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BackgroundPrehospital automated large vessel occlusion (LVO) detection in Mobile Stroke Units (MSUs) could accelerate identification and treatment of patients with LVO acute ischemic stroke. Here, we evaluate the performance of a machine learning (ML) model on CT angiograms (CTAs) obtained from 2 MSUs to detect LVO.MethodsPatients evaluated on MSUs in Houston and Los Angeles with out-of-hospital CTAs were identified. Anterior circulation LVO was defined as an occlusion of the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or anterior cerebral artery vessels and determined by an expert human reader. A ML model to detect LVO was trained and tested on independent data sets consisting of in-hospital CTAs and then tested on MSU CTA images. Model performance was determined using area under the receiver-operator curve statistics.ResultsAmong 68 patients with out-of-hospital MSU CTAs, 40% had an LVO. The most common occlusion location was the middle cerebral artery M1 segment (59%), followed by the internal carotid artery (30%), and middle cerebral artery M2 (11%). Median time from last known well to CTA imaging was 88.0 (interquartile range, 59.5-196.0) minutes. After training on 870 in-hospital CTAs, the ML model performed well in identifying LVO in a separate in-hospital data set of 441 images with area under receiver-operator curve of 0.84 (95% CI, 0.80-0.87). ML algorithm analysis time was under 1 minute. The performance of the ML model on the MSU CTA images was comparable with area under receiver-operator curve 0.80 (95% CI, 0.71-0.89). There was no significant difference in performance between the Houston and Los Angeles MSU CTA cohorts.ConclusionsIn this study of patients evaluated on MSUs in 2 cities, a ML algorithm was able to accurately and rapidly detect LVO using prehospital CTA acquisitions.

Background Evidence suggests intracerebral hemorrhage survivors have earlier recovery compared with ischemic stroke survivors. The Centers for Medicare and Medicaid Services prospective payment system instituted documentation rules for inpatient rehabilitation facilities (IRFs) in 2010, with the goal of optimizing patient selection. We investigated whether these requirements limited IRF and increased skilled nursing facility (SNF) use compared with home discharge. Methods and Results Intracerebral hemorrhage discharges to IRF, SNF, or home were estimated using GWTG (Get With The Guidelines) Stroke registry data between January 1, 2008, and December 31, 2015 (n=265 444). Binary hierarchical models determined associations between the 2010 Rule and discharge setting; subgroup analyses evaluated age, geographic region, and hospital type. From January 1, 2008, to December 31, 2009, 45.5% of patients with intracerebral hemorrhage had home discharge, 22.2% went to SNF, and 32.3% went to IRF. After January 1, 2010, there was a 1.06% absolute increase in home discharge, a 0.46% increase in SNF, and a 1.52% decline in IRF. The adjusted odds of IRF versus home discharge decreased 3% after 2010 (adjusted odds ratio [aOR], 0.97; 95% CI, 0.95-1.00). Lower odds of IRF versus home discharge were observed in people aged <65 years (aOR, 0.92; 95% CI, 0.89-0.96), Western states (aOR, 0.89; 95% CI, 0.84-0.95), and nonteaching hospitals (aOR, 0.90; 95% CI, 0.86-0.95). Adjusted odds of SNF versus home discharge increased 14% after 2010 (aOR, 1.14; 95% CI, 1.11-1.18); there were significant associations in all age groups, the Northeast, the South, the Midwest, and teaching hospitals. Conclusions The Centers for Medicare and Medicaid Services 2010 IRF prospective payment system Rule resulted in fewer discharges to IRF and more discharges to SNF in patients with intracerebral hemorrhage. Health policy changes potentially affect access to intensive postacute rehabilitation.

