Cerebral blood flow and neurocognition in patients undergoing transcatheter aortic valve replacement for severe aortic stenosis.

Aims: Aortic valve stenosis (AS) results in higher systolic pressure to overcome resistance from the stenotic valve, leading to heart failure and decline in cardiac output. There has been no assessment of cerebral blood flow (CBF) association with neurocognition in AS or the effects of valve replacement. The goal was to determine if AS is associated with altered cerebral haemodynamics and impaired neurocognition, and whether transcatheter aortic valve replacement (TAVR) improves haemodynamics and cognition. Methods and results: In 42 patients with planned TAVR, transcranial Doppler (TCD) assessed bilateral middle cerebral artery (MCA) mean flow velocities (MFVs); abnormality was <34.45 cm/s. The neurocognitive battery assessed memory, language, attention, visual-spatial skills, and executive function, yielding a composite Z-score. Impairment was <1.5 SDs below the normative mean. The mean age was 78 years, 59% Male, and the mean valve gradient was 46.87 mm/Hg. Mean follow-up was 36 days post-TAVR (range 27-55). Pre-TAVR, the mean MFV was 42.36 cm/s (SD = 10.17), and the mean cognitive Z-score was -0.22 SDs (range -1.99 to 1.08) below the normative mean. Among the 34 patients who returned after TAVR, the MFV was 41.59 cm/s (SD = 10.42), not different from baseline (P = 0.66, 2.28-3.67). Post-TAVR, average Z-scores were 0.17 SDs above the normative mean, not meeting the pre-specified threshold for a clinically significant 0.5 SD change. Conclusion: Among patients with severe AS, there was little impairment of MFV on TCD and no correlation with cognition. Transcatheter aortic valve replacement did not affect MFV or cognition. Assumptions about diminished CBF and improvement after TAVR were not supported.

Effects of a brief HIIT intervention on cognitive performance in older women.

Cardiorespiratory fitness (CRF) mitigates age-related decline in cognition and brain volume. Little is known, however, about the effects of high-intensity interval training (HIIT) on cognitive aging and the relationship between HIIT, cognition, hippocampal subfield volumes, and cerebral oxygen extraction fraction (OEF). Older sedentary women participated in an 8-week HIIT intervention. We conducted cognitive assessments, fitness assessments (VO2max), MRI scans: asymmetric spin echo oxygen extraction fraction (ASE-OEF), high-resolution multiple image co-registration and averaging (HR-MICRA) imaging, and transcranial Doppler ultrasonography before and after the intervention. VO2max increased from baseline (M = 19.36, SD = 2.84) to follow-up (M = 23.25, SD = 3.61), Z = - 2.93, p < .001, r = 0.63. Composite cognitive (Z = - 2.05, p = 0.041), language (Z = - 2.19, p = 0.028), and visuospatial memory (Z = - 2.22, p = 0.026), z-scores increased significantly. Hippocampal subfield volumes CA1 and CA3 dentate gyrus and subiculum decreased non-significantly (all p > 0.05); whereas a significant decrease in CA2 (Z = - 2.045, p = 0.041, r = 0.436) from baseline (M = 29.51; SD = 24.50) to follow-up (M = 24.50; SD = 13.38) was observed. Right hemisphere gray matter was correlated with language z-scores (p = 0.025; r = 0.679). The subiculum was correlated with attention (p = 0.047; r = 0.618) and verbal memory (p = 0.020; r = 0.700). The OEF and CBF were unchanged at follow-up (all p > .05). Although we observed cognitive improvements following 8 weeks of our HIIT intervention, they were not explained by hippocampal, OEF, or CBF changes.

The predictive validity of a Brain Care Score for dementia and stroke: data from the UK Biobank cohort.

