Endovascular Thrombectomy for Large Ischemic Stroke Across Ischemic Injury and Penumbra Profiles

Importance

Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain.

Objective

To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect.

Design, Setting, and Participants

An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022.

Intervention

EVT vs MM.

Main Outcomes and Measures

Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI.

Results

Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled.

Conclusion and Relevance

In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

Large vessel occlusion prediction scale thresholds that are sensitive for DAWN Trial patients

BACKGROUND

Large vessel occlusion (LVO) prediction scales are used to triage prehospital suspected stroke patients with a high probability of LVO stroke to endovascular therapy centers. The sensitivities of these scales in the 6-to-24-h time window are unknown. Higher scale score thresholds are typically less sensitive and more specific. Knowing the highest scale score thresholds that remain sensitive could inform threshold selection for clinical use. Sensitivities may also vary between left and right-sided LVOs.

METHODS

LVO prediction scale scores were retrospectively calculated using the National Institutes of Health Stroke Scale (NIHSS) scores of patients enrolled in the DAWN Trial. All patients had last known well times between 6 and 24 h, NIHSS scores ≥ 10, intracranial internal carotid artery or proximal middle cerebral artery occlusions, and mismatches between their clinical severities and infarct core volumes. Scale thresholds with sensitivities ≥ 85% were identified, along with scores ≥ 5% more sensitive for left or right-sided LVOs. Specificities could not be calculated because all patients had LVOs.

RESULTS

A total of 201 out of 206 patients had the required NIHSS subitem scores. CPSS = 3, C-STAT ≥ 2, FAST-ED ≥ 4, G-FAST ≥ 3, RACE ≥ 5, and SAVE ≥ 3 were the highest thresholds that were still 85% sensitive for DAWN Trial LVO stroke patients. RACE ≥ 5 was the only typically used score threshold more sensitive for right-sided LVOs, though similar small differences were seen for other scales at higher thresholds.

CONCLUSIONS

Our findings likely represent the maximum sensitivities of the LVO prediction scales tested for ideal thrombectomy candidates in the 6-to-24-h time window because NIHSS scores were documented in hospitals during a clinical trial rather than in the prehospital setting. Patients with NIHSS scores < 10 or more distal LVOs would lower sensitivities further. Selecting even higher scale thresholds for LVO triage would lead to many missed LVO strokes.

Abstract WMP91: The Penumbra Salvage Index (PSI) As A Novel Measure Of Successful Reperfusion

Objective: We propose a novel measure, the PSI, to evaluate procedural success and prognostication after EVT and compare its prognostic ability with successful reperfusion (mTICI ≥2b).

Methods: SELECT EVT patients with adequate follow-up MR DWI imaging were stratified based on PSI [ratio of salvaged tissue volume (Tmax >6s volume at baseline – f/up DWI infarct volume) to the Tmax >6s volume at baseline] into good (PSI≥50%) and poor penumbral salvage (PSI<50%). Multivariable regression models examined the association of PSI with functional outcomes as well as predictors of PSI. ROC curve analysis evaluated the predictive ability of PSI and compared it with mTICI≥2b.

Results: 142/206(69%) had good penumbral salvage, with better CT ASPECTS (Good PSI: 9(7-10) vs Poor PSI: 7(6-9),p<0.001), baseline core infarct (Good PSI: 5.9(0.0-20.0)ml vs Poor PSI: 19.4(3.4-46.3)ml, p<0.001) and mTICI≥2b (Good PSI:91% vs Poor PSI: 64%, p<0.001). Good PSI was independently associated with higher odds of mRS 0-2 (Good PSI: 69% vs Poor PSI: 26%, aOR:5.89, 95%CI:2.25-15.45, p<0.001) and mRS 0-1 (Good PSI: 56% vs Poor PSI: 16%, aOR: 4.98, 95%CI:1.86-13.31, p=0.001). Predictors of a good PSI included a lower presenting NIHSS (aOR: 0.93, 95%CI: 0.87-0.99, p=0.026), smaller ischemic core (aOR: 0.96, 95%CI: 0.95-0.98, p<0.001) larger Tmax>6s volume (aOR: 1.01, 95%CI: 1.00-1.02, p=0.003) and mTICI≥2b (aOR: 8.84, 95%CI: 3.16-24.71, p<0.001). PSI demonstrated better AUC values (0.811) as compared to mTICI≥2b (0.786) in the ROC analysis.

Conclusion: Good penumbral salvage is associated with higher odds of functional independence, and has a better predictive value than successful reperfusion on cerebral angiogram after EVT. Prospective studies are needed to confirm the predictive utility of the PSI.

Abstract WP56: Improvement In Motor And Language Domains Mediates Most Of The Effect Of 24h NIHSS Improvement On Functional Independence

Introduction: Improvement in NIH stroke scale scores on 24h follow-up is considered a key prognostic element after endovascular thrombectomy (EVT). We aimed to evaluate the proportion of effect of 24h NIHSS improvement on mRS 0-2 at 90d mediated through improvement in motor and language domains.

Methods: From SELECT study, EVT patients with detailed NIHSS components on presentation and 24h follow-up as well as complete mRS on discharge and 90d were selected. Motor improvement was defined as ≥2 point in cumulative arms and legs score or 0 score at 24h and language improvement was defined as ≥1 point in cumulative aphasia and dysarthria scores at 24h. Mediation analysis framework using 4-step method (Figure 1a) was used to evaluate the effect of 24h NIHSS improvement mediated through improvement in motor and language scores.

Results: Of 192 eligible EVT patients, 176 demonstrated motor deficits and 187 demonstrated language deficits. 24h NIHSS improvement was significantly associated with mRS 0-2 (aOR:1.15[1.07-1.23], p<0.001) - step 1. 24h NIHSS improvement was also significantly associated with motor (aOR:1.77[1.48-2.12],p<0.001) and speech improvement (aOR:1.25[1.16-1.36],p<0.001) - step 2. In the full model, motor (aOR:3.00[1.07-8.46],p=0.037) and speech improvement (aOR:3.15[1.37-7.27],p=0.007) were significantly associated with mRS 0-2, whereas 24h NIHSS improvement was no longer a significant predictor (aOR:1.05[0.96-1.15],p=0.33) - step 3 of figure 1a. Motor improvement mediated 68% and speech improvement mediated 27% of the association of 24h NIHSS improvement with mRS 0-2 (Figure 1b) - step 4.

Conclusions: Almost all (~95%) of the effect of 24h NIHSS improvement on functional independence (mRS 0-2) was mediated through specific improvement in motor and language domains, suggesting a large role of improvement in motor and language domains in achieving better functional independence. Further studies are needed to confirm the findings.

Abstract 133: Over Estimation Of Percent Stenosis By Physician Operators May Lead To Carotid Stent Over Utilization

Introduction: Based largely on the inclusion criteria of clinical trials, the degree of cervical carotid artery stenosis is often used as an indication for stent placement in the setting of carotid atherosclerotic disease. However, the rigor and consistency with which such stenosis is measured outside of clinical trials is unclear. We compared the percent stenosis as measured by real world physician operators to that measured by independent expert reviewers.

Hypothesis: We hypothesized that the documented degree of stenosis, termed operator-reported stenosis (ORS), from real world facilities performing carotid stent placement would be larger than the reviewer-measured stenosis (RMS) as assessed by clinicians experienced in treating carotid artery disease.

Methods: Images were selected from patient cases used for carotid stenting facility accreditation. Data collected included demographics, National Institutes of Health Stroke Scale, modified Rankin Score, and the documented degree of stenosis (ORS). The ORS was compared to the RMS, derived from a panel of expert clinicians.

