Faculty Bibliography

BACKGROUND:The Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) is a pair of randomized trials assessing the relative efficacy of carotid revascularization in the setting of intensive medical management (IMM) in patients with asymptomatic high-grade atherosclerotic stenosis. One of the trials assesses IMM with or without carotid artery stenting (CAS). Given the low risk of stroke in nonrevascularized patients receiving IMM, it is essential that there be low periprocedural risk of stroke for CAS if it is to show incremental benefit. Thus, credentialing of interventionists to ensure excellence is vital. This analysis describes the protocol-driven approach to credentialing of CAS interventionists for CREST-2 and its outcomes. METHODS:To be eligible to perform stenting in CREST-2, interventionists needed to be credentialed on the basis of a detailed Interventional Management Committee (IMC) review of data from their last 25 consecutive cases during the past 24 months along with self-reported lifetime experience case numbers. When necessary, additional prospective cases performed in a companion registry were requested after webinar training. Here we review the IMC experience from the first formal meeting on March 21, 2014 through October 14, 2017. RESULTS:The IMC had 102 meetings, and 8311 cases submitted by 334 interventionists were evaluated. Most were either cardiologists or vascular surgeons, although no single specialty made up the majority of applicants. The median total experience was 130 cases (interquartile range [IQR], 75-266; range, 25-2500). Only 9% (30/334) of interventionists were approved at initial review; approval increased to 46% (153/334) after submission of new cases with added training and re-review. The median self-reported lifetime case experience for those approved was 211.5 (IQR, 100-350), and the median number of cases submitted for review was 30 (IQR, 27-35). The number of CAS procedures performed per month (case rate) was the only factor associated with approval during the initial cycle of review (P < .00001). CONCLUSIONS:Identification of interventionists who were deemed sufficiently skilled for CREST-2 has required substantial oversight and a controlled system to judge current skill level that controls for specialty-based practice variability, procedural experience, and periprocedural outcomes. High-volume interventionists, particularly those with more recent experience, were more likely to be approved to participate in CREST-2. Primary approval was not affected by operator specialty.

BACKGROUND:The CREST-2 Registry (C2R) was approved by National Institute of Neurological Disorders and Stroke-National Institutes of Health in September 2014 with Centers for Medicare & Medicaid Services, U.S. Food and Drug Administration, and industry collaboration to enroll patients undergoing CAS. The registry credentials interventionists and promotes optimal patient selection, procedural-technique, and outcomes. OBJECTIVES/OBJECTIVE:This study reports periprocedural outcomes in a cohort of carotid artery stenting (CAS) performed for asymptomatic and symptomatic carotid stenosis. METHODS:Asymptomatic patients with ≥70% and symptomatic patients with ≥50% carotid stenosis, ≤80 years of age, and at standard or high risk for carotid endarterectomy are eligible for enrollment. Interventionists are credentialed by a multispecialty committee that reviews experience, lesion selection, technique, and outcomes. The primary endpoint was a composite of stroke and death (S/D) in the 30-day periprocedural period. Myocardial infarction and access-site complications were assessed as secondary outcomes. RESULTS:As of December 2018, 187 interventionists from 98 sites in the United States performed 2,219 CAS procedures in 2,141 patients with primary atherosclerosis (78 were bilateral). The mean age of the cohort was 68 years, 65% were male, and 92% were white; 1,180 (55%) were for asymptomatic disease, and 961 (45%) were for symptomatic disease. All U.S. Food and Drug Administration-approved stents and embolic protection devices were represented. The 30-day rate of S/D was 1.4% for asymptomatic, 2.8% for symptomatic, and 2.0% for all patients. CONCLUSIONS:C2R is the first national registry for CAS cosponsored by federal and industry partners. CAS was performed by experienced operators using appropriate patient selection and optimal technique. In that setting, a broad group of interventionists achieved very low periprocedural S/D rates for asymptomatic and symptomatic patients.