Introduction: The 21-point Brain Care Score (BCS) was developed through a modified Delphi process in partnership with practitioners and patients to promote behavior changes and lifestyle choices in order to sustainably reduce the risk of dementia and stroke. We aimed to assess the associations of the BCS with risk of incident dementia and stroke. Methods: The BCS was derived from the United Kingdom Biobank (UKB) baseline evaluation for participants aged 40-69 years, recruited between 2006-2010. Associations of BCS and risk of subsequent incident dementia and stroke were estimated using Cox proportional hazard regressions, adjusted for sex assigned at birth and stratified by age groups at baseline. Results: The BCS (median: 12; IQR:11-14) was derived for 398,990 UKB participants (mean age: 57; females: 54%). There were 5,354 incident cases of dementia and 7,259 incident cases of stroke recorded during a median follow-up of 12.5 years. A five-point higher BCS at baseline was associated with a 59% (95%CI: 40-72%) lower risk of dementia among participants aged <50. Among those aged 50-59, the figure was 32% (95%CI: 20-42%) and 8% (95%CI: 2-14%) for those aged >59 years. A five-point higher BCS was associated with a 48% (95%CI: 39-56%) lower risk of stroke among participants aged <50, 52% (95%CI, 47-56%) among those aged 50-59, and 33% (95%CI, 29-37%) among those aged >59. Discussion: The BCS has clinically relevant and statistically significant associations with risk of dementia and stroke in approximately 0.4 million UK people. Future research includes investigating the feasibility, adaptability and implementation of the BCS for patients and providers worldwide.

Association Between Mental Health Burden, Clinical Presentation, and Outcomes in Individuals With Symptomatic Peripheral Artery Disease: A Scientific Statement From the American Heart Association.

Along with the rising burden of peripheral artery disease (PAD), mental health concerns are increasingly being recognized as a comorbidity to address in the chronic disease management of symptomatic PAD. Apart from a high prevalence of comorbid mental health conditions, the role of pain and changing health behaviors and the broader impacts of illness and adaptation to living with PAD require specialized behavioral health expertise. This scientific statement builds a case that this expertise should be integrated within the multidisciplinary PAD team. Furthermore, areas such as cognitive dysfunction and palliative care are highlighted as needing psychological interventions. Although much of the evidence of the efficacy of psychological and psychotropic interventions has been extrapolated from other cardiovascular populations, evidence for the role of psychological interventions for behavior change, for example, uptake of exercise regimens, is increasingly being accrued within PAD. Areas for behavioral health needs and interactions with PAD treatment are discussed, including the use of opioids, depression management, anxiety and stress reduction interventions, the use of benzodiazepines and antidepressants, smoking cessation, rehabilitation trajectories after amputation, and the role of cognitive decline for PAD treatment and outcomes. A case summary highlights the stigma around mental health and vascular disease and the fragmentation of care. This scientific statement provides remarks for building a road map for integrated behavioral PAD care and potential solutions to overcome these barriers. Instrumental to reaching these changes are interprofessional advocacy efforts and initiatives that help break down the stigma around mental health and promote evidence-based collaborative, nonhierarchical, and multidisciplinary PAD care.

A rationale and framework for addressing physician cognitive impairment.

Medical error is costly, in terms of the health and wellbeing of the patient, their family, and the financial burden placed on the medical system. Reducing medical error is paramount to minimizing harm and improving outcomes. One potential source of medical error is physician cognitive impairment. Determining how to effectively assess and mange physician cognitive impairment is an important, albeit difficult problem to address. There have been calls and attempts to implement age-based cognitive screening, but this approach is not optimal. Instead, we propose that neuropsychological assessment is the gold standard for fitness-for-duty evaluations and that there is a need for the development of physician-based, normative data to improve these evaluations. Here, we outline the framework of our research protocol in a large, academic medical center, in partnership with hospital leadership and legal counsel, which can be modeled by other medical centers. With high rates of physician burnout and an aging physician population, the United States is facing a looming public health crisis that requires proactive management.

Associations Between Vascular Risk Factor Levels and Cognitive Decline Among Stroke Survivors.

