Brott, Thomas G.

The recently published SPACE-2 trial (Stent-Supported Percutaneous Angioplasty of the Carotid Artery Versus Endarterectomy-2) compared 3 treatments to prevent stroke in patients with asymptomatic carotid stenosis ≥70%: (1) carotid endarterectomy plus best medical treatment (BMT), (2) transfemoral carotid artery stenting plus BMT, or (3) BMT alone. Because of low enrollment, the findings of similar safety and efficacy for carotid endarterectomy, carotid artery stenting, or BMT alone were inconclusive. Publication of the CREST (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial)-2 results should provide level A evidence that has been lacking for 2 to 3 decades, to guide treatment of asymptomatic patients with severe carotid stenosis. For symptomatic patients with ≥70% stenosis, no trials are underway to update the degree of benefit reported for carotid endarterectomy by NASCET (North American Carotid Endarterectomy Trial) and ECST (European Carotid Surgery Trial), published in 1991. Subsequently, the use of cigarettes has plummeted, and major improvements in medical treatments and in carotid revascularization have emerged. These advances have coincided with abrupt decline in the clinical end points necessary for treatment comparisons in procedural trials. One of the advances in the invasive management of carotid disease has been transcarotid artery revascularization, already with limited approval by the US Food and Drug Administration. Establishing safety and efficacy of transcarotid artery revascularization compared with carotid endarterectomy, carotid artery stenting, or BMT alone may be challenging because of enrollment, regulatory, and funding barriers to design and complete an adequately powered randomized trial.

Introduction: Carotid revascularization is known to prevent stroke in patients with high-grade carotid stenosis, but whether carotid revascularization may slow the progression of hemispheric WMD in patients with carotid stenosis to prevent cognitive decline have not been well described. Methods: We conducted a longitudinal study involving patients age ≥40 years with carotid stenosis on ultrasound from 2011-2015 with serial brain MRI scans at least 1 year apart followed for radiographic and clinical outcomes to 2020. Severity of carotid stenosis was defined as moderate 50-69%, high-grade 70-99%, or occluded. Hemispheric WMD volume was quantified from axial T2 FLAIR images. Patients were stratified by revascularization status. Primary outcome was change in WMD volume per year ipsilateral or contralateral to the index carotid. Hemispheric differences in the annual rate of WMD progression (cc/yr) were compared between revascularized vs not revascularized using multivariable linear regression analysis adjusted for variables that differed between revascularization status. Results: Of the 150 patients, moderate stenosis was present in 37.3%, high-grade stenosis in 42.0%, and carotid occlusion in 20.7%. Mean age was 71±10 years, 36.7% were female. Seventy-three (48.7%) had carotid revascularization with a median follow-up of 5.1 years. Baseline WMD volume was 4.86cc ipsilateral and 4.39cc contralateral to the index carotid. Patients who underwent revascularization trended to have slower WMD progression in the hemisphere ipsilateral to the index carotid compared to those not revascularized (0.32cc/yr vs 0.63 cc/yr, p=0.340). The same trend was not observed in the contralateral hemisphere. In adjusted models, carotid revascularization was associated with a 0.33 cc per year decrease in WMD progression between hemispheres compared to those not revascularized (β= -0.33, p=0.070). Conclusions: In this study with a median follow-up of 5 years, we found that carotid revascularization resulted in a 50% reduction in the annual rate of WMD progression. Intervention trials should test whether carotid revascularization slows WMD progression in patients with cognitive impairment to prevent further cerebrovascular events and cognitive decline.

Background: Over 9 million dual-eligible beneficiaries rely on both Medicare and Medicaid to obtain critical medical services. Medicaid serves as a safety net for low-income Medicare beneficiaries with limited assets; however, it is unknown whether dual-eligible patients have comparable outcomes for procedures to non-dual-eligible Medicare beneficiaries. We compared outcomes by dual-eligible status for patients undergoing carotid endarterectomy (CEA). Methods: We identified Medicare fee-for-service beneficiaries aged ≥65y who underwent CEA (ICD-9 38.12) from 2003-2010. Beneficiaries with ≥1m of Medicaid coverage were considered dual eligible. We fit mixed models with a random intercept for state and adjustment for demographics, comorbidities, and symptomatic status to assess the relationship between dual-eligible status and outcomes. Results: A total of 35,832 dual-eligible and 470,134 non-dual-eligible beneficiaries were hospitalized for CEA during the study period. The percentage of dual-eligible CEA patients decreased from 7.9% in 2003 to 6.7% in 2010. Dual eligibles were more likely to be younger, female, of nonwhite race, and living with comorbid conditions (e.g., heart failure, renal failure, diabetes) and symptomatic carotid disease. Dual eligibles had higher 30d composite outcomes including stroke (Table), but the associations with 1y stroke became nonsignificant from 2003-2010. Dual-eligible status was associated with higher 30d and 1y mortality after CEA throughout the study period. Conclusions: Dual-eligible Medicare-Medicaid beneficiaries had worse short-term stroke and mortality outcomes than other beneficiaries, even after adjustment for comorbidities. Our results indicate a need to understand factors contributing to poorer outcomes. Challenges include the split accountability between the two programs and the diverse sociodemographics, clinical characteristics, and generally poorer health of the patients.

