External validation of the SI2NCAL2C score for outcomes following cerebral venous thrombosis

OBJECTIVES

Prognostication for cerebral venous thrombosis (CVT) remains difficult. We sought to validate the SI2NCAL2C score in an international cohort.

MATERIALS AND METHODS

The SI2NCAL2C score was originally developed to predict poor outcome (modified Rankin Scale (mRS) 3-6) at 6 months, and mortality at 30 days and 1 year using data from the International CVT Consortium. The SI2NCAL2C score uses 9 variables: the absence of any female-sex-specific risk factors, intracerebral hemorrhage, central nervous system infection, focal neurological deficits, coma, age, lower level of hemoglobin, higher level of glucose, and cancer. The ACTION-CVT study was an international retrospective study that enrolled consecutive patients across 27 centers. The poor outcome score was validated using 90-day mRS due to lack of follow-up at the 6-month time-point in the ACTION-CVT cohort. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and calibration plots. Missing data were imputed using the additive regression and predictive mean matching methods. Bootstrapping was performed with 1000 iterations.

RESULTS

Mortality data were available for 950 patients and poor outcome data were available for 587 of 1,025 patients enrolled in ACTION-CVT. Compared to the International CVT Consortium, the ACTION-CVT cohort was older, less often female, and with milder clinical presentation. Mortality was 2.5% by 30 days and 6.0% by one year. At 90-days, 16.7% had a poor outcome. The SI2NCAL2C score had an AUC of 0.74 [95% CI 0.69-0.79] for 90-day poor outcome, 0.72 [0.60-0.82] for mortality by 30 days, and 0.82 [0.76-0.88] for mortality by one year.

CONCLUSIONS

The SI2NCAL2C score had acceptable to good performance in an international external validation cohort. The SI2NCAL2C score warrants additional validation studies in diverse populations and clinical implementation studies.

Use of the pRESET LITE thrombectomy device in combined approach for medium vessel occlusions: A multicenter evaluation

PURPOSE

Our purpose was to assess the efficacy and safety of the pRESET LITE stent retriever (Phenox, Bochum, Germany), designed for medium vessel occlusion (MeVO) in acute ischemic stroke (AIS) patients with a primary MeVO.

METHODS

We performed a retrospective analysis of the MAD MT Consortium, an integration of prospectively maintained databases at 37 academic institutions in Europe, North America, and Asia, of AIS patients who underwent mechanical thrombectomy with the pRESET LITE stent retriever for a primary MeVO. We subcategorized occlusions into proximal MeVOs (segments A1, M2, and P1) vs. distal MeVOs/DMVO (segments A2, M3-M4, and P2). We reviewed patient and procedural characteristics, as well as angiographic and clinical outcomes.

RESULTS

Between September 2016 and December 2021, 227 patients were included (50% female, median age 78 [65-84] years), of whom 161 (71%) suffered proximal MeVO and 66 (29%) distal MeVO. Using a combined approach in 96% of cases, successful reperfusion of the target vessel (mTICI 2b/2c/3) was attained in 85% of proximal MeVO and 97% of DMVO, with a median of 2 passes (IQR: 1-3) overall. Periprocedural complications rate was 7%. Control CT at day 1 post-MT revealed a hemorrhagic transformation in 63 (39%) patients with proximal MeVO and 24 (36%) patients with DMVO, with ECASS-PH type hemorrhagic transformations occurring in 3 (1%) patients. After 3 months, 58% of all MeVO and 63% of DMVO patients demonstrated a favorable outcome (mRS 0-2).

CONCLUSION

Mechanical thrombectomy using the pRESET LITE in a combined approach with an aspiration catheter appears effective for primary medium vessel occlusions across several centers and physicians.

First pass effect as an independent predictor of functional outcomes in medium vessel occlusions: An analysis of an international multicenter study

INTRODUCTION

First pass effect (FPE), achievement of complete recanalization (mTICI 2c/3) with a single pass, is a significant predictor of favorable outcomes for endovascular treatment (EVT) in large vessel occlusion stroke (LVO). However, data concerning the impact on functional outcomes and predictors of FPE in medium vessel occlusions (MeVO) are scarce.

PATIENTS AND METHODS

We conducted an international retrospective study on MeVO cases. Multivariable logistic modeling was used to establish independent predictors of FPE. Clinical and safety outcomes were compared between the two study groups (FPE vs non-FPE) using logistic regression models. Good outcome was defined as modified Rankin Scale 0-2 at 3 months.

RESULTS

Eight hundred thirty-six patients with a final mTICI ⩾ 2b were included in this analysis. FPE was observed in 302 patients (36.1%). In multivariable analysis, hypertension (aOR 1.55, 95% CI 1.10-2.20) and lower baseline NIHSS score (aOR 0.95, 95% CI 0.93-0.97) were independently associated with an FPE. Good outcomes were more common in the FPE versus non-FPE group (72.8% vs 52.8%), and FPE was independently associated with favorable outcome (aOR 2.20, 95% CI 1.59-3.05). 90-day mortality and intracranial hemorrhage (ICH) were significantly lower in the FPE group, 0.43 (95% CI, 0.25-0.72) and 0.55 (95% CI, 0.39-0.77), respectively.

CONCLUSION

Over 2/3 of patients with MeVOs and FPE in our cohort had a favorable outcome at 90 days. FPE is independently associated with favorable outcomes, it may reduce the risk of any intracranial hemorrhage, and 3-month mortality.

Incidence and clinical outcomes of perforations during mechanical thrombectomy for medium vessel occlusion in acute ischemic stroke: A retrospective, multicenter, and multinational study

BACKGROUND

Mechanical thrombectomy (MT) has revolutionized the treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO), but its efficacy and safety in medium vessel occlusion (MeVO) remain less explored. This multicenter, retrospective study aims to investigate the incidence and clinical outcomes of vessel perforations (confirmed by extravasation during an angiographic series) during MT for AIS caused by MeVO.

METHODS

Data were collected from 37 academic centers across North America, Asia, and Europe between September 2017 and July 2021. A total of 1373 AIS patients with MeVO underwent MT. Baseline characteristics, procedural details, and clinical outcomes were analyzed.

RESULTS

The incidence of vessel perforation was 4.8% (66/1373). Notably, our analysis indicates variations in perforation rates across different arterial segments: 8.9% in M3 segments, 4.3% in M2 segments, and 8.3% in A2 segments (p = 0.612). Patients with perforation had significantly worse outcomes, with lower rates of favorable angiographic outcomes (TICI 2c-3: 23% vs 58.9%, p < 0.001; TICI 2b-3: 56.5% vs 88.3%, p < 0.001). Functional outcomes were also worse in the perforation group (mRS 0-1 at 3 months: 22.7% vs 36.6%, p = 0.031; mRS 0-2 at 3 months: 28.8% vs 53.9%, p < 0.001). Mortality was higher in the perforation group (30.3% vs 16.8%, p = 0.008).

CONCLUSION

This study reveals that while the occurrence of vessel perforation in MT for AIS due to MeVO is relatively rare, it is associated with poor functional outcomes and higher mortality. The findings highlight the need for increased caution and specialized training in performing MT for MeVO. Further prospective research is required for risk mitigation strategies.

Antithrombotic Treatment for Stroke Prevention in Cervical Artery Dissection: The STOP-CAD Study

Background: Small, randomized trials of cervical artery dissection (CAD) patients showed conflicting results regarding optimal stroke prevention strategies. We aimed to compare outcomes in patients with CAD treated with antiplatelets versus anticoagulation. Methods: This is a multi-center observational retrospective international study (16 countries, 63 sites) that included CAD patients without major trauma. The exposure was antithrombotic treatment type (anticoagulation vs. antiplatelets) and outcomes were subsequent ischemic stroke and major hemorrhage (intracranial or extracranial hemorrhage). We used adjusted Cox regression with Inverse Probability of Treatment Weighting (IPTW) to determine associations between anticoagulation and study outcomes within 30 and 180 days. The main analysis used an "as treated" cross-over approach and only included outcomes occurring on the above treatments. Results: The study included 3,636 patients [402 (11.1%) received exclusively anticoagulation and 2,453 (67.5%) received exclusively antiplatelets]. By day 180, there were 162 new ischemic strokes (4.4%) and 28 major hemorrhages (0.8%); 87.0% of ischemic strokes occurred by day 30. In adjusted Cox regression with IPTW, compared to antiplatelet therapy, anticoagulation was associated with a non-significantly lower risk of subsequent ischemic stroke by day 30 (adjusted HR 0.71 95% CI 0.45-1.12, p=0.145) and by day 180 (adjusted HR 0.80 95% CI 0.28-2.24, p=0.670). Anticoagulation therapy was not associated with a higher risk of major hemorrhage by day 30 (adjusted HR 1.39 95% CI 0.35-5.45, p=0.637) but was by day 180 (adjusted HR 5.56 95% CI 1.53-20.13, p=0.009). In interaction analyses, patients with occlusive dissection had significantly lower ischemic stroke risk with anticoagulation (adjusted HR 0.40 95% CI 0.18-0.88) (Pinteraction=0.009). Conclusions: Our study does not rule out a benefit of anticoagulation in reducing ischemic stroke risk, particularly in patients with occlusive dissection. If anticoagulation is chosen, it seems reasonable to switch to antiplatelet therapy before 180 days to lower the risk of major bleeding. Large prospective studies are needed to validate our findings.

Transcarotid Arterial Revascularization of Symptomatic Internal Carotid Artery Disease: A Systematic Review and Study-Level Meta-Analysis

BACKGROUND

Transcarotid artery revascularization (TCAR) is an interventional therapy for symptomatic internal carotid artery disease. Currently, the utilization of TCAR is contentious due to limited evidence. In this study, we evaluate the safety and efficacy of TCAR in patients with symptomatic internal carotid artery disease compared with carotid endarterectomy (CEA) and carotid artery stenting (CAS).

METHODS

A systematic review was conducted, spanning from January 2000 to February 2023, encompassing studies that used TCAR for the treatment of symptomatic internal carotid artery disease. The primary outcomes included a 30-day stroke or transient ischemic attack, myocardial infarction, and mortality. Secondary outcomes comprised cranial nerve injury and major bleeding. Pooled odds ratios (ORs) for each outcome were calculated to compare TCAR with CEA and CAS. Furthermore, subgroup analyses were performed based on age and degree of stenosis. In addition, a sensitivity analysis was conducted by excluding the vascular quality initiative registry population.

RESULTS

A total of 7 studies involving 24 246 patients were analyzed. Within this patient cohort, 4771 individuals underwent TCAR, 12 350 underwent CEA, and 7125 patients underwent CAS. Compared with CAS, TCAR was associated with a similar rate of stroke or transient ischemic attack (OR, 0.77 [95% CI, 0.33-1.82]) and myocardial infarction (OR, 1.29 [95% CI, 0.83-2.01]) but lower mortality (OR, 0.42 [95% CI, 0.22-0.81]). Compared with CEA, TCAR was associated with a higher rate of stroke or transient ischemic attack (OR, 1.26 [95% CI, 1.03-1.54]) but similar rates of myocardial infarction (OR, 0.9 [95% CI, 0.64-1.38]) and mortality (OR, 1.35 [95% CI, 0.87-2.10]).

CONCLUSIONS

Although CEA has traditionally been considered superior to stenting for symptomatic carotid stenosis, TCAR may have some advantages over CAS. Prospective randomized trials comparing the 3 modalities are needed.

