Cerebral Small Vessel Disease Burden for Bleeding Risk during Antithrombotic Therapy: Bleeding with Antithrombotic Therapy 2 Study

OBJECTIVE

This study was undertaken to determine the excess risk of antithrombotic-related bleeding due to cerebral small vessel disease (SVD) burden.

METHODS

In this observational, prospective cohort study, patients with cerebrovascular or cardiovascular diseases taking oral antithrombotic agents were enrolled from 52 hospitals across Japan between 2016 and 2019. Baseline multimodal magnetic resonance imaging acquired under prespecified conditions was assessed by a central diagnostic radiology committee to calculate total SVD score. The primary outcome was major bleeding. Secondary outcomes included bleeding at each site and ischemic events.

RESULTS

Of the analyzed 5,250 patients (1,736 women; median age = 73 years, 9,933 patient-years of follow-up), antiplatelets and anticoagulants were administered at baseline in 3,948 and 1,565, respectively. Median SVD score was 2 (interquartile range = 1-3). Incidence rate of major bleeding was 0.39 (per 100 patinet-years) in score 0, 0.56 in score 1, 0.91 in score 2, 1.35 in score 3, and 2.24 in score 4 (adjusted hazard ratio [aHR] for score 4 vs 0 = 5.47, 95% confidence interval [CI] = 2.26-13.23), that of intracranial hemorrhage was 0.11, 0.33, 0.58, 0.99, and 1.06, respectively (aHR = 9.29, 95% CI = 1.99-43.35), and that of ischemic event was 1.82, 2.27, 3.04, 3.91, and 4.07, respectively (aHR = 1.76, 95% CI = 1.08-2.86). In addition, extracranial major bleeding (aHR = 3.43, 95% CI = 1.13-10.38) and gastrointestinal bleeding (aHR = 2.54, 95% CI = 1.02-6.35) significantly increased in SVD score 4 compared to score 0.

INTERPRETATION

Total SVD score was predictive for intracranial hemorrhage and probably for extracranial bleeding, suggesting the broader clinical relevance of cerebral SVD as a marker for safe implementation of antithrombotic therapy. ANN NEUROL 2024;95:774-787.

Effects of preceding antiplatelet agents on severity of ischemic stroke in patients with a history of stroke

INTRODUCTION

Antiplatelet agents are effective for secondary prevention of ischemic stroke and can reduce the severity of first-ever ischemic stroke. However, it is uncertain if prophylactic antiplatelet therapy reduces the severity of recurrent ischemic stroke. The aim of this study was to determine the effect of preceding antiplatelet treatment on the severity of thrombotic stroke (TS) in patients with a prior history of stroke.

METHODS

From a prospective hospital registry of 1338 consecutive patients with acute ischemic stroke, we identified patients with a prior history of stroke who were admitted for cardioembolic stroke (CE); TS including large-artery atherosclerosis, small vessel occlusion, and branch atheromatous disease; or other cause or cryptogenic stroke (OCS). Cases in each subtype were categorized based on preceding medication: antiplatelet agents (AP) and none (N). Severity of stroke (National Institutes of Health Stroke Scale: NIHSS) on admission was compared between AP and N cases.

RESULTS

The total cohort of 252 patients included 83 with CE, 102 with TS, and 67 with OCS. After excluding those with prior anticoagulants, the median NIHSS on admission was lower in AP cases than in N cases (3 vs. 5, p = 0.002). In multivariate analysis, preceding AP treatment was independently associated with minor stroke (NIHSS ≤4) on admission in CE group (OR 8.48, 95% CI 1.71-62.9, p = 0.008) and TS group (OR 4.24, 95% CI 1.44-13.4, p = 0.009).

CONCLUSION

Preceding antiplatelet treatment in patients with a prior history of stroke may reduce the severity of subsequent thrombotic and cardiogenic stroke.

How Topographic Diffusion-Weighted Imaging Patterns can Predict the Potential Embolic Source

PURPOSE

To develop an imaging prediction model for patients with embolic stroke of undetermined source (ESUS), we investigated the association of topographic diffusion-weighted imaging (DWI) patterns with potential embolic sources (PES) identified by transesophageal echocardiography.

METHODS

From a total of 992 consecutive patients with embolic stroke, 366 patients with the ESUS group were selected. ESUS was defined as no atrial fibrillation (Af) within 24h from admission and no PES after general examination. Clinical variables include age (> 80years, 70-80 years), sex, vascular risk factors and left atrial diameter > 4 cm. Age, sex and vascular risk factors adjusted odds ratio of each DWI for the different PESs were calculated. DWI was determined based on the arterial territories. Middle cerebral arteries were divided into 4 segments, i.e., M1-M4. Moreover, M2 segments were subdivided into superior and inferior branches.

RESULTS

The 366 patients consisted of 168 with paroxysmal Af (pAf), 77 with paradoxical embolism, 71 with aortic embolism and 50 with undetermined embolism after transesophageal echocardiography. The variables adjusted odds ratio (OR) of internal carotid artery (OR: 12.1, p = 0.037), M1 (4.2, p = 0.001), inferior M2 (7.5, p = 0.0041) and multiple cortical branches (12.6, p < 0.0001) were significantly higher in patients with pAf. Striatocapsular infarction (12.5, p < 0.0001) and posterior inferior cerebellar artery infarcts (3.6, p = 0.018) were significantly associated with paradoxical embolism. Clinical variables adjusted OR of multiple small scattered infarcts (8.3, p < 0.0001) were significantly higher in patients with aortic embolism.

CONCLUSION

The associations of DWI with different PES have their distinctive characteristics and DWI along with clinical variables may help predict PES in patients with ESUS.

D-Dimer Trends Predict Recurrent Stroke in Patients with Cancer-Related Hypercoagulability

INTRODUCTION

In patients with cancer-associated hypercoagulability (CAH)-related stroke, D-dimer trends after anticoagulant therapy may offer a biomarker of treatment efficacy. The purpose of this study was to clarify the association between D-dimer trends and recurrent stroke after anticoagulant therapy in patients with CAH-related stroke.

METHODS

We performed retrospective cohort study of consecutive patients with CAH-related stroke at two stroke centers from 2011 to 2020. The ratio of posttreatment to pretreatment D-dimer levels (post/pre ratio) was used as an indicator of D-dimer trends after anticoagulant therapy. Fine-Gray models were used to evaluate the association between post/pre ratio and recurrent stroke.

