Lazar, Ronald M.

Importance Cerebral hemodynamic impairment in patients with asymptomatic internal carotid artery (ICA) stenosis is associated with reduced cognition. It is uncertain whether revascularization might be an effective treatment for cognitive impairment in these patients. Objective To test whether any cognitive benefit from revascularization of high-grade, asymptomatic ICA stenosis varies based on the degree of baseline cerebral hemodynamic impairment. Design, Setting, and Participants This substudy was conducted within a multicenter phase 3 randomized clinical trial. Adults (aged 35-86 years) without dementia with eighth-grade education or higher and unilateral asymptomatic ICA stenosis greater than or equal to 70% were enrolled from January 2018 to July 2024 at 61 sites in North America (last follow-up in July 2025). Of 607 participants screened from 2485 in CREST-2, 392 were enrolled. Magnetic resonance or computed tomographic perfusion imaging tested for baseline hemodynamic impairment defined by delayed time-to-peak (TTP) arrival of intravenous contrast in the hemisphere ipsilateral minus contralateral to the stenotic artery. Intervention Carotid revascularization (endarterectomy or stenting) plus intensive medical management (IMM) vs IMM alone. Main Outcomes and Measures The primary outcome was the difference in composite cognitive z score over 1 year based on 5 cognitive tests. The primary analysis tested for an interaction between treatment group (revascularization vs IMM alone) and degree of baseline hemodynamic impairment among those with reduced baseline cognition (cognitive z score ≤−1.0 SD). Results Of 392 participants enrolled (mean age, 71 years; 125 [32%] females), 61 were excluded for missing baseline imaging and 40 for missing cognitive examinations or other covariates, leaving 291 with complete data. Fifty-one had reduced cognition at baseline (25 in the revascularization group and 26 in the IMM alone group). TTP ranged from no interhemispheric TTP delay to a more-than-2-second delay. Mean (SD) cognitive z scores were −1.36 (0.51) at baseline and −1.17 (0.47) at 1 year in the revascularization group and −1.34 (0.83) at baseline and −1.01 (0.97) at 1 year in the IMM alone group. The primary analysis showed no difference in cognition by treatment group over 1 year, adjusting for treatment group × hemodynamic status interaction and other covariates (adjusted difference in cognitive z score, −0.15 SD [95% CI, −0.54 to 0.24]). The interaction was not significant (β estimate = 0.018 [95% CI, −0.025 to 0.061]; P = .40). Conclusions and Relevance In this substudy of a randomized clinical trial, there was no differential effect of revascularization vs IMM alone on cognition over 1 year by cerebral hemodynamic status among those with baseline reduced cognition, suggesting that revascularization does not improve cognitive dysfunction by restoring flow to the brain in chronic asymptomatic carotid stenosis. Trial Registration ClinicalTrials.gov Identifier: NCT03121209

Background New antiamyloid therapies (AAT) for treating patients with early Alzheimer disease (AD) have become available in the past 3 years. Although AAT can be beneficial in slowing progression of AD, they also come with potentially serious side effects, particularly for patients requiring anticoagulation or thrombolysis for cardiovascular conditions. Given that most patients with AD are older and likely to have cardiovascular risk factors, there is urgent need for additional guidance for clinicians about potential risks and benefits associated with AAT for patients with cardiovascular comorbidities, best practices for management of these patients, and special considerations with respect to emergency evaluation and treatment of patients on AAT who develop acute neurological symptoms. Methods The American Heart Association convened 75 multidisciplinary experts for the Amyloid‐Related Imaging Abnormalities Summit: Cardiovascular and Stroke Considerations for β‐Amyloid Immunotherapy in AD in July 2025. These experts were divided into 8 work groups to evaluate the current evidence related to AAT usage in patients with cardiovascular risk factors and conditions and develop consensus‐based guidance for clinicians. Results This statement outlines the outcomes of the Summit, including considerations for prescribers, primary care professionals, emergency personnel, and health care system stakeholders. These considerations are intended to improve identification of patients as appropriate candidates for AAT, management of patients with co‐occurring AD and cardiovascular conditions, and their emergency evaluation and treatment. The statement also includes guidance for shared decision‐making, implementation of system changes for improving dementia care, and recommendations for future research and data collection to add to the body of evidence for treating patients with concomitant AD and cardiovascular conditions. Conclusions Building on lessons learned from the establishment of stroke systems of care, the consensus‐based considerations outlined in this document can serve as a foundation for AD systems of care aimed at ensuring optimal use of these ground‐breaking therapies.

