-Eurekalert