Genetic ablation of Sarm1 attenuates expression and mislocalization of phosphorylated TDP-43 after mouse repetitive traumatic brain injury

Traumatic brain injury (TBI), particularly when moderate-to-severe and repetitive, is a strong environmental risk factor for several progressive neurodegenerative disorders. Mislocalization and deposition of transactive response DNA binding protein 43 (TDP-43) has been reported in both TBI and TBI-associated neurodegenerative diseases. It has been hypothesized that axonal pathology, an early event after TBI, may promote TDP-43 dysregulation and serve as a trigger for neurodegenerative processes. We sought to determine whether blocking the prodegenerative Sarm1 (sterile alpha and TIR motif containing 1) axon death pathway attenuates TDP-43 pathology after TBI. We subjected 111 male Sarm1 wild type, hemizygous, and knockout mice to moderate-to-severe repetitive TBI (rTBI) using a previously established injury paradigm. We conducted serial neurological assessments followed by histological analyses (NeuN, MBP, Iba-1, GFAP, pTDP-43, and AT8) at 1 month after rTBI. Genetic ablation of the Sarm1 gene attenuated the expression and mislocalization of phosphorylated TDP-43 (pTDP-43) and accumulation of pTau. In addition, Sarm1 knockout mice had significantly improved cortical neuronal and axonal integrity, functional deficits, and improved overall survival after rTBI. In contrast, removal of one Sarm1 allele delayed, but did not prevent, neurological deficits and neuroaxonal loss. Nevertheless, Sarm1 haploinsufficient mice showed significantly less microgliosis, pTDP-43 pathology, and pTau accumulation when compared to wild type mice. These data indicate that the Sarm1-mediated prodegenerative pathway contributes to pathogenesis in rTBI including the pathological accumulation of pTDP-43. This suggests that anti-Sarm1 therapeutics are a viable approach for preserving neurological function after moderate-to-severe rTBI.

Endovascular therapy versus medical management for mild strokes due to medium and distal vessel occlusions

BACKGROUND

Distal and medium vessel occlusion (DMVO) strokes account for up to 40% of all acute ischemic strokes, many of which have a low initial deficit severity. Increasingly, endovascular treatment (EVT) is considered for these patients. However, there is a paucity of data comparing potential safety and efficacy of EVT versus best medical management (BMT) in these patients, particularly when presenting with mild symptoms.

METHODS

We retrospectively analyzed consecutive DMVO patients with NIHSS ≤6 who presented between January 2018 and December 2021 within 24 h from last seen well. We compared early and late clinical outcomes, as well as safety outcomes using multivariable linear and logistic regression analyses to determine whether EVT was independently associated with the outcomes of interest.

RESULTS

We included 80 subjects that fulfilled our study criteria (n = 41 BMT and n = 39 EVT). On adjusted analyses, when comparing EVT and BMT groups, there was no statistical difference in the NIHSS at discharge (Coefficient = -0.6, 95%-CI = -3.45-2.26, p = 0.678) or in the modified Rankin scale (mRS) at discharge (Coefficient = 0.37, 95%-CI = -0.52-1.25, p = 0.408). Furthermore, there was no difference in the 3-month mRS defined as good (mRS 0-2) (OR = 0.56, 95%-CI = 0.17-1.83, p = 0.341) or excellent (mRS 0-1) (OR = 0.45, 95%-CI = 0.15-1.34, p = 0.152). Finally, there was no difference in the incidence of all-type parenchymal hemorrhage (OR = 0.9, 95%-CI = 0.22-3.62, p = 0.879).

CONCLUSIONS

We found that among DMVO patients with low admission NIHSS treatment with EVT versus BMT was associated with similar outcomes. Larger prospective studies are required to confirm these findings.

Repeated mild traumatic brain injury triggers pathology in asymptomatic C9ORF72 transgenic mice

Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are fatal neurodegenerative diseases that represent ends of the spectrum of a single disease. The most common genetic cause of FTD and ALS is a hexanucleotide repeat expansion in the C9orf72 gene. Although epidemiological data suggest that traumatic brain injury (TBI) represents a risk factor for FTD and ALS, its role in exacerbating disease onset and course remains unclear. To explore the interplay between traumatic brain injury and genetic risk in the induction of FTD/ALS pathology we combined a mild repetitive traumatic brain injury paradigm with an established bacterial artificial chromosome transgenic C9orf72 (C9BAC) mouse model without an overt motor phenotype or neurodegeneration. We assessed 8-10 week-old littermate C9BACtg/tg (n = 21), C9BACtg/- (n = 20) and non-transgenic (n = 21) mice of both sexes for the presence of behavioural deficits and cerebral histopathology at 12 months after repetitive TBI. Repetitive TBI did not affect body weight gain, general neurological deficit severity, nor survival over the 12-month observation period and there was no difference in rotarod performance, object recognition, social interaction and acoustic characteristics of ultrasonic vocalizations of C9BAC mice subjected to repetitive TBI versus sham injury. However, we found that repetitive TBI increased the time to the return of the righting reflex, reduced grip force, altered sociability behaviours and attenuated ultrasonic call emissions during social interactions in C9BAC mice. Strikingly, we found that repetitive TBI caused widespread microglial activation and reduced neuronal density that was associated with loss of histological markers of axonal and synaptic integrity as well as profound neuronal transactive response DNA binding protein 43 kDa mislocalization in the cerebral cortex of C9BAC mice at 12 months; this was not observed in non-transgenic repetitive TBI and C9BAC sham mice. Our data indicate that repetitive TBI can be an environmental risk factor that is sufficient to trigger FTD/ALS-associated neuropathology and behavioural deficits, but not paralysis, in mice carrying a C9orf72 hexanucleotide repeat expansion.

Small vessel disease is associated with later onset of major adverse cardiovascular events after acute cervicocerebral artery dissection

BACKGROUND

Cerebral small vessel disease (CSVD) is common among the elderly and has been associated with an increased risk of major adverse cardiac events (MACE) and increased risk of long-term disability. Little is known whether CSVD affects outcomes after cervicocerebral artery dissection (CAD), which predominantly affects younger patients. Specifically, there is a paucity as to whether CSVD increases the risk of MACE after CAD and whether this risk is different for early versus late events.

METHODS

We retrospectively analyzed 140 consecutive patients with acute CAD. We determined CSVD on MRI using the STRIVE criteria and calculated the CSVD sum score based on the individual CSVD components. For statistical analysis the CSVD burden was dichotomized to mild (score 0-1) versus severe (score 2-4). The primary outcome of interest was the 6-month MACE risk. Secondary outcomes of interest were early versus late MACE, stroke at presentation, and good 90-day outcome (modified Rankin Scale score 0-2).

RESULTS

There was no difference in overall MACE between subjects when stratified by CSVD burden (10.1% versus 9.8%, Log-rank P = 0.953). We found that patients with severe CSVD had significantly more late MACE as compared to mild CSVD (9.8% versus 1.1%, P = 0.024). There was no significant difference in the prevalence of stroke at the time of CAD diagnosis (50.6% versus 47.1%, P = 0.690) and the 90-day disability-free survival in subjects with mild versus severe CSVD (93.7% versus 91.7%, P = 0.729).

CONCLUSION

Severe CSVD burden was associated with a significantly greater risk of late MACE. CSVD assessment in CAD patients may aid risk stratification and treatment optimization.

Delayed Diagnosis in Cerebral Venous Thrombosis: Associated Factors and Clinical Outcomes

Background Identifying factors associated with delayed diagnosis of cerebral venous thrombosis (CVT) can inform future strategies for early detection. Methods and Results We conducted a retrospective cohort study including all participants from ACTION-CVT (Anticoagulation in the Treatment of Cerebral Venous Thrombosis) study who had dates of neurologic symptom onset and CVT diagnosis available. Delayed diagnosis was defined as CVT diagnosis occurring in the fourth (final) quartile of days from symptom onset. The primary study outcome was modified Rankin Scale score of ≤1 at 90 days; secondary outcomes included partial/complete CVT recanalization on last available imaging and modified Rankin Scale score of ≤2. Logistic regression analyses were used to identify independent variables associated with delayed diagnosis and to assess the association of delayed diagnosis and outcomes. A total of 935 patients were included in our study. Median time from symptom onset to diagnosis was 4 days (interquartile range, 1-10 days). Delayed CVT diagnosis (time to diagnosis >10 days) occurred in 212 patients (23%). Isolated headache (adjusted odds ratio [aOR], 2.36 [95% CI, 1.50-3.73]; P<0.001), older age (aOR by 1 year, 1.02 [95% CI, 1.004-1.03]; P=0.01), and papilledema (aOR, 2.00 [95% CI, 1.03-3.89]; P=0.04) were associated with diagnostic delay, whereas higher National Institutes of Health Stroke Scale score was inversely associated with diagnostic delay (aOR by 1 point, 0.95 [95% CI, 0.89-1.00]; P=0.049). Delayed diagnosis was not associated with modified Rankin Scale score of ≤1 at 90 days (aOR, 1.08 [95% CI, 0.60-1.96]; P=0.79). Conclusions In a large multicenter cohort, a quarter of included patients with CVT were diagnosed >10 days after symptom onset. Delayed CVT diagnosis was associated with the symptom of isolated headache and was not associated with adverse clinical outcomes.

Clinical characteristics and risk factors for bilateral lateral geniculate body pathology: a systematic review of the literature

BACKGROUND

Case presentation of acute onset bilateral painless vision loss caused by bilateral infarction of the lateral geniculate bodies (LGB) and a systematic review of the literature.

METHODS

A descriptive case report is presented on a 17-year-old female diagnosed with acute pancreatitis who developed acute onset bilateral painless vision loss. A systematic literature review of cases with bilateral LGB lesions was conducted across three electronic databases (PubMed/PubMed Central/MEDLINE, Scopus, and ScienceDirect). The review was conducted in concordance with PRISMA guidelines and prospectively registered on PROSPERO (CRD42022362491).

RESULTS

The reported 17-year-old female was found to have MRI findings consistent with bilateral hemorrhagic infarction of the LGB and Purtscher-like retinopathy. A systematic literature review of bilateral LGB infarction yielded 23 records for analysis. 19/23 (82.6%) of reported cases occurred in women. Bilateral vision loss was noted in all cases. The average reported age was 27 years old with a range from 2-50. Gastrointestinal pathology (e.g., pancreatitis, gastroenteritis) was present in 8/23 (34.7%) of cases. 8/23 (34.7%) cases had neuroimaging or pathological evidence of hemorrhagic transformation of the infarct. Most cases experienced partial recovery of visual loss; only one case (4.7%) had complete visual recovery. 9/23 (39.1%) cases were reported from the United States and 4/23 (17.3%) from India.

CONCLUSIONS

Bilateral LGB lesion is a rare cause of vision loss, typically caused by systemic diseases and with female preponderance. Purported pathophysiology relates to increased vulnerability of the LGB to ischemic and metabolic stress.

Aspiration Versus Stent‐Retriever as First‐Line Endovascular Therapy Technique for Primary Medium and Distal Intracranial Occlusions: A Propensity‐Score Matched Multicenter Analysis

BACKGROUND

For acute proximal intracranial artery occlusions, contact aspiration may be more effective than stent‐retriever for first‐line reperfusion therapy. Due to the lack of data regarding medium vessel occlusion thrombectomy, we evaluated outcomes according to first‐line technique in a large, multicenter registry.

METHODS

Imaging, procedural, and clinical outcomes of patients with acute proximal medium vessel occlusions (M2, A1, or P1) or distal medium vessel occlusions (M3, A2, P2, or further) treated at 37 sites in 10 countries were analyzed according to first‐line endovascular technique (stent‐retriever versus aspiration). Multivariable logistic regression and propensity‐score matching were used to estimate the odds of the primary outcome, expanded Thrombolysis in Cerebral Infarction score of 2b–3 (“successful recanalization”), as well as secondary outcomes (first‐pass effect, expanded Thrombolysis in Cerebral Infarction 2c‐3, intracerebral hemorrhage, and 90‐day modified Rankin scale, 90‐day mortality) between treatment groups.

