Effect of pioglitazone on vascular events in post-stroke cognitive impairment: Post hoc analysis of the IRIS trial.

BACKGROUND: In stroke patients with insulin resistance (IR), post-stroke cognitive impairment (PSCI) is associated with higher risk of recurrent stroke, but the effect of pioglitazone on that risk has not been explored. The goal of this study was to compare the secondary stroke prevention effect of pioglitazone against placebo in patients with versus without PSCI. METHODS: We studied patients enrolled in the Insulin Resistance Intervention after Stroke (IRIS) trial with a post-stroke modified Mini-Mental State Examination (3MS) cognitive assessment (mean time of assessment: 79 days post-stroke). We considered a baseline score of ⩽ 88 on the 3MS to indicate global PSCI, and domain-specific summary scores in the lowest quartile to indicate attention, language, memory, orientation, and visuospatial impairments. RESULTS: In n = 3338 patients with IR, the effect of pioglitazone versus placebo on secondary stroke significantly differed by initial post-stroke global (interaction p = 0.0127) and memory impairment status (interaction p = 0.0003). Hazard ratios (HRs) were time-dependent such that, among those with either global or memory impairment, pioglitazone has an increasingly stronger protective effect at later timepoints. There was no statistically significant effect of pioglitazone among those without either global or memory impairment. The effect of pioglitazone versus placebo on myocardial infarction (MI) also significantly differed by global impairment status (interaction p = 0.030). Pioglitazone was protective among those with global impairment (HR = 0.23 [95% CI: 0.08, 0.71]) but not among those without (HR = 0.88 [95% CI: 0.59, 1.31]). CONCLUSION: These data indicate that pioglitazone treatment may be more effective at reducing risk of recurrent stroke and MI in stroke patients with PSCI. Simple cognitive testing 2-3 months post-stroke may identify patients for whom treatment would be most beneficial.

Post-stroke cognitive impairment and the risk of stroke recurrence and death in patients with insulin resistance.

OBJECTIVE: Post-stroke cognitive impairment (PSCI) is associated with etiology, severity, and functional outcome of stroke. The risks of recurrent stroke and death in patients with PSCI and insulin resistance (IR) is unknown. The goal of this study was to determine whether global and domain-specific cognitive impairment after stroke in patients with IR was associated with recurrent stroke and death. MATERIALS AND METHODS: We studied patients with recent stroke or transient ischemic attack (TIA) and IR with a baseline Modified Mini-Mental State Examination (3MS) cognitive exam at median of 79 days after stroke. We considered a baseline score of ≤ 88 on the 3MS to indicate global cognitive impairment, and domain-specific summary scores in the lowest quartile to indicate language, attention, orientation, memory and visuospatial impairments. The primary endpoint was fatal or non-fatal recurrent stroke, and the secondary endpoints were all-cause mortality, and fatal or non-fatal myocardial infarction (MI). RESULTS: Among studied n = 3,338 patients 13.6% had global cognitive impairment. During the median 4.96 years of follow-up, 7.4% patients experienced recurrent stroke, 3.5% MI, and 7.3% died. In the fully adjusted model, impairment in language (HR 1.35; 95% CI 1.01-1.81) and orientation (HR 1.41; 95% CI: 1.06-1.87) were associated with a higher risk of recurrent stroke, while attention impairment was associated with all-cause mortality (HR 1.34; 95% CI: 1.01-1.78). DISCUSSION/CONCLUSION: In patients with recent stroke/TIA and IR, post-stroke language and orientation impairments independently predicted recurrent stroke, while attention deficit was associated with increased risk of all-cause mortality.

Estimating Perfusion Deficits in Acute Stroke Patients Without Perfusion Imaging.