RESULTS

Among 360 acute ischemic stroke patients with active cancer, 73 patients with CAH-related stroke were included in this study. Recurrent stroke occurred in 13 patients (18%) during a median follow-up time of 28 days (interquartile range, 11-65 days). Multivariate analysis revealed that high post/pre ratio was independently associated with recurrent stroke (per 0.1 increase: hazard ratio 2.20, 95% confidence interval 1.61-3.01, p = 0.012).

CONCLUSION

D-dimer levels after anticoagulant therapy were associated with recurrent stroke in CAH-related stroke patients. Patients with neutral trends in high D-dimer levels after anticoagulant therapy were at high risk of recurrent stroke.

Thrombolysis for Acute Wake-Up and Unclear-Onset Strokes with Alteplase at 0.6 mg/kg in Clinical Practice: THAWS2 Study

INTRODUCTION

The aim of this study was to determine the safety and efficacy of intravenous (IV) alteplase at 0.6 mg/kg for patients with acute wake-up or unclear-onset strokes in clinical practice.

METHODS

This multicenter observational study enrolled acute ischemic stroke patients with last-known-well time >4.5 h who had mismatch between DWI and FLAIR and were treated with IV alteplase. The safety outcomes were symptomatic intracranial hemorrhage (sICH) after thrombolysis, all-cause deaths, and all adverse events. The efficacy outcomes were favorable outcome defined as an mRS score of 0-1 or recovery to the same mRS score as the premorbid score, complete independence defined as an mRS score of 0-1 at 90 days, and change in NIHSS at 24 h from baseline.

RESULTS

Sixty-six patients (35 females; mean age, 74 ± 11 years; premorbid complete independence, 54 [82%]; median NIHSS on admission, 11) were enrolled at 15 hospitals. Two patients (3%) had sICH. Median NIHSS changed from 11 (IQR, 6.75-16.25) at baseline to 5 (3-12.25) at 24 h after alteplase initiation (change, -4.8 ± 8.1). At discharge, 31 patients (47%) had favorable outcome and 29 (44%) had complete independence. None died within 90 days. Twenty-three (35%) also underwent mechanical thrombectomy (no sICH, NIHSS change of -8.5 ± 7.3), of whom 11 (48%) were completely independent at discharge.

CONCLUSIONS

In real-world clinical practice, IV alteplase for unclear-onset stroke patients with DWI-FLAIR mismatch provided safe and efficacious outcomes comparable to those in previous trials. Additional mechanical thrombectomy was performed safely in them.

Abstract 3: Cerebral Small Vessel Disease Burden For Bleeding Risk During Antithrombotic Therapy -BAT2-

Background: Cerebral small vessel disease (SVD) has received attention as a risk stratification tool for antithrombotic-related intracranial hemorrhage but may also be a predictor for bleeding in other organs.

Purpose: To determine the excess risk of antithrombotic-related bleeding due to cerebral SVD burden.

Methods: Patients with cerebrovascular or cardiovascular diseases taking oral antithrombotic agents were prospectively enrolled from 52 hospitals across Japan between 2016 and 2019. Multimodal brain MRI was acquired at baseline for all patients under prespecified conditions. All MRI examinations were interpreted by a central diagnostic radiology committee for cerebral microbleeds, lacunes, white matter hyperintensities, and enlarged basal ganglia perivascular spaces, for calculation of a total SVD score (range 0-4). The primary outcome was major bleeding during 2-year follow-up. Secondary outcomes included bleeding in each site and ischemic events. Event risks according to SVD score were estimated with multivariable Cox proportional hazards models.

Results: Of the analyzed 5250 patients (1736 women; median age, 73 years; 9933 patient-years follow-up), antiplatelets and anticoagulants were administered at baseline in 3948 and 1565, respectively. Median of the total SVD score was 2 (IQR 1-3). As SVD score increased, advanced age, hypertension, anemia, and chronic kidney disease were more prevalent (P<0.001 for each). A unit increase of SVD score was associated with a higher risk of major bleeding (adjusted hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.29-1.85) and intracranial hemorrhage (adjusted HR 1.61, 95% CI 1.28-2.03). With SVD score 4 compared to score 0, extracranial major bleeding (adjusted HR 3.37, 95% CI 1.12-10.15) and gastrointestinal bleeding (adjusted HR 2.54, 95% CI 1.02-6.35) were also significantly increased. A higher SVD score was associated with a mild but significant elevation of ischemic event risk (adjusted HR per unit increase 1.17, 95% CI 1.06-1.29).

Conclusions: The total SVD score was predictive for intracranial hemorrhage and probably for extracranial bleeding, suggesting a broader clinical relevance of cerebral SVD as a marker for safe implementation of antithrombotic therapy.

Early recurrence in patients with symptomatic, non-cardioembolic, internal carotid artery occlusion

INTRODUCTION

There are limited data on the clinical course of patients with non-cardioembolic, mostly atherosclerotic, internal carotid artery occlusion (ICAO). The purpose of this study was to elucidate the frequency and underlying pathogenesis of early recurrent ischemic stroke in symptomatic non-cardioembolic ICAO.

MATERIALS AND METHODS

Consecutive patients with symptomatic non-cardioembolic ICAO were retrospectively reviewed. Those who had a tandem occlusion of the proximal middle cerebral artery (MCA) or underwent endovascular thrombectomy were excluded. Early recurrent stroke was defined as deterioration of the NIHSS score by ≥1 point with new lesions on magnetic resonance (MR) diffusion-weighted imaging (DWI) in the ipsilateral territory of the ICAO within 30 days of the index stroke onset. Patients were classified into two groups on carotid ultrasonography: cervical occlusion and intracranial occlusion. The presumed pathogenesis of recurrent stroke was categorized as embolic or hemodynamic according to the topographical features of subsequent lesions on DWI.

RESULTS

Of 36 consecutive medically treated patients with symptomatic non-cardioembolic ICAO without tandem MCA occlusion, 23 patients had cervical occlusion, and 13 had intracranial occlusion. Early recurrent stroke occurred in 16 patients (44.4%), which happened much more with intracranial occlusion than with cervical occlusion (69.2% vs 30.4%, p<0.02). Focusing on the presumed pathogenesis, hemodynamic was more common than embolic (68.8% vs 31.2%), especially with intracranial occlusion (77.8%).