RESULTS

Of the 440 included patients (44.5% stent‐retriever versus 55.5% aspiration), those treated with stent‐retriever had lower baseline Alberta Stroke Program Early Computed Tomography Scale scores (median 8 versus 9; P <0.01), higher National Institutes of Health Stroke Scale scores (median 13 versus 11; P =0.02), and nonsignificantly fewer medium‐distal occlusions (M3, A2, P2, or other: 17.4% versus 23.8%; P =0.10). Use of a stent‐retriever was associated with 15% lower odds of successful recanalization (odds ratio [OR], 0.85; [95% CI 0.74–0.98]; P =0.02), but this was not significant after multivariable adjustment in the total cohort (adjusted OR, 0.88; [95% CI 0.72–1.09]; P =0.24), or in the propensity‐score matched cohort (n=105 in each group) (adjusted OR, 0.94; [95% CI 0.75–1.18]; P =0.60). There was no significant association between technique and secondary outcomes in the propensity‐score matched adjusted models.

CONCLUSION

In this large, diverse, multinational medium vessel occlusion cohort, we found no significant difference in imaging or clinical outcomes with aspiration versus stent‐retriever thrombectomy.

Stroke nurse navigator utilization reduces unplanned 30-day readmission in stroke patients treated with thrombolysis

Background

Unplanned 30-day hospital readmissions following a stroke is a serious quality and safety issue in the United States. The transition period between the hospital discharge and ambulatory follow-up is viewed as a vulnerable period in which medication errors and loss of follow-up plans can potentially occur. We sought to determine whether unplanned 30-day readmission in stroke patients treated with thrombolysis can be reduced with the utilization of a stroke nurse navigator team during the transition period.

Methods

We included 447 consecutive stroke patients treated with thrombolysis from an institutional stroke registry between January 2018 and December 2021. The control group consisted of 287 patients before the stroke nurse navigator team implementation between January 2018 and August 2020. The intervention group consisted of 160 patients after the implementation between September 2020 and December 2021. The stroke nurse navigator interventions included medication reviews, hospitalization course review, stroke education, and review of outpatient follow-ups within 3 days following the hospital discharge.

Results

Overall, baseline patient characteristics (age, gender, index admission NIHSS, and pre-admission mRS), stroke risk factors, medication usage, and length of hospital stay were similar in control vs. intervention groups (P > 0.05). Differences included higher mechanical thrombectomy utilization (35.6 vs. 24.7%, P = 0.016), lower pre-admission oral anticoagulant use (1.3 vs. 5.6%, P = 0.025), and less frequent history of stroke/TIA (14.4 vs. 27.5%, P = 0.001) in the implementation group. Based on an unadjusted Kaplan-Meier analysis, 30-day unplanned readmission rates were lower during the implementation period (log-rank P = 0.029). After adjustment for pertinent confounders including age, gender, pre-admission mRS, oral anticoagulant use, and COVID-19 diagnosis, the nurse navigator implementation remained independently associated with lower hazards of unplanned 30-day readmission (adjusted HR 0.48, 95% CI 0.23-0.99, P = 0.046).

Conclusion

The utilization of a stroke nurse navigator team reduced unplanned 30-day readmissions in stroke patients treated with thrombolysis. Further studies are warranted to determine the extent of the results of stroke patients not treated with thrombolysis and to better understand the relationship between resource utilization during the transition period from discharge and quality outcomes in stroke.

Outcomes of Telestroke Inter-Hospital Transfers Among Intervention and Non-Intervention Patients

Background

Telestroke is an established telemedicine method of delivering emergency stroke care. However, not all neurological patients utilizing telestroke service require emergency interventions or transfer to a comprehensive stroke center. To develop an understanding of the appropriateness of inter-hospital neurological transfers utilizing the telemedicine, our study aimed to assess the differences in outcomes of inter-hospital transfers utilizing the service in relation to the need for neurological interventions.

Methods

The pragmatic, retrospective analysis included 181 consecutive patients, who were emergently transferred from telestroke-affiliated regional medical centers between October 3, 2021, and May 3, 2022. In this exploratory study investigating the outcomes of telestroke-referred patients, patients receiving interventions were compared to those that did not following transfer to our tertiary center. Neurological interventions included mechanical thrombectomy (MT) and/or tissue plasminogen activator (tPA), craniectomy, electroencephalography (EEG), or external ventricular drain (EVD). Transfer mortality rate, discharge functional status defined by modified Rankin scale (mRS), neurological status defined by National Institutes of Health Stroke Scale (NIHSS), 30-day unpreventable readmission rate, 90-day clinical major adverse cardiovascular events (MACE), and 90-day mRS, and NIHSS were studied. We used χ2 or Fisher exact tests to evaluate the association between the intervention and categorical or dichotomous variables. Continuous or ordinal measures were compared using Wilcoxon rank-sum tests. All tests of statistical significance were considered to be significant at P < 0.05.

Results

Among the 181 transferred patients, 114 (63%) received neuro-intervention and 67 (37%) did not. The death rate during the index admission was not statistically significant between the intervention and non-intervention groups (P = 0.196). The discharge NIHSS and mRS were worse in the intervention compared to the non-intervention (P < 0.05 each, respectively). The 90-day mortality and cardiovascular event rates were similar between intervention and non-intervention groups (P > 0.05 each, respectively). The 30-day readmission rates were also similar between the two groups (14% intervention vs. 13.4% non-intervention, P = 0.910). The 90-day mRS were not significantly different between intervention and non-intervention groups (median 3 (IQR: 1 - 6) vs. 2 (IQR: 0 - 6), P = 0.109). However, 90-day NIHSS was worse in the intervention compared to non-intervention group (median 2 (IQR: 0 - 11) vs. 0 (IQR: 0 - 3), P = 0.004).

Conclusions

Telestroke is a valuable resource that expedites emergent neurological care via referral to a stroke center. However, not all transferred patients benefit from the transfer process. Future multicenter studies are warranted to study the effects or appropriateness of telestroke networks, and to better understand the patient characteristics, resources allocation, and transferring institutions to improve telestroke care.

Perioperative Acute Ischemic Stroke in Patients with Atrial Fibrillation

OBJECTIVE

Anticoagulation therapy is commonly interrupted in patients with atrial fibrillation (AF) for elective procedures. However, the risk factors of acute ischemic stroke (AIS) during the periprocedural period remain uncertain. We performed a nationwide analysis to evaluate AIS risk factors in patients with AF undergoing elective surgical procedures.

METHODS

Using the Nationwide Readmission Database, we included electively admitted adult patients with AF and procedural Diagnosis-Related Group codes from 2016 to 2019. Diagnoses were identified based on ICD-10 CM codes. We constructed a logistic regression model to identify risk factors and developed a new scoring system incorporating CHA₂ DS₂ VASc to estimate periprocedural AIS risk.

RESULTS

Of the 1,045,293 patients with AF admitted for an elective procedure, the mean age was 71.5 years, 39.2% were female, and 0.70% had a perioperative AIS during the index admission or within 30 days of discharge. Active cancer (adjusted OR [aOR] 1.58, 95% CI 1.42-1.76), renal failure (aOR 1.14, 95% CI 1.04-1.24), neurological surgery (aOR 4.51, 95% CI 3.84-5.30), cardiovascular surgery (aOR 2.74, 95% CI 2.52-2.97), and higher CHA₂ DS₂ VASc scores (aOR 1.25 per point, 95% CI 1.22-1.29) were significant risk factors for periprocedural AIS. The new scoring system (area under the receiver operating characteristic curve [AUC] 0.68; 95% CI, 0.67 to 0.79) incorporating surgical type and cancer outperformed CHA₂ DS₂ VASc (AUC 0.60; 95% CI, 0.60 to 0.61).

INTERPRETATION

In AF patients, periprocedural AIS risk increases with the CHA₂ DS₂ VASc score, active cancer, and cardiovascular or neurological surgeries. Studies are needed to devise better strategies to mitigate perioperative AIS risk in these patients. This article is protected by copyright. All rights reserved.

Intravital Imaging of Fluorescent Protein Expression in Mice with a Closed-Skull Traumatic Brain Injury and Cranial Window Using a Two-Photon Microscope

The goal of this protocol is to demonstrate how to longitudinally visualize the expression and localization of a protein of interest within specific cell types of an animal's brain, upon exposure to exogenous stimuli. Here, the administration of a closed-skull traumatic brain injury (TBI) and simultaneous implantation of a cranial window for subsequent longitudinal intravital imaging in mice is shown. Mice are intracranially injected with an adeno-associated virus (AAV) expressing enhanced green fluorescent protein (EGFP) under a neuronal specific promoter. After 2 to 4 weeks, the mice are subjected to a repetitive TBI using a weight drop device over the AAV injection location. Within the same surgical session, the mice are implanted with a metal headpost and then a glass cranial window over the TBI impacting site. The expression and cellular localization of EGFP is examined using a two-photon microscope in the same brain region exposed to trauma over the course of months.

Abstract 8: Outcomes And Recurrence Rates Among Patients With Provoked And Cryptogenic Cerebral Venous Thrombosis: Analysis Of The ACTION CVT Study

Introduction: Cerebral venous thrombosis (CVT) is a rare cause of stroke. While the standard treatment is anticoagulation, the type and duration of anticoagulation depend on the underlying etiology. This study aims to identify the characteristics and risk of recurrent venous thromboembolism (VTE) in patients with unprovoked CVT (cryptogenic), transient provoked CVT (peripartum, contraception, infection, trauma) and persistent provoked CVT (cancer, hereditary thrombophilias).

Methods: We used the ACTION CVT retrospective database which included consecutive CVT patients in 27 stroke centers in the United States, Europe, and New Zealand from January 2015 to December 2020. Baseline characteristics were compared between the groups using Chi square test, T test or Mann-Whitney-U test, followed by multivariable logistic regression. We used interaction analysis to assess the risk of recurrent venous thromboembolism (VTE).

Results: A total of 1025 CVT patients were included in this study; 363 (35.4%) had transient provoking factors, 152 (14.8%) had persistent provoking factors, and 510 (49.8%) had cryptogenic CVT. Patients with transiently provoked CVT were younger (P=0.003) and more likely to be women (P<0.001), and patients with cryptogenic CVT were less likely to have a prior VTE (P<0.001). Compared to patients with transient provoked, there was higher risk of recurrent VTE in patients with persistent provoking factors (HR 2.59, 95% CI 1.29-5.22, P=0.008) and numerically higher recurrent VTE risk in cryptogenic CVT (HR 1.85, 95% CI 0.98-3.51, P=0.059). These associations did not vary by age, sex, or history of VTE status (p-interaction > 0.1 for all). Results were similar in sensitivity analyses excluding those with positive Factor V Leiden or Prothrombin gene mutation as well as in analyses excluding patients with positive antiphospholipid antibody test.

Conclusions: In this multicenter study, we found that the risk of recurrent VTE after CVT may vary depending on the underlying etiology with higher rates in patients with cryptogenic CVT and those with persistent provoking factors. Longer anticoagulation duration may be needed in such groups compared to CVT with transient provoking factors.

Abstract TMP55: Factors Associated With Delayed Diagnosis Of Cerebral Venous Thrombosis: Secondary Analysis Of ACTION-CVT Study

Introduction: Few clinical features have been associated with delayed diagnosis of cerebral venous thrombosis with variable impact of delay on patient outcomes. We therefore sought to use the data from a recent, multicenter study ACTION-CVT (Anticoagulation in the Treatment of CVT) to identify factors associated with delayed CVT diagnosis and evaluate the effect of delay on functional outcome.

