Risk Modeling Evaluation Of Perioperative Major Adverse Events After Carotid Artery Stenting And Application Of Temporary Cardiac Pacemaker

The world’s population is aging, and stroke has become a serious disease threatinghuman health with high incidence, high morbidity and high mortality. Ischemic strokeaccounts for75%~85%of all stroke population, and extracranial carotid artery stenosis isone of the most importment causes of ischemic stroke. More than20%of ischemic stroke isdue to extracranial carotid atherosclerotic stenosis. Treatment for carotid stenosis canreduce the risk of stroke and stroke-related mortality.For the time being, carotid endarterectomy(CEA)remains the gold standard for thetreatment of carotid stenosis，which shows more significant advantages than medicaltherapy in prevention of stroke. In the last few years, carotid artery stenting (CAS) hasemerged as a possible alternative to CEA for the management of carotid stenosis because ofits effectiveness and less invasive nature of the procedure. However，previous clinical trialshave shown that perioperative complications as stroke, myocardial infarction and death inCAS is not less than CEA. It is urgent to reduce perioperative major adverse cardiac andcerebrovascular events(MACCE)of CAS through some interventional factors.A risk assessment for MACCE is benefical for patients with CAS. Some clinical studywere mainly to evaluate the risk factors of selected high-risk patients with CEA and certainuncontrollable factors such as age, past medical history and lesion characteristics were onlyconsidered. It was reported that such intraoperative complications as vascular spasm,hemodynamic depression(HD) may result in catastrophic events such as stroke or death.Prompt recognition and rapid evaluation of these complications are crucial for good patientoutcome.The aim of the present study was to identify independent risk factors to predictperioperative MACCE for CAS patients. We also aimed to analysis the value of treatmenton certain associated controllable risk factors on the aspect of the prevention of MACCE. Part one Risk modeling evaluation of major adverse events after carotid arterystentingObjectives: To identify independent risk factors to predict perioperative major adversecerebral and cardiovascular events for CAS patients and establish risk evaluation model.Methods: Consecutive patients treated with a standardized CAS procedure wereenrolled in the present study. All patients included underwent independent neurologicalevaluation before and after the procedure and at30days. The rates of transient ischemicattack, stroke, myocardial infarct and death were recorded. Relative regression model wasestablished to evaluate risk factors of perioperative major adverse cardiac andcerebrovascular events.Results:1. A total of403subjects treated with CAS were enrolled into the study at baseline(mean age66.73years, SD7.03), MACCE rate was8.19%(n=33). Whereas the overallstroke, myocardial infarction and death rate at30days was3.97%.2. Multiple regression analysis showed that the following factors significantlypredicted the30-day risk of treatment-relaterd MACCE:(1) age of70or older (OR4.997,95%CI1.633-15.290);(2) ulcerative plaque (OR2.899,95%CI1.214-6.924);(3) severecarotid stenosis (OR3.472,95%CI1.141-10.566);(5) bilateral carotid artery stenting (OR5.007,95%CI1.462-17.151);(6) hemodynamic depression after CAS(OR5.792,95%CI1.226-27.369).3. MACCE risk prediction model was established by the following formula:Log(MACCE prediction probability)=-8.992+1.609×(age of70or older)+1.064×(ulcerative plaque)+1.245×(severe carotid stenosis)+1.611×(bilateral carotid arterystenting)+1.757×(hemodynamic depression).4. A risk score system was generated using Arabic numerals on the basis of statisticalanalysis of each of the aforementioned variables to grade the individual patient risk ofMACCE. The goodness of the score generated is shown by the receiver-operatorcurves(ROC) of the learning and testing and area under curve(AUC) is0.875(p<0.001,95%CI0.825-0.925)Conclusions: Following factors significantly predicted the30-day risk of MACCEof CAS: age of70or older，ulcerative plaque，severe carotid stenosis，bilateral carotid artery stenting， hemodynamic depression after CAS. Among above five factors，hemodynamic depression was controllable factor. The established risk score system seemsto be a usefule tool to help predict MAACE after CAS.Part two Associated factors of hemodynamic depression after carotid arterystenting and application of temporary cardiac pacemakerObjectives: To analysis associated factors of HD after CAS. We also aimed to analysisthe effectiveness of prophylactically use of a transvenous temporary cardiac pacemaker tomanage HD.Methods: Consecutive patients treated with a standardized CAS procedure wereenrolled in the present study. All patients included underwent independent neurologicalevaluation before and after the procedure and at30days. Relative regression model wasestablished to evaluate risk factors of intra-or post-operative HD. Cardiacpacemaker-related complication and incidence of perioperative MACCE were analysedfor the patients treated with transvenous temporary cardiac pacemaker group.Results:1. A total of403subjects treated with CAS were enrolled into the study, and incidenceof HD intra-or post-operative HD was58.90%(n=241). Bradycardia combined withhypotension occurred in176patients (73.03%). Isolated bradycardiawithout hypotension occurred in36patients(14.94%). Isolated hypotension withoutbradycardia occurred in29patients(12.03%)。2. Multiple regression analysis showed that the following factors were significantlyassociated with HD:(1) calcified plaque (OR7.863,95%CI3.221-19.199);(2) eccentricplaque(OR2.744,95%CI1.659-4.538);(3) severe carotid stenosis(OR1.701,95%CI1.006-2.878);(4) lesion length(≥15mm)(OR5.469,95%CI2.753-10.866);(5) bilateralcarotid artery stenting(OR6.921,95%CI1.338-35.795);(6) tapered stenting(OR0.389,95%CI0.195-0.774);(7) balloon pre-dilation(OR4.985,95%CI1.371-18.126)；3.Associated risk prediction model was established by the following formula: Log(HDprediction probability)=-1.152+2.062×calcified plaque+1.009×eccentric plaque+0.531×severe carotid stenosis+1.699×lesion length (≥15mm)+1.935×bilateral carotidartery stenting–0.945×tapered stenting+1.606×balloon pre-dilation. The standardizedregression coefficient of above seven independent risk factors can be in accordance with the order of value as follows: bilateral carotid artery stenting＞balloon pre-dilation＞calcifiedplaque＞lesion length (≥15mm)＞tapered stenting＞eccentric plaque＞severe carotidstenosis.4. MACCE rate in HD group was12.86%which was significantly higher than innon-HD group(p＜0.001);5. Among403patients enrolled，38cases(9.43%)accepted prophylactic placement oftransvenous temporary cardiac pacemaker. No cardiac arrest,syncope and TIA occurredintra-operative of CAS and there were no pacemake-related complications andperioperative MACCE.Conclusions: HD is correlated with perioperative MACCE of CAS. Calcified plaque,eccentric plaque, severe carotid stenosis, lesion length, bilateral carotid artery stenting,tapered stenting and balloon pre-dilation were associated with the occurrence of HD.Prophylactic placement of transvenous temporary cardiac pacemaker for patients at highrisk of HD can reduced perioperative MACCE.