CONCLUSIONS

Early recurrent stroke occurs at a high frequency in symptomatic non-cardioembolic ICAO, and intracranial occlusion may be a risk factor for early recurrent stroke. The pathogenesis of recurrence is more often hemodynamic than embolic.

[Brain infarction and cerebral venous thrombosis in paroxysmal nocturnal hemoglobinuria: case report]

A 65-year-old woman with a six-year history of paroxysmal nocturnal hemoglobinuria (PNH) was admitted due to weakness in the right leg following a seven-day history of fever and upper respiratory infection. MRI revealed several high-intensity areas in bilateral frontal lobe cortices and the left cerebellum on diffusion-weighted imaging, and signal hypointensity along the course of the cortical vein in the left frontal lobe on T₂*-weighted imaging. We diagnosed cerebral venous thrombosis and brain infarction, and commenced heparin infusion. She developed right-sided dens hemiparesis on hospital day 6, when brain CT showed subcortical hemorrhage in the left frontal lobe. Despite eculizumab administration and decompressive craniectomy for hematoma, she died on hospital day 26. Thrombosis in PNH has been recognized as a life-threating complication, and intensive treatment including emergent administration of eculizumab is warranted if this situation arises.

Prediction of recurrent stroke among ischemic stroke patients with atrial fibrillation: Development and validation of a risk score model

BACKGROUND

There is currently no validated risk prediction model for recurrent events among patients with acute ischemic stroke (AIS) and atrial fibrillation (AF). Considering that the application of conventional risk scores has contextual limitations, new strategies are needed to develop such a model. Here, we set out to develop and validate a comprehensive risk prediction model for stroke recurrence in AIS patients with AF.

METHODS

AIS patients with AF were collected from multicenter registries in South Korea and Japan. A developmental dataset was constructed with 5648 registered cases from both countries for the period 2011‒2014. An external validation dataset was also created, consisting of Korean AIS subjects with AF registered between 2015 and 2018. Event outcomes were collected during 1 year after the index stroke. A multivariable prediction model was developed using the Fine-Gray subdistribution hazard model with non-stroke mortality as a competing risk. The model incorporated 21 clinical variables and was further validated, calibrated, and revised using the external validation dataset.

RESULTS

The developmental dataset consisted of 4483 Korean and 1165 Japanese patients (mean age, 74.3 ± 10.2 years; male 53%); 338 patients (6%) had recurrent stroke and 903 (16%) died. The clinical profiles of the external validation set (n = 3668) were comparable to those of the developmental dataset. The c-statistics of the final model was 0.68 (95% confidence interval, 0.66 ‒0.71). The developed prediction model did not show better discriminative ability for predicting stroke recurrence than the conventional risk prediction tools (CHADS2, CHA2DS2-VASc, and ATRIA).

CONCLUSIONS

Neither conventional risk stratification tools nor our newly developed comprehensive prediction model using available clinical factors seemed to be suitable for identifying patients at high risk of recurrent ischemic stroke among AIS patients with AF in this modern direct oral anticoagulant era. Detailed individual information, including imaging, may be warranted to build a more robust and precise risk prediction model for stroke survivors with AF.

Attack Interval Is the Key to the Likely Pathogenesis of Multiple Transient Ischemic Attacks

INTRODUCTION

The aim of this study was to test the hypothesis that the attack interval of multiple transient ischemic attacks (TIAs) is correlated with the underlying pathogenesis of ischemia.

METHODS

Patients with multiple TIAs, defined as 2 or more motor deficits within 7 days, were studied. The attack interval between the last 2 episodes was classified into 3 groups: 2 episodes within an hour (Hour group), over hours within a day (Day group), and over days within a week (Week group). Patients with a lacunar syndrome, no cortical lesions, and no embolic sources were recognized as having a small vessel disease (SVD) etiology for their multiple events.

RESULTS

Of 312 TIA patients admitted over a 9-year period, 50 (37 males, 13 females, mean 67.6 years) had multiple TIAs. Twelve patients were classified as being within the Hour group, 23 within the Day group, and 15 within the Week group. Lacunar syndromes were observed in 30 (75%, 35%, and 67%), embolic sources were detected in 28 (25%, 65%, and 67%), and a high signal lesion on diffusion-weighted imaging was depicted in 30 (75%, 48%, and 67%) patients (18 cortical, 11 subcortical, and one cerebellar). Patients in the Hour group had a significantly higher prevalence of SVD etiology (75%) than those in the Day and Week groups (30%, p = 0.0165; 27%, p = 0.0213, respectively). Four patients had a subsequent stroke within 7 days.

CONCLUSION

Attack intervals of multiple TIAs may be correlated with the underlying pathogenesis of ischemia. Two motor deficits within an hour are more likely to suggest a SVD etiology.

Cerebral microbleeds development after stroke thrombolysis: A secondary analysis of the THAWS randomized clinical trial

BACKGROUND AND AIM

We determined to investigate the incidence and clinical impact of new cerebral microbleeds after intravenous thrombolysis in patients with acute stroke.

METHODS

The THAWS was a multicenter, randomized trial to study the efficacy and safety of intravenous thrombolysis with alteplase in patients with wake-up stroke or unknown onset stroke. Prescheduled T2*-weighted imaging assessed cerebral microbleeds at three time points: baseline, 22-36 h, and 7-14 days. Outcomes included new cerebral microbleeds development, modified Rankin Scale (mRS) ≥3 at 90 days, and change in the National Institutes of Health Stroke Scale (NIHSS) score from 24 h to 7 days.