Methods: All ACTION-CVT patients with available data on date of neurological symptom onset and date of CVT diagnosis were included. Delayed diagnosis of CVT was defined as diagnosis occurring in the fourth (final) quartile of days from symptom onset. We also report the proportion of patients who were discharged from hospital or ED within 3 months prior to index CVT admission for any neurological symptom without being diagnosed with CVT. The primary study outcome was an excellent functional outcome at 90 days defined as modified Rankin Scale (mRS) ≤1. Secondary outcome was partial or complete CVT recanalization on last available venous imaging. Chi-squared and Student’s t-tests were used to identify variables associated with delayed diagnosis. Logistic regression was used to identify independent predictors of delayed diagnosis in CVT as well as the association of delay with outcomes.

Results: We included 935 CVT patients in our analysis. Median time from symptom onset to diagnosis was 4 days (IQR: 1-10). Delayed CVT diagnosis occurred in 212 (23%) patients (median time to diagnosis >10 days). Out of 212 patients with delayed CVT diagnosis, 64 (30.2%) patients were discharged from hospital/ED in the 3 months prior to their index CVT admission. Headache symptoms were a predictor of delayed diagnosis (OR: 2.36 [1.26-4.42]; p<0.01), and seizure was inversely related to delayed diagnosis (0.39 [0.21-0.74]; p=0.001). Delayed diagnosis was not associated with mRS ≤1 at 90 days (OR 0.83 [95% CI: 0.42-1.64]; p=0.58) or venous recanalization (OR 1.78 [95% CI 0.79-3.99]; p=0.16).

Conclusion: In a large, multicenter cohort we found that CVT patients presenting with headache were at increased risk of delayed diagnosis, however, delayed diagnosis was not associated with adverse outcomes. CVT diagnosis should be considered in patients presenting with a new headache.

Abstract WMP18: Stroke Nurse Navigator Team Utilization Towards Reduction Of Unplanned 30-day Readmissions Following Stroke

Background: Unplanned 30-day hospital readmissions following a stroke is recognized as a serious quality and safety issue in the United States. The transition period from the hospital discharge is recognized as a vulnerable period in which medication errors and loss of ambulatory follow-ups can potentially occur. There, we sought to determine if 30-day stroke readmission can be prevented with utilization of a stroke nurse navigator team. Our secondary outcome of interest was 90-day outcome events.

Methods: We first retrospectively analyzed 1657 consecutive patients presenting with ischemic or hemorrhagic strokes, included in an institutional stroke registry between January 2018 and August 2020, the time before the utilization of stroke nurse navigator teams. The stroke nurse navigator interventions included medication reviews, hospitalization course review, stroke education, and establishment of outpatient follow-ups within 3 days following the discharge. Following the stroke nurse navigator team phone checks ins in September 2020, we then retrospectively analyzed 851 consecutive patients presenting with stroke, included in the registry between September 2020 and December 2021.

Results: Baseline 30-day stroke readmission rate was 11.7% (194/1657) before nurse navigator team. The Readmission rate reduced to 8.2% (71/870), which was statistically significant (p<0.05) following the period that utilized stroke nurse navigator team. Baseline 90-day death and cardiovascular events before the stroke nurse intervention was 5.4% (89/1657) and 8.1% (134/1657), respectively. Following the intervention, there was also no statistical difference in the 90-day outcome events of death and cardiovascular event 6.2% (27/433) and 7.3% (32/433), p>0.05.

Conclusion: Utilization of the Stroke nurse navigator team can reduce unplanned 30-day stroke readmissions, but it did not have an impact on 90-day clinical outcome. Further studies are warranted to study the relationship between resource utilization during transition period from discharge and quality outcome in stroke.

Abstract 54: Incidence And Predictors Of Dural Arteriovenous Fistulae After Cerebral Venous Sinus Thrombosis: Analysis Of ACTION-CVT

Background: Intracranial dural arteriovenous fistulae (DAVF) are uncommon vascular anomalies with a reported incidence of 0.2 per 100,000 person years. An association between cerebral venous thrombosis (CVT) and DAVF has been reported; however, the direction of causality between the two remains uncertain. We aimed to identify the incidence and predictors of development of DAVF among patients with CVT.

Methods: This is a post-hoc analysis of Anticoagulation in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT), a multicenter retrospective study comparing outcomes of CVT patients treated with warfarin versus direct oral anticoagulants (DOACs) from 2015 to 2020. Patients were included in this analysis if they did not have DAVF on initial imaging and had follow-up vascular imaging during the study. Clinical, imaging, and anticoagulation characteristics of patients who developed DAVF were compared to those who did not. Stepwise binary logistic regression including important variables (achieving p<0.1 on univariate analyses) was used to determine predictors of DAVF development.

Results: A total of 751 patients (median age 43, 66% female) met inclusion criteria of whom 13 (1.7%) developed DAVF with an estimated rate of 2.40 per 100 patient years. Patients with DAVF were less likely to have headache at presentation (53.8% vs 79.3%, p=0.037), but more likely to have no venous recanalization on follow-up imaging (46.2% vs 14.8%, p=0.008), baseline cortical vein thrombosis (15.4% vs 2.7%, p=0.053), and received warfarin (vs. DOACs) as initial oral anticoagulant (84.6% vs 58.7%, p=0.085) but the latter two missed the statistical significance threshold. In stepwise binary logistic regression analysis, cortical vein thrombosis (OR 7.98, 95% CI 1.40-45.35, p=0.02) and lack of venous recanalization (OR 4.93, 95% CI 1.48-16.39, p=0.01) were associated with development of DAVF.

Conclusion: In this large multicenter study of CVT, the incidence of DAVF development was higher than the previously reported rate in the general population. The presence of cortical vein thrombosis and lack of venous recanalization were associated with increased risk of development of DAVF.

Trends in Venous Thromboembolism Readmission Rates after Ischemic Stroke and Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Venous thromboembolism (VTE) is a life-threatening complication of stroke. We evaluated nationwide rates and risk factors for hospital readmissions with VTE after an intracerebral hemorrhage (ICH) or acute ischemic stroke (AIS) hospitalization.

METHODS

Using the Healthcare Cost and Utilization Project (HCUP) Nationwide Readmission Database, we included patients with a principal discharge diagnosis of ICH or AIS from 2016 to 2019. Patients who had VTE diagnosis or history of VTE during the index admission were excluded. We performed Cox regression models to determine factors associated with VTE readmission, compared rates between AIS and ICH and developed post-stroke VTE risk score. We estimated VTE readmission rates per day over a 90-day time window post-discharge using linear splines.

RESULTS

Of the total 1,459,865 patients with stroke, readmission with VTE as the principal diagnosis within 90 days occurred in 0.26% (3,407/1,330,584) AIS and 0.65% (843/129,281) ICH patients. The rate of VTE readmission decreased within first 4-6 weeks (P<0.001). In AIS, cancer, obesity, higher National Institutes of Health Stroke Scale (NIHSS) score, longer hospital stay, home or rehabilitation disposition, and absence of atrial fibrillation were associated with VTE readmission. In ICH, longer hospital stay and rehabilitation disposition were associated with VTE readmission. The VTE rate was higher in ICH compared to AIS (adjusted hazard ratio 2.86, 95% confidence interval 1.93-4.25, P<0.001).

CONCLUSIONS

After stroke, VTE readmission risk is highest within the first 4-6 weeks and nearly three-fold higher after ICH vs. AIS. VTE risk is linked to decreased mobility and hypercoagulability. Studies are needed to test short-term VTE prophylaxis beyond hospitalization in high-risk patients.

Subsequent ischemic stroke and tobacco smoking: A secondary analysis of the POINT trial

Background:

The aim of this study was to determine the effect of smoking status on subsequent stroke risk in patients with minor ischemic stroke or TIA and to determine whether smoking modifies the effect of clopidogrel-based DAPT on subsequent stroke risk.

Methods:

This was a post-hoc analysis of the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, which had a 90-day follow-up period. We used multivariable Cox regression and subgroup interaction analysis to determine the effect of smoking on the risk of subsequent ischemic stroke and major hemorrhage, respectively.

Results:

Data from 4877 participants enrolled in the POINT trial were analyzed. Among these, 1004 were current smokers and 3873 were non-smokers at the time of index event. Smoking was associated with a non-significant trend toward an increased risk of subsequent ischemic stroke during follow up (adjusted HR, 1.31 (95% CI, 0.97–1.78), p = 0.076). The effect of clopidogrel on ischemic stroke did not differ between non-smokers (HR, 0.74 (95% CI, 0.56–0.98), p = 0.03) and smokers (HR, 0.63 (95% CI, 0.37–1.05), p = 0.078), p for interaction = 0.572. Similarly, the effect of clopidogrel on major hemorrhage did not differ between non-smokers (hazard ratio, 1.67 (95% CI, 0.40–7.00), p = 0.481) and smokers (HR, 2.59 (95% CI, 1.08–6.21), p = 0.032), p for interaction = 0.613.

Conclusions:

In this post-hoc analysis of the POINT trial we found that the effect of clopidogrel on reducing subsequent ischemic stroke as well as risk of major hemorrhage did not depend on smoking status, indicating that smokers benefit to a similar degree from DAPT as non-smokers.

Predictors of Recurrent Venous Thrombosis After Cerebral Venous Thrombosis: Analysis of the ACTION-CVT Study

BACKGROUND AND OBJECTIVE

Cerebral venous thrombosis (CVT) is a rare cause of stroke carrying a nearly 4% risk of recurrence after 1 year. There are limited data on predictors of recurrent venous thrombosis in patients with CVT. In this study, we aim to identify those predictors.

METHODS

This is a secondary analysis of the ACTION-CVT study which is a multicenter international study of consecutive patients hospitalized with a diagnosis of CVT over a 6-year period. Patients with cancer-associated CVT, CVT during pregnancy, or CVT in the setting of known antiphospholipid antibody syndrome were excluded per the ACTION-CVT protocol. The study outcome was recurrent venous thrombosis defined as recurrent venous thromboembolism (VTE) or de novo CVT. We compared characteristics between patients with vs without recurrent venous thrombosis during follow-up and performed adjusted Cox regression analyses to determine important predictors of recurrent venous thrombosis.

RESULTS

Nine hundred forty-seven patients were included with a mean age of 45.2 years, 63.9% were women, and 83.6% had at least 3 months of follow-up. During a median follow-up of 308 (interquartile range 120-700) days, there were 5.05 recurrent venous thromboses (37 VTE and 24 de novo CVT) per 100 patient-years. Predictors of recurrent venous thrombosis were Black race (adjusted hazard ratio [aHR] 2.13, 95% CI 1.14-3.98, p = 0.018), history of VTE (aHR 3.40, 95% CI 1.80-6.42, p < 0.001), and the presence of one or more positive antiphospholipid antibodies (aHR 3.85, 95% CI 1.97-7.50, p < 0.001). Sensitivity analyses including events only occurring on oral anticoagulation yielded similar findings.

DISCUSSION

Black race, history of VTE, and the presence of one or more antiphospholipid antibodies are associated with recurrent venous thrombosis among patients with CVT. Future studies are needed to validate our findings to better understand mechanisms and treatment strategies in patients with CVT.