BACKGROUND: Perfusion weighted imaging (PWI) is critical for determining whether stroke patients presenting in an extended time window are candidates for mechanical thrombectomy. However, PWI is not always available. Fluid-attenuated inversion recovery hyperintense vessels (FHVs) are seen in patients with a PWI lesion. We investigated whether a scale measuring the extent FHV could serve as a surrogate for PWI to determine eligibility for thrombectomy. METHODS: The National Institutes of Health (NIH) FHV score was developed to quantify the burden of FHV and applied to magnetic resonance imaging scans of stroke patients with fluid-attenuated inversion recovery and perfusion imaging. The NIH-FHV was combined with the diffusion weighted image volume to estimate the diffusion-perfusion mismatch ratio. Linear regression was used to compare PWI volumes and mismatch ratios with estimates from the NIH-FHV score. Receiver operating characteristic analysis was used to test the ability of the NIH-FHV score to identify a significant mismatch. RESULTS: There were 101 patients included in the analysis, of whom 78% had a perfusion deficit detected on PWI with a mean lesion volume of 47 (±59) mL. The NIH-FHV score was strongly associated with the PWI lesion volume (P<0.001; R2=0.32; ß-coefficient, 0.57). When combined with diffusion weighted image lesion volume, receiver operating characteristic analysis testing the ability to detect a mismatch ratio ≥1.8 using the NIH-FHV score resulted in an area under the curve of 0.94. CONCLUSIONS: The NIH-FHV score provides an estimate of the PWI lesion volume and, when combined with diffusion weighted imaging, may be helpful when trying to determine whether there is a clinically relevant diffusion-perfusion mismatch in situations where perfusion imaging is not available. Further studies are needed to validate this approach.

Cognitive Impairment after Lacunar Stroke and the Risk of Recurrent Stroke and Death.

INTRODUCTION: Patients with poststroke cognitive impairment appear to be at higher risk of recurrent stroke and death. However, whether cognitive impairment after lacunar stroke is associated with recurrent stroke and death remains unclear. We assessed whether global or domain-specific cognitive impairment after lacunar stroke is associated with recurrent stroke and death. METHODS: We considered patients from the Secondary Prevention of Small Subcortical Strokes (SPS3) trial with a baseline cognitive exam administered in English by certified SPS3 personnel, 14-180 days after qualifying lacunar stroke. We considered a baseline score of ≤86 on the Cognitive Assessment Screening Instrument to indicate global cognitive impairment, <10 on the Clock Drawing on Command test to indicate executive function impairment, and domain-specific summary scores in the lowest quartile to indicate memory and nonmemory impairment. We used Cox proportional hazards models to estimate the association between poststroke cognitive impairment and subsequent risk of recurrent stroke and death. RESULTS: The study included 1,528 participants with a median enrollment time of 62 days after qualifying stroke. During a mean follow-up of 3.9 years, 11.4% of participants had recurrent stroke and 8.2% died. In the fully adjusted models, memory impairment was independently associated with an increased risk of recurrent stroke (hazard ratio, 1.48; 95% confidence interval [95% CI]: 1.04-2.09) and death (hazard ratio, 1.87; 95% CI: 1.25-2.79). Global impairment (hazard ratio, 1.66; 95% CI: 1.06-2.59) and nonmemory impairment (hazard ratio, 1.74; 95% CI: 1.14-2.67) were associated with an increased risk of death. DISCUSSION/CONCLUSION: After lacunar stroke, memory impairment was an independent predictor of recurrent stroke and death, while global and nonmemory impairment were associated with death. Cognitive screening in lacunar stroke may help identify populations at higher risk of recurrent stroke and death.

Prevalence of Imaging Targets in Patients With Minor Stroke Selected for IV tPA Treatment Using MRI: The Treatment of Minor Stroke With MRI Evaluation Study (TIMES).

OBJECTIVE: To determine the IV tissue plasminogen activator (tPA) treatment rate of patients with minor acute ischemic stroke (mAIS) at our centers and compare the frequency of MRI targets by treatment stratification and clinical severity, we evaluated clinical characteristics and baseline MRIs for tPA-treated and untreated patients. METHODS: Patients with ischemic stroke from 2015 to 2017 with admit NIH Stroke Scale (NIHSS) <6 were considered. The treated cohort received standard IV tPA and was screened with baseline MRI. The untreated cohort received no acute intervention and baseline MRI was <4 hours from onset. Patients were stratified into "clearly" and "not clearly" disabling deficits by NIHSS elements. Baseline MRI was evaluated by independent raters for AIS targets, with frequencies compared between groups. RESULTS: Of 255 patients with mAIS ≤4.5 hours from onset, 140 (55%) received IV tPA, accounting for 46% of all IV tPA patients (n = 305). Eighty-five percent (n = 119) were screened with baseline MRI and had significantly more frequent imaging targets compared to those untreated (n = 90). Of this treated cohort, 75% (n = 89) were not clearly disabling. Except for perfusion-diffusion mismatch (81% clearly disabling vs 56% not clearly disabling [p = 0.036]), there were no significant differences in the frequency of imaging targets across the treated cohort stratified by clinical severity. CONCLUSIONS: In MRI-screened mAIS, imaging targets were more frequently seen in patients treated with IV tPA, with similar frequencies even in those without clearly disabling deficits. MRI targets could be used to guide thrombolytic therapy in patients with mAIS; however, a randomized trial is needed to demonstrate efficacy.