RESULTS

Of all 131 patients randomized in the THAWS trial, 113 patients (mean 74.3 ± 12.6 years, 50 female, 62 allocated to intravenous thrombolysis) were available for analysis. Overall, 46 (41%) had baseline cerebral microbleeds (15 strictly lobar cerebral microbleeds, 14 mixed cerebral microbleeds, and 17 deep cerebral microbleeds). New cerebral microbleeds only emerged in the intravenous thrombolysis group (seven patients, 11%) within a median of 28.3 h, and did not additionally increase within a median of 7.35 days. In adjusted models, number of cerebral microbleeds (relative risk (RR) 1.30, 95% confidence interval (CI): 1.17-1.44), mixed distribution (RR 19.2, 95% CI: 3.94-93.7), and cerebral microbleeds burden ≥5 (RR 44.9, 95% CI: 5.78-349.8) were associated with new cerebral microbleeds. New cerebral microbleeds were associated with an increase in NIHSS score (p = 0.023). Treatment with alteplase in patients with baseline ≥5 cerebral microbleeds resulted in a numerical shift toward worse outcomes on ordinal mRS (median [IQR]; 4 [3-4] vs. 0 [0-3]), compared with those with <5 cerebral microbleeds (common odds ratio 17.1, 95% CI: 0.76-382.8). The association of baseline ≥5 cerebral microbleeds with ordinal mRS score differed according to the treatment group (p interaction = 0.042).

CONCLUSION

New cerebral microbleeds developed within 36 h in 11% of the patients after intravenous thrombolysis, and they were significantly associated with mixed-distribution and ≥5 cerebral microbleeds. New cerebral microbleeds development might impede neurological improvement. Furthermore, cerebral microbleeds burden might affect the effect of alteplase.

Abstract MP6: Thrombolysis for Acute Wake-Up And Unclear Onset Strokes With Alteplase at 0.6mg /kg in Clinical Practice: THAWS2 Study

Background and Purpose: IV alteplase at 0.6 mg/kg for acute wake-up and unclear onset strokes was recommended in Japanese stroke guidelines in March 2019. We determined the safety and effectiveness of this newly recommended thrombolysis in clinical practice.

Methods: This is a multicenter observational study, enrolling acute ischemic stroke patients with a time last-known-well >4.5 h who have a mismatch between DWI and FLAIR treated with intravenous alteplase. The safety outcomes are intracranial hemorrhage (ICH) with neurological deterioration within 36 h after thrombolysis, all cause deaths within 90 days, and adverse events. The efficacy outcomes are functionally independence defined as a mRS score of 0-1 at 90 days, and NIHSS change at 24h from baseline.

Results: Between 2019 March and 2020 March, 63 patients (33 females; age, 74±11y; premorbid functionally independence, 50 (82%); median NIHSS on admission, 11) were enrolled at 14 hospitals. Of them, 40 patients (63%) recognized stroke symptoms at wake-up time, and median time between last-known-well and admission was 6.5 h. Baseline MRA showed any vessel occlusion in 52 patients (88%). IV alteplase was disrupted in one patient. Two patients (3%) had symptomatic ICH (≥4 increase in NIHSS) within 36 h. NIHSS change was -5.1±8.1. Twenty-one patients (36%) had functionally independence at discharge and there was no death during acute hospitalization. Of the overall 63 patients, 22 also underwent mechanical thrombectomy (36%, 72±9y, median NIHSS 16), showing no symptomatic ICH, mean NIHSS change of -8.9±7.5, and 8 patients (42%) had functionally independence at discharge.

Conclusions: In clinical practice, IV alteplase for wake-up and unclear onset stroke patients with DWI-FLAIR mismatch seemed to be safe and effective compared with previous randomized control trials. Mechanical thrombectomy could be combined with alteplase safely and effectively.

The bleeding with antithrombotic therapy study 2: Rationale, design, and baseline characteristics of the participants

Aims

The bleeding risk of current antithrombotic strategies in clinical settings, including recently developed agents, needs to be clarified.

Methods and Design

In an investigator-initiated, prospective, multicentre, observational study, patients with cerebrovascular or cardiovascular diseases who were taking oral antiplatelet or anticoagulant agents were enrolled. Compulsory multimodal magnetic resonance images were acquired at baseline to assess cerebral small vessel disease. Six-month follow-up will be performed for two years. The primary outcome is major bleeding as defined by the International Society on Thrombosis and Hemostasis.

Results

Between October 2016 and March 2019, 5306 patients (71.7 ± 11.2 years old, 1762 women) were enrolled. Previous intracranial haemorrhage was documented in 181 patients (3.4%), cerebrovascular disease (including asymptomatic) requiring antithrombotic therapy in 5006 patients (94.3%), and atrial fibrillation in 1061 patients (20.0%). At entry, 3726 patients (70.2%) were taking antiplatelet agents alone, including 551 (10.4%) using dual antiplatelet agents, 1317 (24.8%) taking anticoagulants alone, and the remaining 263 (5.0%) taking both. The leading antiplatelet agent was clopidogrel (2014 patients), and the leading combination of dual antiplatelet medication was clopidogrel plus aspirin (362). Use of direct oral anticoagulants (1029 patients, 19.4%) exceeded warfarin use (554, 10.4%). The number of pivotal bleeding events exceeded 200 in April 2020.

Conclusions

This study is expected to provide the incidence of bleeding complications of recent oral antithrombotics in clinical practice and identify their associations with underlying small vessel disease and other biomarkers. Novel risk stratification models for bleeding risk will be able to be created based on the study results.

FLAIR vascular hyperintensity with DWI for regional collateral flow and tissue fate in recanalized acute middle cerebral artery occlusion

PURPOSE

Fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH) extent or FVH-DWI mismatch as a primary influencing factor of clinical outcome in acute ischemic stroke is controversial. This study elucidated the regional pathophysiology and tissue fate in four types of cortical territories classified by the initial FVH and DWI findings in patients with acute proximal middle cerebral artery (M1) occlusion successfully recanalized using mechanical thrombectomy.

METHODS

We retrospectively evaluated 35 patients successfully recanalized within 24 h of acute M1 occlusion onset between 2016 and 2019. Each Alberta stroke program early CT score area of M1-M6 were categorized as group A (DWI-, FVH-), B (DWI-, FVH+), C (DWI+, FVH+), or D (DWI+, FVH-). Territorial collateral status was graded on a 4-point scale by initial angiogram. Follow-up head computed tomography (CT) findings on days 2-9 were assessed for the territorial outcome.

RESULTS

Overall, 210 cortical territories were identified; of these, 88 (41.9 %) were categorized into group A; 72 (34.3 %), group B; 37 (17.6 %), group C; and 13 (6.2 %), group D. The rate of territories with good collaterals (grade 2 or 3) significantly decreased in the order of groups as 78.3 %, 62.7 %, 27.6 %, and 0%, respectively (P_trend <.001). Conversely, the rate of territories with any hypo- or hyper-density on follow-up CT significantly increased in the order of groups as 13.4 %, 23.1 %, 88.5 %, and 85.7 %, respectively (P_trend <.001).