Background Evidence suggests intracerebral hemorrhage survivors have earlier recovery compared with ischemic stroke survivors. The Centers for Medicare and Medicaid Services prospective payment system instituted documentation rules for inpatient rehabilitation facilities (IRFs) in 2010, with the goal of optimizing patient selection. We investigated whether these requirements limited IRF and increased skilled nursing facility (SNF) use compared with home discharge. Methods and Results Intracerebral hemorrhage discharges to IRF, SNF, or home were estimated using GWTG (Get With The Guidelines) Stroke registry data between January 1, 2008, and December 31, 2015 (n=265 444). Binary hierarchical models determined associations between the 2010 Rule and discharge setting; subgroup analyses evaluated age, geographic region, and hospital type. From January 1, 2008, to December 31, 2009, 45.5% of patients with intracerebral hemorrhage had home discharge, 22.2% went to SNF, and 32.3% went to IRF. After January 1, 2010, there was a 1.06% absolute increase in home discharge, a 0.46% increase in SNF, and a 1.52% decline in IRF. The adjusted odds of IRF versus home discharge decreased 3% after 2010 (adjusted odds ratio [aOR], 0.97; 95% CI, 0.95-1.00). Lower odds of IRF versus home discharge were observed in people aged <65 years (aOR, 0.92; 95% CI, 0.89-0.96), Western states (aOR, 0.89; 95% CI, 0.84-0.95), and nonteaching hospitals (aOR, 0.90; 95% CI, 0.86-0.95). Adjusted odds of SNF versus home discharge increased 14% after 2010 (aOR, 1.14; 95% CI, 1.11-1.18); there were significant associations in all age groups, the Northeast, the South, the Midwest, and teaching hospitals. Conclusions The Centers for Medicare and Medicaid Services 2010 IRF prospective payment system Rule resulted in fewer discharges to IRF and more discharges to SNF in patients with intracerebral hemorrhage. Health policy changes potentially affect access to intensive postacute rehabilitation.

Background Evidence suggests intracerebral hemorrhage survivors have earlier recovery compared with ischemic stroke survivors. The Centers for Medicare and Medicaid Services prospective payment system instituted documentation rules for inpatient rehabilitation facilities (IRFs) in 2010, with the goal of optimizing patient selection. We investigated whether these requirements limited IRF and increased skilled nursing facility (SNF) use compared with home discharge. Methods and Results Intracerebral hemorrhage discharges to IRF, SNF, or home were estimated using GWTG (Get With The Guidelines) Stroke registry data between January 1, 2008, and December 31, 2015 (n=265 444). Binary hierarchical models determined associations between the 2010 Rule and discharge setting; subgroup analyses evaluated age, geographic region, and hospital type. From January 1, 2008, to December 31, 2009, 45.5% of patients with intracerebral hemorrhage had home discharge, 22.2% went to SNF, and 32.3% went to IRF. After January 1, 2010, there was a 1.06% absolute increase in home discharge, a 0.46% increase in SNF, and a 1.52% decline in IRF. The adjusted odds of IRF versus home discharge decreased 3% after 2010 (adjusted odds ratio [aOR], 0.97; 95% CI, 0.95-1.00). Lower odds of IRF versus home discharge were observed in people aged <65 years (aOR, 0.92; 95% CI, 0.89-0.96), Western states (aOR, 0.89; 95% CI, 0.84-0.95), and nonteaching hospitals (aOR, 0.90; 95% CI, 0.86-0.95). Adjusted odds of SNF versus home discharge increased 14% after 2010 (aOR, 1.14; 95% CI, 1.11-1.18); there were significant associations in all age groups, the Northeast, the South, the Midwest, and teaching hospitals. Conclusions The Centers for Medicare and Medicaid Services 2010 IRF prospective payment system Rule resulted in fewer discharges to IRF and more discharges to SNF in patients with intracerebral hemorrhage. Health policy changes potentially affect access to intensive postacute rehabilitation.

Background: Intracerebral haemorrhage growth is associated with poor clinical outcome and is a therapeutic target for improving outcome. We aimed to determine the absolute risk and predictors of intracerebral haemorrhage growth, develop and validate prediction models, and evaluate the added value of CT angiography. Methods: In a systematic review of OVID MEDLINE—with additional hand-searching of relevant studies' bibliographies— from Jan 1, 1970, to Dec 31, 2015, we identified observational cohorts and randomised trials with repeat scanning protocols that included at least ten patients with acute intracerebral haemorrhage. We sought individual patient-level data from corresponding authors for patients aged 18 years or older with data available from brain imaging initially done 0·5–24 h and repeated fewer than 6 days after symptom onset, who had baseline intracerebral haemorrhage volume of less than 150 mL, and did not undergo acute treatment that might reduce intracerebral haemorrhage volume. We estimated the absolute risk and predictors of the primary outcome of intracerebral haemorrhage growth (defined as >6 mL increase in intracerebral haemorrhage volume on repeat imaging) using multivariable logistic regression models in development and validation cohorts in four subgroups of patients, using a hierarchical approach: patients not taking anticoagulant therapy at intracerebral haemorrhage onset (who constituted the largest subgroup), patients taking anticoagulant therapy at intracerebral haemorrhage onset, patients from cohorts that included at least some patients taking anticoagulant therapy at intracerebral haemorrhage onset, and patients for whom both information about anticoagulant therapy at intracerebral haemorrhage onset and spot sign on acute CT angiography were known. Findings: Of 4191 studies identified, 77 were eligible for inclusion. Overall, 36 (47%) cohorts provided data on 5435 eligible patients. 5076 of these patients were not taking anticoagulant t