Introduction: Increasing stenosis has been questioned as a factor increasing risk of carotid endarterectomy (CEA) or carotid stenting (CAS) in patients with severe asymptomatic carotid stenosis. Hypothesis: Greater severity of carotid stenosis is associated with higher rates of periprocedural stroke and death following revascularization for asymptomatic patients. Methods: Asymptomatic patients with carotid stenosis ≥ 70% by ultrasound or ≥ 60% by angiogram were eligible for the Carotid Revascularization Endarterectomy vs Stenting Trial (CREST). Patients who had a catheter-angiogram were divided into tertiles based on the degree of stenosis. Outcomes were the occurrence of any stroke or death at 30 days. Proportional hazards models adjusting for age and treatment were used to assess risk of 30 day stroke or death by tertile of stenosis. Results: Among 1181 asymptomatic patients, qualifying angiograms were done for 662 patients who had assigned procedure performed within 30 days of randomization. Median % stenosis was 62.6, 73.4, and 83.0 for the tertiles that otherwise differed only for female sex (40% female in tertile 1, 36% in tertile 2, 29% in tertile 3, p=0.01). The 30-day stroke and death rates did not differ significantly by severity of stenosis (Table), but the number of stroke and deaths was only 14 across the tertiles (Table). Similarly meaningful comparison of CEA vs CAS was not possible. Conclusion: This is the largest contemporary study of carotid angiograms performed in patients with severe asymptomatic carotid stenosis. No relationship was detected between severity of stenosis and 30-day stroke and death. The safety of CEA and CAS in asymptomatic patients limits detection of other factors that may increase risk because so few events complicate these procedures.

Background: Administrative data such as Medicare data are commonly used for health services research and comparative effectiveness studies. These databases are readily available and a good source of long-term data on healthcare utilization and health outcomes in real-world settings. Outcomes are captured using diagnostic codes, but the evidence on the validity of these codes is scarce in contemporary Medicare data. Methods: We linked the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study data using SSN, date of birth and sex to 2003-2009 Medicare claims. In addition to the events captured by REGARDS phone interviews, medical charts were pursued for Medicare-identified strokes not previously identified in REGRADS. Events were adjudicated by stroke specialists using the retrieved medical charts. Using all the adjudicated strokes as gold standard, we calculated the sensitivity, specificity, PPV and NPV of inpatient stroke algorithms with ICD-9-CM codes [430, 431, 433.x1, 434.x1, 436] in the primary discharge diagnosis. Results: We successfully linked 15,089 REGARDS participants with mean age of 69.3, 52% female and 37% Black. We adjudicated 457 strokes, of which 48 were identified by claims only and not by interviews. The tested algorithms had high specificity (99.8-100%), PPV (88.6-90.5%) and NPV (98.9-99.9%), but low sensitivity (58.6-67.4%) (Table). Conclusions: High specificity and PPV of our algorithms to identify strokes in contemporary Medicare populations support their use in etiological and comparative effectiveness studies. While our inpatient Medicare algorithms identified 12% extra cases of strokes, their usefulness for estimating stroke incidence or related healthcare utilizations is limited by their low sensitivity. Linking cohorts to Medicare data is feasible and should be considered to increase the completeness of follow-up. Further studies are needed to evaluate more sensitive Medicare algorithms.

Objective: To compare the perioperative risk of any stroke, death and MI and the long-term risk of re-stenosis and stroke following CEA with patching (a prosthetic or vein patch sutured to the arterial opening to widen the closure) versus CEA with primary closure in CREST. Methods: We included patients who were randomized and underwent CEA in CREST. We compared peri-procedural and 4-year event rates and 2-year restenosis rates, in addition to rates of reoperation between the two groups. Re-stenosis was defined as elevated peak systolic velocity ≥3.0 m/s on carotid duplex US. Treatment differences were assessed using proportional hazard models adjusting for age, sex, and symptomatic status. Results: There were 1,148 patients who underwent CEA (755 {66%} patch; 328 {29%} primary closure). We excluded 43 patients who underwent eversion CEA and 24 patients missing CEA data (5%). There was no significant difference between the two groups with respect to age, sex, race and comorbidities (Table 1). There were significant reductions in the risk of any periprocedural stroke and death (HR 0.35, 95% CI 0.15-0.82, P<0.02), in re-operation (OR 0.33, 95% CI 0.14-0.80, P<0.01), in the 4-year risk of stroke (HR 0.52, 95% CI 0.28-0.97, P<0.04) and in the 2-year risk of re-stenosis (HR 0.26, 95% CI 0.14-0.45, P<0.0001) in the patch compared to the primary closure group (Table 2). Conclusion: Patch closure should be considered for all CEAs because of the association of patch closure with reductions in risk of periprocedural stroke and death, re-operation, and long-term clinical and anatomic durability.