CONCLUSION

Categorization of cortical areas based on the FVH and DWI findings can stratify territorial collateral status and tissue fate.

Left Atrial Size and Ischemic Events after Ischemic Stroke or Transient Ischemic Attack in Patients with Nonvalvular Atrial Fibrillation

<b><i>Background:</i></b> The present study aimed to clarify the association between left atrial (LA) size and ischemic events after ischemic stroke or transient ischemic attack (TIA) in patients with nonvalvular atrial fibrillation (NVAF). <b><i>Methods:</i></b> Acute ischemic stroke or TIA patients with NVAF were enrolled. LA size was classified into normal LA size, mild LA enlargement (LAE), moderate LAE, and severe LAE. The ischemic event was defined as ischemic stroke, TIA, carotid endarterectomy, carotid artery stenting, acute coronary syndrome or percutaneous coronary intervention, systemic embolism, aortic aneurysm rupture or dissection, peripheral artery disease requiring hospitalization, or venous thromboembolism. <b><i>Results:</i></b> A total of 1,043 patients (mean age, 78 years; 450 women) including 1,002 ischemic stroke and 41 TIA were analyzed. Of these, 351 patients (34%) had normal LA size, 298 (29%) had mild LAE, 198 (19%) had moderate LAE, and the remaining 196 (19%) had severe LAE. The median follow-up duration was 2.0 years (interquartile range, 0.9–2.1). During follow-up, 117 patients (11%) developed at least one ischemic event. The incidence rate of total ischemic events increased with increasing LA size. Severe LAE was independently associated with increased risk of ischemic events compared with normal LA size (multivariable-adjusted hazard ratio, 1.75; 95% confidence interval, 1.02–3.00). <b><i>Conclusion:</i></b> Severe LAE was associated with increased risk of ischemic events after ischemic stroke or TIA in patients with NVAF.

[Utility of transesophageal echocardiography for etiologic diagnosis of centrum ovale infarcts]

A small centrum ovale infarct in the territory of the white matter medullary artery can be caused not only by embolism but also small-vessel disease. In our study, thorough screening for emboligenic diseases was performed, including the modality of transesophageal echocardiography (TEE), in patients with an acute, isolated, small (less than 1.5 cm) infarct in the centrum ovale. Of 79 patients enrolled in this study, 45 had emboligenic diseases, in whom a patent foramen ovale was detected in 29 patients, complicated aortic arch lesion in 15, atrial fibrillation in 6, occlusive carotid disease in 2, and others in 2. The majority (80%) of the emboligenic diseases were diagnosed by TEE. Therefore, TEE may be mandatory for the etiologic diagnosis of centrum ovale infarcts.

[Cerebral deep vascular architectures and subcortical infarcts]

The lenticulostriate arteries (LSA) supply the lateral half of the head of the caudate nucleus, entire putamen, anterior limb, genu and the superior part of the internal capsule (IC) and a part of the corona radiata. The LSA consists with medial, intermediate and lateral branches. The medial branches perfuse the lateral segment of the globus pallidus, the head of the caudate nucleus and the anterior limb of the IC. The intermediate branches supply the anterior half of the LSA territory, while the lateral branches supply the posterior half. The anterior cerebral artery (ACA) perforators, predominantly Heubner's artery, perfuse the inferomedial part of the caudate head, the anteromedial part of putamen, the anterior part of the lateral segment of the globus pallidus and anterior limb of the internal capsule. Such territories can be represented by the anterior and ventral basal ganglions. The anterior choroidal artery (AChA) gives off three main groups of branches including the lateral branches that supply the medial temporal lobe, the medial branches that supply the cerebral peduncle and the superior branches that supply the internal capsule and the basal ganglia. The superior branches are further discriminated into proximal branches that supply the anterior one third of the posterior limb of internal capsule (PLIC) and the medial segment of the globus pallidus and distal branches that supply the posterior two-third of PLIC, retro-lenticular part of the internal capsule and the lateral thalamic nuclei. The superficial penetrating arteries, i.e. medullary arteries, arise from the cortical branches of the middle cerebral artery (MCA) and supply the deep white matter. Infarcts caused by the medullary artery occlusion are located in the centrum-semiovale and half of them were caused by embolic mechanism. The centrum-semiovale corresponds to cortical border-zone (BZ) while the corona radiate corresponds to internal BZ.

Thrombolysis With Alteplase at 0.6 mg/kg for Stroke With Unknown Time of Onset: A Randomized Controlled Trial

Supplemental Digital Content is available in the text.

We assessed whether lower-dose alteplase at 0.6 mg/kg is efficacious and safe for acute fluid-attenuated inversion recovery-negative stroke with unknown time of onset.

[Recurrent cerebral embolism due to the disseminated carcinomatosis of bone marrow with early gastric cancer]

A 67-year-old woman who had undergone laparoscopic proximal gastrectomy for early gastric cancer 10 months previously was admitted to our hospital due to dysarthria. Brain MRI demonstrated acute multiple small infarcts in the right middle cerebral artery (MCA) and the right posterior inferior cerebellar artery (PICA) territory, and she was diagnosed as embolic stroke. Anticoagulant therapy did not prevent further ischemic stroke. No embolic sources were detected by MR angiography, carotid duplex sonography, transthoracic and transesophageal echocardiography, and Holter electrocardiography. We also performed upper gastrointestinal endoscopy and contrast-enhanced CT of the thoracoabdominal area, but there was no evidence of local recurrence or lymph node metastases of gastric cancer. As the ALP and D-dimer levels were gradually increasing, we performed PET/CT, which revealed fluorodeoxyglucose (FDG) uptake in the vertebra bone, and disseminated carcinomatosis of bone marrow with early gastric cancer was diagnosed after bone marrow biopsy on Day 41. After undergoing chemotherapy, she had no further stroke and died on Day 207.

Prior Anticoagulation and Short- or Long-Term Clinical Outcomes in Ischemic Stroke or Transient Ischemic Attack Patients With Nonvalvular Atrial Fibrillation

Background

We aimed to clarify associations between prior anticoagulation and short‐ or long‐term clinical outcomes in ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation.

