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.

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.

Emergency medicine physicians' perspectives on diagnostic accuracy in neurology: a qualitative study.

OBJECTIVES: We sought to understand the knowledge, attitudes, and beliefs of emergency medicine (EM) physicians towards non-specific neurological conditions and the use of clinical decision support (CDS) to improve diagnostic accuracy. METHODS: We conducted semi-structured interviews of EM physicians at four emergency departments (EDs) affiliated with a single US healthcare system. Interviews were conducted until thematic saturation was achieved. Conventional content analysis was used to identify themes related to EM physicians' perspectives on acute diagnostic neurology; directed content analysis was used to explore views regarding CDS. Each interview transcript was independently coded by two researchers using an iteratively refined codebook with consensus-based resolution of coding differences. RESULTS: We identified two domains regarding diagnostic safety: (1) challenges unique to neurological complaints and (2) challenges in EM more broadly. Themes relevant to neurology included: (1) knowledge gaps and uncertainty, (2) skepticism about neurology, (3) comfort with basic as opposed to detailed neurological examination, and (4) comfort with non-neurological diseases. Themes relevant to diagnostic decision making in the ED included: (1) cognitive biases, (2) ED system/environmental issues, (3) patient barriers, (4) comfort with diagnostic uncertainty, and (5) concerns regarding diagnostic error identification and measurement. Most participating EM physicians were enthusiastic about the potential for well-designed CDS to improve diagnostic accuracy for non-specific neurological complaints. CONCLUSIONS: Physicians identified diagnostic challenges unique to neurological diseases as well as issues related more generally to diagnostic accuracy in EM. These physician-reported issues should be accounted for when designing interventions to improve ED diagnostic accuracy.

Biomarkers of Coagulation and Inflammation in COVID-19-Associated Ischemic Stroke.

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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.

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.

The effect of race on composite thrombotic events in patients with COVID-19.

COVID-19 associated coagulopathy and mortality related to thrombotic complications have been suggested as biological mediators in racial disparities related to COVID-19. We studied the adjusted prevalence of acute ischemic stroke, pulmonary embolism, myocardial infarction, and deep venous thrombosis stratified by race in hospitalized patients in one New York City borough during the local COVID-19 surge. The multi-racial cohort included 4299 patients hospitalized with COVID-19, 9% of whom were white, 40% black, 41% Hispanic and 10% Asian or other. We found a 6.1% prevalence of composite thrombotic events. There were no significant race-specific differences in thrombotic events when adjusting for basic demographics, socioeconomic factors, medical comorbidities or biomarkers using a stepwise regression model. We therefore found no evidence that the racial disparities related to COVID-19, and specifically thrombotic complications, are caused by biological differences in race.

Factors associated with hospitalization for ischemic stroke and TIA following an emergency department headache visit.

BACKGROUND: Misdiagnosis of cerebrovascular disease among Emergency Department (ED) patients with headache has been reported. We hypothesized that markers of substandard diagnostic processes would be associated with subsequent ischemic cerebrovascular events among patients discharged from the ED with a headache diagnosis even after adjusting for demographic variables and medical history. METHODS: We conducted a case-control study of adult ED patients diagnosed with a primary headache disorder at Montefiore Medical Center from 9/1/2013-9/1/2018. Cases were defined as patients hospitalized for an ischemic stroke or TIA within 365 days of their index ED visit. Control patients were defined as those who lacked a subsequent hospitalization for cerebrovascular disease. Pre-specified demographic, clinical, and diagnostic process factors were compared between groups; conditional logistic regression was used to assess the separate and joint influence of baseline features on risk of cerebral ischemia. RESULTS: A total of 93 consecutive headache patients with a subsequent ischemic stroke/TIA hospitalization were matched to 93 controls (n = 186). Cases were older than controls and more likely to have traditional cerebrovascular risk factors. Neurological consultation was obtained more often for cases (13% vs. 4%; P = 0.03), cases were in the ED for longer (6 vs. 5 h, P = 0.03), and more frequently received neuroimaging (80% vs. 48%; P < 0.0001). Rates of neurological examination, documented differential diagnoses, and clear discharge follow up plans were similar between cases and controls. In our conditional logistic regression model, only history of prior stroke/TIA was associated with increased odds of subsequent cerebral ischemia. CONCLUSION: Factors associated with diagnostic process failures did not increase the odds of subsequent ischemic stroke/TIA hospitalization following ED headache visit in our study.