BACKGROUND:Most carotid revascularization studies define asymptomatic as symptom-free for more than 180 days; however, it is unknown if intervention carries similar risk among those currently asymptomatic but with previous symptoms (PS) vs those who were always asymptomatic (AA). METHODS:We compared the periprocedural and 4-year risks of PS vs AA patients in the Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) randomized to carotid endarterectomy (CEA) or carotid artery stenting (CAS)/angioplasty. Proportional hazards models adjusting for age, sex, and treatment were used to assess the risk of periprocedural stroke and/or death (S+D; any S+D during periprocedural period), stroke and death at 4 years (any S+D within the periprocedural period and ipsilateral stroke out to 4 years) and the primary end point at 4 years (any stroke, death, and myocardial infarction within the periprocedural period and ipsilateral stroke out to 4 years). Analysis was performed pooling the CEA-treated and CAS-treated patients, and separately for each treatment. RESULTS:Of 1181 asymptomatic patients randomized in CREST, 1104 (93%) were AA and 77 (7%) were PS. There was no difference in risk when comparing the AA and PS cohorts in the pooled CAS+CEA population for periprocedural S+D (2.0% vs 1.3%), S+D at 4 years (3.6% vs 3.2%), or the primary end point (5.2% vs 5.8%). There were also no differences among those assigned to CEA (periprocedural S+D, 1.5% vs 0%; S+D at 4 years, 2.7% vs 0%; or primary end point, 5.1% vs 2.4%) or CAS (periprocedural S+D, 2.5% vs 2.8%; S+D at 4 years, 4.4% vs 6.9%; or primary end point, 5.3% vs 9.8%) when analyzed separately. CONCLUSIONS:In CREST, only a small minority of asymptomatic patients had previous ipsilateral symptoms. The outcomes of periprocedural S+D, periprocedural S+D, and ipsilateral stroke up to 4 years, and the primary end point did not differ for AA patients compared with PS patients.

BACKGROUND:In the Carotid Revascularization Endarterectomy versus Stent Trial (CREST), carotid artery atherosclerotic lesion length and nature of the lesions were important factors that predicted the observed difference in stroke rates between carotid endarterectomy and carotid artery stenting (CAS). Additional patient-related factors influencing CAS outcomes in CREST included age and symptomatic status. The importance of the operator's proficiency and its influence on periprocedural complications have not been well defined. We evaluated data from CREST to determine the impact of use of multiple stents, which we speculate may be related to technical proficiency. METHODS:CREST includes CAS performed for symptomatic ≥50% carotid stenosis and asymptomatic ≥70% stenosis. Both symptomatic and asymptomatic patients were enrolled in the trial and in the lead-in registry. Data from patients enrolled in the CREST registry and randomized trial from 2000 to 2008 were reviewed for patient- and lesion-related characteristics along with number of stents deployed. The occurrence of 30-day stroke and demographic and clinical features were recorded. Odds ratios for 30-day stroke associated with the use of multiple stents were calculated in univariate analysis and on multivariable analysis after adjustment for demographics (age, sex, symptomatic status), lesion characteristics (length, ulceration, eccentric, percentage stenosis), and risk factors (diabetes, hypertension, dyslipidemia, and smoking). RESULTS:The registry (n = 1531) and trial (n = 1121) enrolled 2652 patients undergoing CAS. The mean age was 69 years; 36% were women, and 38% were symptomatic. The mean diameter stenosis was 78%, and the mean lesion length was 18 mm (±standard deviation, 8 mm). Risk factors included hypertension (85%), diabetes (32%), dyslipidemia (84%), and smoking (23%). All patients received Acculink stents (Abbott Vascular, Abbott Park, Ill) that were 20, 30, or 40 mm in length (straight or tapered) and Accunet (Abbot Vascular) embolic protection when possible. Most patients received one stent (n = 2545), whereas 98 patients received two stents and 9 patients received three stents (P < .001) to treat the lesion. Patients receiving more than one stent were older (P = .01) but did not differ in other demographic or risk factors. Strokes occurred in 118 (4.5%) of all CAS procedures, in 102 (4%) with the use of one stent, and in 16 (15%) with the use of two or three stents. After adjustment for demographics, lesion characteristics, and risk factors, the use of more than one stent resulted in 2.90 odds (95% confidence interval, 1.49-5.64) for a stroke. CONCLUSIONS:Although we know that lesion characteristics (length, ulceration) play an important role in CAS outcomes, in this early experience with carotid stenting, a significant and independent relationship existed between the number of stents used and procedural risk of CAS. We postulate that this was an indicator of the operator's inexperience with the procedure.