Methods and Results

A total of 1189 ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation who were hospitalized within 7 days after onset were analyzed. Of these, 813 patients (68.4%) received no prior anticoagulation, 310 (26.1%) received prior warfarin treatment with an international normalized ratio (INR) <2 on admission, 28 (2.4%) received prior warfarin treatment with an INR ≥2 on admission, and the remaining 38 (3.2%) received prior direct oral anticoagulant treatment. Prior warfarin treatment was associated with a lower risk of death or disability at 3 months compared with no prior anticoagulation (INR <2: adjusted odds ratio: 0.58; 95% CI, 0.42–0.81; P=0.001; INR ≥2: adjusted odds ratio: 0.40; 95% CI, 0.16–0.97; P=0.043) but was not associated with a lower risk of death or disability at 2 years. Prior warfarin treatment with an INR ≥2 on admission was associated with a higher risk of ischemic events within 2 years compared with no prior anticoagulation (adjusted hazard ratio: 2.94; 95% CI, 1.20–6.15; P=0.021).

Conclusions

Prior warfarin treatment was associated with a lower risk of death or disability at 3 months but was not associated with a lower risk of death or disability at 2 years in ischemic stroke or transient ischemic attack patients with nonvalvular atrial fibrillation. Prior warfarin treatment with an INR ≥2 on admission was associated with a higher risk of ischemic events within 2 years.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01581502.

[Safety of Dual Antiplatelet Therapy with Argatroban in Patients with Acute Ischemic Stroke]

To prevent early neurological worsening or recurrence in stroke patients with intracranial arterial stenosis or branch atheromatous disease, aggressive antithrombotic therapy, such as dual antiplatelet therapy (DAPT) with or without anticoagulant therapy, is warranted. Such an aggressive antithrombotic therapy, however, may increase the bleeding risk. We studied the risks of DAPT with the anticoagulant argatroban in patients with acute ischemic stroke or transient ischemic attack (TIA). Between October 2011 and September 2015, 341 patients with stroke or TIA, who received DAPT with argatroban within 48 hours after onset, were retrospectively studied. The endpoint was any bleeding event during hospitalization or 30 days after admission. Median duration of DAPT was 12 days, and 66% of the patients received intravenous heparin (median duration, 5 days) following argatroban. No symptomatic intracerebral hemorrhages were observed, while severe, moderate, and mild extracranial hemorrhages occured in one (0.3%), three (0.9%), and four (1.2%) patients, respectively. In conclusion, DAPT with argatroban can be safely administered to patients with acute ischemic stroke or TIA. (Received July 24, 2017; Accepted January 15, 2018; Published May 1, 2018).

Stroke mechanisms and their correlation with functional outcome in medullary infarction

PURPOSE

To study the stroke mechanism of medullary infarction (MI) and their correlation with prognosis.

METHODS

We collected 81 consecutive patients with acute isolated MI including 50 patients with lateral MI (LMI), 30 with medial MI (MMI) and one with combined MI. The stroke mechanisms were defined as follows: 1. Large artery atherosclerotic occlusive disease (LAOD): with severe stenosis (>50%) or occlusion on the relevant arteries. 2. Penetrating artery disease (PAD): occlusion of penetrating arteries that arise from vertebral artery or basilar artery with no significant stenosis of the vertebro-basilar artery. 3. Dissection: angiographic findings met the criteria. 4. Cardiogenic embolism: abrupt onset with atrial fibrillation. The poor outcome was defined as a condition that includes the mRS ≥2 and/or dysphagia at one year after onset.

RESULTS

There were 20 patients with PAD (40%), 18 with dissection (36.0%) and 11 with LAOD (22.0%) in LMI and 17 with PAD (56.6%), 10 with LAOD (33.3%) in MMI. LAOD and dissection compared with PAD were independently correlated with poor outcome in LMI (OR: 12.8, p = 0.029 and OR: 14.9, p = 0.035). LAOD was significantly correlated with poor outcome in MMI (OR: 13.4, p = 0.014).

CONCLUSIONS

PAD was the most predominant stroke mechanism in MI and generally showed favorable outcome. Patients with LAOD and dissection showed worse outcome than those with PAD.

[Vertebrobasilar territory embolisms due to the ununited fracture of the right clavicle from 35 years ago]

A 61-year-old man, with a history of right clavicular fracture 35 years prior, visited our hospital due to the sudden onset of vertigo and tinnitus following weakness and numbness in his left arm and leg. He also had a 6-month history of right arm pain with overuse. Brain MRI showed acute brain infarcts in the right posterior cerebral artery territory. Intravenous alteplase was administered 188 minutes after onset. Although heparin infusion was commenced on day 2, he had vertigo again on day 9, and MRI showed a recurrent brain infarct in the right posterior inferior cerebellar artery territory. Ultrasound examination revealed occlusion of his right subclavian artery beneath the old right clavicular fracture as well as mobile thrombus in the proximal portion of the right subclavian artery. We speculated that a pseudarthrosis at the site of the old right clavicular fracture had repetitively pressed the right subclavian artery. Subsequently, we considered thrombi, which had developed in the proximal portion of the right subclavian artery, migrated into the right vertebral artery, causing recurrent emboli in the vertebrobasilar artery territory.

Late recovery from unconsciousness in a patient with severe posterior reversible encephalopathy syndrome

This study describes a patient case presenting with severe posterior reversible encephalopathy syndrome (PRES) who needed 3 months to recover impaired consciousness. We discuss the protracted time course needed to deal with severe PRES cases. Positive prognoses can emerge from these situations if treatment is prompt and precise.

Cancer-Associated Hypercoagulation Increases the Risk of Early Recurrent Stroke in Patients with Active Cancer

BACKGROUND

This study assessed the incidence and predictors of short-term stroke recurrence in ischemic stroke patients with active cancer, and elucidated whether cancer-associated hypercoagulation is related to early recurrent stroke.

METHODS

We retrospectively enrolled acute ischemic stroke patients with active cancer admitted to our hospital between 2006 and 2017. Active cancer was defined as diagnosis or treatment for any cancer within 12 months before stroke onset, known recurrent cancer or metastatic disease. The primary clinical outcome was recurrent ischemic stroke within 30 days.