CRISPR/Cas9-mediated excision of ALS/FTD-causing hexanucleotide repeat expansion in C9ORF72 rescues major disease mechanisms in vivo and in vitro

A GGGGCC₂₄₊ hexanucleotide repeat expansion (HRE) in the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), fatal neurodegenerative diseases with no cure or approved treatments that substantially slow disease progression or extend survival. Mechanistic underpinnings of neuronal death include C9ORF72 haploinsufficiency, sequestration of RNA-binding proteins in the nucleus, and production of dipeptide repeat proteins. Here, we used an adeno-associated viral vector system to deliver CRISPR/Cas9 gene-editing machineries to effectuate the removal of the HRE from the C9ORF72 genomic locus. We demonstrate successful excision of the HRE in primary cortical neurons and brains of three mouse models containing the expansion (500-600 repeats) as well as in patient-derived iPSC motor neurons and brain organoids (450 repeats). This resulted in a reduction of RNA foci, poly-dipeptides and haploinsufficiency, major hallmarks of C9-ALS/FTD, making this a promising therapeutic approach to these diseases.

Association between the LACE+ index and unplanned 30-day hospital readmissions in hospitalized patients with stroke

Background

The LACE+ index is used to predict unplanned 30-day hospital readmissions, but its utility to predict 30-day readmission in hospitalized patients with stroke is unknown.

Methods

We retrospectively analyzed 1,657 consecutive patients presenting with ischemic or hemorrhagic strokes, included in an institutional stroke registry between January 2018 and August 2020. The primary outcome of interest was unplanned 30-day readmission for any reason after index hospitalization for stroke. The 30-day readmission risk was categorized by LACE+ index to high risk (≥78), medium-to-high risk (59–77), medium risk (29–58), and low risk (≤ 28). Kaplan-Meier analysis, Log rank test, and multivariable Cox regression analysis (with backward elimination) were used to determine whether the LACE+ score was an independent predictor for 30-day unplanned readmission.

Results

The overall 30-day unplanned readmission rate was 11.7% (194/1,657). The median LACE+ score was higher in the 30-day readmission group compared to subjects that had no unplanned 30-day readmission [74 (IQR 67–79) vs. 70 (IQR 62–75); p < 0.001]. On Kaplan-Meier analysis, the high-risk group had the shortest 30-day readmission free survival time as compared to medium and medium-to-high risk groups (p < 0.01, each; statistically significant). On fully adjusted multivariable Cox-regression, the highest LACE+ risk category was independently associated with the unplanned 30-day readmission risk (per point: HR 1.67 95%CI 1.23–2.26, p = 0.001).

Conclusion

Subjects in the high LACE+ index category had a significantly greater unplanned 30-day readmission risk after stroke as compared to lower LACE+ risk groups. This supports the validity of the LACE+ scoring system for predicting unplanned readmission in subjects with stroke. Future studies are warranted to determine whether LACE+ score-based risk stratification can be used to devise early interventions to mitigate the risk for unplanned readmission.

Cumulative effect of simvastatin, L-arginine, and tetrahydrobiopterin on cerebral blood flow and cognitive function in Alzheimer's disease

BACKGROUND AND OBJECTIVES

Vascular disease is a known risk factor for Alzheimer's disease (AD). Endothelial dysfunction has been linked to reduced cerebral blood flow. Endothelial nitric oxide synthase pathway (eNOS) upregulation is known to support endothelial health. This single-center, proof-of-concept study tested whether the use of three medications known to augment the eNOS pathway activity improves cognition and cerebral blood flow (CBF).

METHODS

Subjects with mild AD or mild cognitive impairment (MCI) were sequentially treated with the HMG-CoA reductase synthesis inhibitor simvastatin (weeks 0-16), L-arginine (weeks 4-16), and tetrahydrobiopterin (weeks 8-16). The primary outcome of interest was the change in CBF as measured by MRI from baseline to week 16. Secondary outcomes included standard assessments of cognition.

RESULTS

A total of 11 subjects were deemed eligible and enrolled. One subject withdrew from the study after enrollment, leaving 10 subjects for data analysis. There was a significant increase in CBF from baseline to week 8 by ~13% in the limbic and ~15% in the cerebral cortex. Secondary outcomes indicated a modest but significant increase in the MMSE from baseline (24.2±3.2) to week 16 (26.0±2.7). Exploratory analysis indicated that subjects with cognitive improvement (reduction of the ADAS-cog 13) had a significant increase in their respective limbic and cortical CBF.

CONCLUSIONS

Treatment of mild AD/MCI subjects with medications shown to augment the eNOS pathway was well tolerated and associated with modestly increased cerebral blood flow and cognitive improvement.

TRIAL REGISTRATION

This study is registered in https://www.

CLINICALTRIALS

gov ; registration identifier: NCT01439555; date of registration submitted to registry: 09/23/2011; date of first subject enrollment: 11/2011.

Leukoaraiosis Distribution and Cerebral Collaterals: A Systematic Review and Meta-Analysis

Background and Objective

Microvascular failure might result in the collapse of cerebral collaterals. However, controversy remains regarding the role of leukoaraiosis (LA) in collateral recruitment. We, therefore, performed a systematic review and meta-analysis of the association between LA and cerebral collaterals.

Methods

Ovid Medline, PubMed, Embase, Web of Science, and three Chinese databases were searched from inception to August 2021. Two types of cerebral collaterals, including Circle of Willis (CoW) and leptomeningeal collaterals (LC), were investigated separately. Random effect models were used to calculate the pooled odds ratio (OR). Meta-regression and subgroup analyses were performed to explore the potential sources of heterogeneity.

Results

From 14 studies (n = 2,451) that fulfilled our inclusion criteria, data from 13 could be pooled for analysis. Overall, there was a significant association between severe LA and incomplete CoW (pooled OR 1.66, 95% CI 1.18–2.32, p = 0.003), with low heterogeneity (I² = 5.9%). This association remained significant in deep LA (pooled OR 1.48, 95% CI 1.04–2.11, p = 0.029, I² = 0), but not periventricular LA. Similarly, there was a significant association between LA and LC (pooled OR 1.73, 95% CI 1.03–2.90, p = 0.037), but with high heterogeneity (I² = 67.2%). Meta-regression indicated a negative association of sample size with the effect sizes (p = 0.029). In addition, most of the studies (7/9) included into the analysis of the relationship of severe LA with poor LC enrolled subjects with large vessel occlusion stroke, and this relationship remained significant when pooling the seven studies, but with high heterogeneity.

Conclusion

Severe LA is associated with a higher prevalence of poor collaterals. This association is robust for CoW but weak for LC. Further studies are required to explore the underlying mechanisms.

Novel Oxygen Carrier Slows Infarct Growth in Large Vessel Occlusion Dog Model Based on Magnetic Resonance Imaging Analysis

BACKGROUND

Tissue hypoxia plays a critical role in the events leading to cell death in ischemic stroke. Despite promising results in preclinical and small clinical pilot studies, inhaled oxygen supplementation has not translated to improved outcomes in large clinical trials. Moreover, clinical observations suggest that indiscriminate oxygen supplementation can adversely affect outcome, highlighting the need to develop novel approaches to selectively deliver oxygen to affected regions. This study tested the hypothesis that intravenous delivery of a novel oxygen carrier (Omniox-Ischemic Stroke [OMX-IS]), which selectively releases oxygen into severely ischemic tissue, could delay infarct progression in an established canine thromboembolic large vessel occlusion stroke model that replicates key dynamics of human infarct evolution.

METHODS

After endovascular placement of an autologous clot into the middle cerebral artery, animals received OMX-IS treatment or placebo 45 to 60 minutes after stroke onset. Perfusion-weighted magnetic resonance imaging was performed to define infarct progression dynamics to stratify animals into fast versus slow stroke evolvers. Serial diffusion-weighted magnetic resonance imaging was performed for up to 5 hours to quantify infarct evolution. Histology was performed postmortem to confirm final infarct size.

RESULTS

In fast evolvers, OMX-IS therapy substantially slowed infarct progression (by ≈1 hour, P<0.0001) and reduced the final normalized infarct volume as compared to controls (0.99 versus 0.88, control versus OMX-IS drug, P<0.0001). Among slow evolvers, OMX-IS treatment delayed infarct progression by approximately 45 minutes; however, this did not reach statistical significance (P=0.09). The final normalized infarct volume also did not show a significant difference (0.93 versus 0.95, OMX-IS drug versus control, P=0.34). Postmortem histologically determined infarct volumes showed excellent concordance with the magnetic resonance imaging defined ischemic lesion volume (bias: 1.33% [95% CI, -15% to 18%).

CONCLUSIONS

Intravenous delivery of a novel oxygen carrier is a promising approach to delay infarct progression after ischemic stroke, especially in treating patients with large vessel occlusion stroke who cannot undergo definitive reperfusion therapy within a timely fashion.

Association of Atrial Fibrillation Detected after Stroke with Cardiac Dysfunction and Features of Neurogenic Cardiac Injury

OBJECTIVES

Understanding the link between markers of cardiac injury and atrial fibrillation (AF) detected after stroke (AFDAS) may help refine stroke risk stratification and therapeutic approaches in AFDAS.

MATERIALS AND METHODS

We retrospectively analyzed 988 adult patients admitted for acute ischemic stroke and transient ischemic attack, who presented within 4.5 h from last known well. Pertinent clinical variables including features of neurogenic cardiac injury (so-called stroke heart syndrome [SHS]) as well as electrocardiographic and echocardiographic markers of cardiac dysfunction, and AF status (no AF n = 574; known AF n = 311; AFDAS; n = 103) were collected. Multivariable logistic regression was used to determine the independent associations of variables with AFDAS.

RESULTS

A total of 264 (26.7%) subjects fulfilled criteria for SHS. Of these, 174 of had SHS features other than AFDAS (non-AF SHS). Among 677 subjects without known AF, presence of non-AF SHS was associated with a 5-fold odds of AFDAS (OR 5.0, 95%-CI 3.1-8.0, p < 0.001). After adjustment, non-AF SHS (OR 3.2, 95%-CI 1.6-6.4, p = 0.001) and the left atrial volume index (OR 1.04, 95%-CI 1.01-1.08, p = 0.004) remained independently associated with AFDAS.

CONCLUSIONS

The presence of non-AF SHS features and the left atrial volume index were independently associated with AFDAS indicating diverse mechanisms relating to new onset AF. A better understanding of the links between these markers and AFDAS may help uncover potentially modifiable risk factors for AFDAS as well as aid treatment decisions in patients at risk for new onset AF and ischemic stroke.

Direct Oral Anticoagulants Versus Warfarin in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT): A Multicenter International Study

BACKGROUND

A small randomized controlled trial suggested that dabigatran may be as effective as warfarin in the treatment of cerebral venous thrombosis (CVT). We aimed to compare direct oral anticoagulants (DOACs) to warfarin in a real-world CVT cohort.

METHODS

This multicenter international retrospective study (United States, Europe, New Zealand) included consecutive patients with CVT treated with oral anticoagulation from January 2015 to December 2020. We abstracted demographics and CVT risk factors, hypercoagulable labs, baseline imaging data, and clinical and radiological outcomes from medical records. We used adjusted inverse probability of treatment weighted Cox-regression models to compare recurrent cerebral or systemic venous thrombosis, death, and major hemorrhage in patients treated with warfarin versus DOACs. We performed adjusted inverse probability of treatment weighted logistic regression to compare recanalization rates on follow-up imaging across the 2 treatments groups.

RESULTS

Among 1025 CVT patients across 27 centers, 845 patients met our inclusion criteria. Mean age was 44.8 years, 64.7% were women; 33.0% received DOAC only, 51.8% received warfarin only, and 15.1% received both treatments at different times. During a median follow-up of 345 (interquartile range, 140-720) days, there were 5.68 recurrent venous thrombosis, 3.77 major hemorrhages, and 1.84 deaths per 100 patient-years. Among 525 patients who met recanalization analysis inclusion criteria, 36.6% had complete, 48.2% had partial, and 15.2% had no recanalization. When compared with warfarin, DOAC treatment was associated with similar risk of recurrent venous thrombosis (aHR, 0.94 [95% CI, 0.51-1.73]; P=0.84), death (aHR, 0.78 [95% CI, 0.22-2.76]; P=0.70), and rate of partial/complete recanalization (aOR, 0.92 [95% CI, 0.48-1.73]; P=0.79), but a lower risk of major hemorrhage (aHR, 0.35 [95% CI, 0.15-0.82]; P=0.02).

