**2. Screening for carotid artery disease**

50% ECAS. (Anastasiadis, Karamitsos et al. 2009). Various studies have reported the incidence of ECAS with varies degree of stenosis among the patient populations undergoing CABG

**CABG being evaluated for ECAS**

Wanamaker et al 559 ECAS >50% : 36% Shirani et al 1045 ECAS > 60% : 6.9% Anastasiadis et al 307 ECAS > 70% : 13% Cornily et al 205 ECAS >70% : 5.8% Salasidis et al 387 ECAS > 80% : 8.5%

**Table 1.** Prevalence of extracranial carotid artery stenosis among patients undergoing coronary artery bypass grafting.

Salasidis et al identified increasing age, history of previous carotid revascularization and presence of PAD in addition to severe ECAS as risk factors for neurological events after cardiac surgery, highlighting that ECAS is only 1 of a number of factors that drives peri-operative

Interestingly, the likelihood of having ECAS increases with the underlying severity of CAD

1- vessel CAD 5.3% 2- vessel CAD 13.5% 3- vessel CAD 24.5% Left main disease 40% 3-vessel CAD or left main disease 24%

**Table 2.** Prevalence of significant carotid artery stenosis (extracranial carotid artery stenosis ≥ 50%) among patients with different severity of coronary artery disease based on number of vessels involved or left main disease.

It was postulated that increasing degree of stenosis was associated with increased risk of perioperative stroke by Naylor et al who reported that among 5,453 patients undergoing CABG, the risk of perioperative stroke was <2%, 3%, 5% and 7-11% among patients who had < 50% ECAS, 50-99% unilateral ECAS, 50-99% bilateral ECAS and occluded carotid artery

**Severity of CAD Prevalence of Significant Carotid Atherosclerosis (%)**

**Prevalence of ECAS %**

ECAS > 50% : 22% ECAS > 80% : 12%

**Study Number of patients undergoing**

Abbreviations: CABG, coronary artery bypass grating'; ECAS, extracranial carotid artery stenosis.

Schwartz et al 582

stroke risk.(Salasidis, Latter et al. 1995)

respectively.(Naylor, Mehta et al. 2002)

(Table 2).

which are summarized in table 1.

388 Artery Bypass

Screening for carotid artery disease is usually performed with carotid duplex ultrasound. Screening recommendations for carotid artery disease are somewhat controversial and vary across medical societies.(Goldstein, Adams et al. 2006; Bates, Babb et al. 2007; Qureshi, Alexandrov et al. 2007; 2008; Brott, Halperin et al. 2011) The most widely accepted multisocietal vascular practice guidelines involving 14 different vascular societies including the American College of Cardiology Foundation, American Heart Association Task Force on Practice Guidelines, the American Stroke Association, American Association of Neuroscience Nurses, American Association of Neurological Surgeons, American College of Radiology, American Society of Neuroradiology, Congress of Neurological Surgeons, Society of Atherosclerosis Imaging and Prevention,Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery, Society for Vascular Medicine, and Society for Vascular Surgery recommend screening for patients with carotid bruit or patients with CAD or symptomatic PAD or atherosclerotic aortic aneurysm as well those who may not have evidence of atherosclerosis but have 2 or more cardiovascular risk factors such as hypertension, dyslipidemia, tobacco smoking, family history of premature atherosclerosis or family history of ischemic stroke.(Brott, Halperin et al. 2011). The US Preventive Service Task Force recommended against screening as it was not cost-effective in asymptomatic patients.(Bates, Babb et al. 2007) The American Society of Neuroimaging recommended against the screening of unselected populations but advised the screening of adults older than 65 years of age who have 3 or more cardiovascular risk factors (Qureshi, Alexandrov et al. 2007)

For patients undergoing elective CABG, the multi-societal guidelines recommend screening for carotid artery disease in patients older than 65 years of age and in those with left main stenosis, PAD, history of cigarette smoking, history of stroke or TIA or carotid bruit. The American Heart Association and American College of Cardiology CABG guidelines offer recommendations consistent with the multi-societal vascular guidelines, however they also recommend that patients who have history of hypertension or diabetes mellitus also undergo preoperative carotid duplex scanning.(Hillis, Smith et al. 2011)
