T2 Protect AD: Achieving a rapid recruitment timeline in a multisite clinical trial for individuals with mild to moderate Alzheimer's disease

Introduction

The reporting of approaches facilitating the most efficient and timely recruitment of Alzheimer's disease (AD) patients into pharmacologic trials is fundamental to much-needed therapeutic progress.

Methods

T2 Protect AD (T2), a phase 2 randomized placebo-controlled trial of troriluzole in mild to moderate AD, used multiple recruitment strategies.

Results

T2 exceeded its recruitment target, enrolling 350 participants between July 2018 and December 2019 (randomization rate: 0.87 randomizations/site/month, or 3-fold greater than recent trials of mild to moderate AD). The vast majority (98%) of participants were enrolled during a 10-month window of intense promotion in news media, TV and radio advertisements, and social media. The distribution of primary recruitment sources included: existing patient lists at participating sites (72.3%), news media (12.3%), physician referral (6.0%), word of mouth (3.1%), and paid advertising (2.9%).

Discussion

The rapid recruitment of participants with mild to moderate AD was achieved through a range of approaches with varying success.

Using Biomarkers to Predict Memantine Effects in Alzheimer's Disease: A Proposal and Proof-Of-Concept Demonstration

Memantine's benefits in Alzheimer's disease (AD) are modest and heterogeneous. We tested the feasibility of using sensitivity to acute memantine challenge to predict an individual's clinical response. Eight participants completed a double-blind challenge study of memantine (placebo versus 20 mg) effects on autonomic, subjective, cognitive, and neurophysiological measures, followed by a 24-week unblinded active-dose therapeutic trial (10 mg bid). Study participation was well tolerated. Subgroups based on memantine sensitivity on specific laboratory measures differed in their clinical response to memantine, some by large effect sizes. It appears feasible to use biomarkers to predict clinical sensitivity to memantine.

Mapping a Reliable Stroke Onset Time Course Using Signal Intensity on DWI Scans

BACKGROUND AND PURPOSE

Identifying a last known well (LKW) time surrogate for acute stroke is vital to increase stroke treatment. Diffusion-weighted imaging (DWI) signal intensity initially increases from onset of stroke but mapping a reliable time course to the signal intensity has not been demonstrated.

METHODS

We retrospectively reviewed stroke code patients between 1/2016 and 6/2017 from the prospective; Institutional review board (IRB) approved University of California San Diego Stroke Registry. Patients who had magnetic resonance imaging of brain from onset, with or without intervention, are included. All ischemic strokes were confirmed and timing from onset to imaging was calculated. Raw DWI intensity is measured using IMPAX software and compared to contralateral side for control for a relative DWI intensity (rDWI). LKW and magnetic resonance imaging (MRI) time were collected by chart review. Correlation is assessed using Pearson correlation coefficient between DWI intensity, rDWI, and time to MRI imaging. 1.5T, 3T, and combined modalities were examined.

RESULTS

Seventy-eight patients were included in this analysis. Overall, there was statistically significant positive correlation (.53, P < .001) between DWI intensity and LKW time irrespective of scanner strength. Using 1.5T analyses, there was good correlation (.46, P < .001). 3T MRI analysis further showed comparatively stronger positive correlation (.66, P < .001).

CONCLUSIONS

There is good correlation between DWI intensity and minutes from onset to MRI. This suggests a time-dependent DWI intensity response and supports the potential use of DWI intensity measurements to extrapolate an LKW time. Further studies are being pursued to increase both experience and generalizability.

Abstract 86: Nationwide Differences in Care and Outcomes of Acute Ischemic Stroke

Background: Acute Ischemic Stroke (AIS) remains a leading cause of mortality and morbidity in United States, and poses a major socio-economic burden. Efforts are underway to standardize systems of care for acute stroke treatment. We aim to assess if, despite the attempts towards standardization, regional difference in stroke care practice pattern, cost and/ or outcomes persist.

Methods: Healthcare Cost and Utilization Project's Nationwide Inpatient Sample database was reviewed from 2002 to 2014. Hospitalizations with AIS were identified using ICD-9-CM codes 433.xx-436, tPA use by procedure code 99.10. Care is determined based on tPA utilization, length of stay, and cost of hospitalization. Outcomes are determined based on discharge disposition (home or facility) and death. These were further analyzed based on regions; Northeast, South, Midwest and West. Multivariate linear regression model and Cochran Armitage trend test used for the analysis.

