Roubin, Gary S.

Background: Historical data suggest that patients with recently symptomatic carotid stenosis are at high risk of early recurrent stroke. Guidelines therefore recommend revascularization within 2 weeks of symptoms. We assessed the risk of stroke or death occurring before revascularization in modern trials of symptomatic carotid stenosis. Methods: We pooled data of all individual patients with symptomatic carotid stenosis randomised to stenting (CAS) or endarterectomy (CEA) in the EVA-3S, SPACE, ICSS and CREST trials. The outcome event (OE) was death or any stroke occurring between randomization and treatment by CAS or CEA, or up to 120 days after randomization among patients not undergoing treatment in this period. Results: 4707 patients were included in the analysis. Median time from qualifying event until randomization was 18 (interquartile range 7-50) days. Median time from randomization until treatment was 6 (2-11) days in the CAS group, and 7 (3-12) days in the CEA group (p<0.001). 31% of patients in the CAS group and 27% in the CEA group underwent revascularization within 14 days of the qualifying event. The OE occurred in 21 patients (CAS: 8, CEA: 13), all within 31 days of randomization (Kaplan Meier estimate: 2.4%, standard error 0.7%; fig.), including 18 non-fatal strokes, 1 fatal stroke, and 2 non-stroke related deaths. In 2 of the patients, the date of the qualifying event was unknown, in 8 patients the OE occurred within 14 days of the qualifying event and in 11 patients >14 days after the qualifying event. All patients with the OE had severe (70-99% degree) stenosis. No other baseline variables predicted the OE. Discussion: Despite the fact that less than a third of patients underwent revascularization within 14 days of the qualifying event, only 2.4% of patients had a recurrent stroke or died before treatment. The risk is lower than expected from historical data, which may reflect advances in medical therapy. Patients at risk are those with severe degree of stenosis.

Purpose: The safety of revascularization for asymptomatic carotid stenosis, and the efficacy of medical therapy for stroke prevention have improved. Therefore, results of prior randomized trials may not apply to current treatment decisions. The NINDS-funded CREST-2 will compare carotid endarterectomy and intensive medical therapy (IMT) versus IMT alone (n=1240), and carotid stenting and IMT versus IMT alone (n=1240) in asymptomatic patients with≥70% stenosis. Materials & Methods: CREST-2 consists of two parallel randomized clinical trials to be conducted at a target of ≈120 centers, including within NINDS StrokeNet. The composite primary outcome is stroke or death during the peri-procedural period or ipsilateral ischemic stroke thereafter up to 4 years. Blinded assessment of cognition will be done periodically. Centrally directed IMT includes tight control of blood pressure (systolic target <140 mm Hg) and cholesterol (LDL target <70 mg/dl) as well as lifestyle coaching. Results: As of June 12, 2015, 94 centers have been approved by the Site Selection Committee. Credentialing is ongoing, with 198 approved surgeons and 64 approved interventionists; 124 additional conditionally approved interventionists will be able to submit additional cases for review under the CREST-2 Registry. The Centers for Medicare and Medicaid will offer CAS reimbursement for Registry enrollees. As of June 12, 2015, there are 39 actively enrolling centers, and 37 patients have been randomized. Conclusion: CREST-2 is designed to identify the best approach for asymptomatic carotid stenosis. The first patient was randomized in December, 2014. An update will be provided regarding the numbers of patients randomized, centers certified, as well as surgeons and interventionists fully approved. Registration: ClinicalTrials.gov Identifier: NCT02089217