Anticoagulation Type and Early Recurrence in Cardioembolic Stroke: The IAC Study.

BACKGROUND AND PURPOSE: In patients with acute ischemic stroke and atrial fibrillation, treatment with low molecular weight heparin increases early hemorrhagic risk without reducing early recurrence, and there is limited data comparing warfarin to direct oral anticoagulant (DOAC) therapy. We aim to compare the effects of the treatments above on the risk of 90-day recurrent ischemic events and delayed symptomatic intracranial hemorrhage. METHODS: We included consecutive patients with acute ischemic stroke and atrial fibrillation from the IAC (Initiation of Anticoagulation after Cardioembolic) stroke study pooling data from stroke registries of 8 comprehensive stroke centers across the United States. We compared recurrent ischemic events and delayed symptomatic intracranial hemorrhage between each of the following groups in separate Cox-regression analyses: (1) DOAC versus warfarin and (2) bridging with heparin/low molecular weight heparin versus no bridging, adjusting for pertinent confounders to test these associations. RESULTS: We identified 1289 patients who met the bridging versus no bridging analysis inclusion criteria and 1251 patients who met the DOAC versus warfarin analysis inclusion criteria. In adjusted Cox-regression models, bridging (versus no bridging) treatment was associated with a high risk of delayed symptomatic intracranial hemorrhage (hazard ratio, 2.74 [95% CI, 1.01-7.42]) but a similar rate of recurrent ischemic events (hazard ratio, 1.23 [95% CI, 0.63-2.40]). Furthermore, DOAC (versus warfarin) treatment was associated with a lower risk of recurrent ischemic events (hazard ratio, 0.51 [95% CI, 0.29-0.87]) but not delayed symptomatic intracranial hemorrhage (hazard ratio, 0.57 [95% CI, 0.22-1.48]). CONCLUSIONS: Our study suggests that patients with ischemic stroke and atrial fibrillation would benefit from the initiation of a DOAC without bridging therapy. Due to our study limitations, these findings should be interpreted with caution pending confirmation from large prospective studies.

Anticoagulation Timing in Cardioembolic Stroke and Recurrent Event Risk.

OBJECTIVE: Guidelines recommend initiating anticoagulation within 4 to 14 days after cardioembolic stroke. Data supporting this did not account for key factors potentially affecting the decision to initiate anticoagulation, such as infarct size, hemorrhagic transformation, or high-risk features on echocardiography. METHODS: We pooled data from stroke registries of 8 comprehensive stroke centers across the United States. We included consecutive patients admitted with ischemic stroke and atrial fibrillation. The primary predictor was timing of initiating anticoagulation (0-3 days, 4-14 days, or >14 days), and outcomes were recurrent stroke/transient ischemic attack/systemic embolism, symptomatic intracerebral hemorrhage (sICH), and major extracranial hemorrhage (ECH) within 90 days. RESULTS: Among 2,084 patients, 1,289 met the inclusion criteria. The combined endpoint occurred in 10.1% (n = 130) subjects (87 ischemic events, 20 sICH, and 29 ECH). Overall, there was no significant difference in the composite endpoint between the 3 groups (0-3 days: 10.3%, 64/617; 4-14 days: 9.7%, 52/535; >14 days: 10.2%, 14/137; p = 0.933). In adjusted models, patients started on anticoagulation between 4 and 14 days did not have a lower rate of sICH (vs 0-3 days; odds ratio [OR] = 1.49, 95% confidence interval [CI] = 0.50-4.43), nor did they have a lower rate of recurrent ischemic events (vs >14 days; OR = 0.76, 95% CI = 0.36-1.62, p = 0.482). INTERPRETATION: In this multicenter real-world cohort, the recommended (4-14 days) time frame to start oral anticoagulation was not associated with reduced ischemic and hemorrhagic outcomes. Randomized trials are required to determine the optimal timing of anticoagulation initiation. ANN NEUROL 2020;88:807-816.

