The Role Of Carotid Artery Stenosis In Predicting Stroke After Off Pump Coronary Artery Bypass Grafting

Background:Coronary artery bypass grafting(CABG)has become the standard-of-care for patients with complex coronary artery disease(CAD)due to its long-term reliability and effectiveness.Data from previous large retrospective reports indicated that the overall incidence of perioperative stroke has decreased to 1.6%,and stroke remains one of the most common complications of CABG.Several studies reported that patients with stroke after CABG have more severe hospital complications,longer time in the ICU,longer postoperative stay,and higher in-hospital mortality.Also,a few studies have shown that patients with carotid artery stenosis(CAS)have an increased risk of stroke after CABG.However,controversy remains as to whether unilateral asymptomatic carotid stenosis is an independent risk factor for ipsilateral ischemic stroke after CABG.In addition,carotid revascularization by concurrent carotid endarterectomy or carotid stenting appeared to be feasible in patients with symptomatic carotid artery disease and bilateral carotid stenosis of 70%to 99%.While other studies suggest that the benefit of such interventions was uncertain.A previous study has shown that a stroke-history is correlated with CAS in a Chinese cohort undergoing CABG.However,large-scale clinical studies and meta-analyses analyzing the incidence and risk of CAS in Chinese patients undergoing CABG are still scarce.Objective:The aim of this study was to investigate the contemporary incidence of postoperative stroke and severe CAS in patients undergoing off pump coronary artery bypass grafting(OPCABG),to investigate the risk factors for severe CAS,to perform a nomogram of severe CAS,and to assess the efficacy of carotid artery stenting in preventing postoperative stroke.Materials and Methods:This study is a retrospective cohort study.From January 1,2015,to December 31,2021,1799 consecutive patients undergoing isolated OPCABG surgery was recruited at Shandong Provincial Hospital.Stroke occurring after CABG was the primary study endpoint.Secondary endpoints included in-hospital mortality,postoperative myocardial infarction,length of hospital stay,intubation time,ICU stay,readmission to the ICU,and reoperation.Statistical analyses were performed using SPSS statistical software version 25.0 and Stata statistical software version 16.0.Univariate and multivariate logistic regression models were used to explore potential factors and estimate their weights by severe CAS.Variables with p<0.05 and those possible predictor variables in the univariate model were entered into the multivariate logistic regression model and Forward:LR was performed with probabilities of entry and removal of 0.05 and 0.10,respectively.Based on these important risk factors,the screening was candidate nomogram models with appropriate predictive power.The predictive performance of the nomogram and other models to predict severe CAS rates was quantified using the area under the curve(AUC).The capability of the nomogram was also tested by fitting a well-calibrated curve.To assess the association between severe CAS and stroke,we used propensity matching to group patients with and without severe CAS.The propensity matching model was quantified using Kdensity plots and propensity matching test plots.Results:1.The incidence of postoperative stroke in this cohort study was 1.67%.Patients were divided into the stroke occurrence and non-stroke groups overall.Patients with stroke after CABG had a longer ICU and hospital stay.In-hospital survival was similar for patients with and without stroke.2.The incidence of CAS with stenosis≥50%and≥70%was 19.2%and 6.9%.1702(94.6%)patients with bilateral carotid duplex ultrasound data were divided into no or mild CAS group,moderate CAS group,severe CAS group,and carotid occlusion group.Also,CAS was further divided into left-sided alone group,right-sided alone group,unilateral group(left-sided alone+right-sided alone),and bilateral group.The risk of postoperative stroke was higher in the severe CAS group(P<0.001),severe unilateral CAS group(P=0.007),severe bilateral CAS group(P=0.001)and occluded unilateral CAS group(P=0.033)compared with all patients.3.After propensity matching,the incidence of stroke was 8.0%in the severe CAS group and 0%in the non-severe CAS group,with a statistically significant difference between the two groups.4.In univariate logistic regression analysis,compared with patients without severe CAS,patients with severe CAS were older(P<0.001)and shorter(P=0.002)in terms of demographics;patients with severe CAS had higher systolic blood pressure at admission(P=0.045)and lower diastolic blood pressure at admission(P=0.034)in terms of medical history,and most patients had a history of cerebrovascular accident(P<0.001)and chronic kidney disease(P=0.036);preoperatively patients with severe CAS had lower hemoglobin(P<0.001)and eGFR(P=0.001),higher C-reactive protein(P=0.017)and B-type natriuretic peptide(P=0.031),and more severe left main stem lesions(P<0.001).In terms of surgery,more patients with severe CAS had undergone carotid stenting(P<0.001);in terms of postoperative examination,patients with severe CAS had low hemoglobin(P=0.001)and neutrophils(P=0.024);in terms of prognosis,patients with severe CAS were more likely to have stroke(P<0.001).5.We successfully established and validly evaluated an optimal predictive nomogram including age≥65 years,systolic blood pressure(SBP),diastolic blood pressure(DBP),chronic kidney disease(CKD),and preoperative hemoglobin for predicting severe CAS in patients undergoing CABG.6.Carotid artery stenting was found ineffective in preventing postoperative stroke.Conclusions:1.The present study provided the incidence of CAS and postoperative stroke in a Chinese cohort.2.This study identified severe CAS as an independent risk factor for postoperative stroke after CABG.3.A total of 11 factors including age≥65 years,height,systolic blood pressure at admission,diastolic blood pressure at admission,cerebrovascular accident,chronic kidney disease,preoperative hemoglobin,C-reactive protein,B-type natriuretic peptide,eGFR and left main stem disease were associated with the incidence of severe CAS4.This study constructed and validated a nomogram predicting the incidence of severe CAS.5.This study evaluated the effectiveness of carotid artery stenting in preventing postoperative stroke after CABG.