Background: Presence of atherosclerotic disease in more than one vascular bed (polyvascular disease) is associated with an increased risk of long-term vascular events. In the setting of asymptomatic carotid stenosis, the predictors of disease in other vascular beds is not well delineated. Objective: To identify the frequency and predictors of disease in other vascular beds the CREST 2 randomized trial population with hemodynamically significant stenosis. Methods: Recorded baseline characteristics among CREST 2 participants included: demographics, past medical history, lifestyle factors, and laboratory studies. Each variable was tested against three potential definitions of disease in other beds (cardiac, peripheral arterial disease (PAD) or disease in cardiac + PAD). Statistical analysis was done with Chi square and t tests as appropriate. Results: Data from 1447 patients were available for analysis. In these subjects with carotid disease, 51% also had cardiac disease, 24% also had PAD, and 16% had disease in in both cardiac and PAD. There was no relationship between age or race and presence of disease in other beds. Those with cardiac disease were more likely to be male. Diabetes, hypertension, hypercholesterolemia, and former history of smoking were all more common in those with either cardiac and PAD (TABLE). Elevated triglyceride and low HDL levels were also associated with all three definitions of disease in other beds. Those with either PAD or cardiac + PAD were more likely to be current smokers. Conclusions: Among CREST 2 participants, several medical conditions and lifestyle factors were associated with an increased frequency of disease in other vascular beds. Smoking, in particular, appears to be more common in those with PAD. Future analyses will address whether those with disease in other beds have higher rates of stroke or death.

Baseline Differences in Risk Factor Control and Medication Use Between 2 Trials Employing Intensive Medical Management (SAMMPRIS & CREST2) Background: The CREST2 trial Intensive Medical Management (IMM) protocol was adapted from the SAMMPRIS trial. However, since the 2011 publication of initial results of SAMMPRIS, there has been a greater appreciation for the importance of risk factor control in patients at risk of stroke associated with atherosclerosis. Therefore, we sought to determine differences in baseline risk factor control and medication use between SAMMPRIS and CREST2. Methods: Baseline risk factor and medication use data from 451 patients enrolled in SAMMPRIS (2008-2011) with severe symptomatic intracranial atherosclerosis and 1473 patients enrolled in CREST2 (2014-2019) with severe asymptomatic carotid stenosis were compared using the Chi-square test and t-test. Results: The Table shows baseline risk factor values and medications. SAMMPRIS patients were younger but had significantly worse risk factor control than CREST2 patients for all measures. There was no significant difference in statin use at baseline, but the mean SAMMPRIS subjects’ LDL was 16.1 mg/dL higher than in CREST2. CREST2 patients had higher rates of use of angiotensin receptor blockers (ARB), calcium channel blockers (CCB), and thiazides, but lower rates of use of angiotensin converting enzyme (ACE) inhibitors. Conclusions: Despite being older, CREST2 patients have significantly better baseline risk factor profiles than SAMMPRIS patients. This could be due to greater appreciation of the importance of risk factor control and healthy lifestyle habits for stroke prevention or more aggressive treatment targets in guideline recommendations. Although risk factor control appears to be improving since SAMMPRIS, many CREST2 patients are still not meeting recommended risk factor goals at baseline and may benefit from IMM protocols.

Introduction: Using pooled data from randomized trials of symptomatic patients assigned to carotid artery stenting (CAS) versus carotid endarterectomy (CEA), we have previously shown age to be an effect modifier, with increasing risk at older ages for CAS but not for CEA. To extend assessment of age as an effect modifier to the asymptomatic population, we combined the asymptomatic patients from CREST with the patients from ACT I. Methods: We analyzed data from 2544 subjects with >= 70% carotid stenosis randomized to CAS or CEA in addition to standard management of cardiovascular risk factors. CREST enrolled 1091 (548 CAS, 543 CEA) and ACT I enrolled 1453 (1089 CAS, 364 CEA) asymptomatic patients less than 80 years old (upper age eligibility in ACT I). We examined the impact of age on risk within CAS-treated and CEA-treated patients using Kaplan-Meier methods. Age was considered in three strata (< 65, 65 to 74, and 75+). The pre-specified, primary composite endpoint was stroke, myocardial infarction, or death during the periprocedural period or any ipsilateral stroke within 4 years after randomization. Results: For patients assigned to CAS, risk differed between the age strata (p <0.0001) where relative to those under age 65, there was no difference in risk for those aged 65 to 74 (HR = 1.3 ; 95% CI: 0.7, 2.3, p=0.38), but those aged 75+ were at substantially higher risk (HR = 2.9; 95% CI: 1.5, 5.5, p=0.001). In contrast, risk did not differ by age strata (p = 0.80) for those assigned to CEA. Conclusions: Age-related risk factors, e.g. carotid anatomy and underlying cerebral pathology, should be considered before selecting patients aged 75+ for CAS.

