Study On The Safety And Feasibility Of Carotid Artery Stenting In The Treatment Of High Risk Carotid Artery Stenosis

Part I:Comparison of the Safety of Simultaneous Bilateral Carotid Artery Stenting and Unilateral Carotid Artery StentingBackground and Objective:As one of the high risk factors in carotid endarterectomy, significant bilateral carotid stenosis in patients undergoing carotid artery stenting (CAS) is not uncommon. Such patients have high stroke risk. Many studies show CAS is an alternative to treat unilateral carotid stenosis. However, in the absence of randomized trials, the optimal strategy for bilateral carotid stenosis remains unclear. The purpose of this study was to evaluate the safety of simultaneous bilateral carotid artery stenting (SBCAS) compared with unilateral carotid artery stenting (UCAS).Methods:In this single-center retrospective controlled study, we analyzed637consecutive patients who underwent carotid artery stenting from Jan.2005to Dec.2012.120patients (18.8%) underwent SBCAS and the others (n=517) received UCAS. Indication for CAS was defined as carotid artery diameter reduction of≥60%(symptomatic) or≥80%(asymptomatic). The end points included hyperperfusion syndrome (HPS), hemodynamic depression (HD) major stroke, minor stroke, death, myocardial infarction (MI) and their combination within30days after carotid stenting.Results:Symptomatic carotid stenosis (73.3%vs.61.3%, P=0.015) and congestive heart failure (14.2%vs.5.8%, P=0.015) was more common in SBCAS group. There were no statistically significant differences in other baseline clinical characteristics, target lesion and procedural characteristics (pre-procedure diameter reduction, post-procedure diameter reduction, the location of target lesions, and the treatment of target lesions). There was not statistically significant difference between SBCAS group and UCS group in HD (27.5%vs.21.9%, P=0.187), HPS (2.5%vs.1.5%, P=0.441), major stroke (0.8%vs.1.5%, P=1.000), minor stroke (3.3%vs.1.9%, P＝0.313), death (0.8%vs.0.8%, P=1.000), MI (0.8%vs.0.8%, P=1.000) and the composite of major stroke, MI, or death (2.5%vs.2.5%, P=1.000) within30days. Movemore, congestive heart failure (OR4.3,95%CI7:1.3～14.1, P=0.016) and renal insufficiency (OR4.0,95%CI:1.2～13.1,P=0.022) other than SBCAS (P=0.736) were identified as independent risk factors of the composite of major stroke, MI, or death by multivariate analysis.Conclusions:The data from our study showed that simultaneous bilateral carotid stenting was a technically feasible and safe alternative for patients with severe bilateral carotid stenosis. However, this was a small retrospective study, which should be investigated further. Part II:Clinical Outcomes of Carotid Artery Stenting in Patients with Coexistent Carotid and Coronary Artery DiseaseBackground and Objective:Coexistent carotid and coronary artery diseases are common in clinical practice. Management of such patients has been a point of continuing controversy. Carotid artery stenting (CAS) has become a reasonable alternative to carotid endarterectomy, especially in patients with high surgical risks including those with coronary artery disease. The aim of the study was to evaluate the safety and feasibility of carotid artery stenting (CAS) for treating patients with coexistent carotid and coronary artery disease.Methods:The clinical data of526consecutive patients with coexistent carotid and coronary artery disease undergoing CAS in our institution from January2005to December2012were collected and analyzed retrospectively. Indication for CAS was defined as carotid artery diameter reduction of>60%(symptomatic) or>80%(asymptomatic). The primary end point of this study was the composite of major stroke, myocardial infarction (MI), or death within30days.Results:The patients were43-84(65.8±7.6)years old, there were426(81.0%) male. All patients suffered from coronary artery disease, of whom149(28.3%) had previous MI,50(9.5%) underwent previous percutaneous coronary intervention,17(3.2%) underwent pervious coronary artery bypass grafting, and366(69.6%) planned to undergo open heart surgery. The procedural success rate of CAS was99.4%(523/526). Cerebral protection devices were used in517patients (98.9%). Among