Point/Counterpoint: Is screening for asymptomatic carotid artery stenosis justified?
Introduction
The U.S. Preventive Services Task Force has just published its latest guidance on carotid screening for asymptomatic disease, basically stating that it should not be done (see story page 1). In this Point-Counterpoint Dr. Zierler and Dr. Berland provide their views on this controversial issue. From my perspective the debate must revolve around the following questions: The gist of the USPSTF statement seems to be that screening is being performed only to detect patients with critical carotid stenosis so that an intervention (CEA or CAS) can be performed. However, shouldn’t screening also be used to identify atherosclerotic burden in order to prevent cardiovascular morbidity? Whatever the reasons for screening, should national health systems pay for screening? If not, what about individual physicians charging for screenings on selected/nonselected patients? What about free screenings? And as Dr. Zierler and Dr. Berland suggest, is screening getting a bad rap just because screening and subsequent CEA or CAS are being poorly performed? Finally, I wouldn\'t be surprised if some of the task force members have had their own carotids screened despite their negative recommendation. We would be interested in your viewpoint, so please take our online, interactive poll on our home page (bottom right) to weigh in on this important issue.
Dr. Russell Samson is the Medical Editor of Vascular Specialist.
YES: Screen, but screen well.
By Todd Berland, M.D.
Every patient with symptomatic carotid artery stenosis was asymptomatic the day before. The impact of stroke can be devastating, with a 20% mortality from the acute event and 40%-50% survival over the next 5 years. Of those surviving the initial event, a significant percentage of patients are unable to return to work, and up to 25% over the age of 65 require long-term institutional care.1 There is no doubt that the emotional, financial, and societal burden of caring for stroke patients is significant. The Asymptomatic Carotid Atherosclerosis Study and the Asymptomatic Carotid Surgery Trial demonstrated a significant reduction in stroke in asymptomatic, high-grade carotid artery stenosis patients treated with carotid endarterectomy compared to medical management alone.2,3 So wouldn’t it seem as if carotid artery screening would be beneficial?
The U.S. Preventive Services Task Force recommended against routine carotid screening because of its "high risk" and low reward. I believe that when a certified lab screens the appropriate population such as individuals over 55 with cardiovascular risk factors that include hypertension, diabetes, smoking, and hypercholesterolemia, and combines this with an intervention that has a low stroke and morbidity rate, then the balance is tipped and carotid screening becomes both low risk and high reward.
One of the problems with carotid ultrasound is that too many entrepreneurs have made a business of it. Suboptimal equipment is being used by uncertified technicians in medical offices and church parking lots all across this country. It’s no surprise that the false positives are going to be high in these situations. Also, when one combines all of the above with the screening of those who aren’t at risk, where the general prevalence of disease is low, it can be a recipe for disaster. This is going to lead to additional studies such as CT angiograms or possibly even cerebral angiograms, both of which have inherent risks.
Even though it’s possible to understand why the USPSTF may have concluded against routine screening, I believe that at-risk patients should be screened by a certified lab, and that physicians performing the interventions should be able to do so with low morbidity and mortality. Vascular surgeons have been marginalized over recent years as many others have become interested in finding and treating carotid disease. Most of us are either registered vascular technologists or registered physicians in vascular interpretation, and our labs are certified by the Intersocietal Accreditation Commission. We go through hours of continuing medical education in regard to vascular ultrasound, and our labs’ results are tested and certified for accuracy.
We need to convince insurance companies and the Centers for Medicare & Medicaid Services that these studies should be permitted only in certified labs and the results interpreted by certified physicians such as vascular surgeons.
Moreover, when indicated, the interventions should be carried out by vascular surgeons who are trained to perform both carotid endarter- ectomy and carotid artery stenting to be able to offer the patient the best individualized treatment.
Dr. Berland is director of outpatient vascular interventions at NYU Langone Medical Center.
References
1. Circulation 2012;125:188.
2. JAMA 1995:273:1421-8.
3. Lancet 2004;363:1491-502.
NO: General screening is not appropriate.
