Evaluation of Asymptomatic Carotid Artery Stenosis Prior to Coronary Artery Bypass Grafting - A Prospective Observational Study in North Indian Population

BACKGROUND: Carotid artery stenosis (CAS) is an established risk factor for peri-operative neurological complications in patients following coronary artery bypass grafting (CABG). However, routine pre-surgical screening for CAS is still a matter of debate. This study was conducted to study the prevalence of asymptomatic carotid artery disease in patients undergoing CABG and to determine the predictors of significant carotid stenosis in them. METHODS: In this prospective observational study, 112 patients, who were planned for CABG, were enrolled, and their demographic details, risk factor profile, and coronary angiogram parameters were analyzed. RESULTS: Carotid stenosis was observed in 75.0% of the study population with 11.6% having unilateral and 63.4% having bilateral carotid stenosis. A total of 56.2% of the patients had mild, 14.3% had moderate, and 4.5% had severe carotid stenosis. The presence of significant carotid stenosis showed a correlation with chronic stable angina (P = 0.009), significant left main (LM) disease (P = 0.001), chronic total occlusion (P = 0.043), and coronary vessel calcification (P = 0.004). Multivariate analysis of all the predictor variables in a regression model showed that significant LM disease (Odds ratio (OR):6.5, P = 0.002) and coronary artery calcification (OR: 4.3, P = 0.024) were the only independent predictors of significant CAS in the study population. CONCLUSION: The presence of significant carotid vessel stenosis in patients undergoing CABG in the Indian population has a stronger association with the chronicity of the coronary artery disease rather than the coronary atheroma load (as determined by the modified Gensini score). The presence of significant LM disease and coronary artery calcification may be useful in detecting high-risk patients for significant CAS during the pre-surgical workup.