RESULTS

One hundred ten acute ischemic stroke patients with active cancer (73 men, age 71.3 ± 10.1 years) were enrolled. Of those, recurrent stroke occurred in 12 patients (11%). When patients with and without recurrent stroke were compared, it was found that those with recurrent stroke had a higher incidence of pancreatic cancer (33 vs. 10%), systemic metastasis (75 vs. 39%), multiple vascular territory infarctions (MVTI; 83 vs. 40%), and higher -D-dimer levels (16.9 vs. 2.9 µg/mL). Multivariable logistic regression analysis showed that each factor mentioned above was not significantly associated with stroke recurrence independently, but high D-dimer (hDD) levels (≥10.4 µg/mL) and MVTI together were significantly associated with stroke recurrence (OR 6.20, 95% CI 1.42-30.7, p = 0.015).

CONCLUSIONS

Ischemic stroke patients with active cancer faced a high risk of early recurrent stroke. The concurrence of hDD levels (≥10.4 µg/mL) and MVTI was an independent predictor of early recurrent stroke in active cancer patients. Our findings suggest that cancer-associated hypercoagulation increases the early recurrent stroke risk.

Associations between Pre-Admission Risk Scores and Two-Year Clinical Outcomes in Ischemic Stroke or Transient Ischemic Attack Patients with Non-Valvular Atrial Fibrillation

BACKGROUND

We aimed to clarify associations between pre-admission risk scores (CHADS2, CHA2DS2-VASc, and HAS-BLED) and 2-year clinical outcomes in ischemic stroke or transient ischemic attack (TIA) patients with non-valvular atrial fibrillation (NVAF) using a prospective, multicenter, observational registry.

METHODS

From 18 Japanese stroke centers, ischemic stroke or TIA patients with NVAF hospitalized within 7 days after onset were enrolled. Outcome measures were defined as death/disability (modified Rankin Scale score ≥3) at 2 years, 2-year mortality, and ischemic or hemorrhagic events within 2 years.

RESULTS

A total of 1,192 patients with NVAF (527 women; mean age, 78 ± 10 years), including 1,141 ischemic stroke and 51 TIA, were analyzed. Rates of death/disability, mortality, and ischemic or hemorrhagic events increased significantly with increasing pre-admission CHADS2 (p for trend <0.001 for death/disability and mortality, p for trend = 0.024 for events), CHA2DS2-VASc (p for trend <0.001 for all), and HAS-BLED (p for trend = 0.004 for death/disability, p for trend <0.001 for mortality, p for trend = 0.024 for events) scores. Pre-admission CHADS2 (OR per 1 point, 1.52; 95% CI 1.35-1.71; p <0.001 for death/disability; hazard ratio (HR) per 1 point, 1.23; 95% CI 1.12-1.35; p <0.001 for mortality; HR per 1 point, 1.14; 95% CI 1.02-1.26; p = 0.016 for events), CHA2DS2-VASc (1.55, 1.41-1.72, p < 0.001; 1.21, 1.12-1.30, p < 0.001; 1.17, 1.07-1.27, p < 0.001; respectively), and HAS-BLED (1.33, 1.17-1.52, p < 0.001; 1.23, 1.10-1.38, p < 0.001; 1.18, 1.05-1.34, p = 0.008; respectively) scores were independently associated with all outcome measures.

CONCLUSIONS

In ischemic stroke or TIA patients with NVAF, all pre-admission risk scores were independently associated with death/disability at 2 years and 2-year mortality, as well as ischemic or hemorrhagic events within 2 years.

[Ischemic stroke with vertebrobasilar artery dissection extended to posterior cerebral artery]

A 45-year-old woman was admitted with headache following sudden disturbance of consciousness that occurred two hours beforehand. A neurological examination identified disorientation, left homonymous hemianopia, left hemiplegia, and sensory disturbance in the left limbs. Brain MRI DWI showed acute infarcts in the right occipital lobe and bilateral thalami, and MRA poorly depicted right vertebral artery and right posterior cerebral artery. Anticoagulation was started to treat acute ischemic stroke, but her consciousness level deteriorated at 12 hours after onset. MRI revealed a double lumen in the basilar artery, indicating a diagnosis of vertebrobasilar artery dissection. Serial MRA findings showed that images of the basilar artery and posterior cerebral artery changed over time, suggesting vertebral artery dissection extension to the posterior cerebral artery.

Higher Risk of Ischemic Events in Secondary Prevention for Patients With Persistent Than Those With Paroxysmal Atrial Fibrillation

Background and Purpose—

The discrimination between paroxysmal and sustained (persistent or permanent) atrial fibrillation (AF) has not been considered in the approach to secondary stroke prevention. We aimed to assess the differences in clinical outcomes between mostly anticoagulated patients with sustained and paroxysmal AF who had previous ischemic stroke or transient ischemic attack.

Methods—

Using data from 1192 nonvalvular AF patients with acute ischemic stroke or transient ischemic attack who were registered in the SAMURAI-NVAF study (Stroke Management With Urgent Risk-Factor Assessment and Improvement-Nonvalvular AF; a prospective, multicenter, observational study), we divided patients into those with paroxysmal AF and those with sustained AF. We compared clinical outcomes between the 2 groups.

Results—

The median follow-up period was 1.8 (interquartile range, 0.93–2.0) years. Of the 1192 patients, 758 (336 women; 77.9±9.9 years old) and 434 (191 women; 77.3±10.0 years old) were assigned to the sustained AF group and paroxysmal AF groups, respectively. After adjusting for sex, age, previous anticoagulation, and initial National Institutes of Health Stroke Scale score, sustained AF was negatively associated with 3-month independence (multivariable-adjusted odds ratio, 0.61; 95% confidence interval, 0.43–0.87; P =0.006). The annual rate of stroke or systemic embolism was 8.3 and 4.6 per 100 person-years, respectively (multivariable-adjusted hazard ratio, 1.95; 95% confidence interval, 1.26–3.14) and that of major bleeding events was 3.4 and 3.1, respectively (hazard ratio, 1.13; 95% confidence interval, 0.63–2.08).

Conclusions—

Among patients with previous ischemic stroke or transient ischemic attack, those with sustained AF had a higher risk of stroke or systemic embolism compared with those with paroxysmal AF.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01581502.

