Association of Intracranial Atherosclerotic Disease With Brain β-Amyloid Deposition: Secondary Analysis of the ARIC Study

Importance

Intracranial atherosclerotic disease (ICAD) is an important cause of stroke and has also been recently identified as an important risk factor for all-cause dementia, but the mechanism of its association with cognitive performance is not fully understood.

Objective

To test the hypothesis that ICAD is associated with cerebral β-amyloid deposition as a marker of Alzheimer disease.

Design, Setting, and Participants

This cross-sectional analysis of data collected from August 2011 through November 2014 was a community-based cohort study conducted in 3 US communities. Of 346 adults without dementia aged 70 to 90 years who were sequentially recruited from 3 of 4 sites of the larger Atherosclerosis Risk in Communities study into a study of brain florbetapir positron emission tomography (ARIC-PET), 300 met inclusion criteria. A total of 589 were approached about recruitment, of whom 346 (58.7%) consented (the remainder either met exclusion criteria for ARIC-PET or refused to participate). Data were analyzed from July 2017 through October 2019.

Exposures

Intracranial atherosclerotic disease presence, frequency, and extent of stenosis, by high-resolution vessel wall magnetic resonance imaging.

Main Outcomes and Measures

Global cortical standardized uptake value ratio (SUVR) of greater than 1.2 as measured by florbetapir PET. Models were conducted using logistic regression methods. In secondary analyses, we tested effect modifications by apolipoprotein E ε4 genotype with interaction terms and in stratified models and evaluated regional patterns of associations.

Results

In 300 participants (mean [SD] age, 76 [5] years; 132 African American individuals [44%], 167 women [56%], and 94 carriers of at least 1 apolipoprotein E ε4 allele [31%]), ICAD was found in 105 participants (35%) and mean (SD) SUVR was higher in individuals with vs without intracranial plaques (1.34 [0.29] vs 1.27 [0.23]; P = .03). In adjusted models, ICAD presence (plaque presence [adjusted odds ratio (aOR), 1.20; 95% CI, 0.69-2.07] and frequency [aOR, 1.10; 95% CI, 0.96-1.26]) was not associated significantly with elevated SUVR in the total sample. Furthermore, modest stenosis of the intracranial vessels (defined as >50% stenosis) was not associated with elevated SUVR (aOR, 2.33; 95% CI, 0.82-6.60).

Conclusions and Relevance

In this community-based cohort of adults without dementia, intracranial atherosclerotic plaque or stenosis was not associated with brain β-amyloid deposition.

Adherence to the Healthy Eating Index-2015 (HEI-2015), Cognitive Function, and Incident Dementia in the Atherosclerosis Risk in Communities (ARIC) Study (OR32-01-19)

Objectives

The Healthy Eating Index-2015 (HEI-2015) score was created to measure adherence to the 2015–2020 Dietary Guidelines for Americans. It remains undetermined whether adherence to the newly released guidelines is associated with improved cognitive function or reduced incident dementia.

Methods

We assessed the diet of 13,632 participants from the Atherosclerosis Risk in Communities (ARIC) study who were recruited from 1987–1989 and calculated their HEI-2015 scores (0–100) using responses to food frequency questionnaires. Baseline cognitive function was assessed using the Delayed Word Recall, Digit Symbol Substitution, and Word Fluency Tests. We used linear regression models to assess the cross-sectional association of adherence to HEI-2015 and standardized cognitive test scores. Incident dementia was ascertained through the end of 2017. Dementia status at the ARIC Neurocognitive Study visits (2011–13, 2016–17) was determined by detailed neurocognitive battery, informant interviews, and adjudicated review as well as through dementia screening by phone interview and informant review, or by ICD-9 dementia code for a hospitalization or death. We used Cox proportional hazards regression models adjusted for demographic, lifestyle, genetic, and clinical covariates to estimate the association between HEI-2015 score and risk of incident dementia.

Results

Compared to participants in the lowest quintile of HEI-2015 score, participants in the highest quintile scored higher on the Digit Symbol Substitution Test (β: 0.07, 95% CI: 0.03 to 0.11, P for trend < 0.001), Word Fluency Test (β: 0.07, 95% CI: 0.02 to 0.12, P for trend < 0.001) and global cognitive score (β: 0.05, 95% CI: 0.01 to 0.10, P for trend = 0.003) (Table). In total, there were 2354 cases of incident dementia over a median follow-up of 25 years. Compared to participants in the lowest quintile, participants in other quintiles had a lower risk of incident dementia after adjusting for covariates. Participants in the highest quintile had a 19% lower risk of dementia compared to those in the lowest (HR: 0.81, 95% CI: 0.71–0.93, P for trend = 0.01).