Background and purposeAlthough the modified Rankin Scale (mRS) is the most commonly used primary end point in acute stroke trials, its power is limited when analyzed in dichotomized fashion and its indication of effect size challenging to interpret when analyzed ordinally. Weighting the 7 Rankin levels by utilities may improve scale interpretability while preserving statistical power.MethodsA utility-weighted mRS (UW-mRS) was derived by averaging values from time-tradeoff (patient centered) and person-tradeoff (clinician centered) studies. The UW-mRS, standard ordinal mRS, and dichotomized mRS were applied to 11 trials or meta-analyses of acute stroke treatments, including lytic, endovascular reperfusion, blood pressure moderation, and hemicraniectomy interventions.ResultsUtility values were 1.0 for mRS level 0; 0.91 for mRS level 1; 0.76 for mRS level 2; 0.65 for mRS level 3; 0.33 for mRS level 4; 0 for mRS level 5; and 0 for mRS level 6. For trials with unidirectional treatment effects, the UW-mRS paralleled the ordinal mRS and outperformed dichotomous mRS analyses. Both the UW-mRS and the ordinal mRS were statistically significant in 6 of 8 unidirectional effect trials, whereas dichotomous analyses were statistically significant in 2 to 4 of 8. In bidirectional effect trials, both the UW-mRS and ordinal tests captured the divergent treatment effects by showing neutral results, whereas some dichotomized analyses showed positive results. Mean utility differences in trials with statistically significant positive results ranged from 0.026 to 0.249.ConclusionsA UW-mRS performs similar to the standard ordinal mRS in detecting treatment effects in actual stroke trials and ensures the quantitative outcome is a valid reflection of patient-centered benefits.

Background and purposeIntra-arterial therapy (IAT) promotes recanalization of large artery occlusions in acute ischemic stroke. Despite high recanalization rates, poor clinical outcomes are common. We attempted to optimize a score that combines clinical and imaging variables to more accurately predict poor outcome after IAT in anterior circulation occlusions.MethodsPatients with acute ischemic stroke undergoing IAT at University of Texas (UT) Houston for large artery occlusions (middle cerebral artery or internal carotid artery) were reviewed. Independent predictors of poor outcome (modified Rankin Scale, 4-6) were studied. External validation was performed on IAT-treated patients at Emory University.ResultsA total of 163 patients were identified at UT Houston. Independent predictors of poor outcome (P≤0.2) were identified as score variables using sensitivity analysis and logistic regression. Houston Intra-Arterial Therapy 2 (HIAT2) score ranges 0 to 10: age (≤59=0, 60-79=2, ≥80 years=4), glucose (<150=0, ≥150=1), National Institute Health Stroke Scale (≤10=0, 11-20=1, ≥21=2), the Alberta Stroke Program Early CT Score (8-10=0, ≤7=3). Patients with HIAT2≥5 were more likely to have poor outcomes at discharge (odds ratio, 6.43; 95% confidence interval, 2.75-15.02; P<0.001). After adjusting for reperfusion (Thrombolysis in Cerebral Infarction score≥2b) and time from symptom onset to recanalization, HIAT2≥5 remained an independent predictor of poor outcome (odds ratio, 5.88; 95% confidence interval, 1.96-17.64; P=0.02). Results from the cohort of Emory (198 patients) were consistent; patients with HIAT2 score≥5 had 6× greater odds of poor outcome at discharge and at 90 days. HIAT2 outperformed other previously published predictive scores.ConclusionsThe HIAT2 score, which combines clinical and imaging variables, performed better than all previous scores in predicting poor outcome after IAT for anterior circulation large artery occlusions.

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BACKGROUND: Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis.METHODS: We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patient's symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis.FINDINGS: Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.

BACKGROUND: Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis.METHODS: We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patient's symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis.FINDINGS: Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.

Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis.

Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis.

Cryptogenic stroke is associated with an increased prevalence of patent foramen ovale. The Paradoxical Emboli From Large Veins in Ischemic Stroke (PELVIS) study hypothesized that patients with cryptogenic stroke have an increased prevalence of pelvic deep venous thrombosis (DVT).At 5 sites, patients 18 to 60 years of age received an MRI venogram (MRV) of the pelvis within 72 hours of new symptom onset. Clinical data were then determined. Radiologists blinded to clinical data later read the scans.The 95 patients who met entry criteria were scanned. Their mean+/-SD age was 46+/-10 years, and time from stroke onset to pelvic MRV scan was 49+/-16 hours. Compared with those with stroke of determined origin (n=49), patients with cryptogenic stroke (n=46) were significantly younger, had a higher prevalence of patent foramen ovale (61% versus 19%), and had less atherosclerosis risk factors. Cryptogenic patients had more MRV scans with a high probability for pelvic DVT (20%) than patients with stroke of determined origin (4%, P<0.03), with most having an appearance of a chronic DVT.In this study of young stroke patients evaluated early after stroke, patients with cryptogenic stroke showed differences in several clinical features compared with patients with stroke of determined origin, including increased prevalence of pelvic DVT. The results require confirmation but suggest that paradoxical embolus from the pelvic veins may be the cause of stroke in a subset of patients classified as having cryptogenic stroke.