Importance: Incident stroke is associated with accelerated cognitive decline. Whether poststroke vascular risk factor levels are associated with faster cognitive decline is uncertain. Objective: To evaluate associations of poststroke systolic blood pressure (SBP), glucose, and low-density lipoprotein (LDL) cholesterol levels with cognitive decline. Design, Setting, and Participants: Individual participant data meta-analysis of 4 US cohort studies (conducted 1971-2019). Linear mixed-effects models estimated changes in cognition after incident stroke. Median (IQR) follow-up was 4.7 (2.6-7.9) years. Analysis began August 2021 and was completed March 2023. Exposures: Time-dependent cumulative mean poststroke SBP, glucose, and LDL cholesterol levels. Main Outcomes and Measures: The primary outcome was change in global cognition. Secondary outcomes were change in executive function and memory. Outcomes were standardized as t scores (mean [SD], 50 [10]); a 1-point difference represents a 0.1-SD difference in cognition. Results: A total of 1120 eligible dementia-free individuals with incident stroke were identified; 982 (87.7%) had available covariate data and 138 (12.3%) were excluded for missing covariate data. Of the 982, 480 (48.9%) were female individuals, and 289 (29.4%) were Black individuals. The median age at incident stroke was 74.6 (IQR, 69.1-79.8; range, 44.1-96.4) years. Cumulative mean poststroke SBP and LDL cholesterol levels were not associated with any cognitive outcome. However, after accounting for cumulative mean poststroke SBP and LDL cholesterol levels, higher cumulative mean poststroke glucose level was associated with faster decline in global cognition (-0.04 points/y faster per each 10-mg/dL increase [95% CI, -0.08 to -0.001 points/y]; P = .046) but not executive function or memory. After restricting to 798 participants with apolipoprotein E4 (APOE4) data and controlling for APOE4 and APOE4 × time, higher cumulative mean poststroke glucose level was associated with a faster decline in global cognition in models without and with adjustment for cumulative mean poststroke SBP and LDL cholesterol levels (-0.05 points/y faster per 10-mg/dL increase [95% CI, -0.09 to -0.01 points/y]; P = .01; -0.07 points/y faster per 10-mg/dL increase [95% CI, -0.11 to -0.03 points/y]; P = .002) but not executive function or memory declines. Conclusions and Relevance: In this cohort study, higher poststroke glucose levels were associated with faster global cognitive decline. We found no evidence that poststroke LDL cholesterol and SBP levels were associated with cognitive decline.

Longitudinal associations of anticholinergic medications on cognition and possible mitigating role of physical activity.

BACKGROUND: Many older adults take at least one prescription medication with anticholinergic (ACH) activity, which can impact the central nervous system and can lead to cognitive decline and impairment especially in an aging population susceptible to cognitive changes. We examined this relationship between ACH burden and cognitive function in middle-aged and older adults. We further determined if increased activity levels mitigated the relationships between ACH burden and cognition. METHODS: Data from The Reasons for Geographic and Racial Differences in Stroke project were used. We included 20,575 adults aged ≥45 years with longitudinal cognitive testing. The anticholinergic cognitive burden (ACB) scale was used to assess for ACH use and overall burden. Cognitive data included an overall composite score, a memory, and verbal fluency composites. Mixed effects models were conducted to determine if cognitive function worsened over time for participants with higher ACB (>3) scores. The full model adjusted for age, sex, race, education, diabetes, hypertension, cardiovascular disease, congestive heart failure, and dyslipidemia, self-reported physical activity (PA) and depressive symptoms. RESULTS: A significant relationship between ACH burden and composite cognitive scores was found (p = <0.001), with those with higher ACB showing more rapid cognitive decline over time. There was an effect of age for participants with higher ACB (>3) scores and ACB as a continuous variable. Baseline PA level was associated with less cognitive decline over time and this effect was greater in older cohorts. CONCLUSIONS: We observed an effect of ACHs on cognition in adults ≥45 years old that worsened with age. ACH users showed more cognitive effects, whereas PA emerged as a possible mitigating factor.

Cortical Thinning in High-Grade Asymptomatic Carotid Stenosis.

BACKGROUND AND PURPOSE: High-grade carotid artery stenosis may alter hemodynamics in the ipsilateral hemisphere, but consequences of this effect are poorly understood. Cortical thinning is associated with cognitive impairment in dementia, head trauma, demyelination, and stroke. We hypothesized that hemodynamic impairment, as represented by a relative time-to-peak (TTP) delay on MRI in the hemisphere ipsilateral to the stenosis, would be associated with relative cortical thinning in that hemisphere. METHODS: We used baseline MRI data from the NINDS-funded Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis-Hemodynamics (CREST-H) study. Dynamic contrast susceptibility MR perfusion-weighted images were post-processed with quantitative perfusion maps using deconvolution of tissue and arterial signals. The protocol derived a hemispheric TTP delay, calculated by subtraction of voxel values in the hemisphere ipsilateral minus those contralateral to the stenosis. RESULTS: Among 110 consecutive patients enrolled in CREST-H to date, 45 (41%) had TTP delay of at least 0.5 seconds and 9 (8.3%) subjects had TTP delay of at least 2.0 seconds, the maximum delay measured. For every 0.25-second increase in TTP delay above 0.5 seconds, there was a 0.006-mm (6 micron) increase in cortical thickness asymmetry. Across the range of hemodynamic impairment, TTP delay independently predicted relative cortical thinning on the side of stenosis, adjusting for age, sex, hypertension, hemisphere, smoking history, low-density lipoprotein cholesterol, and preexisting infarction (P=0.032). CONCLUSIONS: Our findings suggest that hemodynamic impairment from high-grade asymptomatic carotid stenosis may structurally alter the cortex supplied by the stenotic carotid artery.