Results: A total of 68 angiograms were reviewed from 39 symptomatic and 29 asymptomatic patients. The RMS values demonstrated excellent agreement with an intra-class correlation of 0.80. The median ORS was 90.0% (IQR 80.0, 90.0) versus a median RMS of 61.1% (IQR 49.8, 73.6), with a median difference of 21.8% (IQR 13.7, 34.4), p < 0.001. This discrepancy persisted within several subpopulations and was larger among asymptomatic patients and those treated at facilities granted delayed accreditation. Based on RMS values, 72% of symptomatic patients and only 10% of asymptomatic patients would meet the Centers for Medicare and Medicaid Services criteria for carotid stent placement.

Conclusions: Real world operators tend to overestimate cervical carotid artery stenosis compared to external expert reviewers. Since decisions regarding carotid revascularization are often based at least partially on percent stenosis, such measuring discrepancies inevitably lead to a higher volume of procedures, which may in turn represent a degree of procedural over utilization.

Mediation of Successful Reperfusion Effect through Infarct Growth and Cerebral Edema: A Pooled, Patient-Level Analysis of EXTEND-IA Trials and SELECT Prospective Cohort

OBJECTIVE

Reperfusion therapy is highly beneficial for ischemic stroke. Reduction in both infarct growth and edema are plausible mediators of clinical benefit with reperfusion. We aimed to quantify these mediators and their interrelationship.

METHODS

In a pooled, patient-level analysis of the EXTEND-IA trials and SELECT study, we used a mediation analysis framework to quantify infarct growth and cerebral edema (midline shift) mediation effect on successful reperfusion (modified Treatment in Cerebral Ischemia ≥ 2b) association with functional outcome (modified Rankin Scale distribution). Furthermore, we evaluated an additional pathway to the original hypothesis, where infarct growth mediated successful reperfusion effect on midline shift.

RESULTS

A total 542 of 665 (81.5%) eligible patients achieved successful reperfusion. Baseline clinical and imaging characteristics were largely similar between those achieving successful versus unsuccessful reperfusion. Median infarct growth was 12.3ml (interquartile range [IQR] = 1.8-48.4), and median midline shift was 0mm (IQR = 0-2.2). Of 249 (37%) demonstrating a midline shift of ≥1mm, median shift was 2.75mm (IQR = 1.89-4.21). Successful reperfusion was associated with reductions in both predefined mediators, infarct growth (β = -1.19, 95% confidence interval [CI] = -1.51 to -0.88, p < 0.001) and midline shift (adjusted odds ratio = 0.36, 95% CI = 0.23-0.57, p < 0.001). Successful reperfusion association with improved functional outcome (adjusted common odds ratio [acOR] = 2.68, 95% CI = 1.86-3.88, p < 0.001) became insignificant (acOR = 1.39, 95% CI = 0.95-2.04, p = 0.094) when infarct growth and midline shift were added to the regression model. Infarct growth and midline shift explained 45% and 34% of successful reperfusion effect, respectively. Analysis considering an alternative hypothesis demonstrated consistent results.

INTERPRETATION

In this mediation analysis from a pooled, patient-level cohort, a significant proportion (~80%) of successful reperfusion effect on functional outcome was mediated through reduction in infarct growth and cerebral edema. Further studies are required to confirm our findings, detect additional mediators to explain successful reperfusion residual effect, and identify novel therapeutic targets to further enhance reperfusion benefits. ANN NEUROL 2023.

Abstract P137: Large Vessel Occlusion Prediction Scale Thresholds That Are Sensitive for DAWN Trial Participants

Introduction: Large Vessel Occlusion (LVO) prediction scales are used to triage prehospital suspected stroke patients with a high probability of LVO stroke to endovascular therapy centers. The sensitivities of these scales in the 6 to 24 hour window are unknown. Higher scale score thresholds are typically less sensitive and more specific. Knowing the highest scale score thresholds that remain sensitive could inform threshold selection for clinical use. Sensitivities may also vary between left and right sided LVOs.

Methods: LVO prediction scale scores were retrospectively calculated using the NIHSS sub-item scores of patients enrolled in the DAWN Trial. All patients had last known well times between 6 to 24 hours, NIHSS scores ≥ 10, intracranial ICA or proximal MCA occlusions, and mismatches between their exam severities and infarct core volumes. Scale thresholds with sensitivities ≥ 85% were identified. Scores ≥ 5% more sensitive for left or right sided LVOs were identified. Specificities could not be calculated because all DAWN Trial patients had LVOs.

Results: 201 out of 206 patients had the required NIHSS sub-item scores. The highest score thresholds that maintained sensitivities ≥ 85% are bolded in the table.

Conclusions: CPSS = 3, C-STAT ≥ 2, FAST-ED ≥ 4, G-FAST ≥ 3, RACE ≥ 5, and SAVE ≥ 3 are likely the highest thresholds that can be selected for extended window LVO triage without missing more than 15% of DAWN Trial eligible LVO strokes. For CPSS and SAVE, these are higher than the thresholds suggested by prior studies. CPSS = 3 and RACE ≥ 5 were more sensitive for right sided LVOs. These findings represent the maximum anticipated sensitivities of LVO prediction scales since the NIHSS scores were documented in hospitals during a clinical trial rather than in the prehospital setting. Inclusion of lower NIHSS or more distal LVO patients would lower sensitivities further. Selecting even higher scale thresholds for LVO triage would lead to many missed LVO strokes.

Impact of Periprocedural and Technical Factors and Patient Characteristics on Revascularization and Outcome in the DAWN Trial

Background and Purpose- Because of unique attributes of mechanical thrombectomy performed between 6 and 24 hours after symptom onset in acute ischemic stroke patients, it is not known if predictors of angiographic recanalization and favorable outcome in patients treated with thrombectomy in the late (6-24 hour) time window are similar to those treated in the early time window. Methods- We analyzed data from the DAWN trial (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) which enrolled patients with symptom onset 6 to 24hours after last known well and occlusion of the intracranial internal carotid artery or proximal middle cerebral artery with a mismatch between severity of clinical deficit and infarct core volume as identified by computed tomography-perfusion or diffusion magnetic resonance imaging. We evaluated the effect of tandem occlusions, periprocedural heparin use, procedural speed (from puncture to procedure completion), general anesthesia, balloon-guide catheters, thrombectomy device size, and number of passes on substantial reperfusion (modified Thrombolysis in Cerebral Infarction 2b/3) and on likelihood of obtaining a modified Rankin Scale at 3 months indicating functional independence. Results- Of 107 patients who underwent MT in the interventional arm of DAWN, substantial reperfusion and modified Rankin Scale score 0 to 2 at 3 months was seen in 90 (84%) and 52 (49%), respectively. In univariate analysis, general anesthesia (odds ratio [OR] 0.27; P=0.042) and ≥3 passes with stent retriever (OR, 0.17; P=0.002) were inversely associated with substantial reperfusion. In multivariate analyses, only ≥3 passes were associated with lack of revascularization (OR, 0.17; P=0.002). in univariate analysis ≥3 passes (OR, 0.24; P =0.003) and baseline National Institutes of Health Stroke Scale score >17 (OR, 0.19; P<0.001) were inversely associated with functional independence at 3 months. In multivariate analyses, ≥3 passes (OR, 0.24; P=0.003) and National Institutes of Health Stroke Scale score >17 (OR, 0.19; P<0.001) remained inversely associated with favorable outcome at 3 months. Conclusions- Patients requiring ≥3 thrombectomy passes had reduced substantial reperfusion and favorable outcome at 3 months in DAWN. Whether or not additional thrombectomy techniques beyond ≥3 thrombectomy passes with the Trevo stent retriever are beneficial for patient outcomes in this patient population remains to be clarified by future studies. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT02142283.

