Is Canadian cardiac surgeons' management of symptomatic carotid artery stenosis at coronary artery bypass supported by the literature? A survey and acritical appraisal of the literature

OBJECTIVE: TO document: and compare the management of asymptomatic carotid stenosis (ACS) by Canadian cardiac surgeons at coronary artery bypass graft ing (CABG) against a critical literature analysis. DESIGN: A multiple choice survey and a structured literature review. DATA SOURCES: Seventy-seven surgeons and 272 publications selected from the English literature between 1980 and 1997. Search terms used were "carotid, " "coronary bypass," and "cardiac surgery." STUDY SELECTION: Five natural history studies were identified, and 58 studi es were found that had objective documentation of ACS of 50% or more before cardiac surgery, and both operative stroke and mortality data reported for CABG with and without carotid endarterectomy (CEA). DATA EXTRACTION: Natural history and outcome studies were independently rat ed against published guide lines. Outcome data were independently pooled an d compared. Data discrepancy was resolved by consensus sus. Survey results were tabulated for simple descriptive statistics. DATA SYNTHESIS: No methodologically sound natural history studies were foun d to document an increased risk of stroke from ACS after CABG. There were n o randomized controlled studies to guide treatment recommendations. Pooled data for stroke or death did nor support CEA for risk reduction from ACS at CABG (relative risk 0.9, p = 0.5). Ninety-four percent of surgeons believe d that the literature is insufficient to support the routine use of CEA to reduce the risk of stroke from ACS after CABG. Despite this, 20% of surgeon s advocated CEA for this purpose. CONCLUSION: The management of ACS at CABG by the majority of Canadian cardi ac surgeons is consistent with the results of the literature review; howeve r, significant management variation exists.