Risk of Hemorrhagic Transformation with Early Use of Direct Oral Anticoagulants after Acute Ischemic Stroke: A Pooled Analysis of Prospective Studies and Randomized Trials

INTRODUCTION

Precise risk of hemorrhagic transformation (HT) in acute ischemic stroke (AIS) remains unknown, leading to delays in anticoagulation initiation for secondary stroke prevention. We sought to assess the rate of HT associated with direct oral anticoagulant (DOAC) initiation within and beyond 48 hours post-AIS.

METHODS

A pooled analysis of DOAC initiation within 14 days of AIS or transient ischemic attack (TIA) was conducted with 6 studies (4 prospective open label treatment, blinded outcome studies and 2 randomized trials; NCT02295826 and NCT02283294). The primary endpoint was incident radiographic HT on follow-up imaging (day 7-30). Secondary endpoints included symptomatic HT, new parenchymal hemorrhage, recurrent ischemic events, extracranial hemorrhage, study-period mortality, and follow-up modified Rankin Scale score. The results were reported as odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

We evaluated 509 patients; median infarct volume was 1.5 (0.1-7.8) ml, and median National Institutes of Health Stroke Scale was 2 (0-3). Incident radiographic HT was seen on follow-up scan in 34 (6.8%) patients. DOAC initiation within 48 hours from index event was not associated with incident HT (adjusted OR 0.67, [0.30 - 1.50] P=0.32). No patients developed symptomatic HT. Conversely, 31 (6.1%) patients developed recurrent ischemic events, 64% of which occurred within 14 days. Initiating a DOAC within 48 hours of onset was associated with similar recurrent ischemic event rates compared to those in which treatment was delayed (HR 0.42, [0.17 - 1.008] P=0.052). In contrast to HT, recurrent ischemic events were associated with poor functional outcomes (OR=6.8, [2.84 - 16.24], p<0.001).

CONCLUSIONS

In this pooled analysis, initiation of DOAC within 48 hours post-stroke was not associated with increased incident risk of HT, and none developed symptomatic HT. The analysis was underpowered to determine the effect of early DOAC use upon recurrent ischemic events.

Abstract WP61: Impact Of Post-stroke Post Traumatic Stress Disorder On Quality Of Life

Introduction: After an ischemic stroke or transient ischemic attack (TIA), patients may have post-event anxiety and re-experience transient neurological symptoms. However, some stroke patients develop persistent and disabling symptoms of post-traumatic stress disorder (PTSD). Data on post-stroke post-traumatic stress disorder (PS-PTSD) is sparse.

Methods: We conducted a single-center observational pilot study of 20 adult patients diagnosed with stroke or TIA in the previous 31 days to 1 year. Patients completed the PTSD Check List-5 (PCL-5), Patient Health Questionnaire-9 (PHQ-9), stroke specific Quality of Life Scale-12 (SS-QOL-12), modified Rankin Scale of disability, and the National Institutes of Health Stroke Scale. The PCL-5 is a 20 item self-report score assessing symptoms of re-experiencing (Criterion B), avoidance (Criterion C), negative alterations in cognition or mood (Criterion D), and hyperarousal (Criterion E). Subjects were classified as having PS-PTSD with PCL-5 score ≥33 or endorsement of moderate symptoms in at least one B item, one C item, two D items, and two E items.

Results: Twenty patients completed the PCL-5 and 19 completed the follow up scales. Seven patients (35%) were found to have PS-PTSD. Higher PCL-5 scores were significantly correlated with lower SS-QOL12 scores indicating worsened quality of life (r= -0.709, P=.001) and higher PHQ9 scores representing more depressive symptoms (r= 0.727, P<0.001). The effect was most prominent in the SS-QOL-12 domains of mood, language, upper extremity function, and family roles (Table 1).

Conclusion: PS-PTSD was found to be prevalent after stroke and TIA with 35% of patients having significant PTSD symptomology. These patients were also more likely to have concurrent depressive symptoms and worsened quality of life.