Routine use of FLAIR-negative MRI in the treatment of unknown onset stroke.

BACKGROUND: Treatment of FLAIR-negative stroke in patients presenting in an unknown time window has been shown to be safe and effective. However, implementation can be challenging due to the need for hyper-acute MRI screening. The purpose of this study was to review the routine application of this practice outside of a clinical trial. METHODS: Patients presenting from 3/1/16 to 8/22/18 in a time window <4.5 h from symptom discovery but >4.5 h from last known normal were included if they had a hyper-acute MRI performed. Quantitative assessment based on the MR WITNESS trial and qualitative assessment based on the WAKE-UP trial were used to grade the FLAIR images. The MR WITNESS trial used a quantitative assessment of FLAIR change where the fractional increase in signal change had to be <1.15, whereas the WAKE-UP trial used a visual assessment requiring the absence of marked FLAIR signal changes. RESULTS: During the study period, 136 stroke patients presented and were imaged in the specified time window. Of these, 17 (12.5%) received IV tPA. Three patients had hemorrhage on 24-h MRI follow up; none had an increase in NIHSS ≥4. Of the 119 patients who were screened but not treated, 18 (15%) were eligible based on FLAIR quantitative assessment and 55 (46%) were eligible based on qualitative assessment. In all cases where patients were not treated, there was an identifiable exclusion based on trial criteria. During the study period, IV tPA utilization was increased by 5.6% due to screening and treating patients with unknown onset stroke. CONCLUSIONS: Screening stroke patients in an unknown time window with MRI is practical in a real-world setting and increases IV tPA utilization.

MRI-based thrombolytic therapy in patients with acute ischemic stroke presenting with a low NIHSS.

OBJECTIVE: Treatment of patients with stroke presenting with minor deficits remains controversial, and the recent Potential of rtPA for Ischemic Strokes with Mild Symptoms (PRISMS) trial, which randomized patients to thrombolysis vs aspirin, did not show benefit. We studied the safety and efficacy of thrombolysis in a population of patients with acute stroke presenting with low NIH Stroke Scale (NIHSS) scores screened using MRI. METHODS: The NIH Natural History of Stroke database was reviewed from January 2006 to December 2016 to identify all patients with an initial NIHSS score ≤5 who received thrombolysis within 4.5 hours of symptom onset after being screened with MRI. The 24-hour postthrombolysis MRIs were reviewed for hemorrhagic transformation. Primary outcomes were symptomatic intracranial hemorrhage (sICH) and favorable 90-day outcome modified Rankin Scale score 0-1. Subgroup analysis was performed on patients who would have been eligible for the PRISMS trial, which enrolled patients with a nondisabling neurologic deficit. RESULTS: A total of 121 patients were included in the study with a median age of 65 and an NIHSS score of 3; 63% were women. The rate of any hemorrhagic transformation was 13%, with 11% of them being limited to petechial hemorrhage. The rate of sICH was <1%. Sixty-six patients had 90-day outcome data; of those, 74% had a favorable outcome. For the subgroup of 81 PRISMS-eligible patients, none experienced sICH. Fifty of these patients had 90-day outcome data; of these, 84% had a favorable outcome. CONCLUSIONS: Thrombolytic therapy was safe in our patients with stroke with minor deficits who were initially evaluated by MRI. Future studies of this population may benefit from MRI selection. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with acute ischemic stroke and NIHSS ≤5 screened with MRI, IV tissue plasminogen activator is safe.

Rapid Apparent Diffusion Coefficient Evolution After Early Revascularization.