Benefit of Endovascular Thrombectomy by Mode of Onset

Background and Purpose—

It is unknown whether the benefit of thrombectomy in late presenting acute stroke patients with imaging evidence of clinical-infarct mismatch is different in patients presenting with wake-up stroke compared with those presenting with witnessed onset or unwitnessed onset.

Methods—

Prespecified secondary analysis was performed from DAWN (Diffusion Weighted Imaging [DWI] or Computerized Tomography Perfusion [CTP] Assessment With Clinical Mismatch in the Triage of Wake Up and Late Presenting Strokes Undergoing Neurointervention), a multicenter, prospective, randomized clinical trial with blinded end point assessment comparing thrombectomy with the Trevo device against standard medical therapy in patients with acute stroke and clinical-infarct mismatch presenting 6 to 24 hour after the time last seen well. For the purposes of this study, the primary outcome was the proportion of modified Rankin Scale score 0 to 2 at 90 days. Univariable analysis and multivariable logistic regression was used to assess the relationship between outcome and mode of onset.

Results—

All 206 enrolled patients were included in the study. Mode of onset was: wake-up stroke (55.3%, n=114), witnessed onset (12.1%, n=25), and unwitnessed onset (32.5%, n=67) with median time last seen well to randomization (13.4±3.7, 10.0±3.7, 14.1±4.9 hours) respectively. Rates of 90-day modified Rankin Scale score of 0 to 2 and symptomatic intracerebral hemorrhage in the thrombectomy arm were not statistically different across patient onset subtypes ( P =0.79 and P =0.40, respectively). The benefit of thrombectomy compared with best medical therapy was maintained across all 3 onset modes (rates of 90-day modified Rankin Scale score of 0 to 2 in patients allocated to thrombectomy versus control: wake-up stroke—49.3% versus 10.6%, witnessed onset—63.6% versus 21.4%, UW—41.4% versus 13.2%; P ×interaction=0.79). In univariable and multivariable analyses, mode of onset was not identified as a significant predictor of modified Rankin Scale score 0 to 2 at 90 days.

Conclusions—

In patients with acute ischemic stroke presenting between 6 and 24 hours from time last seen well and harboring clinical-infarct mismatch, the benefit of thrombectomy was similar regardless of the wake-up, unwitnessed, or witnessed mode of onset.

Noncontrast Computed Tomography Alberta Stroke Program Early CT Score May Modify Intra-Arterial Treatment Effect in DAWN

Background and Purpose—

It is unknown whether noncontrast computed tomography (NCCT) can identify patients who will benefit from intra-arterial treatment (IAT) in the extended time window. We sought to characterize baseline Alberta Stroke Program Early CT Score (ASPECTS) in DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) and to assess whether ASPECTS modified IAT effect.

Methods—

Core lab adjudicated ASPECTS scores were analyzed. The trial cohort was divided into 2 groups by qualifying imaging (computed tomography versus magnetic resonance imaging). ASPECTS-by-treatment interaction was tested for the trial coprimary end points (90-day utility-weighted modified Rankin Scale (mRS) score and mRS, 0–2), mRS 0 to 3, and ordinal mRS. ASPECTS was evaluated separately as an ordinal and a dichotomized (0–6 versus 7–10) variable.

Results—

Of 205 DAWN subjects, 123 (60%) had NCCT ASPECTS, and 82 (40%) had diffusion weighted imaging ASPECTS. There was a significant ordinal NCCT ASPECTS-by-treatment interaction for 90-day utility-weighted mRS (interaction P =0.04) and mRS 0 to 2 (interaction P =0.02). For both end points, IAT effect was more pronounced at higher NCCT ASPECTS. The dichotomized NCCT ASPECTS-by-treatment interaction was significant only for mRS 0 to 2 (interaction P =0.04), where greater treatment benefit was seen in the ASPECTS 7 to 10 group (odds ratio, 7.50 [2.71–20.77] versus odds ratio, 0.48 [0.04–5.40]). A bidirectional treatment effect was observed in the NCCT ASPECTS 0 to 6 group, with treatment associated with not only more mRS 0 to 3 outcomes (50% versus 25%) but also more mRS 5 to 6 outcomes (40% versus 25%). There was no significant modification of IAT effect by diffusion weighted imaging ASPECTS.

Conclusions—

Baseline NCCT ASPECTS appears to modify IAT effect in DAWN. Higher NCCT ASPECTS was associated with greater benefit from IAT. No treatment interaction was observed for diffusion weighted imaging ASPECTS.

Abstract WP27: Alteration in Clinical Outcome Between Discharge and Three Months After Mechanical Thrombectomy versus Medical Management in Late-Presenting Stroke Patients

Background: Mechanical thrombectomy in late-presenting stroke patients with a limited infarct core on CTP/DWI is highly effective. We aimed to evaluate the degree of disability at discharge as an indicator for functional impairment at one and three months after mechanical thrombectomy compared to medical management in these patients.

Methods: This study concerns a post-hoc analysis of the DAWN-trial population. Patients presenting 6-24h after symptom onset of an emergent large vessel occlusion with mismatch between symptom severity and infarct size on CTP/DWI, were randomized for medical management versus mechanical thrombectomy. We assessed the change in modified Rankin score (mRS) from discharge up to three months post-stroke for DAWN-patients treated with mechanical thrombectomy compared to those randomized to medical management. Kendall’s tau test was used to evaluate the correlation between the mRS at discharge, at 30 days, and at 90 days. Mixed models were used to explore the potential difference between treatment arms in the change of utility weighted mRS over time.

Results: Ninety-eight of 107 patients treated with mechanical thrombectomy and 89/99 controls survived at discharge and were included in the analysis. We found a strong correlation between the mRS at discharge, at 30 days, and at 90 days for both treatment arms with a tau varying from 0.52 to 0.72 for mechanical thrombectomy and 0.56 to 0.71 for medical management. All correlation coefficients were statistically significant (p < 0.0001). The utility weighted mRS after mechanical thrombectomy was consistently superior to medical management (p < 0.0001). Although there was a trend towards a stronger dispersion of the utility weighted mRS over time after mechanical thrombectomy, there was no statistically significant interaction effect between time and treatment arm (p 0.44).

Conclusion: The treatment effect of mechanical thrombectomy occurs early and further improvement over time is similar to that of medical management. The mRS at discharge is a robust indicator for functional status at one and three months post stroke and may therefore be used as an alternative measure for clinical outcome.

2017 Cardiovascular and Stroke Endpoint Definitions for Clinical Trials

This publication describes uniform definitions for cardiovascular and stroke outcomes developed by the Standardized Data Collection for Cardiovascular Trials Initiative and the US Food and Drug Administration (FDA). The FDA established the Standardized Data Collection for Cardiovascular Trials Initiative in 2009 to simplify the design and conduct of clinical trials intended to support marketing applications. The writing committee recognizes that these definitions may be used in other types of clinical trials and clinical care processes where appropriate. Use of these definitions at the FDA has enhanced the ability to aggregate data within and across medical product development programs, conduct meta-analyses to evaluate cardiovascular safety, integrate data from multiple trials, and compare effectiveness of drugs and devices. Further study is needed to determine whether prospective data collection using these common definitions improves the design, conduct, and interpretability of the results of clinical trials.