Introduction: Outcomes from endovascular procedures are highly dependent on the experience and skill of the operating physician. The multi-disciplinary CREST-2 Interventional Management Committee (IMC) was charged with credentialing a cohort of skilled interventionists with adequate contemporary case volumes. Methods: Applicants were required to submit 25 consecutive cases completed within 5 years as primary operator out of a required total experience of ≥ 50 cases (≥ 20 for operators completing training). Interventionists not approved on initial review were asked to submit additional cases (with procedural angiograms), the number depending on quality and recent-quantity of the cases. Results: The IMC has had 102 meetings, and 283 interventionists have been evaluated: 104 (37%) interventionists were cardiologists, 64 (23%) vascular surgeons, 42 (15%) neurosurgeons, 32 (11%) neuroradiologists, 26 (9%) neurologists, 9 (3%) interventional radiologists, and 6 (2%) other. The mean total experience among the 226 interventionists with available information was 220±263 carotid stent cases (median 135; range 10-2500). A total of 7037 cases have been reviewed by the IMC, dating from August 2001 to April 2016, with 3366 symptomatic, 3541 asymptomatic and 130 undetermined. The range of cases reviewed per interventionist was 5 to 50. Of the 251 interventionists with sufficient periprocedural follow-up data, no stroke events were reported by 152 (60.5%), and at least one or more stroke events were reported by 99 (39.5%). The IMC has approved 115 interventionists, 29 at the first review and 86 subsequently, based upon submission and review of 631 additional contemporary cases (mean=7 cases per interventionist); 122 have approval pending submission of additional cases; 33 have been denied; 8 have been deferred; 4 have been approved for the CREST-2 Companion Registry only; and 1 is pending decision. Discussion: Rigorous evaluation and credentialing of carotid stenters in CREST-2 has been demanding, for the candidates and for the evaluators. Yet the cohort of interventionists so selected should be able to provide the high-quality stenting outcomes necessary for acceptance of the trial results.

Introduction: Occurrence of stroke and myocardial infarction (MI) after carotid endarterectomy or stenting have each been associated with increased later mortality. Methods: In the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) 69 strokes, 37 protocol MIs, and 19 biomarker + only events occurred within 30 days among 2272 patients followed up to 10 years. Mortality was determined and compared for patients with stroke, MI, or biomarker + only to those without. Cox proportional hazard models adjusting for age, sex, symptomatic status and treatment were calculated to assess the relationship between mortality and stroke and mortality and MI status. Kaplan-Meier survival curves were plotted. Results: Patients with peri-procedural stroke had a 67% greater likelihood of long-term mortality compared to those without stroke (HR=1.67, 95% CI 1.15,2.43; p<0.007)(Figure A). Patients with a protocol MI had a 249% greater likelihood of mortality, and biomarker+ only patients had a 104% greater likelihood of mortality, compared to those without MI (HR=3.49; 95%CI 2.20,5.53, p<0.0001; and HR=2.04; 95% CI 1.09,3.83, p=0.03)(Figure B). Discussion: Stroke, MI, and biomarker + only events following CEA or CAS are associated with increased long-term mortality. The higher risk for MI may be a marker for patients with serious underlying heart disease, rather than causal, providing an opportunity to decrease long-term mortality through aggressive diagnostic evaluation and preventive treatment.

