Is Duplex carotid artery screening prior to CABG justified?

Abstract

Objective: To evaluate the use of duplex carotid artery screening in patients undergoing coronary artery bypass graft (CABG).

Methods: This descriptive, observational study was conducted in Radiology Department at King Fahad Military Medical Complex, Dhahran, Kingdom of Saudi Arabia from April 2015-2018. All Saudi patients (n=178) who underwent duplex carotid sonography prior to CABG were retrospectively reviewed for essential morphologic and hemodynamic information to estimate severity of extra-cranial internal carotid artery (ICA) stenosis. Patients with combined CABG and cardiac surgery, and those with limited carotid studies were excluded. Advancing age (65 years or above), gender, smoking, obesity, diabetes (DM), hypertension (HTN), dyslipidemia, coronary vessel disease, cardiac disease and previous stroke were recorded. Post-coronary artery bypass graft neurologic event (namely, transient ischemic attack [TIA] or stroke) was recorded. Chi-square test was used to determine association of stenosis degree with post-CABG neurologic event.

Results: One hundred twenty eight patients (72%) were having ICA disease, while significant carotid artery stenosis (>70%) was seen in 11 patients (6.2%). Post-coronary artery bypass graft neurologic event was seen in 4.5% of patients. Advancing age, significant ICA stenosis and multi-vessel coronary disease were seen associated with a post-CABG event.

Conclusion: Significant ICA stenosis on duplex screening in elderly patients with multi-vessel coronary artery disease or certain risk factors may predict post-CABG stroke.

Figure 1

Normal doppler waveforms of A) internal carotid artery (ICA) (left image) and B) External carotid artery (ECA) (right image).

Figure 2

Duplex and color doppler images of a patient showing A) significant internal carotid artery (ICA) stenosis by velocity and B) degree of luminal stenosis by the European Carotid Surgery Trial (ESCT) method.