Background and Purpose- We investigated whether procedural stroke or death risk of carotid artery stenting (CAS) compared with carotid endarterectomy (CEA) is different in patients with and without history of coronary heart disease (CHD) and whether the treatment-specific impact of age differs. Methods- We combined individual patient data of 4754 patients with symptomatic carotid stenosis from 4 randomized trials (EVA-3S [Endarterectomy Versus Angioplasty in Patients With Symptomatic Severe Carotid Stenosis], SPACE [Stent-Protected Angioplasty Versus Carotid Endarterectomy], ICSS [International Carotid Stenting Study], and CREST [Carotid Revascularization Endarterectomy Versus Stenting Trial]). Procedural risk was defined as any stroke or death ≤30 days after treatment. We compared procedural risk between both treatments with Cox regression analysis, stratified by history of CHD and age (<70, 70-74, ≥75 years). History of CHD included myocardial infarction, angina, or coronary revascularization. Results- One thousand two hundred ninety-three (28%) patients had history of CHD. Procedural stroke or death risk was higher in patients with history of CHD. Procedural risk in patients treated with CAS compared with CEA was consistent in patients with history of CHD (8.3% versus 4.6%; hazard ratio [HR], 1.96; 95% CI, 0.67-5.73) and in those without (6.9% versus 3.6%; HR, 1.93; 95% CI, 1.40-2.65; P_interaction=0.89). In patients with history of CHD, procedural risk was significantly higher after CAS compared with CEA in patients aged ≥75 (CAS-to-CEA HR, 2.78; 95% CI, 1.32-5.85), but not in patients aged <70 (HR, 1.71; 95% CI, 0.79-3.71) and 70 to 74 years (HR, 1.09; 95% CI, 0.45-2.65). In contrast, in patients without history of CHD, procedural risk after CAS was higher in patients aged 70 to 74 (HR, 3.62; 95% CI, 1.80-7.29) and ≥75 years (HR, 2.64; 95% CI, 1.52-4.59), but equal in patients aged <70 years (HR, 1.05; 95% CI, 0.63-1.73; 3-way P_interaction=0.09). Conclusions- History of CHD does not modify procedural stroke or death risk of CAS compared with CEA. CAS might be as safe as CEA in patients with history of CHD aged <75 years, whereas for patients without history of CHD, risk after CAS compared with CEA was only equal in those aged <70 years.