Background and Purpose- In this era of endovascular therapy (EVT) with early, complete recanalization and reperfusion, we have observed an even more rapid apparent diffusion coefficient (ADC) normalization within the acute ischemic lesion compared with the natural history or IV-tPA-treated patient. In this study, we aimed to evaluate the effect of revascularization on ADC evolution within the core lesion in the first 24 hours in acute ischemic stroke patients. Methods- This retrospective study included anterior circulation acute ischemic stroke patients treated with EVT with or without intravenous tPA (IVT) from 2015 to 2017 compared with a consecutive cohort of IVT-only patients treated before 2015. Diffusion-weighted imaging and ADC maps were used to quantify baseline core lesions. Median ADC value change and core reversal were determined at 24 hours. Diffusion-weighted imaging lesion growth was measured at 24 hours and 5 days. Good clinical outcome was defined as modified Rankin Scale score of 0 to 2 at 90 days. Results- Twenty-five patients (50%) received IVT while the other 25 patients received EVT (50%) with or without IVT. Between these patient groups, there were no differences in age, sex, baseline National Institutes of Health Stroke Scale, interhospital transfer, or IVT rates. Thirty-two patients (64%) revascularized with 69% receiving EVT. There was a significant increase in median ADC value of the core lesion at 24 hours in patients who revascularized compared with further ADC reduction in nonrevascularization patients. Revascularization patients had a significantly higher rate of good clinical outcome at 90 days, 63% versus 9% (P=0.003). Core reversal at 24 hours was significantly higher in revascularization patients, 69% versus 22% (P=0.002). Conclusions- ADC evolution in acute ischemic stroke patients with early, complete revascularization, now more commonly seen with EVT, is strikingly different from our historical understanding. The early ADC normalization we have observed in this setting may include a component of secondary injury and serve as a potential imaging biomarker for the development of future adjunctive therapies. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00009243.

Frequency of Blood-Brain Barrier Disruption Post-Endovascular Therapy and Multiple Thrombectomy Passes in Acute Ischemic Stroke Patients.

Background and Purpose- The high prevalence of hyperintense acute reperfusion marker (HARM) seen after endovascular therapy is suggestive of blood-brain barrier disruption and hemorrhage risk and may be attributable to multiple thrombectomy passes needed to achieve recanalization. Methods- Patients with acute stroke were included if they were screened from January 2015 through February 2019, received an acute ischemic stroke diagnosis involving the anterior circulation, treated with or without IV tPA (intravenous tissue-type plasminogen activator), consented to the NINDS Natural History Study, and imaged with a baseline magnetic resonance imaging before receiving endovascular therapy. Consensus image reads for HARM and hemorrhagic transformation were performed. Good clinical outcome was defined as 0-2 using the latest available modified Rankin Scale score. Results- Eighty patients met all study criteria and were included in the analyses. Median age was 65 years, 64% female, 51% black/African American, median admit National Institutes of Health Stroke Scale=19, 56% treated with IV tPA, and 84% achieved Thrombolysis in Cerebral Infarction score of 2b/3. Multiple-pass patients had significantly higher rates of severe HARM at 24 hours (67% versus 29%; P=0.001), any hemorrhagic transformation (60% versus 36%; P=0.04) and poor clinical outcome (67% versus 36%; P=0.008). Only age (odds ratio, 1.1; 95% CI, 1.01-1.12; P=0.022) and severe HARM at 24 hours post-endovascular therapy were significantly associated with multiple passes (odds ratio, 7.2; 95% CI, 1.93-26.92; P=0.003). Conclusions- In this exploratory study, multiple thrombectomy passes are independently associated with a significant increase in blood-brain barrier disruption detected at 24 hours. Patients with HARM post-endovascular therapy had a >7-fold increase in the odds of having multiple- versus single-pass thrombectomy. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00009243.

Molecular signature of penumbra in acute ischemic stroke: a pilot transcriptomics study.

We aimed to characterize peripheral blood gene expression profile of penumbra defined as MRI perfusion-diffusion mismatch (PD MM) in peripheral blood of patients with acute ischemic stroke. We studied 23 patients. Perfusion-diffusion mismatch volume was observed to be associated and significantly correlated with the expression of 34 genes including those related to inflammation, SUMOylation, and coagulation; while lipopolysaccharide inhibition was identified to be a candidate upstream regulator of these processes (z-score -2.38, P = 0.04). Penumbral volume is correlated with a specific gene expression profile in the peripheral blood characterized by overlap of inflammatory and neuroprotective pathways that are regulated by lipopolysaccharide inhibition.

Post-Stroke Blood-Brain Barrier Disruption and Poor Functional Outcome in Patients Receiving Thrombolytic Therapy.