them,105(20.0%) patients received simultaneous bilateral CAS and199(37.8%) patients underwent simultaneous percutaneous intervention of other arteries, including57(10.8%) left subclavian arteries,15(2.9%) right subclavian arteries,99(18.8%) renal arteries,31(5.9%) iliac arteries,35(6.7%) vertebral arteries, and8(1.5%)superficial femoral arteries and/or below-knee arteries. Within30days after CAS,284(54.0%) patients underwent coronary revascularization, including261(49.6%) coronary artery bypass grafting and23(4.4%) percutaneous coronary intervention. The rate of primary end point, major stroke, minor stroke, death, MI from time of CAS to30days was2.9%,1.7%,2.5%,0.8%and1.0%respectively. Meanwhile, congestive heart failure (OR6.5,95%CI:1.7～15.7, P=0.007) and renal insufficiency (OR7.8,95%CI:2.0±30.8, P=0.003) were identified as independent risk factors of primary end point by multivariate analysis.Conclusions:This study indicated that CAS was safe and effective, with a low incidence of periprocedural complications in patients with coexistent carotid and coronary artery disease. Congestive heart failure and renal insufficiency had a significant association with major adverse cardiovascular events during the perioperative period. Part Ⅲ:The Safety of Synchronous or Staged Carotid Artery Stenting and Open Heart SurgeryBackground and Objective:Even if asymptomatic, patients with significant carotid stenosis undergoing open heart surgery (OHS) face a high risk of perioperative stroke. Thus, planning appropriate treatment for patients with severe carotid stenosis before OHS is an important clinical issue. Recently, some observational studies have shown that synchronous or staged CAS before OHS may be a more effective method for patients with coexisting carotid and cardiac disease compared with combined CEA and OHS. However, in the absence of randomized trails, the safety of CAS followed by OHS remains controversial. The purpose of this study was to evaluate the safety of synchronous or staged carotid artery stenting (CAS) and in patients with coexistent severe carotid and cardiac disease.Methods:The clinical data of323consecutive patients with coexistent severe carotid and cardiac disease undergoing CAS and OHS in our institution from January2005to December2012were collected and analyzed retrospectively. Indication for CAS was defined as carotid artery diameter reduction of>60%(symptomatic) or>80%(asymptomatic). The OHS procedures included coronary artery bypass grafting (CABG), valve replacement, aneurysm resection and modified Maze procedure for atrial fibrillation. The end points of the study included major stroke, minor stroke, death, myocardial infarction (MI), acute kidney injury (AKI) and their combination from time of CAS to30days after cardiac surgery.Results:There were263(81.4%) men and60(18.6%) women, with a mean age of65.2±7.3years.73(22.6%) had bilateral carotid stenosis,193(59.8%) patients had symptomatic carotid stenosis, and18(5.6%) had contralateral carotid artery occlusion. Three hundred twenty two (99.7%) patients suffered from severe coronary artery disease, of whom175(54.3%) had three-vessel disease and166(51.6%) had left stem involvement by coronary angiography. The overall procedural success rate of CAS was99.4%(321/323). Cerebral protection devices were used in320patients (99.7%). Among them,61(18. patients received simultaneous bilateral CAS and110(34.1%) patients underwent simultaneous percutaneous intervention of other arteries, including32(9.9%) left subclavian arteries,5(1.5%) right subclavian arteries,58(18.0%) renal arteries,13(4.0%) iliac arteries,18(5.6%) vertebral arteries. The mean angiographic degree of stenosis was reduced from (86.5±7.6)%to (7.8±6.8)%(P<0.001). The mean interval time of CAS and OHS were22.4±15.7days in all321patients undergoing OHS.320patients underwent CABG after CAS. Simultaneous aneurysm resection, modified Maze procedure for atrial fibrillation and valve replacement were performed in4(1.3%),3(0.9%), and17(5.3%) patients undergoing CABG respectively. The remaining patient only had valve replacement. The rate of major stroke, minor stroke, death, MI, AKI and the composite of major stroke, MI or death from time of CAS to30days after OHS