Association of carotid duplex ultrasonography screening with stroke and mortality among patients undergoing coronary artery bypass grafting

Abstract

Objective: Selection criteria for carotid duplex ultrasonography screening (DUS) before coronary artery bypass grafting (CABG) is primarily based on limited observational analysis, and the risks associated with carotid artery stenosis (CAS) detected by this approach to preoperative DUS are uncertain. This study aimed to determine the association of carotid DUS with stroke and mortality among patients undergoing CABG.

Methods: Adult patients with coronary artery disease who underwent isolated CABG or CABG with concomitant valvular or congenital procedure were identified. CHA₂DS₂-VASc score was assessed before CABG, and patients were recorded as high risk if they had a score of 3 or higher. The primary outcomes were stroke and all-cause mortality. Secondary outcomes included ischemic stroke, non-ischemic stroke, transient ischemic attack, and cardiovascular mortality.

Results: Among 8958 patients who underwent CABG, 70.9% (n = 6347) received carotid DUS preoperatively (low-risk, 57.3%; high-risk, 42.7%). In the low-risk cohort, there was no significant difference in the risk of stroke (20.7 per 1000 patient-years for CAS vs 13.1 per 1000 patient-years for no CAS; adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 0.78-1.68) or mortality (20.5 per 1000 patient-years for CAS vs 16.8 per 1000 patient-years for no CAS; aHR, 1.33; 95% CI, 0.97-1.83) at 15 years. In the high-risk cohort, CAS was associated with significantly higher risks of stroke at 30 days (433.2 vs 279.5 per 1000 patient-years; aHR, 1.92; 95% CI, 1.00-3.70) and mortality at 15 years (38.4 vs 32.7 per 1000 patient-years; aHR, 1.25; 95% CI, 1.01-1.57) compared with no CAS.

Conclusions: CAS did not impact the incidence of stroke or mortality in the low-risk cohort who underwent CABG. However, in the high-risk cohort, CAS was associated with a significant increase in the risks of 30-day stroke and 15-year mortality, indicating selective carotid DUS is necessarily recommended for these patients.

Keywords: Carotid artery stenosis; Coronary artery bypass grafting; Duplex ultrasonography screening; Mortality; Stroke.