Results: AIS admissions increased throughout the US, more so in the South. There is an increase in tPA utilization all regions, which is significantly higher in the West compared to other regions. Midwest and South have significantly lower cost of hospitalization compared to West despite having higher length of stay. (Graph).

Conclusion: AIS care is noted to be remarkably non-uniform across the USA. This lack of uniformity seems to affect outcomes. Further studies are required to determine the causation of these findings.

Abstract WP66: Anticoagulant Use is Not Associated With Higher Post tPA Hemorrhagic Conversion

Introduction: Even though tissue plasminogen activator (tPA) has unequivocally shown to improve outcomes in Acute Ischemic stroke (AIS), its utilization remains low due to various concerns/contraindications. Many clinicians are concerned about the risk of hemorrhage after tPA in patients on anti-coagulation (AC). With the rise of AC use, we aimed to explored the relationship between anticoagulation use and hemorrhagic conversions (HC) in patients treated with IV tPA in a large and representative national patient registry.

Method: We analyzed Nationwide Inpatient Sample (NIS) and Healthcare Cost and Utilization Project (HCUP) data for years 2002-2014. We identified AIS with ICD-9-CM codes 433.xx-436, IV tPA with procedure code 99.10, and HC with ICD-9 431. Anticoagulation use was identified by previously validated ICD-9-CM codes. Parametric tests and survey logistic procedure were used to analyze group comparison and multivariate regression.

Results: A total of 264,643 patients with AIS received IV tPA, of which 12,690 (4.8%) were on AC prior to admission. Unadjusted, the frequency of HC was higher among AC group (9.1% v 8.0%; p<0.001). However, after adjusting for confounders with multivariate analysis, there was no difference in HC between AC and ‘not on AC’ group [OR 0.87; 95% Confidence Interval(CI) 0.75-1.01; p=0.071]. Additionally, there was no difference in in-hospital mortality [OR 0.91; 95% CI 0.79-1.05; p=0.178] and discharge to home [OR 1.1; 95% CI 0.99-1.2; p=0.05] among AC and ‘not on AC’ group.

Conclusion: Our study shows, AC use prior to AIS onset is not associated with higher HC with tPA use. Moreover, no significant differences in outcomes were observed in AC and ‘not on AC’ group. Being on AC should not be a prohibitive factor for tPA utilization in AIS patients. Further prospective studies, that includes precise anticoagulant measurements, are required to better understand the relationship between AC use and HC.

Abstract TP59: The Sustained DeyeCOM Sign as a Predictor of Large Vessel Occlusion

Introduction: Rapid imaging in acute stroke is critical and often occurs before full examination. Early, reliable exam findings clarify diagnosis and improve treatment times. Suspected stroke patients typically undergo both acute non-contrast CT and CT Angiogram (CTA). The DeyeCOM sign (conjugate gaze deviation on CT) has been described as a predictor of ischemic stroke with good specificity. In this study, we further evaluate a sustained DeyeCOM sign on both CT and CTA in early prediction of anterior large vessel occlusion (LVO).

Methods: We retrospectively reviewed 46 acute stroke code patients between April and June 2017 from the prospective, IRB approved UCSD Stroke Registry. Patients had both CT and CTA as part of their acute stroke work-up as standard of care. DeyeCOM(+) sign was defined as a conjugate gaze deviation on CT or CTA of at least 15 degrees measured by caliper technique on Agfa IMPAX software (v.6.6.1.3525). DeyeCOM(++) was defined as sustained gaze deviation on both CT and CTA.

Results: Three groups of patients were observed: 1) gaze deviation on both CT and CTA (DeyeCOM(++)), 2) non-sustained gaze deviation (+ on CT or CTA but not both), and 3) no gaze deviation (DeyeCOM(--)). All patients with DeyeCOM(++) (8/8, 100%) had anterior LVO. Of those with non-sustained gaze deviation, 2/7 (29%) had LVO. No DeyeCOM(--) patients (0/31, 100%) had LVO. Of the DeyeCOM(--) patients, 16/31 (52%) were stroke mimics and 15/31 (48%) had strokes that were not LVO. The specificity and sensitivity of DeyeCOM(++) for LVO was 100% (CI .90-1.0) and 80% (CI .44-.97). The specificity and sensitivity of DeyeCOM(--) for absence of LVO was 100% (CI .69-.10) and 86% (CI .70-.95).

