SHOULD PATIENTS BE SCREENED FOR ASYMPTOMATIC CAROTID-ARTERY STENOSIS

OBTECTIVE: TO evaluate, against published guidelines, the potential ro le of screening to reduce the risk of stroke and death from asymptomat ic carotid artery stenosis (ACAS). DATASOURCES: Papers selected for re view were identified through a GRATEFUL MED literature search, from pe rsonal files and from references documented in identified papers. STUD Y SELECTION: Population studies concerning disease prevalence, natural history studies related to risk of stroke, randomized controlled tria ls related to carotid endarterectomy and natural history studies relat ed to the risk of developing ACAS were considered for review. DATA EXT RACTION: An estimate was made of the potential for stroke resulting fr om ACAS in the general population. This was evaluated against the posi tive predictive value of duplex scanning, and the number of patients n eeding to be screened to prevent a stroke was estimated. DATA SYNTHESI S: The prevalence of ACAS in the general population Ir as estimated to range from 2% to 8% for ACAS 50% or greater and to range from 1% to 2 % for ACAS 80% or greater. The yearly risk of stroke or death from und etected ACAS was estimated to be 0.16% for ACAS 50% or greater and 0.0 6% for ACAS 80% or greater. The estimated number of patients needing t o be screened to prevent 1 stroke would range from 850 to 1700 (and po tentially as high as 8500). CONCLUSIONS: General screening for ACAS to prevent stroke and death cannot he recommended when evaluated against available guidelines. The decision to screen individual patients will require judgement, continued evaluation and surveillance of the resul ts of such screening by the treating physician.