Abstract 78: Time to Endovascular Treatment and Outcomes in the DAWN Trial

Introduction: It is well-established that, within 0-6 hours, the benefit of thrombectomy rapidly decays over time. The DAWN trial demonstrated that, in the presence of clinical-core mismatch (CCM), thrombectomy remains beneficial within 6-24 hours. We aim to assess the effect of time to randomization on outcomes in the DAWN.

Methods: We used traditional multivariate logistic regression controlling age and NIHSS at baseline adding an interaction between Trevo and Time last seen well and then generated the odds ratio of the interaction of Trevo and time at particular time points.

Results: Each 1-hour delay to treatment markedly impacted functional independence (OR,0.89 [95% CI 0.75 to 1.03]). Although the odds of functional independence at 90 days (mRS 0-2) with thrombectomy declined with longer time from last seen well (TLSW) to puncture, treatment benefit was observed through 24 hours : cOR at 8 hours, 6.8 (95% CI, 2.1 to 22.0), absolute risk difference (ARD) for mRS 0-2, 24.4%; cOR at 12 hours, 9.4 (95% CI, 4.1 to 21.6), ARD, 35.1%; cOR at 16 hours, 13.0 (95% CI, 4.1 to 41.3), ARD, 37.2%; cOR at 20 hours, 17.8 (95% CI, 2.9 to 110.4), ARD, 36.5%; cOR at 24 hours, 24.6 (95% CI, 1.9 to 322), ARD, 35.5% (Figure). Comparable analysis using time from symptoms first observed (TSFO) yielded similar results.

Conclusion: In patients selected based on CCM, treatment benefit persists all the way to 24 hours; however, both the chances of good outcome and the overall treatment effect continuously drop over time.

Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct

BACKGROUND

The effect of endovascular thrombectomy that is performed more than 6 hours after the onset of ischemic stroke is uncertain. Patients with a clinical deficit that is disproportionately severe relative to the infarct volume may benefit from late thrombectomy.

METHODS

We enrolled patients with occlusion of the intracranial internal carotid artery or proximal middle cerebral artery who had last been known to be well 6 to 24 hours earlier and who had a mismatch between the severity of the clinical deficit and the infarct volume, with mismatch criteria defined according to age (<80 years or ≥80 years). Patients were randomly assigned to thrombectomy plus standard care (the thrombectomy group) or to standard care alone (the control group). The coprimary end points were the mean score for disability on the utility-weighted modified Rankin scale (which ranges from 0 [death] to 10 [no symptoms or disability]) and the rate of functional independence (a score of 0, 1, or 2 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating more severe disability) at 90 days.

RESULTS

A total of 206 patients were enrolled; 107 were assigned to the thrombectomy group and 99 to the control group. At 31 months, enrollment in the trial was stopped because of the results of a prespecified interim analysis. The mean score on the utility-weighted modified Rankin scale at 90 days was 5.5 in the thrombectomy group as compared with 3.4 in the control group (adjusted difference [Bayesian analysis], 2.0 points; 95% credible interval, 1.1 to 3.0; posterior probability of superiority, >0.999), and the rate of functional independence at 90 days was 49% in the thrombectomy group as compared with 13% in the control group (adjusted difference, 33 percentage points; 95% credible interval, 24 to 44; posterior probability of superiority, >0.999). The rate of symptomatic intracranial hemorrhage did not differ significantly between the two groups (6% in the thrombectomy group and 3% in the control group, P=0.50), nor did 90-day mortality (19% and 18%, respectively; P=1.00).

CONCLUSIONS

Among patients with acute stroke who had last been known to be well 6 to 24 hours earlier and who had a mismatch between clinical deficit and infarct, outcomes for disability at 90 days were better with thrombectomy plus standard care than with standard care alone. (Funded by Stryker Neurovascular; DAWN ClinicalTrials.gov number, NCT02142283 .).

Deep Vein Thrombosis in Acute Stroke - A Systemic Review of the Literature

We present a systemic review of available literature on the complications of deep venous thrombosis that develops in patients presenting with acute stroke. There are several pharmacological and physical treatment options available and used. We aim to summarize the management plans currently used at different centers. In conclusion, low-dose anticoagulant therapy for ischemic stroke is recommended. In the case of intracerebral hemorrhage, pneumatic sequential compression devices should be placed initially, followed by the administration of ultra-fractioned heparin on the next day, and then oral anticoagulant therapy to replace the heparin after a week in high-risk patients. Similar prophylactic treatment recommendations are used for subarachnoid hemorrhage.

Baseline Quality of Life and Risk of Stroke in the ALLHAT Study (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial)

BACKGROUND AND PURPOSE

The visual analogue scale is a self-reported, validated tool to measure quality of life (QoL). Our purpose was to determine whether baseline QoL predicted strokes in the ALLHAT study (Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial) and evaluate determinants of poststroke change in QoL. In the ALLHAT study, among the 33 357 patients randomized to treatment arms, 1525 experienced strokes; 1202 (79%) strokes were nonfatal. This study cohort includes 32 318 (97%) subjects who completed the baseline visual analogue scale QoL estimate.

METHODS

QoL was measured on a visual analogue scale and adjusted using a Torrance transformation (transformed QoL [TQoL]). Kaplan-Meier curves and adjusted proportional hazards analyses were used to estimate the effect of TQoL on the risk of stroke, on a continuous scale (0-1) and by quartiles (≤0.81, >0.81≤0.89, >0.89≤0.95, >0.95). We analyzed the change from baseline to first poststroke TQoL using adjusted linear regression.

RESULTS

After adjusting for multiple stroke risk factors, the hazard ratio for stroke events for baseline TQoL was 0.93 (95% confidence interval, 0.89-0.98) per 0.1 U increase. The lowest baseline TQoL quartile had a 20% increased stroke risk (hazard ratio=1.20 [95% confidence interval, 1.00-1.44]) compared with the reference highest quartile TQoL. Poststroke TQoL change was significant within all treatment groups (P≤0.001). Multivariate regression analysis revealed that baseline TQoL was the strongest predictor of poststroke TQoL with similar results for the untransformed QoL.

CONCLUSIONS

The lowest baseline TQoL quartile had a 20% higher stroke risk than the highest quartile. Baseline TQoL was the only factor that predicted poststroke change in TQoL.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000542.

Safety and efficacy of multipotent adult progenitor cells in acute ischaemic stroke (MASTERS): a randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

Multipotent adult progenitor cells are a bone marrow-derived, allogeneic, cell therapy product that modulates the immune system, and represents a promising therapy for acute stroke. We aimed to identify the highest, well-tolerated, and safest single dose of multipotent adult progenitor cells, and if they were efficacious as a treatment for stroke recovery.