Silent Brain Infarction, Delirium, and Cognition in Three Invasive Cardiovascular Procedures: a Systematic Review.

Silent brain infarctions (SBIs) are brain lesions noted on neuroimaging that are not associated with clinical symptoms. SBIs are associated with a number of vascular risk factors and are common following invasive cardiovascular procedures such as atrial fibrillation (AF) ablation, coronary artery bypass graft (CABG), and transcatheter aortic valve replacement (TAVR). Although not eliciting signs of clinical stroke, SBIs are associated with increased frailty, and motor and mood features. Less is known, however, about the relationship between SBI, cognition, and delirium following invasive cardiac procedures and most investigations into these relationships have been reported in large-scale epidemiological studies. In the current paper, we conducted a systematic review to evaluate evidence of a relationship between SBI, delirium, and cognitive decline following CABG, AF ablation, and TAVR. Twenty studies met inclusion criteria. In general, our review identified conflicting results for each cardiac procedure, with some studies suggesting a relationship between SBI, cognitive impairment, and delirium, whereas others showed no relationship between SBI, cognitive impairment, and delirium. Potential reasons for this discrepancy as well as suggestions for future research are discussed.

Formal Neuropsychological Testing: Test Batteries, Interpretation, and Added Value in Practice.

Neuropsychologists evaluate patients for cognitive decline and dementia, using validated psychometric tests, along with behavioral observation, record review, clinical interview, and information about psychological functioning, to evaluate brain-behavior relationships and aid in differential diagnosis and treatment planning. Also considered are premorbid functioning, education, sex, socioeconomic status, primary language, culture, and race-related health disparities when selecting tests, interpreting performance, and providing a diagnostic impression. Neuropsychologists provide diagnostic clarity, explain symptoms and likely disease course to patients and family members, and assist the family with future planning, behavioral management strategies, and ways to mitigate caregiver burden.

Educational Intervention in the Emergency Department to Address Disparities in Stroke Knowledge.

OBJECTIVES: In the United States, Black individuals have higher stroke incidence and mortality when compared to white individuals and are also at risk of having lower stroke knowledge and awareness. With the need to implement focused interventions to decrease stroke disparities, the objective of this study is to evaluate the feasibility and efficacy of an emergency department-based educational intervention aimed at increasing stroke awareness and preparedness among a disproportionately high-risk group. MATERIALS AND METHODS: Over a three-month timeframe, an emergency department-based, prospective educational intervention was implemented for Black patients in an urban, academic emergency department. All participants received stroke education in the forms of a video, written brochure and verbal counseling.  Stroke knowledge was assessed pre-intervention, immediately post-intervention, and at one-month post-intervention. RESULTS: One hundred eighty-five patients were approached for enrollment, of whom 100 participants completed the educational intervention as well as the pre- and immediate post- intervention knowledge assessments. Participants demonstrated increased stroke knowledge from baseline knowledge assessment (5.35 ± 1.97) at both immediate post-intervention (7.66 ± 2.42, p < .0001) and one-month post-intervention assessment (7.21 ± 2.21, p < .0001). CONCLUSIONS: Emergency department-based stroke education can result in improved knowledge among this focused demographic. The emergency department represents a potential site for educational interventions to address disparities in stroke knowledge.

Baseline Cognitive Impairment in Patients With Asymptomatic Carotid Stenosis in the CREST-2 Trial.

BACKGROUND AND PURPOSE: Studies of carotid artery disease have suggested that high-grade stenosis can affect cognition, even without stroke. The presence and degree of cognitive impairment in such patients have not been reported and compared with a demographically matched population-based cohort. METHODS: We studied cognition in 1000 consecutive CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) patients, a treatment trial for asymptomatic carotid disease. Cognitive assessment was after randomization but before assigned treatment. The cognitive battery was developed in the general population REGARDS Study (Reasons for Geographic and Racial Differences in Stroke), involving Word List Learning Sum, Word List Recall, and Word List fluency for animal names and the letter F. The carotid stenosis patients were >45 years old with ≥70% asymptomatic carotid stenosis and no history of prevalent stroke. The distribution of cognitive performance for the patients was standardized, accounting for age, race, and education using performance from REGARDS, and after further adjustment for hypertension, diabetes, dyslipidemia, and smoking. Using the Wald Test, we tabulated the proportion of Z scores less than the anticipated deviate for the population-based cohort for representative percentiles. RESULTS: There were 786 baseline assessments. Mean age was 70 years, 58% men, and 52% right-sided stenosis. The overall Z score for patients was significantly below expected for higher percentiles (P<0.0001 for 50th, 75th, and 95th percentiles) and marginally below expected for the 25th percentile (P=0.015). Lower performance was attributed largely to Word List Recall (P<0.0001 for all percentiles) and for Word List Learning (50th, 75th, and 95th percentiles below expected, P≤0.01). The scores for left versus right carotid disease were similar. CONCLUSIONS: Baseline cognition of patients with severe carotid stenosis showed below normal cognition compared to the population-based cohort, controlling for demographic and cardiovascular risk factors. This cohort represents the largest group to date to demonstrate that poorer cognition, especially memory, in this disease. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02089217.