Background: Data from the CDC show that approximately one-quarter of adults have elevated triglyceride (TG) levels. Recent trials have demonstrated that pharmacologic treatment of high TG levels, in patients already on statin therapy, reduces the rate of major vascular events such as myocardial infarction and stroke (REDUCE-IT trial). We sought to assess how often patients with asymptomatic carotid stenosis (CS) have elevated TG levels and factors associated with high TG values. Methods: Patients enrolled in the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST 2) were analyzed. Baseline lipid profiles were evaluated to determine high TG treatment eligibility as per the REDUCE-IT trial. We also evaluated baseline use of pharmacologic treatment for high TG levels. Demographic factors and baseline medical conditions were studied in relation to high (>150 mg/dl) TG values. Chi square and t tests were used to assess baseline factors and abnormal TG values. Results: As of August 10, 2020, 1655 of 1689 randomized patients (mean age 69.7 years, 61% men) had baseline lipid profiles suitable for analysis. Treatment eligibility according to REDUCE-IT (LDL 41-100 mg/dl, TG>150 mg/dl) was present in 21% (345) of subjects. In these patients, the median TG value was 205 (IQR 93) mg/dl. Fibrate medications were used at baseline in 4.5% of patients. Analysis of demographic and medical history factors and TG values greater than 150 mg/dl is found in the Table. There was significant positive correlation between baseline hemoglobin A1C and triglyceride values (p<0.0001) Conclusions: One in five patients in CREST 2 has TG values that potentially justify pharmacologic treatment. Elevated TG levels are most correlated with diabetes, hypertension, obesity, decreased physical activity, and heart disease. Clinicians should investigate treatment of elevated TG levels as a component of intensive medical therapy for stroke prevention.

Introduction: Previous analyses of randomized trials comparing carotid artery stenting (CAS) versus carotid endarterectomy (CEA) have revealed varying sex-associated risk. To better understand sex as an effect modifier in the asymptomatic population, we combined the asymptomatic patients from CREST with the asymptomatic patients from ACT I. Methods: We analyzed data from 2544 subjects with ≥ 70% carotid stenosis randomized to CAS or CEA in addition to standard management of cardiovascular risk factors. CREST enrolled 1091 (548 CAS, 543 CEA) and ACT I enrolled 1453 (1089 CAS, 364 CEA) asymptomatic patients less than 80 years old (upper age eligibility in ACT I). We examined the impact of sex on risk within CAS-treated and CEA-treated patients using Kaplan-Meier methods. The pre-specified, primary composite endpoint was stroke, myocardial infarction, or death during the periprocedural period (within 30 days of randomization) or any ipsilateral stroke within 4 years after randomization. Results: For patients assigned to CAS, there was no difference in risk between the sexes (female-to-male HR = 1.04, 95% CI 0.65 -- 1.66, P = 0.87). For patients assigned to CEA, the difference in risk detected was not significant (female-to-male HR = 1.43, 95% CI 0.77 - 2.67, P = 0.26). Conclusions: Sex-differences in risk were not significant for those assigned CAS nor those assigned CEA in this largest pooled analysis of asymptomatic patients comparing CAS to CEA.

Background: The importance of physical activity in preventing major vascular events has received increased attention in the past decade. Due to the inclusion of the INTERVENT lifestyle modification program, the CREST2 trial provides a unique opportunity to study physical activity profiles in patients with severe asymptomatic extracranial carotid stenosis. Hypothesis: Based on data from a trial of intracranial stenosis patients, we aimed to evaluate the hypothesis that <40% of carotid stenosis subjects will have optimal physical activity levels. We also assessed key subgroups to determine patterns of physical activity. Methods: We analyzed 1087 CREST2 participants with baseline data on physical activity. The Physician-based Assessment and Counseling for Exercise (PACE) score is recorded for each patient and dichotomized as “in target” (4-8 points) or “out of target” (<4 points). A PACE score of <4 indicates a subject who does not engage in regular exercise. Results are analyzed for the entire trial. Chi square testing and t-tests were performed for evaluation of subgroup differences. Results: The mean age of the study population is 69.5±7.8 years (60% male). The median PACE score at baseline is 4.0 (mean 3.8±2.1; IQR 2 to 6). The Table shows baseline characteristics of patients by mean PACE score. Being male, not having diabetes mellitus, having a body mass index <30kg/m2, being a non-smoker, and not having a history of peripheral arterial disease were associated with significantly higher mean PACE scores (P<0.01). Conclusions: We have defined several patient groups with asymptomatic carotid stenosis that have suboptimal physical activity. These results provide opportunities for targeted efforts to improve primary stroke prevention. These baseline data will also allow investigators to determine if trial involvement and the INTERVENT program leads to improvement in the level of physical activity.