METHODS

We did a phase 2, randomised, double-blind, placebo-controlled, dose-escalation trial of intravenous multipotent adult progenitor cells in 33 centres in the UK and the USA. We used a computer-generated randomisation sequence and interactive voice and web response system to assign patients aged 18-83 years with moderately severe acute ischaemic stroke and a National Institutes of Health Stroke Scale (NIHSS) score of 8-20 to treatment with intravenous multipotent adult progenitor cells (400 million or 1200 million cells) or placebo between 24 h and 48 h after symptom onset. Patients were ineligible if there was a change in NIHSS of four or more points during at least a 6 h period between screening and randomisation, had brainstem or lacunar infarct, a substantial comorbid disease, an inability to undergo an MRI scan, or had a history of splenectomy. In group 1, patients were enrolled and randomly assigned in a 3:1 ratio to receive 400 million cells or placebo and assessed for safety through 7 days. In group 2, patients were randomly assigned in a 3:1 ratio to receive 1200 million cells or placebo and assessed for safety through the first 7 days. In group 3, patients were enrolled, randomly assigned, and stratified by baseline NIHSS score to receive 1200 million cells or placebo in a 1:1 ratio within 24-48 h. Patients, investigators, and clinicians were masked to treatment assignment. The primary safety outcome was dose-limiting toxicity effects. The primary efficacy endpoint was global stroke recovery, which combines dichotomised results from the modified Rankin scale, change in NIHSS score from baseline, and Barthel index at day 90. Analysis was by intention to treat (ITT) including all patients in groups 2 and 3 who received the investigational agent or placebo. This study is registered with ClinicalTrials.gov, number NCT01436487.

FINDINGS

The study was done between Oct 24, 2011, and Dec 7, 2015. After safety assessments in eight patients in group 1, 129 patients were randomly assigned (67 to receive multipotent adult progenitor cells and 62 to receive placebo) in groups 2 and 3 (1200 million cells). The ITT populations consisted of 65 patients who received multipotent adult progenitor cells and 61 patients who received placebo. There were no dose-limiting toxicity events in either group. There were no infusional or allergic reactions and no difference in treatment-emergent adverse events between the groups (64 [99%] of 65 patients in the multipotent adult progenitor cell group vs 59 [97%] of 61 in the placebo group). There was no difference between the multipotent adult progenitor cell group and placebo groups in global stroke recovery at day 90 (odds ratio 1·08 [95% CI 0·55-2·09], p=0·83).

INTERPRETATION

Administration of multipotent adult progenitor cells was safe and well tolerated in patients with acute ischaemic stroke. Although no significant improvement was observed at 90 days in neurological outcomes with multipotent adult progenitor cells treatment, further clinical trials evaluating the efficacy of the intervention in an earlier time window after stroke (<36 h) are planned.

FUNDING

Athersys Inc.

In Vivo Characterization of Carotid Neointimal Hyperplasia by use of Optical Coherence Tomography: Before and After Cutting Balloon Angioplasty

Optical coherence tomography (OCT) is a modern intravascular imaging modality that has the capability to provide detailed, in vivo characterization of the arterial wall and atherosclerotic plaque. The current understanding of the appearance of atherosclerotic plaque via OCT is largely based on coronary arterial studies where OCT information has been employed to guide therapeutic management and permits the immediate evaluation of percutaneous intervention. The clinical success of OCT in the coronary arteries has laid the foundation for investigation of the carotid artery and thus, stroke risk assessment. We report the novel use of OCT for tissue characterization of severe stenosis subsequent to carotid artery stenting (CAS), both before and after treatment with cutting balloon angioplasty.

Abstract W P172: Baseline Quality of Life and Risk of Stroke in the Antihypertensive and Lipid Lowering to Prevent Heart Attack (ALLHAT) Trial

Background: Quality of Life (QoL) is an integrative health status measure that may predict medical outcomes. No prospective study assessed relationship between QoL, subsequent stroke risk, and post-stroke outcome.

Objective: Determine how baseline QoL predicted non-fatal stroke, as well as the impact of stroke risk factors on QoL in ALLHAT using visual analogue scale (VAS) – a validated QoL tool.

Methods: ALLHAT randomized hypertensive patients to Chlorthalidone (C), Amlodipine (A) or Lisinopril (L), and used VAS to measure global QoL (0.00 -1.00) at baseline, 2, 4, and 6 yrs. QoL values underwent statistical Torrance transformation (TQoL). Mean QoL and TQoL pre (baseline) and post non-fatal stroke were analyzed. Hazard ratios (HR) and Kaplan-Meier curves for each quartile of baseline QoL were calculated. Baseline QOL, TQoL, and stroke risk factors were used in a multiple linear regression model to predict post-stroke QoL. QoL changes were examined by study arm, age, gender, and race.

Results: 28,534 (86%) participants completed at least one VAS. Of the 1,517 strokes; 22% (n=322) were fatal. QoL and TQoL results were similar. Patients who experienced in-trial stroke in C and A arms had lower baseline QoL than those who did not (HR =.71 vs .74, p<0.001and .71 vs .74, p=0.004, respectively), but not in L (HR=.73 vs .74, p=0.24). A 10% increment in baseline QoL or TQoL was associated with 5% and 7% reduction in the risk of stroke respectively (adjusted HR; 95% CI = .95; .91 -.99) and .93; .89 –.98). In risk factor adjusted models, lowest baseline QoL quartile had a 20% higher stroke risk (HR =1.20; 95% CI: 1.00-1.44) than highest quartile. QoL worsened post stroke, dropping most in elderly >75 yrs (-.08 units, p<0.0001), compared to groups 55-64 (-.04, p<0.05) and 65-75 yrs, (-.07, p <0.0001), and in A arm (-.09 units, p<0.0001) compared with C (-.05, p=0.0006) and L (-.07, p< 0.0001), but did not differ by gender or race. In a multiple linear regression model, baseline QoL predicted post-stroke QoL.

Conclusions: Lower baseline QoL was associated with higher stroke risk. Qol was lower post stroke. Baseline QoL was the only factor predicting post stroke QoL, and QoL change increased with age. Investigation of factors determining QoL may be fertile ground for stroke risk reduction.

Extended-release niacin therapy and risk of ischemic stroke in patients with cardiovascular disease: the Atherothrombosis Intervention in Metabolic Syndrome with low HDL/High Triglycerides: Impact on Global Health Outcome (AIM-HIGH) trial

BACKGROUND AND PURPOSE

In Atherothrombosis Intervention in Metabolic Syndrome with low HDL/High Triglycerides: Impact on Global Health Outcomes (AIM-HIGH) trial, addition of extended-release niacin (ERN) to simvastatin in participants with established cardiovascular disease, low high-density lipoprotein cholesterol, and high triglycerides had no incremental benefit, despite increases in high-density lipoprotein cholesterol. Preliminary analysis based on incomplete end point adjudication suggested increased ischemic stroke risk among participants randomized to ERN.

METHODS

This final analysis was conducted after complete AIM-HIGH event ascertainment to further explore potential relationship between niacin therapy and ischemic stroke risk.

RESULTS

There was no group difference in trial primary composite end point at a mean 36-month follow-up among 3414 patients (85% men; mean age, 64±9 years) randomized to simvastatin plus ERN (1500-2000 mg/d) versus simvastatin plus matching placebo. In the intention-to-treat analysis, there were 50 fatal or nonfatal ischemic strokes: 18 (1.06%) in placebo arm versus 32 (1.86%) in ERN arm (hazard ratio [HR], 1.78 [95% confidence interval {CI}, 1.00-3.17; P=0.050). Multivariate analysis showed independent associations between ischemic stroke risk and >65 years of age (HR, 3.58; 95% CI, 1.82-7.05; P=0.0002), history of stroke/transient ischemic attack/carotid disease (HR, 2.18; 95% CI, 1.23-3.88; P=0.0079), elevated baseline Lp(a) (HR, 2.80; 95% CI, 1.25-6.27 comparing the middle with the lowest tertile; HR, 2.31; 95% CI, 1.002-5.30 comparing the highest with the lowest tertile; overall P=0.042) but a nonsignificant association with ERN (HR, 1.74; 95% CI, 0.97-3.11; P=0.063).