BACKGROUND AND PURPOSE: The role played by post-stroke inflammation after an ischemic event in limiting functional recovery remains unclear. One component of post-stroke inflammation is disruption of the blood-brain barrier (BBB). This study examines the relationship between post-stroke BBB disruption and functional outcome. METHODS: Acute stroke patients treated with thrombolysis underwent magnetic resonance imaging scanning 24 h and 5 days after their initial event. BBB permeability maps were generated from perfusion weighted imaging. Average permeability was calculated in the affected hemisphere. Good functional outcome, defined as a modified Rankin score of 0 or 1, was compared with average permeability using logistic regression. RESULTS: Of the 131 patients enrolled, 76 patients had the necessary data to perform the analysis at 24 h, and 58 -patients had data for the 5-day assessment. Higher BBB permeability measured at 24 h (OR 0.57; 95% CI 0.33-0.99, p = 0.045) and at 5 days (OR 0.24; 95% CI 0.09-0.66, p = 0.005) was associated with worse functional outcome 1-3 months after the acute ischemic stroke. For every percentage increase in BBB disruption at 5 days, there was a 76% decrease in the chance of achieving a good functional outcome after stroke. Multivariate analysis found this to be independent of age, stroke volume, or clinical stroke severity. CONCLUSIONS: Post-stroke BBB disruption appears to be predictive of functional outcome irrespective of stroke size.

Mild Cognitive Impairment in Republic of Georgia.

Objective: The goal of this study was to estimate the prevalence of mild cognitive impairment (MCI) in Georgia. Method: A population-based study was conducted using Georgian version of the Montreal Cognitive Assessment (MoCA) and its cognitive domain index score. Results: Of the initial cohort of 1,000 subjects, 851 met inclusion criteria. The prevalence of MCI was 13.3%, and it was associated with age >65 years (odds ratio [OR] = 4.51, 95% confidence interval [CI] = [3.00, 6.75]), urban residence (OR = 0.53, 95% CI = [0.33, 0.88]), lower education (OR = 3.99, 95% CI = [2.66, 5.93]), and hypertension (OR = 2.51, 95% CI = [1.68, 3.76]), while amnestic MCI was documented in 9.3%, with higher risk in older subjects (OR = 2.69, 95% CI = [1.66, 4.20]), and diabetics (OR = 2.69, 95% CI = [1.25, 5.98]). Conclusion: In this first population-based study of MCI in Georgia, prevalence was comparable with those reported from the United States and Europe. Observed association of MCI with cardiovascular risk factors has important clinical implication for dementia prevention in Georgia.

An MRI Hyperintense Acute Reperfusion Marker Is Related to Elevated Peripheral Monocyte Count in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Blood-brain barrier (BBB) disruption detected on magnetic resonance imaging (MRI) in acute ischemic stroke as a hyperintense acute reperfusion marker (HARM) is associated with upregulation of matrix metalloproteinase-9 (MMP-9). Although activated leukocytes, including monocytes, are the main source of MMPs, limited data exist to support relationship between leukocyte activation and BBB disruption in patients with acute ischemic stroke. The goal of this study is to investigate the relationship between neutrophils, lymphocytes, and monocytes with BBB disruption detected as HARM (+) in patients with acute ischemic stroke. METHODS: We conducted a retrospective analysis of prospectively collected data in patients who did not receive any reperfusion therapy with acute (<12 hours) ischemic stroke. MRI scans were obtained at baseline, 24 hours, and 5 days. HARM was evaluated on the 24-hour follow-up scan. RESULTS: Thirty-three patients were studied. HARM was detected in 27% of patients. Median volumes of baseline perfusion (mean transit time [MTT]) deficit (219.4 mL vs. 158.4 mL, P = .029) and DWI infarct growth at 24 hours (18.50 mL vs. .14 mL, P = .017), as well as the median absolute numbers (1 × 103 /mm3 ) of monocytes, were significantly higher in HARM (+) versus HARM (-) patients (0.9 vs. 0.6, p = 0.011). CONCLUSION: Increased monocyte count associated with HARM supports importance of systemic inflammation in BBB disruption in acute ischemic stroke.

Helistroke: neurointerventionalist helicopter transport for interventional stroke treatment: proof of concept and rationale.