Conclusions

Higher adherence to the 2015–2020 Dietary Guidelines for Americans was associated with higher baseline cognitive function and lower risk of incident dementia.

Funding Sources

NHLBI, NIDDK, NIA, NINDS, NIH, HHS.

Supporting Tables, Images and/or Graphs

Abstract WP514: Association Between Statin Utilization and Short- and Long-term Mortality Among Patients With TIA and Ischemic Stroke

Introduction: Current hyperlipidemia guidelines recommend prescribing a moderate/high potency statin after a cerebrovascular event. We sought to compare 30-day and 1-year mortality rates among patients who were discharged on moderate/high potency statin versus those discharged on low dose or no statin.

Methods: Administrative data from 10,871 Veterans presenting to one of 134 Veterans Health Administration facilities with a stroke/TIA in fiscal year 2011 were analyzed. Statin medication was assessed two times: at the time of admission and within 7 days of discharge. Each time point was categorized as low, moderate, or high potency, thus creating six mutually categories. Patients were considered at goal if they were prescribed moderate/high-potency statin at baseline and within 7-days of discharge. Deintensification occurred when patients were at goal at baseline but not at the second-time point. We used multivariate logistic regressions to compare the 30-day and 1-year mortality among statin treatment groups, controlling for patients’ demographic characteristics and medical comorbidities.

Results: Among 9,380 eligible patients (86.3%), 79.5 % (n=7,456) were prescribed statins by the 7-days post-discharge, with a majority (59.2%) of patients receiving moderate/high potency statins. The multivariate regression analysis did not identify a significant difference in 30-day or 1-year post-event mortality among patients receiving moderate/high potency statins at both time points or at the second-time point (purple and orange shading in the table). Statin deintensification or never receiving a statin was associated with 1.26 to 1.93 higher odds of mortality as compared to participants who were on medium or high potency statins.

Conclusions: Prescribing moderate/high potency statins soon after a cerebrovascular event is associated with reduced short- and long-term mortality, whereas statin deintensification is associated with worse outcomes. This data supports current secondary stroke prevention guidelines. Providers should be aware that deintensifying statin therapy is associated with worse post-stroke/TIA outcomes.

Safety of intravenous alteplase within 4.5 hours for patients awakening with stroke symptoms

Background

Up to 25% of acute stroke patients first note symptoms upon awakening. We hypothesized that patients awaking with stroke symptoms may be safely treated with intravenous alteplase (IV tPA) using non-contrast head CT (NCHCT), if they meet all other standard criteria.

Methods

The SAfety of Intravenous thromboLytics in stroke ON awakening (SAIL ON) was a prospective, open-label, single treatment arm, pilot safety trial of standard dose IV tPA in patients who presented with stroke symptoms within 0–4.5 hours of awakening. From January 30, 2013, to September 1, 2015, twenty consecutive wakeup stroke patients selected by NCHCT were enrolled. The primary outcome was symptomatic intracerebral hemorrhage (sICH) in the first 36 hours. Secondary outcomes included NIH stroke scale (NIHSS) at 24 hours; and modified Rankin Score (mRS), NIHSS, and Barthel index at 90 days.

Results

The average age was 65 years (range 47–83); 40% were women; 50% were African American. The average NIHSS was 6 (range 4–11). The average time from wake-up to IV tPA was 205 minutes (range 114–270). The average time from last known well to IV tPA was 580 minutes (range 353–876). The median mRS at 90 days was 1 (range 0–5). No patients had sICH; two of 20 (10%) had asymptomatic ICH on routine post IV tPA brain imaging.

Conclusions

Administration of IV tPA was feasible and may be safe in wakeup stroke patients presenting within 4.5 hours from awakening, screened with NCHCT. An adequately powered randomized clinical trial is needed.

Clinical trial registration

ClinicalTrials.gov NCT01643902.

Abstract 151: Intracranial Atherosclerotic Disease and Brain Amyloid Deposition: The ARIC Study

Background: Increasing evidence points to intracranial atherosclerosis as a risk factor not only for stroke but also for dementia, but whether it is linked to Alzheimer’s disease-specific pathology itself is less understood. In the community-based Atherosclerosis Risk in Communities (ARIC) study, we evaluated the cross-sectional association between intracranial atherosclerosis and cerebral amyloid deposition, in nondemented participants.

Methods: In 2011-2014, a subset of participants from the ARIC Neurocognitive Study underwent both a brain MRI, including high-resolution vessel wall imaging, and florbetapir PET, as a marker of amyloid deposition. We analyzed the association between elevated amyloid (defined as a global cortical florbetapir standardized uptake value ratio (SUVR)>1.2) and intracranial arterial plaque presence, frequency, and extent of stenosis, with adjustment for demographic and vascular risk factors. We tested effect modification by APOE ε4 genotype.