CONCLUSIONS

Although there were numerically more ischemic strokes with addition of ERN to simvastatin that reached nominal significance, the number was small, and multivariable analysis accounting for known risk factors did not support a significant association between niacin and ischemic stroke risk.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00120289.

A double-blind placebo-controlled clinical evaluation of MultiStem for the treatment of ischemic stroke

BACKGROUND

There is growing interest in neurorestorative and reparative therapies after acute stroke. MultiStem is an allogeneic cell therapy treatment comprising a population of multipotent adherent bone marrow cells that has shown safety in clinical trials of myocardial infarction and graft vs. host disease, as well as preclinical evidence of activity in stroke and other neurological damage models. MultiStem is now being evaluated in a clinical trial in patients that have suffered an ischemic stroke, in which the product is administered intravenously 24-36 h after the ischemic event.

METHODS

The Phase 2 randomized, double-blind, placebo-controlled, multicenter dose-escalation trial will consist of three treatment cohorts, including a placebo group, and two treatment groups involving dose tiers of either 400 million or 1200 million cells per patient. Patients will be treated at 24-36 h after stroke. The two primary objectives are to determine the highest well-tolerated and safe single dose of MultiStem up to a maximum of 1200 million total cells in subjects with ischemic stroke and to determine the efficacy of MultiStem on functional outcome in subjects with stroke as measured by the modified Rankin Scale at 90 days. Patients will also be evaluated using the National Institutes of Health Stroke Scale and Barthel Index. The study will explore other aspects including, uniquely, the measurement of spleen size after stroke by magnetic resonance imaging or computed tomography imaging.

CONCLUSIONS AND FUTURE DIRECTION

If MultiStem is safe and there is a signal of efficacy, a late stage phase IIb-III trial is planned.

Inclusion of stroke in cardiovascular risk prediction instruments: a statement for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

Current US guideline statements regarding primary and secondary cardiovascular risk prediction and prevention use absolute risk estimates to identify patients who are at high risk for vascular disease events and who may benefit from specific preventive interventions. These guidelines do not explicitly include patients with stroke, however. This statement provides an overview of evidence and arguments supporting (1) the inclusion of patients with stroke, and atherosclerotic stroke in particular, among those considered to be at high absolute risk of cardiovascular disease and (2) the inclusion of stroke as part of the outcome cluster in risk prediction instruments for vascular disease.

METHODS AND RESULTS

Writing group members were nominated by the committee co-chairs on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee and the AHA Manuscript Oversight Committee. The writers used systematic literature reviews (covering the period from January 1980 to March 2010), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and, when appropriate, formulate recommendations using standard AHA criteria. All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. The guideline underwent extensive AHA internal peer review, Stroke Council leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the AHA Science Advisory and Coordinating Committee. There are several reasons to consider stroke patients, and particularly patients with atherosclerotic stroke, among the groups of patients at high absolute risk of coronary and cardiovascular disease. First, evidence suggests that patients with ischemic stroke are at high absolute risk of fatal or nonfatal myocardial infarction or sudden death, approximating the ≥20% absolute risk over 10 years that has been used in some guidelines to define coronary risk equivalents. Second, inclusion of atherosclerotic stroke would be consistent with the reasons for inclusion of diabetes mellitus, peripheral vascular disease, chronic kidney disease, and other atherosclerotic disorders despite an absence of uniformity of evidence of elevated risks across all populations or patients. Third, the large-vessel atherosclerotic subtype of ischemic stroke shares pathophysiological mechanisms with these other disorders. Inclusion of stroke as a high-risk condition could result in an expansion of ≈10% in the number of patients considered to be at high risk. However, because of the heterogeneity of stroke, it is uncertain whether other stroke subtypes, including hemorrhagic and nonatherosclerotic ischemic stroke subtypes, should be considered to be at the same high levels of risk, and further research is needed. Inclusion of stroke with myocardial infarction and sudden death among the outcome cluster of cardiovascular events in risk prediction instruments, moreover, is appropriate because of the impact of stroke on morbidity and mortality, the similarity of many approaches to prevention of stroke and these other forms of vascular disease, and the importance of stroke relative to coronary disease in some subpopulations. Non-US guidelines often include stroke patients among others at high cardiovascular risk and include stroke as a relevant outcome along with cardiac end points.

CONCLUSIONS

Patients with atherosclerotic stroke should be included among those deemed to be at high risk (≥20% over 10 years) of further atherosclerotic coronary events. Inclusion of nonatherosclerotic stroke subtypes remains less certain. For the purposes of primary prevention, ischemic stroke should be included among cardiovascular disease outcomes in absolute risk assessment algorithms. The inclusion of atherosclerotic ischemic stroke as a high-risk condition and the inclusion of ischemic stroke more broadly as an outcome will likely have important implications for prevention of cardiovascular disease, because the number of patients considered to be at high risk would grow substantially.

Prediction of worsening consciousness from edema after hemispheric infarction

We sought to develop a risk profile that would predict worsening consciousness from edema after hemispheric infarction. Charts were reviewed correlating initial computed tomography scan, neurologic examination, demographic features, and ischemic mechanism with worsening consciousness from massive edema after hemispheric infarction. An edema risk profile composed of two of three clinical factors (gaze preference, hemiplegia, or hemineglect) and evidence of acute cortical infarction on initial computed tomography scan highly correlated with the later development of worsening consciousness from edema. The edema risk profile correlated with worsening consciousness from edema after hemispheric infarction. The profile requires prospective verification before use for family counseling, for anticipatory care, and for randomizing patients in acute stroke trials aimed at controlling the formation and sequelae of edema after ischemic stroke.

Warfarin and low-dose aspirin for stroke prevention from severe intracranial stenosis

Management of symptomatic, intracranial, large-arterial atherosclerosis is controversial. We assessed the safety and efficacy of combining warfarin and low-dose aspirin to prevent stroke from intracranial atherosclerotic stenosis failing prior treatment with either aspirin or warfarin. Patients with severe intracranial stenosis were prescribed combination therapy, warfarin (international normalized ratio [INR] 2 to 3) and aspirin 81 mg daily. Ten men and six women treated with combination therapy had one recurrent ischemic event during 382 months of therapy. No patient suffered a myocardial infarction or sudden vascular death. No serious hemorrhagic complication occurred. The combination of warfarin and low-dose aspirin seems safe and effective in preventing recurrent stroke from symptomatic, intracranial, large-arterial occlusive disease after failure with either aspirin or warfarin monotherapy.

Warfarin vs aspirin for symptomatic intracranial stenosis: subgroup analyses from WASID

The WASID trial showed no advantage of warfarin over aspirin for preventing the primary endpoint of ischemic stroke, brain hemorrhage, or vascular death. In analyses of selected subgroups, there was no definite benefit from warfarin. Warfarin reduced the risk of the primary endpoint among patients with basilar artery stenosis, but there was no reduction in stroke in the basilar artery territory or benefit for vertebral artery stenosis or posterior circulation disease in general.

Single-vessel Versus Multivessel Territory Acute Ischemic Stroke: Value of Transesophageal Echocardiography in the Differentiation of Embolic Stroke

OBJECTIVES

We sought to assess the presence of potential aortic or cardiac sources of embolism in patients presenting with acute ischemic stroke in one or more vascular territories.

BACKGROUND

In patients with acute ischemic stroke, involvement of multiple vascular territories has been used to implicate a cardiac or aortic source of embolus. It remains unclear whether patients with multivessel stroke have a higher frequency of cardiac or aortic embolic sources on transesophageal echocardiography (TEE) compared with patients with single-territory stroke.