Sources, variability and parameterizations of intra-city factors obtained from dispersion-normalized multi-time resolution factor analyses of PM2.5 in an urban environment

Ambient fine particulate matter (PM_2.5) data of similar continuously monitored species at two air monitoring sites with different characteristics within the City of Toronto were used to gauge the intra-city variations in the PM composition over a largely concurrent period spanning two years. One location was <8 m from the side of a major highway while the other was an urban background location. For the first time, multi-time resolution factor analysis was applied to dispersion-normalized concentrations to identify and quantify source contributions while reducing the influence of local meteorology. These factors were particulate sulphate (pSO4), particulate nitrate (pNO3), secondary organic aerosols (SOA), crustal matter (CrM) that were common to both sites, a hydrocarbon-like organic matter (HOM) exclusive to the urban background site, three black carbon related factors (BC, BC-HOM at the highway site, and a brown carbon rich factor (BC-BrC) at the urban background site), biomass burning organic matter (BBOM) and brake dust (BD) factors exclusive to the highway site. The PM_2.5 composition was different between these two locations, over only a 10 km distance. The sum of SOA, pSO4 and pNO3 at the urban background site averaged 57% of the PM_2.5 mass while the same species represented 43% of the average PM_2.5 mass at the highway site. Local or site-specific factors may be of greater interest for control policy design. Thus, regression analyses with potential explanatory, site-specific variables were performed for results from the highway site. Three model approaches were explored: multiple linear regression (MLR), regression with a generalized reduced gradient (GRG) algorithm, and a generalized additive model (GAM). GAM gave the largest fraction of variance for the locally-found factors at the highway site. Heavy-duty vehicles were most important for explaining the black carbon (BC and BC-HOM) factors. Light-duty vehicles were dominant for the brake dust (BD) factor. The auxiliary modelling for the local factors showed that the traffic-related factors likely originated along the main roadways at their respective sites while the more regional factors, - pSO4, pNO3, SOA, - had sources that were both regional and local in origin and with contributions that varied seasonally. These results will be useful in understanding ambient particulate matter sources on a city scale that will support air quality management planning.

Abstract TP401: Impact of Vital Signs and Neurological Assessments After Alteplase for Acute Stroke

Background: Vital signs and neurologic assessments are currently performed using the schedule utilized during the clinical trials which led to the approval of alteplase for acute stroke. These assessments can be disruptive to patients and represent a considerable staffing and infrastructural demand. While the goal of this approach is to improve outcomes by rapidly detecting actionable changes, its impact has been questioned. Despite its widespread use there has been limited systematic review regarding its influence on outcomes.

Purpose: This project’s aim was to determine the impact of these assessments by conducting a retrospective review at our large, urban, comprehensive stroke center. We sought to evaluate the rate of compliance with established guidelines, and assess its correlation with patient outcomes.

Methods: This retrospective review of patients receiving alteplase for acute stroke was approved by our institutional review board. A total of 130 patients were identified during 2018. Data was collected from the electronic medical record and The Get with the Guidelines database.

Results: Our institutional guideline includes a total of 36 vital signs and 24 neurological assessments during first 24-hours after alteplase administration, for a total of 60 assessments. 63% of patients had full compliance with all 60 assessments. The discharge modified Rankin scale (mRS) for those with full compliance was 2.35 versus 2.31 for patients without 100% compliance (p>0.05; NS). There was less compliance with vital signs compared to neurological assessments (73.8% versus 76.9%).

Conclusions: The majority of patients were complaint with all assessments however a notable portion missed at least one assessment, occurring more frequently with vital signs. Full compliance with all assessments was not associated with improved mRS.

Protocol for AREST: Apixaban for Early Prevention of Recurrent Embolic Stroke and Hemorrhagic Transformation-A Randomized Controlled Trial of Early Anticoagulation After Acute Ischemic Stroke in Atrial Fibrillation

