Carotid Artery Stenosis Associated with Increased Mortality in Patients who Underwent Coronary Artery Bypass Grafting: A Single Center Experience

Evaluating the Safety of Transcarotid Artery Revascularization under Local Anesthesia Prior to Coronary Artery Bypass Grafting Surgery

BACKGROUND

Controversy exists regarding the timing of intervention for patients with critical coronary artery disease (CAD) awaiting coronary artery bypass and severe carotid artery stenosis (CAS). Transcarotid artery revascularization (TCAR) is a minimally invasive revascularization alternative through direct transcervical carotid access that minimizes the chance of arch manipulation and consequent antegrade embolic stroke rate. While the TCAR procedure can be performed under local anesthesia (monitored anesthesia care [MAC]) versus general anesthesia, the hemodynamic benefits of local anesthesia in patients with severe CAD are significant. Patients receiving staged TCAR-coronary artery bypass grafting (CABG) have high-risk cardiovascular disease and require accurate perioperative neurological and hemodynamic evaluation that can be safely provided with local anesthesia.

METHODS

In this retrospective single-center study, 14 patients were systematically identified to have undergone staged TCAR prior to CABG surgery from December 2018 to October 2021. All patients underwent TCAR with local anesthesia and minimal sedation. Relevant patient demographics, medical and surgical history, preoperative covariates, and type of anesthesia administered were obtained from patients' charts. CAD was confirmed by either carotid duplex imaging or computed tomography angiography (CTA) of the head/neck.

RESULTS

Staged TCAR-CABG interventions were performed on 14 patients (64% male; mean age 65.0 years). No major adverse cardiac events were reported including transient ischemic attack (TIA), stroke, myocardial infarction (MI), or TCAR-related death in the interval between their TCAR and CABG as well as in a 12-month follow-up period. One patient required to return to the operating room (OR) for evacuation of a neck hematoma.

CONCLUSIONS

This study demonstrated high success rate of TCAR under local anesthesia prior to CABG (100%) with no incidence of perioperative stroke, MI, or death at 1-month, 6-month, and 12-month follow-up intervals. The authors support the use of staged TCAR-CABG with local anesthesia as a safe and promising treatment option for patients with high-grade cardiac disease, high risk of stroke, or multiple comorbidities that preclude a carotid endarterectomy (CEA).

Prevalence of carotid artery stenosis in ischaemic heart disease patients in Bangladesh

Background:

Concurrent carotid artery stenosis and ischaemic heart disease rates are increasing day by day in Bangladesh. Moreover, carotid artery stenosis has been identified as a high-risk factor for postoperative ischaemic cerebral inconvenience following coronary artery bypass graft surgery.

Methods:

This observational cross-sectional study was performed to evaluate 200 study patients from July 2017 to June 2018. Patients with coronary artery disease scheduled for isolated elective coronary artery bypass graft surgery were included in the study, excluding those with coexisting valvular or congenital heart disease and emergency coronary artery bypass graft surgery.

Results:

About two-thirds of the study patients were 50–59 years old, with a mean age of 57.7 ± 3.06 years. Approximately 70% patients were male; the male:female ratio was 2.1:1. Most of the patients (74.5%) were Muslim. The majority of patients (59.0%) were overweight, and severe carotid artery stenosis was significantly higher in obese patients (p ⩽ 0.05). Furthermore, hypertension and diabetes mellitus were significantly associated with moderate to severe carotid artery stenosis (p ⩽ 0.05). Multi-vessel coronary artery disease was significantly associated with the severity of carotid artery stenosis. Bilateral carotid artery stenosis was significantly associated with the severity of carotid artery stenosis (p ⩽ 0.05).

Conclusion:

Routine duplex screening will identify significant carotid artery disease and will subsequently reduce the risk of perioperative stroke in ischaemic heart disease patients undergoing coronary artery bypass graft surgery.

Functional assessment of the stenotic carotid artery by CFD-based pressure gradient evaluation

The functional assessment of a hemodynamic significant stenosis base on blood pressure variation has been applied for evaluation of the myocardial ischemic event. This functional assessment shows great potential for improving the accuracy of the classification of the severity of carotid stenosis. To explore the value of grading the stenosis using a pressure gradient (PG)-we had reconstructed patient-specific carotid geometries based on MRI images-computational fluid dynamics were performed to analyze the PG in their stenotic arteries. Doppler ultrasound image data and the corresponding MRI image data of 19 patients with carotid stenosis were collected. Based on these, 31 stenotic carotid arterial geometries were reconstructed. A combinatorial boundary condition method was implemented for steady-state computer fluid dynamics simulations. Anatomic parameters, including tortuosity (T), the angle of bifurcation, and the cross-sectional area of the remaining lumen, were collected to investigate the effect on the pressure distribution. The PG is highly correlated with the severe stenosis (r = 0.902), whereas generally, the T and the angle of the bifurcation negatively correlate to the pressure drop of the internal carotid artery stenosis. The calculation required <10 min/case, which made it prepared for the fast diagnosis of the severe stenosis. According to the results, we had proposed a potential threshold value for distinguishing severe stenosis from mild-moderate stenosis (PG = 0.88). In conclusion, the PG could serve as the additional factor for improving the accuracy of grading the severity of the stenosis.

Risk Factors for Carotid Artery Stenosis in Chinese Patients Undergoing Coronary Artery Bypass Graft Interventions

Current guidelines established in the USA and Europe for coronary artery bypass graft (CABG) suggest that patients ≥65 and ≥70 years of age, or with certain atherosclerotic-risk factors, should be screened preoperatively for extracranial carotid artery stenosis (CAS) to assess their risk of perioperative stoke. We sought factors that should be taken into consideration when treating Chinese CABG patients using CABG guidelines based on an analysis of CAS in a large cohort of Chinese CABG patients. We analyzed data for 1558 Chinese CABG patients who were screened preoperatively for CAS using duplex ultrasonography at a single institution. We defined significant and severe CAS as ≥50% and ≥70% stenosis, respectively, in one or more common or internal carotid arteries. We investigated the prevalence of CAS, the incidence of perioperative stroke, and the risk factors for CAS in the CABG cohort. The prevalence of CAS in the CABG cohort was 21.2%. Multivariate stepwise logistic regression analysis showed that an age ≥50 years and a history of smoking (odds ratios = 8.36 and 1.83, respectively) were independent risk factors for CAS (P < 0.05 for both). The incidence of perioperative stroke among CABG patients with significant or severe CAS was significantly higher (2.4% and 2.9%, respectively) than in CABG patients with <50% stenosis (0.5%; P = 0.004 and 0.029, respectively). Chinese CABG patients with a history of smoking or ≥50 years of age should undergo preoperative screening for CAS to assess their risk of perioperative stroke.