A Primary Care Agenda for Brain Health: A Scientific Statement From the American Heart Association.

A healthy brain is critical for living a longer and fuller life. The projected aging of the population, however, raises new challenges in maintaining quality of life. As we age, there is increasing compromise of neuronal activity that affects functions such as cognition, also making the brain vulnerable to disease. Once pathology-induced decline begins, few therapeutic options are available. Prevention is therefore paramount, and primary care can play a critical role. The purpose of this American Heart Association scientific statement is to provide an up-to-date summary for primary care providers in the assessment and modification of risk factors at the individual level that maintain brain health and prevent cognitive impairment. Building on the 2017 American Heart Association/American Stroke Association presidential advisory on defining brain health that included "Life's Simple 7," we describe here modifiable risk factors for cognitive decline, including depression, hypertension, physical inactivity, diabetes, obesity, hyperlipidemia, poor diet, smoking, social isolation, excessive alcohol use, sleep disorders, and hearing loss. These risk factors include behaviors, conditions, and lifestyles that can emerge before adulthood and can be routinely identified and managed by primary care clinicians.

Predicting post-LVAD outcome: Is there a role for cognition?

BACKGROUND: Cognition has been found to influence risk of stroke and death for a variety of patient groups but this association has not been examined in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implant. We aimed to study the relationship between cognition, stroke, and death in a cohort of patients who received LVAD therapy. It was hypothesized that cognitive test results obtained prior to LVAD placement would predict stroke and death after surgery. METHODS: We retrospectively identified 59 HF patients who had cognitive assessment prior to LVAD placement. Cognitive assessment included measures of attention, memory, language, and visualmotor speed and were averaged to produce one z-score variable per patient. Survival analyses, censored for transplant, evaluated predictors for stroke and death within a follow-up period of 900 days. RESULTS: For patients with stroke or death during the follow up period, the average cognitive z-score predicted post-LVAD stroke (HR = 0.513, 95% CI = 0.31-0.86, p = 0.012) and death (HR = 0.166, 95% CI = 0.06-0.47, p = 0.001). Cognitive performances were worse in the patients who suffered stroke or died. No other variable predicted stroke and death within the follow up period when the cognitive variable was in the model. CONCLUSION: Cognitive performance was predictive of post-LVAD risk of stroke and death. Results are consistent with findings from other studies in non-LVAD samples and may reflect early signs of neurologic vulnerability. Further studies are needed to clarify the relationship between cognition and LVAD outcomes in order to optimize patient selection, management, and advanced care planning.

Gait Measures at Admission to Inpatient Rehabilitation after Ischemic Stroke Predict 3-Month Quality of Life and Function.

BACKGROUND: Ischemic stroke can impact a patient's quality of life, but the extent is unknown. OBJECTIVE: To evaluate the association between gait measures during inpatient rehabilitation with quality-of-life scores and function at 3 months in patients with stroke. SETTING: Single-Center inpatient rehabilitation facility. PARTICIPANTS: Eight five patients with ischemic stroke. METHODS: A 6-Minute Walk Test and a 10-Meter Walk Test were recorded on admission to rehabilitation. We analyzed the association between gait function at rehabilitation and 3-month quality of life and poor functional outcome (modified Rankin Scale score >2) using multivariable logistic regression. MAIN OUTCOME: Measures 3-month health related quality of life. RESULTS: Eighty-five patients (mean age 68.3 14.9 years; 54.3% male) were enrolled. In adjusted analyses, an increase of 0.31 m/s (ie, 1 SD) on the 10-meter walk test was linked with a decreased odds of impaired lower extremity quality of life by 94% (odds ratio [OR] 0.06, 95% confidence interval [CI] 0.01-0.52; P =.01), and decreased odds of poor functional outcome by 98% (OR 0.02, 95% CI <0.01-0.47; P =.01). For the 6-minute walk test, an increase of 109.5 meters (ie, 1 SD) was linked with decreased odds of having impaired lower extremity quality of life by 1% (OR 0.99, 95% CI 0.98-1.00; P < .01) and poor functional outcome by 1% (OR 0.99, 95% CI 0.99-1.00; P = .04). CONCLUSION: Gait measurements at rehabilitation can predict 3-month lower extremity quality of life and function.