was1.9%,2.2%,1.5%,2.2%,5.0%and4.6%respectively.Conclusions:CAS before OHS was safe and feasible for patients with severe carotid artery stenosis and cardiac disease. Part IV:The Safety and Influencing Factors of Carotid Artery Stenting for Surgically High-risk Carotid StenosisBackground and Objective:Large-scale randomized trials have demonstrated that carotid endarterectomy is an effective treatment strategy for the prevention of ischemic stroke in patients with symptomatic and asymptomatic significant carotid stenosis. However, some patients with carotid stenosis have anatomic or physiologic co-morbidities that place them at high risk for carotid endarterectomy. The purpose of this study was to evaluate the safety and influencing factors of carotid artery stenting (CAS) for the treatment of surgically high-risk carotid stenosis.Methods:In this single-center retrospective study,548consecutive surgically high-risk patients undergoing carotid stenting from January2005to December2012were collected. All patients were required to have at least one anatomic or physiologic co-morbidities that placed them at high risk for surgery. Physiologic co-morbidities included age^80years old, severe coronary artery disease (left main artery/≥2coronary arteries involvement), unstable angina (class Ⅲ/Ⅳ), new myocardial infarction (<30d), open heart surgery within30days after CAS, congestive heart failure (class Ⅲ/Ⅳ), renal insufficiency and severe pulmonary disease. Anatomic risk factors comprised of bilateral carotid stenosis, contralateral carotid occlusion, restenosis post-carotid endarterectomy, previous neck or head radiation therapy/surgery and surgically inaccessible lesions at or above C2or below clavicle. Indication for CAS was defined as carotid artery diameter reduction of≥60%(symptomatic) or ≥80%(asymptomatic). The primary end point was the composite of major stroke, myocardial infarction (MI), or death within30days.Results:The patients were43～84(65.7±7.6) years old, and there were447(81.6%) male.502(91.6%) patients suffered from coronary artery disease, of whom45(8.2%) underwent percutaneous coronary intervention,15(2.7%) underwent coronary artery bypass graft.340(62.0%) patients had symptomatic carotid stenosis.513(93.6%) patients had physiologic co-morbidity, including8(1.5%) age≥80years old,439(80.1%) severe coronary artery disease(left main artery/≥2coronary arteries involvement),150(27.4%) unstable angina (class Ⅲ/Ⅳ),130(23.7%) new myocardial infarction (<30d),262(47.8%) open heart surgery within30days after CAS,47(8.6%) congestive heart failure (class Ⅲ/Ⅳ),50(9.1%) renal insufficiency and27(4.9%) severe pulmonary disease.237(43.2%) patients had anatomic risk factors, including120(21.9%) bilateral carotid stenosis,43(7.8%) contralateral carotid occlusion,25(4.6%) restenosis post-carotid endarterectomy,24(4.4%)previous neck or head radiation therapy/surgery and62(11.3%) surgically inaccessible lesions at or above C2or below clavicle. The procedural success rate of CAS was99.5%(545/548). Cerebral protection devices were used in538patients (98.7%). Among them,120(21.9%) patients received simultaneous bilateral carotid stenting and207(37.8%) patients underwent simultaneous percutaneous intervention of other arteries. The angiographic diameter stenosis reduced from (86.2±8.1)%to (8.9±6.8)%after stenting (P<0.001). The rate of major stroke, minor stroke, death, MI and the primary end point from time of CAS to30days was1.1%,2.6%,0.7%、0.9%and2.2%respectively. There was no significant statistical difference in primary end point among patients with pure physiologic risk factors, pure anatomic risk factors, and both anatomic and physiologic risk factors (1.9%vs.0vs.3.0%, P=0.632). Moreover, congestive heart failure (OR5.742,95%CI:1.620-20.354, P=0.007) and renal insufficiency (OR5.335,95%CI:1.507-18.890, P=0.009) were identified as independent risk factors of primary end point by multivariate analysis.Conclusions:This study indicated that CAS was safe and feasible with a low incidence of periprocedural complications in patients with surgically high-risk carotid stenosis. Congestive heart failure and renal insufficiency were independent predictors of periprocedural major adverse cardiovascular events.