Objectives: Cerebral hemodynamic impairment in patients with asymptomatic high-grade internal carotid artery (ICA) stenosis confers a risk of stroke and cognitive decline, but correlations between degree of stenosis and hemodynamic impairment are derived from small case series only. Using baseline data from 282 participants in the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis – Hemodynamics (CREST-H) study, we hypothesized that degree of stenosis, measured by peak systolic velocity (PSV) and end diastolic velocity (EDV) in the ipsilateral ICA, would correlate with time-to-peak (TTP) delay using MR (n=275) or CT (n=7) perfusion scans, adjusting for demographic and cardiovascular risk variables. Methods: Using a 7-10MHz Doppler probe, ICA PSV and EDV were assessed. Doppler results were adjudicated centrally. Dynamic contrast perfusion imaging was standardized across 61 CREST-H sites, using sequential T2*-weighted time-sequence scanning (e.g. TR=1500, TE=25ms, flip angle=60deg, phase=128, slice thickness=5mm for GE 3T magnet). CTP was acquired with standard clinical protocols. TTP delay was calculated in the ipsilateral versus contralateral MCA/ACA territories using OLEA software. Linear regression used TTP delay as the outcome variable and PSV and EDV as predictor variables, adjusting for covariates.The 282 with complete data for all variables were included in the analysis. Results: Among 392 CREST-H participants, 63% were men, 7% Black, 3% Hispanic, 33% with less than college education. Tables 1a/b show the regression results for PSV and EDV as main predictor variables. PSV and EDV on the index side significantly correlated with TTP delay (p=0.004, p=0.002 respectively). Neither PSV nor EDV on the non-index side correlated with TTP delay (p=0.49, p=0.82). Compared with moderate exercise, vigorous exercise correlated with lower TTP delay in both models (p=0.05. p=0.04). Compared with college graduates, those with HS education had longer TTP delays in both models (p=0.03. p=0.02). Conclusions: In this large cohort of patients with high-grade asymptomatic carotid stenosis, higher flow velocities correlated with greater TTP delays, suggesting an increasing hemodynamic impairment with greater degree of stenosis above 70%. Our findings have implications for management of asymptomatic carotid stenosis which are being tested in the CREST-H and CREST-2 studies. Exercise and education may independently impact cerebral hemodynamics.

BACKGROUND: Cerebral hemodynamic impairment in patients with asymptomatic high-grade (>70%) internal carotid artery (ICA) stenosis is associated with risk of stroke and cognitive decline, but correlations between the degree of stenosis and hemodynamic impairment are derived from small case series. Using baseline data from 242 participants in the CREST-H study (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis–Hemodynamics), we hypothesized that the degree of stenosis in the ICA would correlate with time-to-peak (TTP) delay in ipsilateral cerebral blood flow using MR/CT perfusion scans, adjusting for demographic and cardiovascular risk variables. METHODS: From all participants, ICAs were insonated using a 7 to 10 MHz probe for peak systolic velocity (PSV) and end diastolic velocity. Dynamic contrast perfusion imaging was standardized across 61 CREST-H sites, using standard sequential T2*-weighted perfusion imaging. CT perfusion used standard clinical protocols. TTP delay was calculated in the ipsilateral versus contralateral hemispheres. In cross-sectional analysis, linear regression was used to model TTP delay as the outcome variable and PSV, end diastolic velocity, and PSV ICA/common carotid artery ratio on the index and nonindex side as primary predictor variables in 6 separate models, adjusting for covariates, followed by automated backward elimination model reduction. RESULTS: Among 392 CREST-H participants, the 242 with complete data for all variables were included in the regression analysis (age, 70±7.6; 62% M). End diastolic velocity on the index side correlated with TTP delay (β=0.003, P =0.005). PSV had a similar correlation but did not reach significance (β=0.001, P =0.099), nor did ICA/common carotid artery ratio (β=0.003, P =0.126). Nonindex side PSV, end diastolic velocity, and ICA/common carotid artery ratio showed no correlation with TTP delay ( P =0.268, P =0.495, P =0.380, respectively). Circle of Willis completeness did not correlate with TTP. CONCLUSIONS: In this large cohort of patients with high-grade asymptomatic carotid stenosis, higher end-diastolic flow velocities correlated with greater TTP delays, supporting a definition of hemodynamically significant stenosis. Our findings have implications for the management of asymptomatic carotid stenosis, which will be tested in the CREST-H study. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03121209.

Background: Previous reports have established a relationship between asymptomatic high-grade carotid artery stenosis (CAS) and impaired cognition. Different forms of cardiac disease have also been associated with cognitive impairment and dementia. The effect of concurrent high-grade CAS and cardiac disease on cognition is unknown. We hypothesize the presence of comorbid cardiac disease has a synergistic effect on cognitive impairment in patients with asymptomatic CAS. Methods: Patients with ≥80% internal carotid artery stenosis with no history of stroke were recruited from inpatient and outpatient practices at a single, large, comprehensive stroke center. Patients with vs without comorbid cardiac disease (coronary artery disease [CAD], CAD with history of coronary artery bypass graft [CABG] or percutaneous intervention [PCI], heart failure [HF], atrial fibrillation [AF], or valvular disease [aortic or mitral]) were identified. Cognitive assessments were performed using a battery of 14 standardized tests of attention, memory, processing speed, visual construction, language and executive function. Z-scores were generated based on age-specifc norms. Multivariable linear regression was used to compare test-specific Z-scores in patients with vs without cardiac disease controlling for age, sex, years of education and depression. Results: Thirty-three patients with asymptomatic CAS were identified (21 males, age 74+/-10 years, education=16+/-3 years). Twenty-six (79%) had cardiac disease. Patients with comorbid cardiac disease had significantly lower Z-scores across multiple tests of memory compared to patients without cardiac disease (Fig). After adjusting for age, sex, years of education and depression, significant differences persisted in tests of memory in patients with CAD [Hopkins Recognition Memory Test, β= -1.127 (95% CI: -2.234, -0.020), P=0.046], CABG [Hopkins Learning Trial Memory Test, β= -1.441 (95% CI: -2.532, -0.350), P=0.012], and valvular disease [Hopkins Learning Trials Memory Test, β= -1.121 (95% CI: -2.224, -0.018), P=0.047]. Conclusion: Cardiac disease is common among patients with asymptomatic high-grade carotid stenosis and may have a synergistic effect on impairments in memory in a manner not mediated by stroke. Further work is needed to confirm these relationships and their longterm implications on vascular brain health.