Conclusion: In this study, DeyeCOM(++) had 100% specificity for anterior LVO while DeyeCOM(--) had a 100% specificity for absence of LVO. DeyeCOM(++) false positive rates were low. Sustained DeyeCOM, whether positive or negative, is a strong predictor of ultimate diagnosis. These results should support practitioners’ confidence that DeyeCOM(++) reflects LVO stroke and is unlikely to be a mimic and DeyeCOM(--) patients likely do not have LVO. This data point can potentially lead to quicker endovascular treatment times. Further comparisons in this dataset are ongoing and work in a larger data set is needed.

Abstract TMP84: Substantial Rise in tPA Utilization for Acute Ischemic Stroke in the United States Corresponds with Significant Improvement in Outcomes

Background: Tissue plasminogen activator (tPA) is known to improve outcomes in Acute Ischemic stroke (AIS). Earlier studies showed low tPA utilization rates (1-4%) in AIS, ~6% hemorrhagic conversion (HC) with tPA and ~50% mortality in those who had HC. Results from interval studies and enhanced stroke systems of care have likely led to higher tPA utilization in recent times.

Objective: To assess real-world trends in tPA utilization in AIS, and corresponding clinical outcomes in the United States.

Methods: Healthcare Cost and Utilization Project’s Nationwide Inpatient Sample database was reviewed from 2002 to 2014. Hospitalizations with AIS were identified using ICD-9-CM codes 433.xx-436, tPA use by procedure code 99.10 and post tPA and HC with ICD-9 431 as secondary diagnosis. Cochran Armitage trend test and survey logistic regression procedure were used to analyze trends and outcomes.

Results: Of 5,577,707 hospitalizations with diagnosis of AIS, 264,643 (4.74%) received tPA. There is an ~950% increase in tPA utilization in AIS from 2002 to 2014 (Table). In-patient mortality in tPA group has been reduced by ~50%, with 35% increase in discharge to home. There was an ~80% increase in hemorrhagic conversion in tPA group (5.15% to 9.47%; p<0.001). Although HC increased, there was a ~60% decrease in in-patient mortality and ~60% increase in discharge to home among HC.

Conclusions: Over the last decade, there was a substantial increase in tPA utilization for AIS in the United States. HC remains a major concern, however outcomes in those with HC were remarkably better than perceived earlier. Though enhanced stroke systems of care may be a confounding factor, decreased mortality and improved functional outcomes should drive the treating physicians to be aggressive with tPA utilization in AIS.

Factors Influencing Acute Stroke Thrombolytic Treatments in Hispanics In the San Diego Region

BACKGROUND

Since the introduction of recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke, rt-PA rate and number of stroke centers have increased. Despite this, studies have shown racial and ethnic disparities in stroke care especially in Black and Hispanic populations. What factors are related to the administration of rt-PA within the Hispanic population has to date been unclear.

METHODS

We performed a retrospective review of IRB approved, prospectively collected data from the UC San Diego Stroke Registry from 7/2004-7/2016. Patients were included based on the primary diagnosis of Transient Ischemic Attack or Ischemic Stroke. Hispanic vs non-Hispanic patients were compared to assess for overall rt-PA treatment rates and process of care intervals. For the Hispanic cohort itself, demographics and NIHSS scores were assessed to determine why some Hispanics received rt-PA while others were not.

RESULTS

Overall, 1489 patients (300 Hispanic vs. 1189 non-Hispanic) were included. Comparing Hispanics to non-Hispanics, there was no difference in rt-PA rate (35.3% vs. 33.1%; p=0.49). In rt-PA treated patients, "onset to arrival" interval was higher in Hispanics (1.03 vs. 0.88 hours; p=0.04), while the "arrival to treatment" interval was not different (1.13 vs. 1.02 hours; p=0.07). When looking at Hispanic patients only, there was no difference in baseline characteristics except for initial NIHSS in treated vs. non-treated patients (13.27 vs. 7.24; p<.001).

CONCLUSION

Our analyses sought to determine the factors important to administration of rt-PA to Hispanic patients. These findings highlight the need for strategies to improve recognition and presentation pathways for Hispanics.

Biochemical markers in vascular cognitive impairment associated with subcortical small vessel disease - A consensus report

Background

Vascular cognitive impairment (VCI) is a heterogeneous entity with multiple aetiologies, all linked to underlying vascular disease. Among these, VCI related to subcortical small vessel disease (SSVD) is emerging as a major homogeneous subtype. Its progressive course raises the need for biomarker identification and/or development for adequate therapeutic interventions to be tested. In order to shed light in the current status on biochemical markers for VCI-SSVD, experts in field reviewed the recent evidence and literature data.