BACKGROUND:The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) previously reported increased mortality in patients who sustained a periprocedural stroke or cardiac event (myocardial infarction [MI] or biomarker only) in follow-up to 4 years. We now extend these observations to 10 years. METHODS AND RESULTS/RESULTS:CREST is a randomized controlled trial designed to compare the outcomes of carotid stenting versus carotid endarterectomy. Proportional hazards models were used to assess the association between mortality and periprocedural stroke, MI, or biomarker-only events. For 10-year follow-up, patients with periprocedural stroke were at 1.74× the risk of death compared with those without stroke (adjusted hazard ratio [HR]=1.74; 95% CI, 1.21-2.50; P<0.003). This increased risk was driven by increased early (between 0 and 90 days) mortality (adjusted HR=14.41; 95% CI, 5.33-38.94; P<0.0001), with no significant increase in late (between 91 days and 10 years) mortality (adjusted HR=1.40; 95% CI, 0.93-2.10; P=0.11). Patients with a protocol MI were at 3.61× increased risk of death compared with those without MI (adjusted HR=3.61; 95% CI, 2.28-5.73; P<0.0001), with an increased hazard both early (adjusted HR=8.20; 95% CI, 1.86-36.2; P=0.006) and late (adjusted HR=3.40; 95% CI, 2.09-5.53; P<0.0001). Patients with a biomarker-only event were at 2.04× increased risk overall (adjusted HR=2.04; 95% CI, 1.09-3.84; P=0.03) than those without MI, with an increased early hazard (adjusted HR=8.44; 95% CI, 1.09-65.5; P=0.04) and a suggestive but nonsignificant association toward higher 91-day to 10-year risk (1.88; 95% CI, 0.97-3.64; P=0.062) contributing to the increased risk. CONCLUSIONS:In the CREST trial, patients with periprocedural events demonstrate a substantial increase in future mortality to 10 years. For stroke, this risk is largely confined to an early time frame while periprocedural MI or biomarker-only events confer a continuous increased mortality for 10 years. Strategies to reduce periprocedural events and to optimize the evaluation and management of patients with cardiac events should be considered in efforts to reduce not only early but also long-term mortality. CLINICAL TRIAL REGISTRATION/BACKGROUND:URL: https://www.clinicaltrials.gov . Unique identifier: NCT00004732.

We describe 5 years of follow-up of a previously reported case of disabling ionizing radiation (IR)-related cutaneous cancer in a high-volume interventional cardiologist. This case illustrates the cycle of exposure, disease, remission, and re-exposure that demonstrates the cause-and-effect relationship between radiation exposure and cutaneous cancer. Prior cautions for working in environments with radiation exposure emphasized strict adherence to the ALARA principle and called for improved radiation protection equipment. New studies stress that radiation exposure should be as near to zero as possible and place a call for research and technologies that mitigate the use of IR for all interventionists.

Rationale Trials conducted decades ago demonstrated that carotid endarterectomy by skilled surgeons reduced stroke risk in asymptomatic patients. Developments in carotid stenting and improvements in medical prevention of stroke caused by atherothrombotic disease challenge understanding of the benefits of revascularization. Aim Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) will test whether carotid endarterectomy or carotid stenting plus contemporary intensive medical therapy is superior to intensive medical therapy alone in the primary prevention of stroke in patients with high-grade asymptomatic carotid stenosis. Methods and design CREST-2 is two multicenter randomized trials of revascularization plus intensive medical therapy versus intensive medical therapy alone. One trial randomizes patients to carotid endarterectomy plus intensive medical therapy versus intensive medical therapy alone; the other, to carotid stenting plus intensive medical therapy versus intensive medical therapy alone. The risk factor targets of centrally directed intensive medical therapy are LDL cholesterol <70 mg/dl and systolic blood pressure <140 mmHg. Study outcomes The primary outcome is the composite of stroke and death within 44 days following randomization and stroke ipsilateral to the target vessel thereafter, up to four years. Change in cognition and differences in major and minor stroke are secondary outcomes. Sample size Enrollment of 1240 patients in each trial provides 85% power to detect a treatment difference if the event rate in the intensive medical therapy alone arm is 4.8% higher or 2.8% lower than an anticipated 3.6% rate in the revascularization arm. Discussion Management of asymptomatic carotid stenosis requires contemporary randomized trials to address whether carotid endarterectomy or carotid stenting plus intensive medical therapy is superior in preventing stroke beyond intensive medical therapy alone. Whether carotid endarterectomy or carotid stenting has favorable effects on cognition will also be tested. Trial registration United States National Institutes of Health Clinicaltrials.gov NCT02089217.