Cognitive Impairment Correlates Linearly with Mean Flow Velocity by Transcranial Doppler below a Definable Threshold.

INTRODUCTION: Low cerebral blood flow can affect cognition in patients with high-grade asymptomatic internal carotid artery stenosis. Current clinical algorithms use stroke risk to determine which patients should undergo revascularization without considering cognitive decline. Although correlations between low-flow and cognitive impairment have been reported, it is not known whether a threshold exists below which such a correlation expresses itself. Such information would be critical in treatment decisions about whether to intervene in patients with high-grade carotid artery stenosis who are at risk for cognitive decline. OBJECTIVE: To determine how reduced blood flow correlates with lower cognitive scores. METHODS: Patients with ≥80% unilateral internal carotid artery stenosis with no history of stroke were recruited from inpatient and outpatient practices at a single, large, comprehensive stroke center. Patients underwent bilateral insonation of middle cerebral arteries with standard 2-Hz probes over the temporal windows with transcranial Doppler. Cognitive assessments were performed by an experienced neuropsychologist using a cognitive battery comprising 14 standardized tests with normative samples grouped by age. Z-scores were generated for each test and averaged to obtain a composite Z-score for each patient. Multivariable linear regression examined associations between mean flow velocity (MFV) and composite Z-score, adjusting for age, education, and depression. The Davies test was used to determine if there was a breakpoint for a non-zero difference in slope of a segmented relationship over the range of composite Z-score values. RESULTS: Forty-two patients with unilateral high-grade internal carotid artery stenosis without stroke were enrolled (26 males, age = 74 ± 9 years, education = 16 ± 3 years). Average composite Z-score was -0.31 SD below the age-specific normative mean (range -2.8 to +1.2 SD). In linear regression adjusted for age, education, and depression, MFV correlated with cognitive Z-score (ß = 0.308, p = 0.043). A single breakpoint in the range of composite Z-scores was identified at 45 cm/s. For MFV <45 cm/s, Z-score decreased 0.05 SD per cm/s MFV (95% CI: 0.01-0.10). For MFV >45 cm/s, Z-score change was nonsignificant (95% CI: -0.07 to 0.05). CONCLUSIONS: In high-grade, asymptomatic carotid artery stenosis, cognitive impairment correlated linearly with lower flow in the hemisphere fed by the occluded internal carotid artery, but only below a threshold of MFV = 45 cm/s. Identifying a hemodynamic threshold for cognitive decline using a simple, noninvasive method may influence revascularization decision-making in otherwise "asymptomatic" carotid disease.

Spatial coefficient of variation of arterial spin labeling MRI as a cerebrovascular correlate of carotid occlusive disease.

Clinical interpretation of arterial spin labeling (ASL) perfusion MRI in cerebrovascular disease remains challenging mainly because of the method's sensitivity to concomitant contributions from both intravascular and tissue compartments. While acquisition of multi-delay images can differentiate between the two contributions, the prolonged acquisition is prone to artifacts and not practical for clinical applications. Here, the utility of the spatial coefficient of variation (sCoV) of a single-delay ASL image as a marker of the intravascular contribution was evaluated by testing the hypothesis that sCoV can detect the effects of differences in label arrival times between ipsi- and contra-lateral hemispheres even in the absence of a hemispheric difference in CBF. Hemispheric lateralization values for sCoV and CBF were computed from ASL images acquired on 28 patients (age 73.9 ± 10.2 years, 8 women) with asymptomatic unilateral carotid occlusion. The results showed that sCoV lateralization predicted the occluded side with 96.4% sensitivity, missing only 1 patient. In contrast, the sensitivity of the CBF lateralization was 71.4%, with 8 patients showing no difference in CBF between hemispheres. The findings demonstrate the potential clinical utility of sCoV as a cerebrovascular correlate of large vessel disease. Using sCoV in tandem with CBF, vascular information can be obtained in image processing without the need for additional scan-time.