METHODS

We identified 210 patients with acute ischemic stroke documented by neuroimaging undergoing TEE for identification of a potential embolic source. Patients were divided into 3 groups (lacunar stroke, nonlacunar stroke/single-vessel involvement, nonlacunar stroke/multivessel involvement) and the frequency of potential embolic sources on TEE was compared.

RESULTS

Of the 210 patients, 121 (58%) were male and the mean age was 61 years. In all, 139 patients (66%) were classified as having single-vessel stroke, 47 (22%) as having multivessel stroke, and 24 (11%) as having lacunar stroke. On TEE, 87 patients (41%) had at least one potential source of embolism. Patients with multivessel strokes had fewer potential embolic sources on TEE than patients with single-vessel or lacunar strokes (26% vs 46% and 46%, respectively; P = .043).

CONCLUSIONS

In patients with acute ischemic stroke, the incidence of a potential cardiac or aortic source of embolism is high, regardless of the vascular distribution of the stroke. TEE may be a useful tool to assess the source of stroke in single-vessel, multivessel, and lacunar territory stroke distribution. We aimed to assess the presence of potential aortic or cardiac sources of embolism in patients presenting with acute ischemic stroke in one or more vascular territories. A total of 210 patients with acute ischemic stroke were divided into 3 groups (lacunar stroke, nonlacunar stroke/single-vessel involvement, nonlacunar stroke/multivessel involvement) and the frequency of potential embolic sources on transesophageal echocardiography was compared. Patients with multivessel strokes had fewer potential embolic sources on transesophageal echocardiography than patients with single-vessel or lacunar strokes, but the frequency of a potential cardiac or aortic source of embolism was high, regardless of the vascular distribution of stroke.

Heart diseases and stroke

A heterogeneous group of heart diseases, varying by cardiac anatomy and physiology, are responsible for a variety of embolic materials that result in cerebral and systemic embolism. Atrial fibrillation accounts for nearly half of all cardioembolic stroke, particularly in the elderly, but in the young congenital septal abnormalities such as patent foramen ovale play a more important role. Therapeutic strategies include stabilization or treatment of the underlying heart disease and prevention of embolism. Oral anticoagulant therapy is indicated for many but decision making on balancing the benefits versus risks can be difficult. New endovascular therapies and devices have become available and await clinical trials that allow them to be compared with existing medical therapies.

Predictors of Ischemic Stroke in the Territory of a Symptomatic Intracranial Arterial Stenosis

Background— Antithrombotic therapy for intracranial arterial stenosis was recently evaluated in the Warfarin versus Aspirin for Symptomatic Intracranial Disease (WASID) trial. A prespecified aim of WASID was to identify patients at highest risk for stroke in the territory of the stenotic artery who would be the target group for a subsequent trial comparing intracranial stenting with medical therapy.

Methods and Results— WASID was a randomized, double-blinded, multicenter trial involving 569 patients with transient ischemic attack or ischemic stroke due to 50% to 99% stenosis of a major intracranial artery. Median time from qualifying event to randomization was 17 days, and mean follow-up was 1.8 years. Multivariable Cox proportional hazards models were used to identify factors associated with subsequent ischemic stroke in the territory of the stenotic artery. Subsequent ischemic stroke occurred in 106 patients (19.0%); 77 (73%) of these strokes were in the territory of the stenotic artery. Risk of stroke in the territory of the stenotic artery was highest with severe stenosis ≥70% (hazard ratio 2.03; 95% confidence interval 1.29 to 3.22; P =0.0025) and in patients enrolled early (≤17 days) after the qualifying event (hazard ratio 1.69; 95% confidence interval 1.06 to 2.72; P =0.028). Women were also at increased risk, although this was of borderline significance (hazard ratio 1.59; 95% confidence interval 1.00 to 2.55; P =0.051). Location of stenosis, type of qualifying event, and prior use of antithrombotic medications were not associated with increased risk.

Conclusions— Among patients with symptomatic intracranial stenosis, the risk of subsequent stroke in the territory of the stenotic artery is greatest with stenosis ≥70%, after recent symptoms, and in women.

Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis

BACKGROUND

Atherosclerotic intracranial arterial stenosis is an important cause of stroke. Warfarin is commonly used in preference to aspirin for this disorder, but these therapies have not been compared in a randomized trial.

METHODS

We randomly assigned patients with transient ischemic attack or stroke caused by angiographically verified 50 to 99 percent stenosis of a major intracranial artery to receive warfarin (target international normalized ratio, 2.0 to 3.0) or aspirin (1300 mg per day) in a double-blind, multicenter clinical trial. The primary end point was ischemic stroke, brain hemorrhage, or death from vascular causes other than stroke.

RESULTS

After 569 patients had undergone randomization, enrollment was stopped because of concerns about the safety of the patients who had been assigned to receive warfarin. During a mean follow-up period of 1.8 years, adverse events in the two groups included death (4.3 percent in the aspirin group vs. 9.7 percent in the warfarin group; hazard ratio for aspirin relative to warfarin, 0.46; 95 percent confidence interval, 0.23 to 0.90; P=0.02), major hemorrhage (3.2 percent vs. 8.3 percent, respectively; hazard ratio, 0.39; 95 percent confidence interval, 0.18 to 0.84; P=0.01), and myocardial infarction or sudden death (2.9 percent vs. 7.3 percent, respectively; hazard ratio, 0.40; 95 percent confidence interval, 0.18 to 0.91; P=0.02). The rate of death from vascular causes was 3.2 percent in the aspirin group and 5.9 percent in the warfarin group (P=0.16); the rate of death from nonvascular causes was 1.1 percent and 3.8 percent, respectively (P=0.05). The primary end point occurred in 22.1 percent of the patients in the aspirin group and 21.8 percent of those in the warfarin group (hazard ratio, 1.04; 95 percent confidence interval, 0.73 to 1.48; P=0.83).

CONCLUSIONS

Warfarin was associated with significantly higher rates of adverse events and provided no benefit over aspirin in this trial. Aspirin should be used in preference to warfarin for patients with intracranial arterial stenosis.

Incidence and characteristics of stroke during 90-day follow-up in patients stabilized after an acute coronary syndrome

BACKGROUND

Stroke is a rare but serious event that complicates the course of patients with acute coronary syndromes (ACS). The type, outcome, and risk factors of stroke occurring in stabilized patients with ACS have not been previously reported.

METHODS

We evaluated stroke incidence, subtypes, and outcomes, in addition to demographics and clinical risk characteristics associated with stroke among patients enrolled in the Sibrafiban versus Aspirin to Yield Maximum Protection from Ischemic Heart Events Post-acute Coronary Syndromes (SYMPHONY) and 2nd SYMPHONY trials.

RESULTS

Of 15,904 stabilized patients with ACS, 113 (0.71%) had a stroke over a median follow-up of 90 days. The majority of strokes occurred within 30 days of presentation, and the time course for stroke occurrence paralleled that of myocardial (re)infarction. Most strokes were ischemic (78%), and 52% resulted in moderate or severe disability or death. Patients with stroke were older and more often had hypertension, diabetes, peripheral vascular disease, and atrial fibrillation. Among patients with stroke who had cardiac catheterization, percutaneous coronary intervention, or coronary artery bypass grafting, stroke occurred predominantly after the procedure. No difference in occurrence or type of stroke was observed in the assigned treatment groups. In multivariable modeling age, heart failure, prior stroke, left bundle branch block, and systolic blood pressure predicted the occurrence of stroke.