Results: In 300 participants (mean age of 76y, 44% African-American, 56% female, 31% carriers of at least one APOE ε4 allele), intracranial plaque was found in 105 (35%) participants. Mean SUVR was higher in individuals with vs without plaque (1.34 ± 0.29 vs 1.27 ± 0.23, p=0.03). In adjusted models, plaque presence was not associated significantly with elevated SUVR in the total sample, nor was number of plaques. Associations between plaque presence and extent were generally stronger in APOE ε4 carriers than noncarriers (p<0.05 for interaction for some plaque features; see Table).

Conclusions: Although intracranial arterial plaque or stenosis was not definitively associated with brain amyloid in this sample of nondemented older adults, associations with brain amyloid appeared stronger in carriers of an APOE ε4 allele, consistent with studies demonstrating a similar relationship as that seen with other more traditionally measured vascular risk factors.

Abstract 101: Pioglitazone Prevents Stroke in Patients With a Recent TIA or Ischemic Stroke: a Secondary Analysis of the IRIS Trial

Background: The Insulin Resistance Intervention after Stroke (IRIS) trial demonstrated that pioglitazone reduced risk for the composite outcome of stroke or myocardial infarction among non-diabetic patients with insulin resistance and a recent ischemic stroke or TIA. The drug also reduced risk for stroke alone, but the finding did not reach statistical significance. During the trial, the Data & Safety Monitoring Board approved a secondary analysis using updated 2013 consensus criteria for ischemic stroke. Our objective is to examine the effect of pioglitazone, compared with placebo, on risk for stroke alone defined by the 2013 criteria.

Methods: Participants were randomized to pioglitazone (45 mg per day target dose) or placebo and followed for a maximum of 5 years. An independent committee, blinded to treatment assignments, adjudicated all potential stroke outcomes. The primary outcome was any stroke, but we also examined type of stroke (ischemic or hemorrhagic), and ischemic stroke subtype.

Results: Among 3876 IRIS participants (mean age 63 years, 65% male), 377 stroke events were observed in 319 participants over a median follow-up of 4.8 years (329 stroke events by the original trial criteria plus 48 new events identified by applying the 2013 stroke criteria). Pioglitazone was associated with a 25% risk reduction for any stroke (8.0% compared to 10.7%; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.60 to 0.94) and a 28% reduction for ischemic stroke (HR, 0.72; 95% CI, 0.57 to 0.9) but not hemorrhagic stroke (HR, 1.00; 95% CI, 0.50-2.00). Pioglitazone was associated with fewer numbers of all subtypes of ischemic stroke, but the difference from placebo reached or approached significance only for lacunar (HR, 0·46; 95% CI, 0·22-0·93; p=0·03) and large vessel (HR, 0·59; 95% CI, 0·33-1·04; p=0·07) strokes.

Conclusion: Pioglitazone prevents recurrent ischemic stroke among non-diabetic patients with insulin resistance.

Abstract TMP14: Thrombolysis in Ischemic Stroke Patients with Prior History of Intracranial Hemorrhage

Introduction: The recently updated FDA label for intravenous recombinant tissue plasminogen activator (IV-tPA) for stroke removed a history of intracranial hemorrhage (ICH) as a contraindication. The safety of IV-tPA in patients with prior ICH is not well-established, as only a few cases are described in the literature. We sought to determine (1) the proportion of patients treated with IV-tPA for stroke who have prior history of ICH and (2) whether this circumstance influences in-hospital mortality.

Methods: Using administrative claims data on admissions to California hospitals between 2005-2011, we performed a cross-sectional study of adult patients admitted with acute ischemic stroke who received IV-tPA. ICD-9-CM codes were used to identify these patients and to ascertain prior diagnoses of (1) ICH, including intracerebral hemorrhage (IPH), subarachnoid hemorrhage (SAH), subdural hematoma (SDH), or epidural hematoma (EDH); and (2) existing comorbidities. We used multivariable logistic regression to model the odds of in-hospital mortality as a function of prior ICH, after adjusting for potential confounders.

Results: Among 372,167 patients admitted with acute ischemic stroke during the study period, 10,882 (2.9%) received IV-tPA (mean age 70.6 [SD 14.6], female 5,614 [54.8%]). Among these, 268 (2.5%) patients had a diagnosis of prior ICH on admission, including IPH 194 (1.8%), SAH 81 (0.7%), SDH 9 (0.1%) and EDH 2 (0.0%). In-hospital mortality was 12.2% overall, 11.7% for patients without prior ICH, and 31.0% for patients with prior ICH (p<0.001). In adjusted analyses, prior ICH remained independently associated with in-hospital mortality (OR 3.48, 95% CI 2.63-4.56, p<0.001), as did most ICH subtypes, including IPH (OR 2.97, CI 2.12-4.09, P<0.001), SAH (OR 3.15, CI 1.89-5.12, P<0.001), and SDH (OR 4.27, CI 0.87-16.95, P=0.047).