CONCLUSIONS

In patients with CVT, treatment with DOACs was associated with similar clinical and radiographic outcomes and favorable safety profile when compared with warfarin treatment. Our findings need confirmation by large prospective or randomized studies.

Differential association of baseline body weight and body-weight loss with neurological deficits, histology, and death after repetitive closed head traumatic brain injury

Clinical observations indicate that body weight (BW) extremes are associated with worse outcome after traumatic brain injury (TBI); yet, it is uncertain whether the baseline BW (bBW) may affect outcome after mouse TBI. We retrospectively analyzed 129 similarly aged (9-12 weeks) male C57BL6/J mice that were subjected to repetitive closed head TBI (rTBI) using an established weight drop paradigm as well as 55 sham injured mice. We sought to determine whether the bBW as well as the post-TBI weight relative to baseline (%BW) were associated with a variety of post-rTBI outcomes, including acute model complications (skull fractures and macroscopic hemorrhage), impact seizures, return of the righting reflex (RR), the neurological severity score (NSS), post-rTBI BW-change, and 28-day mortality. In a subset of rTBI mice, we also assessed for potential associations between the bBW and %BW and performance in the novel object recognition (NOR) task and various histological outcomes at 28 days. We found no association between the bBW with acute model complications, impact seizure burden, RR, NSS, and NOR performance at 28 days, as well as cerebral microbleed burden, presence of hyperphosphorylated tau, and TDP-43 pathology after rTBI. However, a higher bBW was associated with a longer time to first impact seizure, a greater microglial activation, astrocytosis, and neuronal loss in the injured cerebral cortex at 28 days. A greater %BW-loss was associated with a shorter impact seizure-free survival, longer time to return of the righting reflex, greater neurological deficit severity as assessed by the NSS and NOR, and worse mortality. On multiple linear regression there was no independent association of the %BW-loss with neuronal loss and neuroinflammation after adjustment for the bBW. These observations indicate that the bBW and %BW-loss may be important biological variables in certain experimental mouse TBI investigations, depending on the outcome measures of interest.

Abstract WMP58: Association Of The Lace+ Score With Unplanned 30-day Hospital Readmissions After Stroke

The LACE+ score is used to predict unplanned 30-day hospital readmissions, but its association with 30-day readmission after stroke is unknown. We retrospectively analyzed 1,656 consecutive patients presenting with strokes, included in an institutional stroke registry between January 2018 and August 2020. The primary outcome of interest was unplanned 30-day readmission. The 30-day readmission risk was categorized by LACE+ scores: high risk (>81), medium high (59-80) and medium risk (29-58). Kaplan-Meier curve, Log rank test, and multivariable cox regression analysis (with backward elimination) were used to determine whether the LACE+ score was associated with 30-day readmission. The overall incidence of 30-day unplanned readmission was 11.7% (194/1,656). The median LACE+ score was higher in the 30-day readmission group compared to subjects that had no unplanned 30-day readmission (74 (IQ 67-79) vs. 70 (IQ 62-75); p<0.001). On univariate analysis, readmitted patients were older, had a longer index admission length of stay, higher index admission cost, were more likely to be discharged to inpatient rehab, and with higher presence of hypertension, diabetes, history of prior stroke/TIA, and cardiovascular risk factors (p<0.05, each) as compared to non-readmitted group. On Kaplan-Meier analysis, the cumulative 30-day readmission free survival stratified by LACE+ risk category was lowest in the high-risk group and greatest in the medium risk group (Log-rank p<0.001). On multivariable Cox-regression, LACE+ score was independently associated with the unplanned 30-day readmission risk (HR 1.033; 95% CI 1.017-1.050, p<0.001) after adjustment for other variables. This is the first study looking at the association between LACE+ scores and unplanned readmissions in stroke, noting higher LACE+ scores associated with a greater unplanned 30-day readmission after stroke. Future studies on 30-day readmission risks in stroke are needed for quality improvement.

Abstract 159: Recurrent Ischemic Stroke And Cigarette Smoking: A Secondary Analysis Of The POINT Trial

Background: Recent data suggest that in patients with acute myocardial infarction (MI), the effect of clopidogrel on risk reduction of cardiovascular outcomes is more pronounced in smokers. The aim of this study was to determine the effect of smoking status on subsequent stroke risk in patients with minor ischemic stroke or TIA and determine whether smoking improves the effect of clopidogrel treatment on subsequent stroke risk reduction.

Methods: This was a post-hoc analysis of the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial. The POINT trial compared clopidogrel plus aspirin (DAPT) to aspirin alone for prevention of recurrent stroke, myocardial infarction, or vascular death within 3 months of a high-risk TIA or minor ischemic stroke. We used multivariable cox-regression models to determine the effect of smoking on the risk of subsequent ischemic stroke. We also performed interaction analyses to determine whether the effect of clopidogrel on subsequent ischemic stroke differed with respect to smoking status.

Results: Data from 4,877 participants enrolled in the POINT trial were analyzed. Among these, 1,004 were current smokers and 3,873 were non-smokers. Smoking was associated with a non-significantly increased risk of recurrent ischemic stroke during follow up (hazard ratio, 1.31 [95% CI, 0.97 - 1.78], P=0.076). The effect of clopidogrel on ischemic stroke was not significantly different in non-smokers (hazard ratio, 0.74 [95% CI, 0.56 - 0.98], P=0.03) compared to smokers (adjusted hazard ratio, 0.63 [95% CI, 0.37 - 1.05], P=0.078), P for interaction = 0.572. In addition, the effect of clopidogrel on major hemorrhage was not significantly different in current smokers (hazard ratio, 2.59 [95% CI, 1.08 - 6.21], P=0.032) compared to non-smokers (hazard ratio, 1.67 [95% CI, 0.40 - 7.00], P=0.481), P for interaction = 0.613.

Conclusions: Cigarette smoking was associated with a non-significantly higher risk of subsequent ischemic stroke and smoking did not modify the effect of clopidogrel-based dual antiplatelet therapy on subsequent ischemic stroke risk reduction. Every effort should be made to encourage tobacco dependence treatment and cessation in patients with minor ischemic stroke and TIA.

Abstract WP114: Elevated Troponin Is Associated With Mortality In Patients With Acute Cardioembolic Stroke And Atrial Fibrillation

Introduction: Stroke is the fifth leading cause of death in the US and a major cause of disability. Atrial fibrillation (AF) increases the risk of ischemic stroke fivefold. Cardioembolic stroke in patients with AF is associated with high mortality. The association of elevated cardiac troponin with mortality in patients with acute ischemic stroke has been studied previously; however, there is limited data in subgroups of ischemic stroke etiology. We sought to determine the association of troponin elevation at presentation with 90-day all-cause mortality in patients with acute ischemic stroke and AF.

Methods: The I nitiation of A nticoagulation after C ardioembolic Stroke (IAC) study is a multicenter cohort drawn from eight US Stroke Centers. We included consecutive patients hospitalized with acute ischemic stroke and AF between 2015-2018, who had an initial baseline cardiac troponin I (bcTnI) obtained at presentation. The primary outcome was all-cause mortality at 90 days from stroke onset. We undertook multivariable logistic regression to determine the association between elevated bcTnl (≥0.1 ng/mL) and 90-day mortality.

Results: Of the 2084 patients enrolled in IAC, 1889 patients had 90-day follow-up of which 1461 patients had bcTnI available. 239 of the included patients (16.4%) had an elevated bcTnl, and death within 90-days occurred in 323 patients (22.1%). Elevated bcTnI was associated with 90-day mortality in univariable analysis (49.4% vs 24.9%; OR 1.71, 95% CI 1.17-2.50, p<0.001). This association persisted after adjusting for potential confounders: age, NIHSS, coronary artery disease, congestive heart failure and initial systolic blood pressure (OR 1.71, 95% CI 1.17-2.50, p=0.006); and in sensitivity analysis adding CrCl to the adjusted model above (OR 1.57, 95% CI 1.03-2.39, p=0.037).

Conclusion: In acute ischemic stroke patients with AF, elevated bcTnI was independently associated with 90-day all-cause mortality.

Infarct on Brain Imaging, Subsequent Ischemic Stroke, and Clopidogrel-Aspirin Efficacy: A Post Hoc Analysis of a Randomized Clinical Trial

IMPORTANCE

In the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, acute treatment with clopidogrel-aspirin was associated with significantly reduced risk of recurrent stroke. There may be specific patient groups who are more likely to benefit from this treatment.

OBJECTIVE

To investigate whether the association of clopidogrel-aspirin with stroke recurrence in patients with minor stroke or high-risk transient ischemic attack (TIA) is modified by the presence of infarct on imaging attributed to the index event (index imaging) among patients enrolled in the POINT Trial.

DESIGN, SETTING, AND PARTICIPANTS

In the POINT randomized clinical trial, patients with high-risk TIA and minor ischemic stroke were enrolled at 269 sites in 10 countries in North America, Europe, Australia, and New Zealand from May 28, 2010, to December 19, 2017. In this post hoc analysis, patients were divided into 2 groups according to whether they had an acute infarct on index imaging. All POINT trial participants with information available on the presence or absence of acute infarct on index imaging were eligible for this study. Univariable Cox regression models evaluated associations between the presence of an infarct on index imaging and subsequent ischemic stroke and evaluated whether the presence of infarct on index imaging modified the association of clopidogrel-aspirin with subsequent ischemic stroke risk. Data were analyzed from July 2020 to May 2021.

EXPOSURES

Presence or absence of acute infarct on index imaging.

MAIN OUTCOMES AND MEASURES

The primary outcome is whether the presence of infarct on index imaging modified the association of clopidogrel-aspirin with subsequent ischemic stroke risk.

RESULTS

Of the 4881 patients enrolled in POINT, 4876 (99.9%) met the inclusion criteria (mean [SD] age, 65 [13] years; 2685 men [55.0%]). A total of 1793 patients (36.8%) had an acute infarct on index imaging. Infarct on index imaging was associated with ischemic stroke during follow-up (hazard ratio [HR], 3.68; 95% CI, 2.73-4.95; P < .001). Clopidogrel-aspirin vs aspirin alone was associated with decreased ischemic stroke risk in patients with an infarct on index imaging (HR, 0.56; 95% CI, 0.41-0.77; P < .001) compared with those without an infarct on index imaging (HR, 1.11; 95% CI, 0.74-1.65; P = .62), with a significant interaction association (P for interaction = .008).

CONCLUSIONS AND RELEVANCE

In this study, the presence of an acute infarct on index imaging was associated with increased risk of recurrent stroke and a more pronounced benefit from clopidogrel-aspirin. Future work should focus on validating these findings before targeting specific patient populations for acute clopidogrel-aspirin treatment.

Antiplatelet Use and Ischemic Stroke Risk in Minor Stroke or Transient Ischemic Attack: A Post Hoc Analysis of the POINT Trial

BACKGROUND AND PURPOSE

Dual antiplatelet therapy has been shown to reduce the risk of recurrent stroke in patients with minor stroke or transient ischemic attack. However, whether the effect of dual antiplatelet therapy is modified by pretreatment antiplatelet status is unclear.

METHODS

This is a post hoc analysis of the POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke). Patients were divided into 2 groups based on pretreatment antiplatelet use. The primary outcome was ischemic stroke within 90 days of randomization.