Cryptogenic stroke is associated with an increased prevalence of patent foramen ovale. The Paradoxical Emboli From Large Veins in Ischemic Stroke (PELVIS) study hypothesized that patients with cryptogenic stroke have an increased prevalence of pelvic deep venous thrombosis (DVT).At 5 sites, patients 18 to 60 years of age received an MRI venogram (MRV) of the pelvis within 72 hours of new symptom onset. Clinical data were then determined. Radiologists blinded to clinical data later read the scans.The 95 patients who met entry criteria were scanned. Their mean+/-SD age was 46+/-10 years, and time from stroke onset to pelvic MRV scan was 49+/-16 hours. Compared with those with stroke of determined origin (n=49), patients with cryptogenic stroke (n=46) were significantly younger, had a higher prevalence of patent foramen ovale (61% versus 19%), and had less atherosclerosis risk factors. Cryptogenic patients had more MRV scans with a high probability for pelvic DVT (20%) than patients with stroke of determined origin (4%, P<0.03), with most having an appearance of a chronic DVT.In this study of young stroke patients evaluated early after stroke, patients with cryptogenic stroke showed differences in several clinical features compared with patients with stroke of determined origin, including increased prevalence of pelvic DVT. The results require confirmation but suggest that paradoxical embolus from the pelvic veins may be the cause of stroke in a subset of patients classified as having cryptogenic stroke.

PURPOSE: The increased prevalence of patent foramen ovale in patients with cryptogenic strokes suggests the occurrence of paradoxical embolism. The identification of deep venous thromboses (DVTs) in this population would strengthen this hypothesis. The purpose of this study was to image the subdiaphragmatic venous system in a cohort of patients with cryptogenic strokes. MATERIALS AND METHODS: In 37 patients with cryptogenic brain ischemia and interatrial communication, duplex studies of calf, popliteal, and femoral veins, and magnetic resonance imaging venograms of the pelvis veins were performed. RESULTS: In 10 patients, DVTs were diagnosed that were considered to be the cause of cryptogenic brain ischemia on probable (n = 6) or possible (n = 4) bases. In these patients, the median time from stroke to DVT was 3.25 days. In 5 of these 10 patients, DVTs did not involve popliteal and femoral veins, areas thought most important to pulmonary embolism, but instead were isolated to calf or pelvic veins. Although none of these 10 patients had abnormal blood hypercoagulation tests, 8 of the 10 did have clinical conditions suggesting predisposition to developing DVTs, such as concomitant neoplasms or pulmonary embolism. CONCLUSIONS: Increased evidence for paradoxical embolism may emerge when diagnostic strategies use multiple imaging methods and evaluate a broad extent of the subdiaphragmatic veins.

PURPOSE: The increased prevalence of patent foramen ovale in patients with cryptogenic strokes suggests the occurrence of paradoxical embolism. The identification of deep venous thromboses (DVTs) in this population would strengthen this hypothesis. The purpose of this study was to image the subdiaphragmatic venous system in a cohort of patients with cryptogenic strokes. MATERIALS AND METHODS: In 37 patients with cryptogenic brain ischemia and interatrial communication, duplex studies of calf, popliteal, and femoral veins, and magnetic resonance imaging venograms of the pelvis veins were performed. RESULTS: In 10 patients, DVTs were diagnosed that were considered to be the cause of cryptogenic brain ischemia on probable (n = 6) or possible (n = 4) bases. In these patients, the median time from stroke to DVT was 3.25 days. In 5 of these 10 patients, DVTs did not involve popliteal and femoral veins, areas thought most important to pulmonary embolism, but instead were isolated to calf or pelvic veins. Although none of these 10 patients had abnormal blood hypercoagulation tests, 8 of the 10 did have clinical conditions suggesting predisposition to developing DVTs, such as concomitant neoplasms or pulmonary embolism. CONCLUSIONS: Increased evidence for paradoxical embolism may emerge when diagnostic strategies use multiple imaging methods and evaluate a broad extent of the subdiaphragmatic veins.