Method

The group conducted a comprehensive search on Medline, PubMed and Embase databases for studies published until 15.01.2017. The proposal on current status of biochemical markers in VCI-SSVD was reviewed by all co-authors and the draft was repeatedly circulated and discussed before it was finalized.

Results

This review identifies a large number of biochemical markers derived from CSF and blood. There is a considerable overlap of VCI-SSVD clinical symptoms with those of Alzheimer’s disease (AD). Although most of the published studies are small and their findings remain to be replicated in larger cohorts, several biomarkers have shown promise in separating VCI-SSVD from AD. These promising biomarkers are closely linked to underlying SSVD pathophysiology, namely disruption of blood-CSF and blood–brain barriers (BCB-BBB) and breakdown of white matter myelinated fibres and extracellular matrix, as well as blood and brain inflammation. The leading biomarker candidates are: elevated CSF/blood albumin ratio, which reflects BCB/BBB disruption; altered CSF matrix metalloproteinases, reflecting extracellular matrix breakdown; CSF neurofilment as a marker of axonal damage, and possibly blood inflammatory cytokines and adhesion molecules. The suggested SSVD biomarker deviations contrasts the characteristic CSF profile in AD, i.e. depletion of amyloid beta peptide and increased phosphorylated and total tau.

Conclusions

Combining SSVD and AD biomarkers may provide a powerful tool to identify with greater precision appropriate patients for clinical trials of more homogeneous dementia populations. Thereby, biomarkers might promote therapeutic progress not only in VCI-SSVD, but also in AD.

Abstract TP180: DERrAME: Disparities Among Ethnicities Regarding rt-PA in Acute Stroke Management and Evaluations

Background: Since the introduction of recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke, rt-PA rate and number of stroke centers have increased. Despite this, studies have shown racial and ethnic disparities in stroke care especially in Black and Hispanic populations. How Hispanic ethnicity affects rt-PA evaluations has to date been unclear. In our patient population, we investigated whether ethnicity is associated with rt-PA use for acute ischemic strokes in the Hispanic population.

Methods: We performed a retrospective review of IRB approved, prospectively collected data from the UC San Diego Stroke Registry. Patients were selected based on the presentation and primary diagnosis of Transient Ischemic Attack or Ischemic Stroke. Characteristics including risk factors were compared in Hispanic vs non-Hispanic samples to assess rt-PA treatment rates, process of care intervals for Hispanics vs non-Hispanics and rt-PA vs non-rt-PA patients.

Results: We assessed 1489 patients (300 Hispanic vs. 1189 non-Hispanic whites) from July 2004 to July 2016. Comparing Hispanics to non-Hispanics, there was no difference in rt-PA rate (35.3% vs. 33.1%; p=0.49). In a subset evaluation of Hispanics only, comparing rt-PA(-) to rt-PA(+), there was no difference for male sex (56%), Hypertension (71%), Hyperlipidemia (29%), Diabetes (43%), Atrial Fibrillation (23%), and Smoking (20%). There was a noted difference in the Hispanic-only untreated vs treated subset for initial NIHSS (7.24 vs. 13.27; p<.001). In rt-PA treated patients only, the “onset to treatment” interval was significantly higher in Hispanics (2.42 vs. 2.13 hours p=0.003), while the “door to treatment” interval was not different (1.13 vs. 1.02 hours; p=0.07).

Conclusions: This study shows the rate of rt-PA treatment and “door to treatment” intervals were not significantly different in Hispanic vs non-Hispanic patients. This data is supportive of current overall treatment decision models. However, the “onset to treatment” interval was significantly longer for Hispanic patients showing that it may take longer for this population to reach the treating hospital. This supports the need to develop culturally relevant education programs to address barriers in this population.

Abstract 44: Enlarged Perivascular Spaces Correlate With CSF Biomarkers for Abnormal Blood-brain Barrier Permeability and Neuroinflammation in Patients With Vascular Cognitive Impairment

Background: Enlarged perivascular spaces (PVS) in the brain are common but their etiology and specificity are unclear. Multiple studies have shown a correlation between enlarged PVS and white matter hyperintensities (WMHs), but the relationship with vascular disease is uncertain. We used albumin CSF to blood ratio as a method to measure permeability of the blood-brain barrier (BBB) in patients with vascular cognitive impairment (VCI). It is possible that the enlarged PVS are associated with an increase in BBB permeability, which could interfere with perivascular fluid flow. Therefore, we hypothesized that enlarged PVS correlate with CSF markers of increased BBB permeability and neuroinflammation.