RESULTS

We included 4881 patients of whom 41% belonged to the no pretreatment antiplatelet. Ischemic stroke occurred in 6% and 5% in the antiplatelet pretreatment and no antiplatelet pretreatment, respectively. Antiplatelet pretreatment was not associated with the risk of ischemic stroke (adjusted hazard ratio, 1.05 [95% CI, 0.81-137]) or risk of major hemorrhage (hazard ratio, 1.10 [95% CI, 0.55-2.21]; P=0.794). The effect of dual antiplatelet therapy on recurrent ischemic stroke risk was not different in patients who were on antiplatelet before randomization (adjusted hazard ratio, 0.69 [95% CI, 0.50-0.94]) as opposed to those who were not (adjusted hazard ratio, 0.75 [95% CI, 0.50-1.12]), P for interaction = 0.685.

CONCLUSIONS

In patients with minor stroke and high-risk transient ischemic attack, dual antiplatelet therapy reduces the risk of ischemic stroke regardless of premorbid antiplatelet use.

Development of heart failure in long-term survivors of childhood cancer: results from the cvss study

Background

Long-term survivors of childhood cancer (CCS) are at increased risk for cardiovascular sequelae, including heart failure (HF) as the largest non-malignant contributor to excess death. Yet, little is known about the risk factors, mechanisms of cardiac dysfunction and prevalence of different stages of HF in these patients.

Purpose

To investigate the development and prevalence of HF phenotypes in CCS compared to the general population.

Methods

The CVSS study is a prospective single-center cohort study investigating cardiovascular sequelae of CCS. Patients were eligible for the study when they were diagnosed with a neoplasia according to the International Classification of Childhood Cancer (ICCC 3) at an age prior to 15 years between 1980 and 1990, survived more than five years after initial cancer diagnosis and received antineoplastic treatment. Between 2013 and 2016, study individuals underwent a comprehensive, standardized clinical investigation in the CVSS cohort study including echocardiographic examination. HF was categorized as stages A to D according to current HF guidelines of the American Heart Association (AHA). A population-based sample free of cancer (age- and sex matched) serves as control group.

Results

From 1,002 individuals, all CCS with history of chemo- or radiotherapy and no subsequent neoplasia (n=877) were included (mean age 34.2 (±5.5) years, 44.7% (N=392) female). Age at diagnosis was 6.28 years (±4.24) and the mean interval from the date of diagnosis of cancer to the date of completion of baseline examination 28.5±3.2 years. Based on echocardiographic examination, clinical data and biomarker assessment, 26.6% of CCS were diagnosed with HF stage A, 21.1% with HF stage B and 2.1% with symptomatic HF, i.e. HF stage C/D. Importantly, prevalence of different HF stages varied strongly by specific tumor history. Compared to the population, the prevalence ratio (PR) was 1.16 [95% confidence interval 1.02/1.31] for stage A HF and 1.91 [1.63/2.23] for the composite of stage B to D HF in an age- and sex-adjusted Poisson regression model. Multivariable linear regression with the systolic marker left ventricular ejection fraction as dependent variable and adjustment for tumor entities, age, sex, and cardiovascular risk factors (CVRF) revealed a lower EF in patients with history of bone tumors (β −6.0 [−8.1/−3.0]), soft tissue sarcoma (β −2.2 [−4.1/−0.35]), leukemia (β −0.84 [−1.8/0.08]) and renal tumors (β −1.8 [−4.0/0.27]) compared to the population. In contrast, the same model for the diastolic marker E/E', showed an association only with CVRF, but not with tumor entities.

Conclusion

The prevalence of stage B to D HF was significantly higher among long-term CCS in the 3rd to 5th age decade compared to the population and varied strongly by tumor entity. Systolic dysfunction was primarily associated with history of tumor entities, whereas diastolic dysfunction was associated with the higher burden of CVRF in CCS.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study is funded by the Deutsche Forschungsgemeinschaft (DFG) (SP 1381/2-1&2, FA 1038/2-1&2, WI 3881/2-1&2)

Ischaemic stroke on anticoagulation therapy and early recurrence in acute cardioembolic stroke: the IAC study

BACKGROUND AND PURPOSE

A subset of ischaemic stroke patients with atrial fibrillation (AF) have ischaemic stroke despite anticoagulation. We sought to determine the association between prestroke anticoagulant therapy and recurrent ischaemic events and symptomatic intracranial haemorrhage (sICH).

METHODS

We included consecutive patients with acute ischaemic stroke and AF from the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study from eight comprehensive stroke centres in the USA. We compared recurrent ischaemic events and delayed sICH risk using adjusted Cox regression analyses between patients who were prescribed anticoagulation (ACp) versus patients who were naïve to anticoagulation therapy prior to the ischaemic stroke (anticoagulation naïve).

RESULTS

Among 2084 patients in IAC, 1518 had prior anticoagulation status recorded and were followed for 90 days. In adjusted Cox hazard models, ACp was associated with some evidence of a higher risk higher risk of 90-day recurrent ischaemic events only in the fully adjusted model (adjusted HR 1.50, 95% CI 0.99 to 2.28, p=0.058) but not increased risk of 90-day sICH (adjusted HR 1.08, 95% CI 0.46 to 2.51, p=0.862). In addition, switching anticoagulation class was not associated with reduced risk of recurrent ischaemic events (adjusted HR 0.41, 95% CI 0.12 to 1.33, p=0.136) nor sICH (adjusted HR 1.47, 95% CI 0.29 to 7.50, p=0.641).

CONCLUSION

AF patients with ischaemic stroke despite anticoagulation may have higher recurrent ischaemic event risk compared with anticoagulation-naïve patients. This suggests differing underlying pathomechanisms requiring different stroke prevention measures and identifying these mechanisms may improve secondary prevention strategies.

Targeting autophagy in ischemic stroke: From molecular mechanisms to clinical therapeutics

Stroke constitutes the second leading cause of death and a major cause of disability worldwide. Stroke is normally classified as either ischemic or hemorrhagic stroke (HS) although 87% of cases belong to ischemic nature. Approximately 700,000 individuals suffer an ischemic stroke (IS) in the US each year. Recent evidence has denoted a rather pivotal role for defective macroautophagy/autophagy in the pathogenesis of IS. Cellular response to stroke includes autophagy as an adaptive mechanism that alleviates cellular stresses by removing long-lived or damaged organelles, protein aggregates, and surplus cellular components via the autophagosome-lysosomal degradation process. In this context, autophagy functions as an essential cellular process to maintain cellular homeostasis and organismal survival. However, unchecked or excessive induction of autophagy has been perceived to be detrimental and its contribution to neuronal cell death remains largely unknown. In this review, we will summarize the role of autophagy in IS, and discuss potential strategies, particularly, employment of natural compounds for IS treatment through manipulation of autophagy.

Dorsal vagal nucleus involvement relates to QTc-prolongation after acute medullary infarction

BACKGROUND

Infarction of the medulla has been associated with prolongation of the QTc, severe arrhythmia, and sudden cardiac death, yet the precise anatomical substrate remains uncertain.

AIMS

We sought to determine the possible anatomical structures relating to QTc-prolongation in patients with acute medullary infarction.

METHODS

We included 12 subjects with acute ischemic medullary infarction on brain MRI, who presented within 4.5 h from the last known well time, with a 90-day follow-up. For an unbiased lesion analysis, medullary infarcts were manually outlined on diffusion weighted MRI and co-registered with an anatomical atlas.

RESULTS

Nine out of 12 had QTc-prolongation. Qualitative and semi-quantitative comparisons were made between infarct location and QTc-prolongation. Among patients with QTc-prolongation, the greatest degree of congruence of the infarct location was over the dorsal vagal nucleus (DVN, 8 out of 9). There was a significant correlation between the number of sections showing infarction of the DVN and presence of QTc-prolongation (r = .582, p = .047). Among patients without QTc-prolongation, the maximum lesion overlap included the medial aspect of the gigantocelluar reticular nucleus of the reticular formation.

CONCLUSION

We found that the DVN is a key anatomical substrate related to QTc-prolongation. Further studies with more patients and high-resolution, volumetric MRI are needed to confirm our findings.

Effect of Alteplase Use on Outcomes in Patients With Atrial Fibrillation: Analysis of the Initiation of Anticoagulation After Cardioembolic Stroke Study

Background

Intravenous alteplase improves outcome after acute ischemic stroke without a benefit in 90‐day mortality. There are limited data on whether alteplase is associated with reduced mortality in patients with atrial fibrillation (AF)‐related ischemic stroke whose mortality rate is relatively high. We sought to determine the association of alteplase with hemorrhagic transformation and mortality in patients with AF.

Methods and Results

We retrospectively analyzed consecutive patients with acute ischemic stroke between 2015 and 2018 diagnosed with AF included in the IAC (Initiation of Anticoagulation After Cardioembolic Stroke) study, which pooled data from stroke registries at 8 comprehensive stroke centers across the United States. For our primary analysis, we included patients who did not undergo mechanical thrombectomy (MT), and secondary analyses included patients who underwent MT. We used binary logistic regression to determine whether alteplase use was associated with risk of hemorrhagic transformation and 90‐day mortality. There were 1889 patients (90.6%) who had 90‐day follow‐up data available for analyses and were included; 1367 patients (72.4%) did not receive MT, and 522 patients (27.6%) received MT. In our primary analyses we found that alteplase use was independently associated with an increased risk for hemorrhagic transformation (odds ratio [OR], 2.23; 95% CI, 1.57–3.17) but reduced risk of 90‐day mortality (OR, 0.58; 95% CI, 0.39–0.87). Among patients undergoing MT, alteplase use was not associated with a significant reduction in 90‐day mortality (OR, 0.68; 95% CI, 0.45–1.04).

Conclusions

Alteplase reduced 90‐day mortality of patients with acute ischemic stroke with AF not undergoing MT. Further study is required to assess the efficacy of alteplase in patients with AF undergoing MT.

Mouse closed head traumatic brain injury replicates the histological tau pathology pattern of human disease: characterization of a novel model and systematic review of the literature

Traumatic brain injury (TBI) constitutes one of the strongest environmental risk factors for several progressive neurodegenerative disorders of cognitive impairment and dementia that are characterized by the pathological accumulation of hyperphosphorylated tau (p-Tau). It has been questioned whether mouse closed-head TBI models can replicate human TBI-associated tauopathy. We conducted longitudinal histopathological characterization of a mouse closed head TBI model, with a focus on pathological features reported in human TBI-associated tauopathy. Male C57BL/6 J mice were subjected to once daily TBI for 5 consecutive days using a weight drop paradigm. Histological analyses (AT8, TDP-43, pTDP-43, NeuN, GFAP, Iba-1, MBP, SMI-312, Prussian blue, IgG, βAPP, alpha-synuclein) were conducted at 1 week, 4 weeks, and 24 weeks after rTBI and compared to sham operated controls. We conducted a systematic review of the literature for mouse models of closed-head injury focusing on studies referencing tau protein assessment. At 1-week post rTBI, p-Tau accumulation was restricted to the corpus callosum and perivascular spaces adjacent to the superior longitudinal fissure. Progressive p-Tau accumulation was observed in the superficial layers of the cerebral cortex, as well as in mammillary bodies and cortical perivascular, subpial, and periventricular locations at 4 to 24 weeks after rTBI. Associated cortical histopathologies included microvascular injury, neuroaxonal rarefaction, astroglial and microglial activation, and cytoplasmatic localization of TDP-43 and pTDP-43. In our systematic review, less than 1% of mouse studies (25/3756) reported p-Tau using immunostaining, of which only 3 (0.08%) reported perivascular p-Tau, which is considered a defining feature of chronic traumatic encephalopathy. Commonly reported associated pathologies included neuronal loss (23%), axonal loss (43%), microglial activation and astrogliosis (50%, each), and beta amyloid deposition (29%). Our novel model, supported by systematic review of the literature, indicates progressive tau pathology after closed head murine TBI, highlighting the suitability of mouse models to replicate pertinent human histopathology.