CONCLUSIONS

In patients stabilized after presenting with a spectrum of ACS and treated with sibrafiban and/or aspirin, stroke occurred in fewer than 1% within 90 days but carried a significant mortality and morbidity risk.

Risk of intracranial haemorrhage with combined fibrinolytic and glycoprotein IIb/IIIa inhibitor therapy in acute myocardial infarction Dichotomous response as a function of age in the GUSTO V trial

BACKGROUND

Intracranial haemorrhage is an important limitation to pharmacologic reperfusion therapy for acute myocardial infarction. The combination of a glycoprotein IIb/IIIa inhibitor, half-dose plasminogen activator and reduced-dose heparin has been evaluated as an alternative to standard fibrinolytic therapy in this setting.

METHODS AND RESULTS

We evaluated the relation between univariate and multivariate predictors of intracranial haemorrhage and the effect of treatment with either reteplase alone (10 U bolus twice, 30 min apart) with standard-dose heparin (5000 U bolus followed by an infusion of 1000 Uh(-1)for patients > or =80 kg and 800 Uh(-1)for those <80 kg) or combination therapy with abciximab (0.25mg/kg bolus and 0.125 microg/kg/min for 12h) and half-dose reteplase (two boluses of 5U 30 min apart) with reduced-dose heparin (60 Ukg(-1)bolus, maximum 5000 U, followed by an infusion of 7 Ukg(-1)h(-1)) in the 16 588 patients randomized in the GUSTO V trial. Overall, the incidence of intracranial haemorrhage was similar in the two groups (0.6% vs 0.6%; OR 1.05, 95% CI 0.71, 1.56). The median (25th-75th) time from drug administration to intracranial haemorrhage was 5.5 (3.4-11) hours with combination therapy and 9.2 (5.9-22) hours with reteplase (P=0.048). Among the multivariable predictors of intracranial haemorrhage, only age showed a significant interaction with treatment effect (age per treatment interaction chi-square 4.60, P=0.032) with a lower risk of combination therapy for younger patients and a higher risk for the elderly.

CONCLUSIONS

Although no additional risk of intracranial haemorrhage has been observed with combination therapy in the whole population, a significant age pertreatment interaction exists, with a lower risk with combination therapy in younger patients, and a higher risk in the elderly.

West Nile virus infection: a new acute paralytic illness

OBJECTIVE

To determine the clinical, laboratory, electrodiagnostic, radiologic, and pathologic characteristics that define the spectrum of CNS disease caused by West Nile virus (WNV) infection.

METHODS

The records of all patients hospitalized at the Cleveland Clinic from August 2002 to September 2002 with WNV infection were reviewed.

RESULTS

Of 23 cases, the median age was 74 years old, and 74% were men. Symptoms included fever (100%), altered mental status (74%), gastrointestinal complaints (43%), back pain (35%), and rash (26%). In half, meningitis or encephalitis overlapped with flaccid weakness that progressed over 3 to 8 days, with a tendency to be proximal and asymmetric. Laboratory abnormalities included hyponatremia (30%) and initial CSF neutrophilic pleocytosis. Electrodiagnostic studies in two patients showed reduced motor amplitudes with normal conduction velocities and active denervation. In two other patients, reduced sensory amplitudes were also seen. MRI changes included cauda equina enhancement and parenchymal spinal cord signal abnormalities and parenchymal or leptomeningeal signal changes in the brain. Autopsy in three cases showed chronic perivascular inflammation in the brain and inflammatory changes with anterior horn cell loss in the spinal cord.

CONCLUSION

An overlapping spectrum of meningitis, encephalitis, and myeloradiculitis occurs in CNS WNV infection. Fever, rash, abdominal and back pain, preceding a proximal, asymmetric flaccid weakness, with CSF pleocytosis help distinguish the motor syndrome from Guillain-Barré syndrome. Pathologic changes in the CNS resembled poliomyelitis.

Cuyahoga County Operation Stroke speed of emergency department evaluation and compliance with National Institutes of Neurological Disorders and Stroke time targets

BACKGROUND AND PURPOSE

Although the National Institutes of Neurological Disorders and Stroke (NINDS) has established time targets for the evaluation of acute stroke patients, little is known about how often these targets are met in the community. To track compliance with NINDS guidelines, Cuyahoga County Operation Stroke implemented a countywide data collection process that provides comparative reporting of hospital performance.

METHODS

Data on the emergency department evaluation of stroke patients have been retrospectively collected since January 2000 by hospitals participating in Cuyahoga County Operation Stroke. All hospitals used a 1-page form that includes NINDS time target information.

RESULTS

Median time to emergency department arrival for the 1003 patients in this cohort was 115 minutes; 382 patients (38%) arrived in <3 hours; 506 (50%) arrived in <6 hours. After arrival, median time to physician contact was 12 minutes, time to CT was 65 minutes, and time to imaging results was 105 minutes. Earlier arrival intervals after symptom onset were independently associated with shorter evaluation times. All time targets were met in patients receiving intravenous tissue plasminogen activator.

CONCLUSIONS

A countywide data collection system for acute stroke evaluation is feasible. In the Cleveland metropolitan area, time to physician contact is close to the recommended NINDS target. Time to CT and time to imaging results are substantially longer than recommended. However, there was wide variation between hospitals. The association between time to arrival, speed of evaluation, and administration of intravenous tissue plasminogen activator suggests that community physicians selectively accelerate the evaluation and management of potential thrombolysis candidates.

Cryptogenic stroke in relation to genetic variation in clotting factors and other genetic polymorphisms among young men and women

BACKGROUND AND PURPOSE

The purpose of the present study was to compare the prevalences of genetic polymorphisms in persons with cryptogenic stroke with those among stroke patients with evidence of large-artery occlusive disease or an unequivocal cardioembolic source (noncryptogenic stroke).

METHODS

We compared the prevalences of genetic polymorphisms thought to be related to thrombi formation in young stroke patients with evidence of large-artery occlusive disease or an unequivocal cardioembolic source (noncryptogenic stroke; controls; n=79) with those in young stroke patients without such sources (cryptogenic stroke; cases; n=67). Common variations in the genes encoding factor V, prothrombin, angiotensin I-converting enzyme, 5,10-methylenetetrahydrofolate reductase, endothelial cell nitric oxide synthase, tissue plasminogen activator, plasminogen activator inhibitor-1, and fibrinogen were evaluated. We also compared the allele prevalence of these genes among all stroke patients with those among a large pool of historical controls assayed for these genes.

RESULTS

None of these genetic polymorphisms was statistically significantly related to cryptogenic stroke. With respect to a comparison of all ischemic stroke with historical controls, only the prevalence of tissue plasminogen activator D allele among stroke subjects was statistically significantly higher than that of the historical controls (P=0.0014).

CONCLUSIONS

These findings generally do not support the hypothesis that genes associated with a prothrombotic state are risk factors among a subgroup of young people with stroke of undetermined cause. Except for the D tissue plasminogen activator allele, the findings also indicated that these genetic factors are unrelated, or only weakly related, to all ischemic stroke.

MRI findings in a case of transient cortical blindness after cardiac catheterization

The magnetic resonance imaging findings in a case of transient cortical blindness (TCB) after cardiac catheterization are described for the first time. In addition, a literature review of TCB, comparison with reversible posterior leukoencephalopathy, and a hypothesis regarding the pathophysiology of TCB are presented.