Methods: We prospectively recruited 107 VCI patients with white matter disease. At entry, they had brain MRIs with standardized ranking for enlarged PVS. Sixty-one had lumbar puncture to obtain CSF for analysis of albumin ratio, matrix metalloproteinases-2 (MMP-2) index, and amyloid-beta1-42 (Abeta42). The data was analyzed statistically with nonparametric correlation methods.

Results: Enlarged PVS had a positive correlation with CSF albumin ratio, which is a biomarker for increased BBB permeability ( p <0.01), and a negative correlation with the neuroinflammatory biomarker, MMP2 index ( p <0.02), and with Abeta42 ( p <0.02), which is cleared by the PVS.

Conclusion: Our results suggest an association between PVS, MMP-mediated increased BBB permeability, and clearance of Abeta42. The role of perivascular fluid movement and its relationship with CSF biomarkers will require further investigation.

1H-MR spectroscopy metabolite levels correlate with executive function in vascular cognitive impairment

BACKGROUND

White matter hyperintensities (WMHs) are associated with vascular cognitive impairment (VCI) but fail to correlate with neuropsychological measures. As proton MR spectroscopy ((1)H-MRS) can identify ischaemic tissue, we hypothesised that MRS detectable brain metabolites would be superior to WMHs in predicting performance on neuropsychological tests.

METHODS

60 patients with suspected VCI underwent clinical, neuropsychological, MRI and CSF studies. They were diagnosed as having subcortical ischaemic vascular disease (SIVD), multiple infarcts, mixed dementia and leukoaraiosis. We measured brain metabolites in a white matter region above the lateral ventricles with (1)H-MRS and WMH volume in this region and throughout the brain.

RESULTS

We found a significant correlation between both total creatine (Cr) and N-acetylaspartyl compounds (NAA) and standardised neuropsychological test scores. Cr levels in white matter correlated significantly with executive function (p=0.001), attention (p=0.03) and overall T score (p=0.007). When lesion volume was added as a covariate, NAA also showed a significant correlation with executive function (p=0.003) and overall T score (p=0.015). Furthermore, while metabolite levels also correlated with total white matter lesion volume, adjusting the Cr levels for lesion volume did not diminish the strength of the association between Cr levels and neuropsychological scores. The lowest metabolite levels and neuropsychological scores were found in the SIVD group. Finally, lesion volume alone did not correlate significantly with any neuropsychological test score.

CONCLUSION

These results suggest that estimates of neurometabolite levels provide additional and useful information concerning cognitive function in VCI not obtainable by measurements of lesion load.

Assessment of long-term outcomes for the STRokE DOC telemedicine trial

Telemedicine can provide stroke evaluations in locations with limited available expertise. The reliability of telestroke has been established. Decision making efficacy has been shown in the National Institutes of Health's STRokE DOC trial. No prospective trial has assessed long-term telestroke outcomes, however. In an institutional review board-approved trial (NCT00936455), we contacted patients originally enrolled in the STRokE DOC trial. A telephone script was used to verify consent. Patients were asked standardized questions regarding disposition, modified Rankin Scale (mRS) score, mortality, and recurrent stroke for 2 retrospective time points (6 and 12 months postevent) and one current time point. Blind was maintained. Primary outcome measures of mortality and percent mRS score of 0-1 [%mRS(0-1)] at 6 months are reported. Wilcoxon's rank-sum test was used for continuous variables, and Fisher's exact was used for categorical variables. Of the original 222 participants, 75 patients or surrogates could be contacted. Mean time from enrollment was 3.96 ± 1.0 years (range, 2.33-5.45 years). Mean National Institutes of Health Stroke Scale (NIHSS) score was 8 ± 7 (5 ± 8 for telephone; 12 ± 8 for telemedicine; P = .002). The rate of intravenous recombinant tissue plasminogen activator (rt-PA) use was 31%. Six-month %mRS(0-1) outcome was not different, at 42%. Mortality after imputation to the entire study sample also was not different, at 18%. There was no difference in the rate of recurrent stroke (P = .61). Some 85% of patients were home at 6 months. This study reports a good 6-month outcome for stroke patients evaluated by telemedicine or telephone. This design is limited by the time since original enrollment and resultant inability to contact participants. Although these findings can add to the limited data on telemedicine outcomes, a prospective trial is needed.