Carotid Stenosis and Recurrent Ischemic Stroke: A Post-Hoc Analysis of the POINT Trial

BACKGROUND AND PURPOSE

Randomized trials demonstrated the benefit of dual antiplatelet therapy in patients with minor ischemic stroke or high-risk transient ischemic attack. We sought to determine whether the presence of carotid stenosis was associated with increased risk of ischemic stroke and whether the addition of clopidogrel to aspirin was associated with more benefit in patients with versus without carotid stenosis.

METHODS

This is a post-hoc analysis of the POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke) that randomized patients with minor ischemic stroke or high-risk transient ischemic attack within 12 hours from last known normal to receive either clopidogrel plus aspirin or aspirin alone. The primary predictor was the presence of ≥50% stenosis in either cervical internal carotid artery. The primary outcome was ischemic stroke. We built Cox regression models to determine the association between carotid stenosis and ischemic stroke and whether the effect of clopidogrel was modified by ≥50% carotid stenosis.

RESULTS

Among 4881 patients enrolled POINT, 3941 patients met the inclusion criteria. In adjusted models, ≥50% carotid stenosis was associated with ischemic stroke risk (hazard ratio, 2.45 [95% CI, 1.68-3.57], P<0.001). The effect of clopidogrel (versus placebo) on ischemic stroke risk was not significantly different in patients with <50% carotid stenosis (adjusted hazard ratio, 0.68 [95% CI, 0.50-0.93], P=0.014) versus those with ≥50% carotid stenosis (adjusted hazard ratio, 0.88 [95% CI, 0.45-1.72], P=0.703), P value for interaction=0.573.

CONCLUSIONS

The presence of carotid stenosis was associated with increased risk of ischemic stroke during follow-up. The effect of added clopidogrel was not significantly different in patients with versus without carotid stenosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03354429.

Targeting autophagy in neurodegenerative diseases: From molecular mechanisms to clinical therapeutics

Many neurodegenerative diseases are associated with pathological aggregation of proteins in neurons. Autophagy is a natural self-cannibalization process that can act as a powerful mechanism to remove aged and damaged organelles as well as protein aggregates. It has been shown that promoting autophagy can attenuate or delay neurodegeneration by removing protein aggregates. In this paper, we will review the role of autophagy in Alzheimer's disease (AD), Parkinson's Disease (PD), and Huntington's Disease (HD) and discuss opportunities and challenges of targeting autophagy as a potential therapeutic avenue for treatment of these common neurodegenerative diseases.

Abstract P12: Alteplase Reduces Mortality in Patients With Ischemic Stroke and Atrial Fibrillation: Analysis of the IAC Study

Background and Purpose: Multiple studies have established that intravenous thrombolysis with alteplase improves outcome after acute ischemic stroke. However, assessment of thrombolysis’ efficacy in stroke patients with atrial fibrillation (AF) has yielded mixed results. We sought to determine the association of alteplase with mortality, hemorrhagic transformation (HT), infarct volume, and mortality in patients with AF and acute ischemic stroke.

Methods: We retrospectively analyzed consecutive acute ischemic stroke patients with AF included in the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study, which pooled data from 8 comprehensive stroke centers in the United States. 1889 (90.6%) had available 90-day follow up data and were included. For our primary analysis we used a cohort of 1367/1889 (72.4%) patients who did not undergo mechanical thrombectomy (MT). Secondary analyses were repeated in the patients that underwent MT (n=522). Binary logistic regression was used to determine whether alteplase use was independently associated with risk of HT, final infarct volume, and 90-day mortality, respectively, adjusting for potential confounders.

Results: In our primary analyses we found that alteplase use was independently associated with an increased risk for HT (adjusted OR 2.14, 95% CI 1.49 - 3.07, p <0.001) but overall reduced risk of 90-day mortality (adjusted OR 0.58, 95% CI 0.39 - 0.87, p = 0.009). Among patients undergoing MT, alteplase use was associated with a trend towards a reduction in 90-day mortality (adjusted OR 0.68 95% CI 0.45 - 1.04, p = 0.077). In the subgroup of patients prescribed DOAC treatment (n = 327; 24 received alteplase), alteplase treatment was associated with a trend towards smaller infarct size (< 10 mL), (adjusted OR 0.40, 95% CI 0.15 - 1.12, p = 0.082) without a significant difference in the odds of 90-day mortality (adjusted OR 0.51, 95% CI 0.12 - 2.13, p = 0.357) or hemorrhagic transformation (adjusted OR 0.27, 95% CI 0.03 - 2.07, p = 0.206).

Conclusion: Thrombolysis with intravenous alteplase was associated with reduced 90-day mortality in AF patients with acute ischemic stroke not undergoing MT. Further study is required to assess the safety and efficacy of alteplase in AF patients undergoing MT and those on DOACs.

Abstract P100: Hemorrhagic Stroke in the Setting of COVID-19 is Associated With Anticoagulation Use

Introduction: While the thrombotic complications of COVID-19 have been described, there are limited data on its implications in hemorrhagic stroke. The clinical characteristics, underlying stroke mechanism, and outcomes in this group of patients are especially salient as empiric therapeutic anticoagulation becomes increasingly common in the treatment and prevention of thrombotic complications of COVID-19.

Methods: We conducted a retrospective cohort study of patients with hemorrhagic stroke (both non-traumatic intracerebral hemorrhage and spontaneous non-aneurysmal subarachnoid hemorrhage) who were hospitalized between 3/1/20-5/15/20 at a NYC hospital system, during the coronavirus pandemic. We compared the demographic and clinical characteristics of patients with hemorrhagic stroke and COVID-19 to those without COVID-19 admitted to our hospital between 3/1/20-5/15/20 (contemporary controls) and 3/1/19-5/15/19 (historical controls), using Fischer’s exact test and non-parametric testing. We adjusted for multiple comparisons using the Bonferroni method.

Results: During the study period, 19 out of 4071 (0.5%) patients who were hospitalized with COVID-19 had hemorrhagic stroke on imaging. Of all COVID-19 with hemorrhagic stroke, only 3 had non-aneurysmal SAH without intraparenchymal hemorrhage. Among hemorrhagic stroke and COVID-19 patients, coagulopathy was the most common etiology (73.7%); empiric anticoagulation was started in 89.5% vs 4.2% of contemporary and 10.0% of historical controls (both with p =<0.001). Compared to contemporary and historical controls, COVID-19 patients had higher initial NIHSS scores, INR, PTT and fibrinogen levels. These patients also had higher rates of in-hospital mortality [84.6% vs. 4.6%, p =<0.001]. Sensitivity analyses excluding patients with strictly subarachnoid hemorrhage yielded similar results.

Conclusion: We observed an overall low rate of imaging-confirmed hemorrhagic stroke among patients hospitalized with COVID-19. Most hemorrhages in COVID-19 patients occurred in the setting of therapeutic anticoagulation and were associated with increased mortality. Further studies are needed to evaluate the safety and efficacy of therapeutic anticoagulation in COVID-19 patients.

Abstract P130: QTc Prolongation in Acute Medullary Infarction Maps to the Dorsal Vagal Nucleus

Objective: To determine the spatial relationship between acute medullary infarction and QTc prolongation.

Background: Ischemic stroke has been associated with QTc-prolongation which increases the risk of cardiac arrhythmia and sudden cardiac death. In particular, pathological arrhythmia and unexpected sudden cardiac death has been described after acute medullary infarction (AMI). Nevertheless, it is not well understood why only as subset of patients with AMI develop significant cardiac arrhythmia. To gain insight into this issue, we sought to determine the possible anatomical structures relating to QTc-prolongation in patients.

Methods: We retrospectively reviewed 1072 consecutive adult patients admitted for an acute ischemic stroke or a transient ischemic attack, who presented within 4.5 hours from the last known well time and had an admission ECG available. 724 patients had brain MRIs and among these, 13 (1.8 %) patients had an AMI and were included. For an unbiased lesion analyses, medullary infarcts were manually outlined on diffusion weighted MRI and manually co-registered with an anatomical atlas. Infarct lesions were then superimposed on each other as stratified by normal versus prolonged (men > 430 ms, women > 450 ms) QTc to determine the area of greatest degree of congruence.

Results: 76.9 % of patients (10 out of 13, 9 men and 1 woman) had a prolonged QTc (476.9 ± 43.3 ms for men, 515 ms for women). There was no significant difference in electrolyte levels and preexisting comorbidities between subjects with normal and prolonged QTc. Among patients with QTc prolongation, the greatest degree of congruence of the infarct location was the dorsal vagal nucleus (DVN, 7 out of 10 patients).

Conclusions: Our unbiased lesion segmentation approach identified the DVN a key anatomical substrate related to QTc-prolongation. Biological plausibility of our data and the presence of a causal link between the DVN and cardiac arrhythmia stems from the prior animal experimental data showing that selectively silencing the DVN via a pharmacogenetic approach caused QTc-prolongation in the rat. Further studies with more patients and high-resolution, volumetric MRI are needed to confirm our findings.

Abstract P387: Stroke Despite Anticoagulation Therapy Predicts Early Recurrence After Cardioembolic Stroke: The IAC-Study

Background and purpose: A proportion of patients with ischemic stroke and atrial fibrillation (AF) have an ischemic stroke despite being prescribed anticoagulation therapy. In this study of patients with ischemic stroke in the setting of AF, we aim to determine the association between prior anticoagulant therapy and 90-day recurrent ischemic events and delayed symptomatic intracranial hemorrhage (sICH).

Methods: We included consecutive patients with acute ischemic stroke and AF from the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study from 8 comprehensive stroke centers in the United States. We compared recurrent ischemic events and delayed sICH risk using unadjusted and adjusted cox-regression analyses between patients who were prescribed anticoagulation (AC p ) vs. were naïve to anticoagulation therapy prior to the ischemic stroke (AC n ). For ischemic events, we adjusted for CHA 2 DS 2 -Vasc, anticoagulation initiation, and switching anticoagulant (DOAC to Warfarin or Warfarin to DOAC). For delayed sICH, we adjusted for age, sex, NIHSS score, and early hemorrhagic transformation.

Results: 2070 patients had home anticoagulation treatment status recorded. When compared to the AC n group, the AC p group were more likely to have higher median (IQR) CHA 2 DS 2 -Vasc score [5 (4-6) vs. 5 (3-6), p = 0.001], lower NIHSS score [8 (3 - 18) vs. 10 (4 - 18), p = 0.015], severe left atrial enlargement (43.5% vs. 34.5%, p < 0.001), and less likely to receive alteplase (14.4% vs. 36.2%, p < 0.001). In the adjusted cox hazard model, AC p was associated with increased risk of 90-day recurrent ischemic events (adjusted HR 1.52 95% CI 1.01 - 2.29, p = 0.047) but not increased risk of 90-day sICH (adjusted HR 1.10 95% CI 0.46 - 2.61, p = 0.838). In a sensitivity analysis, with severe left atrial enlargement added to the model, the association between AC p and recurrent ischemic event risk did not meaningfully change (adjusted HR 1.41 95% CI 0.87 - 2.28, p = 0.162).

Conclusion: Patients with AF and ischemic stroke despite being prescribed anticoagulation therapy are at higher risk of recurrent events. Studies are needed to understand mechanisms of ischemic stroke in these patients to improve stroke prevention strategies.