Early ischaemic and haemorrhagic complications after atrial fibrillation-related ischaemic stroke: analysis of the IAC study.

INTRODUCTION: Predictors of long-term ischaemic and haemorrhagic complications in atrial fibrillation (AF) have been studied, but there are limited data on predictors of early ischaemic and haemorrhagic complications after AF-associated ischaemic stroke. We sought to determine these predictors. METHODS: The Initiation of Anticoagulation after Cardioembolic stroke study is a multicentre retrospective study across that pooled data from consecutive patients with ischaemic stroke in the setting of AF from stroke registries across eight comprehensive stroke centres in the USA. The coprimary outcomes were recurrent ischaemic event (stroke/TIA/systemic arterial embolism) and delayed symptomatic intracranial haemorrhage (d-sICH) within 90 days. We performed univariate analyses and Cox regression analyses including important predictors on univariate analyses to determine independent predictors of early ischaemic events (stroke/TIA/systemic embolism) and d-sICH. RESULTS: Out of 2084 patients, 1520 patients qualified; 104 patients (6.8%) had recurrent ischaemic events and 23 patients (1.5%) had d-sICH within 90 days from the index event. In Cox regression models, factors associated with a trend for recurrent ischaemic events were prior stroke or transient ischemic attack (TIA) (HR 1.42, 95% CI 0.96 to 2.10) and ipsilateral arterial stenosis with 50%-99% narrowing (HR 1.54, 95% CI 0.98 to 2.43). Those associated with sICH were male sex (HR 2.68, 95% CI 1.06 to 6.83), history of hyperlipidaemia (HR 2.91, 95% CI 1.08 to 7.84) and early haemorrhagic transformation (HR 5.35, 95% CI 2.22 to 12.92). CONCLUSION: In patients with ischaemic stroke and AF, predictors of d-sICH are different than those of recurrent ischaemic events; therefore, recognising these predictors may help inform early stroke versus d-sICH prevention strategies.

Factors associated with therapeutic anticoagulation status in patients with ischemic stroke and atrial fibrillation.

BACKGROUND AND PURPOSE: Understanding factors associated with ischemic stroke despite therapeutic anticoagulation is an important goal to improve stroke prevention strategies in patients with atrial fibrillation (AF). We aim to determine factors associated with therapeutic or supratherapeutic anticoagulation status at the time of ischemic stroke in patients with AF. METHODS: The Initiation of Anticoagulation after Cardioembolic stroke (IAC) study is a multicenter study pooling data from stroke registries of eight comprehensive stroke centers across the United States. Consecutive patients hospitalized with acute ischemic stroke in the setting of AF were included in the IAC cohort. For this study, we only included patients who reported taking warfarin at the time of the ischemic stroke. Patients not on anticoagulation and patients who reported use of a direct oral anticoagulant were excluded. Analyses were stratified based on therapeutic (INR ≥2) versus subtherapeutic (INR <2) anticoagulation status. We used binary logistic regression models to determine factors independently associated with anticoagulation status after adjustment for pertinent confounders. In particular, we sought to determine whether atherosclerosis with 50% or more luminal narrowing in an artery supplying the infarct (a marker for a competing atherosclerotic mechanism) and small stroke size (≤ 10 mL; implying a competing small vessel disease mechanism) related to anticoagulant status. RESULTS: Of the 2084 patients enrolled in the IAC study, 382 patients met the inclusion criteria. The mean age was 77.4 ± 10.9 years and 52.4% (200/382) were women. A total of 222 (58.1%) subjects presented with subtherapeutic INR. In adjusted models, small stroke size (OR 1.74 95% CI 1.10-2.76, p = 0.019) and atherosclerosis with 50% or more narrowing in an artery supplying the infarct (OR 1.96 95% CI 1.06-3.63, p = 0.031) were independently associated with INR ≥2 at the time of their index stroke. CONCLUSION: Small stroke size (≤ 10 ml) and ipsilateral atherosclerosis with 50% or more narrowing may indicate a competing stroke mechanism. There may be important opportunities to improve stroke prevention strategies for patients with AF by targeting additional ischemic stroke mechanisms to improve patient outcomes.