Background: Optimal timing to initiate anticoagulation after acute ischemic stroke (AIS) from atrial fibrillation (AF) is currently unknown. Compared to other stroke etiologies, AF typically provokes larger infarct volumes and greater concern of hemorrhagic transformation, so seminal randomized trials waited weeks to months to begin anticoagulation after initial stroke. Subsequent data are limited and non-randomized. Guidelines suggest anticoagulation initiation windows between 3 and 14 days post-stroke, with Class IIa recommendations, and level of evidence B in the USA and C in Europe. Aims: This open-label, parallel-group, multi-center, randomized controlled trial AREST (Apixaban for Early Prevention of Recurrent Embolic Stroke and Hemorrhagic Transformation) is designed to evaluate the safety and efficacy of early anticoagulation, based on stroke size, secondary prevention of ischemic stroke, and risks of subsequent hemorrhagic transformation. Methods: Subjects are randomly assigned in a 1:1 ratio to receive early apixaban at day 0-3 for transient ischemic attack (TIA), 3-5 for small-sized AIS (<1.5 cm), and 7-9 for medium-sized AIS (1.5 cm or greater but less than a full cortical territory), or warfarin at 1 week post-TIA or 2 weeks post-stroke. Large AISs are excluded. Study Outcomes: Primary: recurrent ischemic stroke, TIA, and fatal stroke; secondary: intracranial hemorrhage (ICH); hemorrhagic transformation (HT) of ischemic stroke; cerebral microbleeds (CMBs); neurologic disability [e.g., modified Rankin Scores (mRS), National Institutes of Health Stroke Scale (NIHSS), Stroke Specific Quality of Life scale (SS-QOL)]; and cardiac biomarkers [e.g., AF burden, transthoracic echo (TTE)/transesophageal echo (TEE) abnormalities]. Sample Size Estimates: Enrollment goal was 120 for 80% power (two-sided type I error rate of 0.05) to detect an absolute risk reduction of 16.5% postulated to occur with apixaban in the primary composite outcome of fatal stroke/recurrent ischemic stroke/TIA within 180 days. Enrollment was suspended at 91 subjects in 2019 after a focused guideline update recommended direct oral anticoagulants (DOACs) over warfarin in AF, excepting valvular disease (Class I, level of evidence A). Discussion: AREST will offer randomized controlled trial data about timeliness and safety of anticoagulation in AIS patients with AF. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02283294.

Abstract TMP86: Improved Outcomes After Mechanical Thrombectomy for In-Hospital Strokes

Background: Most stroke patients have their stroke in the community setting, however a significant minority occur while hospitalized for another condition. Prior studies have noted worse outcomes for in-hospital strokes(IHS) compared to community-onset strokes(COS). IHS are also less likely to receive intravenous thrombolytic therapy. The increased use of mechanical thrombectomy(MT) and distinct eligibility criteria from thrombolysis provide additional therapy options for these patients. We present one of the first comparison of outcomes looking specifically at MT for IHS versus COS.

Methods: We performed an IRB-approved, retrospective cross-sectional study on patients who underwent MT at our center for acute ischemic stroke between Jan 2012 and Nov 2017. Variables reviewed included patient demographics, vascular risk factors, symptom recognition time, treatment time, and disability as measured by the Modified Rankin Scale(mRS). Statistical analyses were performed using logistic regression to assess the relationship between IHS versus COS.

Results: We studied 334 patients (290 COS and 44 IHS) who were treated with MT for acute ischemic stroke. Patients who presented in-hospital were younger (60.7 vs. 70.4 years; p<0.001). IHS were more likely to have a history of coronary artery disease (48% vs. 25%; p<0.003) and tobacco use (32% vs. 16%; p<0.032), conversely, they had a lower rate of atrial fibrillation (20% vs. 42% p<0.005). No significant difference was noted in history of diabetes, hypertension, and dyslipidemia. IHS treated with MT had lower use of intravenous thrombolysis (14% vs 34%; p<0.006). Patients with IHS had a significantly shorter mean symptom recognition to femoral stick time (p<0.039). In addition, IHS patients had significantly better outcomes at discharge as measured by mRS 0-3 (mRS range, 0-6; lower scores indicating less disability). After adjustment for age and stroke severity (National Institute of Health Stroke Scale) IHS continued to have better outcomes at discharge as measured by mRS 0-3; AOR=4.832; 95% Cl, (1.207-19.348); P< 0.026.

Conclusion: In conclusion, time from symptom recognition to MT is faster for IHS vs. COS. In addition, IHS had less disability after mechanical thrombectomy for large vessel occlusion.