BACKGROUND AND PURPOSE: It is increasingly recognized that time is one of the key determinants in acute stroke outcome when interventional stroke therapy is applied. With increasing device efficacy and understanding of imaging triage options, reducing pre-treatment time loss may be a critical component of improving interventional stroke outcomes for the population at large. Time sensitive procedures such as organ harvest have transported physicians to the patient site to improve time to procedure. Applying this same principle to interventional stroke management may be a valid paradigm. METHODS: Previous logistical deliberation with hospital and Medevac companies was carried out to provide the rationale and funding for helicopter transfer of a neurointerventionalist to an in-network hospital with an on-site angiographic suite. An appropriate patient with large vessel occlusion and an NIH Stroke Scale score >8 was identified. MRI was performed, then the Medevac transport system was activated and the intervention was carried out. Times were collected during the case and assessed for time efficiency. RESULTS: The proof of concept case was identified and Medevac was consulted at 12:13 after verifying that no in-house emergencies would prevent physician departure. Weather clearance was obtained and stroke intervention confirmed as a go at 12:24. Groin puncture occurred at 13:07 and the intervention was completed at 13:41. The total time from decision-to-treat to groin puncture was 43 min and groin closure was completed at 77 min from decision-to-treat. CONCLUSIONS: This proof of concept case is presented for logistical, financial and use-case analysis. As it is a first case, times can likely be improved. We assert that this model may be another option in the spoke-and-hub design of stroke systems of care.

Effects of increasing IV tPA-treated stroke mimic rates at CT-based centers on clinical outcomes.

OBJECTIVE: To determine to what degree stroke mimics skew clinical outcomes and the potential effects of incorrect stroke diagnosis. METHODS: This retrospective analysis of data from 2005 to 2014 included IV tissue plasminogen activator (tPA)-treated adults with clinical suspicion for acute ischemic stroke who were transferred or admitted directly to our 2 hub hospitals. Primary outcome measures compared CT-based spoke hospitals' and MRI-based hub hospitals' mimic rates, hemorrhagic transformation, follow-up modified Rankin Scale (mRS), and discharge disposition. Secondary outcomes were compared over time. RESULTS: Of the 725 thrombolysis-treated patients, 29% were at spoke hospitals and 71% at hubs. Spoke hospital patients differed from hubs by age (mean 62 ± 15 vs 72 ± 15 years, p < 0.0001), risk factors (atrial fibrillation, 17% vs 32%, p < 0.0001; alcohol consumption, 9% vs 4%, p = 0.007; smoking, 23% vs 13%, p = 0.001), and mimics (16% vs 0.6%, p < 0.0001). Inclusion of mimics resulted in better outcomes for spokes vs hubs by mRS ≤1 (40% vs 27%, p = 0.002), parenchymal hematoma type 2 (3% vs 7%, p = 0.037), and discharge home (47% vs 37%, p = 0.01). Excluding mimics, there were no significant differences. Comparing epochs, spoke stroke mimic rate doubled (9%-20%, p = 0.03); hub rate was unchanged (0%-1%, p = 0.175). CONCLUSIONS: Thrombolysis of stroke mimics is increasing at our CT-based spoke hospitals and not at our MRI-based hub hospitals. Caution should be used in interpreting clinical outcomes based on large stroke databases when stroke diagnosis at discharge is unclear. Inadvertent reporting of treated stroke mimics as strokes will artificially elevate overall favorable clinical outcomes with additional downstream costs to patients and the health care system.

Perfusion Deficits and Association with Clinical Outcome in Patients with Anterior Choroidal Artery Stroke.

BACKGROUND AND PURPOSE: Anterior choroidal artery (AChA) strokes have a varied pattern of tissue injury, prognosis, and clinical outcome. It is unclear whether perfusion deficit in AChA stroke is associated with the clinical outcome. This study aims to determine the frequency of perfusion abnormalities in AChA stroke and association with clinical outcome. METHODS: The study cohort was derived from ischemic stroke patients admitted to 2 stroke centers between July 2001 and July 2014. All patients received an acute magnetic resonance imaging (MRI) scan. Patients with ischemic stroke restricted to the AChA territory were included in the study. Lesion size was measured as the largest diameter on diffusion-weighted imaging (DWI) or apparent diffusion coefficient and divided into 2 groups (<20 mm or ≥20 mm). Group comparisons were performed among patients with and without perfusion abnormalities and based on diffusion diameter. Favorable clinical outcome was defined as discharge to home. RESULTS: A total of 120 patients were included in the study. Perfusion deficits were identified in 67% of patients. The admission National Institutes of Health Stroke Scale (NIHSS) was higher in patients with perfusion abnormalities (P = .027). Diameter lesion size on DWI was larger among patients with a perfusion deficit median [interquartile range], 1.63 [1.3-2.0], as compared with those without, 1.18 [1.0-1.7], P < .0001. Patients with a perfusion deficit were less likely to be discharged to home than those without (36% versus 60%, P = .013). CONCLUSIONS: Two thirds of patients with an AChA stroke have a perfusion deficit on MRI, higher admission NIHSS, and larger DWI lesion size at presentation.