Conclusions: In California between 2005-2011, 2.5% of acute ischemic stroke patients who received thrombolysis had a prior diagnosis of ICH. In this population, a history of ICH was associated with mortality; this association held true for ICH subtypes IPH, SAH and SDH. Further observational and experimental studies are needed to confirm the observed associations.

Pioglitazone Prevents Stroke in Patients With a Recent Transient Ischemic Attack or Ischemic Stroke: A Planned Secondary Analysis of the IRIS Trial (Insulin Resistance Intervention After Stroke)

BACKGROUND

The IRIS trial (Insulin Resistance Intervention after Stroke) demonstrated that pioglitazone reduced the risk for a composite outcome of stroke or myocardial infarction among nondiabetic patients with insulin resistance and a recent stroke or transient ischemic attack. The current planned secondary analysis uses updated 2013 consensus criteria for ischemic stroke to examine the effect of pioglitazone on stroke outcomes.

METHODS

Participants were randomly assigned to receive pioglitazone (45 mg/d target dose) or placebo within 180 days of a qualifying ischemic stroke or transient ischemic attack and were followed for a maximum of 5 years. An independent committee, blinded to treatment assignments, adjudicated all potential stroke outcomes. Time to first stroke event was compared by treatment group, overall and by type of event (ischemic or hemorrhagic), using survival analyses and Cox proportional hazards models.

RESULTS

Among 3876 IRIS participants (mean age, 63 years; 65% male), 377 stroke events were observed in 319 participants over a median follow-up of 4.8 years. Pioglitazone was associated with a reduced risk for any stroke at 5 years (8.0% in comparison with 10.7% for the placebo group; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.60-0.94; log-rank P=0.01). Pioglitazone reduced risk for ischemic strokes (HR, 0.72; 95% CI, 0.57-0.91; P=0.005) but had no effect on risk for hemorrhagic events (HR, 1.00; 95% CI, 0.50-2.00; P=1.00).

CONCLUSIONS

Pioglitazone was effective for secondary prevention of ischemic stroke in nondiabetic patients with insulin resistance.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00091949.

Neglect performance in acute stroke is related to severity of white matter hyperintensities

BACKGROUND

Leukoaraiosis and its progression have longitudinally been associated with cognitive decline and dementia. Its role in acute cognitive function and response to acute cerebral ischemia is less well understood. We evaluated whether the presence and extent of leukoaraiosis, or white matter hyperintensities (WMH), had an impact on performance on tests of hemispatial neglect in acute ischemic stroke patients.

METHODS

A series of 206 acute ischemic right-hemispheric stroke patients at Johns Hopkins Hospital underwent brain MRI and cognitive assessment for hemispatial neglect within 5 days of symptom onset. Error rates on neglect tests were evaluated, as were dichotomized measures of neglect, including 'any', 'severe' or 'worst' neglect, based on Z scores of at least 2 on 1, 2 or 3 tests (respectively) within a neglect battery. Acute infarct volumes were measured on diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery images were reviewed for WMH, using the Cardiovascular Health Study (CHS) rating scale (ranging from 0 to 9, with 9 being 'most extensive'). Linear regression was used to evaluate 'error rate on neglect test' as the dependent variable, as a measure of neglect severity, with 'WMH category' as the primary independent variable, including adjustment for age, sex, race and infarct volume (on DWI). Logistic regression was used to evaluate a binary definition of neglect (defined as above) relative to the same independent variable and covariates.

RESULTS

Each 1-point increase in CHS leukoaraiosis category was associated with 1.20-fold increased odds (95% CI: 1.00-1.43) of having any neglect, 1.23-fold increased odds (95% CI: 1.02-1.49) of having severe neglect and 1.33-fold increased odds of having worst neglect (95% CI: 1.01-1.76) after adjusting for infarct volume, age, sex and race. Increasing age and infarct size were also important predictors of neglect severity, with a 2.36% higher error rate (95% CI: 0.75-3.97%) on the line cancellation test associated with each category increase in CHS score; similar results were found for each of the neglect tests. Line cancellation neglect scores were worse in individuals with both severe WMH and large infarcts (p interaction, unadjusted=0.03).

CONCLUSIONS

More severe leukoaraiosis is associated with more hemispatial neglect after acute ischemic stroke, independent of infarct volume, age and sex. We found not only more frequent neglect but also more severe neglect, based on error rates on neglect tests, in individuals with increasing leukoaraiosis. This emphasizes the importance of preexisting brain microvascular disease in outcomes of stroke patients. Further studies of the possible mechanism behind this association are needed.