[Multiple cerebral artery occlusion due to non-bacterial thrombotic endocarditis: an autopsy case report]

A 60-year-old man was admitted to our hospital because of vertigo and repeated vomiting, which suddenly occurred 25 hours before admission. Neurologic examination revealed Wallenberg syndrome on the left side, and brain MRI showed acute infarcts in the left lateral medulla as well as in the left internal carotid artery (ICA) territory. MR angiography did not depict the left vertebral artery (VA) and the left ICA. Despite antithrombotic treatment, he developed bulbar palsy, and then, brain herniation due to infarct growth in the left middle cerebral artery territory. He died on day 9. Histopathlogical examination found verruca involving the mitral leaflet, which was consistent with non-bacterial thrombotic endocarditis (NBTE). Atherosclerosis was also found in the systemic arteries, and there was sclerotic stenosis with calcification at the portion of piercing dulla matter in the left VA and at the cavernous segment of the left ICA. Because the cerebral emboli in the narrowed lumen presented a histologic appearance similar to that of the verruca, the diagnosis of brain embolism due to NBTE was confirmed.

Three-month risk-benefit profile of anticoagulation after stroke with atrial fibrillation: The SAMURAI-Nonvalvular Atrial Fibrillation (NVAF) study

Aims

This study was performed to determine the short-term risk-benefit profiles of patients treated with oral anticoagulation for acute ischemic stroke or transient ischemic attack using a multicenter, prospective registry.

Methods

A total of 1137 patients (645 men, 77 ± 10 years old) with acute ischemic stroke/transient ischemic attack taking warfarin (662 patients) or non-vitamin K antagonist oral anticoagulants (dabigatran in 205, rivaroxaban in 245, apixaban in 25 patients) for nonvalvular atrial fibrillation who completed a three-month follow-up survey were studied. Choice of anticoagulants was not randomized. Primary outcome measures were stroke/systemic embolism and major bleeding.

Results

Both warfarin and non-vitamin K antagonist oral anticoagulants were initiated within four days after stroke/transient ischemic attack onset in the majority of cases. Non-vitamin K antagonist oral anticoagulant users had lower ischemia- and bleeding-risk indices (CHADS2, CHA2DS2-VASc, HAS-BLED) and milder strokes than warfarin users. The three-month cumulative rate of stroke/systemic embolism was 3.06% (95% CI 1.96%–4.74%) in warfarin users and 2.84% (1.65%–4.83%) in non-vitamin K antagonist oral anticoagulant users (adjusted HR 0.96, 95% CI 0.44–2.04). The rate of major bleeding was 2.61% (1.60%–4.22%) and 1.11% (0.14%–1.08%), respectively (HR 0.63, 0.19–1.78); that for intracranial hemorrhage was marginally significantly lower in non-vitamin K antagonist oral anticoagulant users (HR 0.17, 0.01–1.15). Major bleeding did not occur in non-vitamin K antagonist oral anticoagulant users with a CHADS2 score <4 or those with a discharge modified Rankin Scale score ≤2.

Conclusions

Stroke or systemic embolism during the initial three-month anticoagulation period after stroke/transient ischemic attack was not frequent as compared to previous findings regardless of warfarin or non-vitamin K antagonist oral anticoagulants were used. Intracranial hemorrhage was relatively uncommon in non-vitamin K antagonist oral anticoagulant users, although treatment assignment was not randomized. Early initiation of non-vitamin K antagonist oral anticoagulants during the acute stage of stroke/transient ischemic attack in real-world clinical settings seems safe in bleeding-susceptible Japanese population.

Abstract TP67: Cerebral Microbleeds Are Associated With Hemorrhagic Infarction Among Acute Ischemic Stroke Patients With NVAF: The SAMURAI-NVAF Study

Background and purpose: Cerebral microbleeds (CMBs) are prevalent among stroke patients, and have shown to be the risk factor for the future ischemic or hemorrhagic stroke in several reports. However, the significance of CMBs among acute ischemic stroke patients, especially those with non-valvular arterial fibrillation (NVAF), remains unknown.

Methods: Of 1,192 patients who participated in the SAMURAI-NVAF study (an ongoing prospective, multicenter, observational study), 1,099 patients (77.6±10.0 y.o, 620 men) underwent a T2* weighted image (T2*WI). Association of CMBs detected on T2*WI with the incidence of any hemorrhagic infarction (any HI and PH) and PH2 seven days after the index stroke and symptomatic hemorrhagic events and modified Rankin Scale (mRS) at discharge were assessed.

Results: CMBs were detected in 256 patients (23.2%); single CMB in 96, 2-4 CMBs in 109, and ≥5 CMBs in 51. Hemorrhagic infarction was more frequent as the number of CMBs increased (21.5%, 21.9%, 26.6%, and 33.3% in patients with 0, 1, 2-4, and ≥5 CMBs, respectively: p=0.024, analyzed by Cochran-Armitage test for trend). PH2 was identified in 2.5%, 0%, 2.8% and 3.9%, respectively (p=0.824), symptomatic hemorrhagic event in 1.2%, 1.0%, 0%, and 0%, respectively (p=0.5910), and mRS 3-6 in 51.5%, 54.2%, 54.1%, and 62.7%, respectively (p=0.4370). Presence of CMBs was independently associated with any hemorrhagic infarction [odds ratio (OR) 1.72; 95% confidence interval (CI) 1.18-2.51; p=0.005] after adjustment for age, sex, premorbid mRS, infarct size, infarct number, and intravenous thrombolysis, but not with PH2 (p=0.639), symptomatic hemorrhagic events (p=0.633), or mRS 3-6 (p=0.212). Among 253 patients receiving intravenous thrombolysis or endvascular therapy, CMBs were also independently associated with hemorrhagic infarction (OR 2.75; 95%CI 1.27-6.04; p=0.010), but not with the other outcomes.

Conclusions: CMBs were associated with any hemorrhagic infarction in acute ischemic stroke patients with NVAF regardless of receiving thrombolysis or not. However, they were not associated with PH2, symptomatic hemorrhagic events, or unfavorable vital or functional outcomes.

Abstract TMP92: Higher Risk of Ischemic Events in Secondary Prevention for Patients With Persistent Versus Paroxysmal Atrial Fibrillation: The SAMURAI-NVAF Study

Background and purpose: The discrimination between paroxysmal and persistent atrial fibrillations (AF) has not been considered to guide secondary stroke prevention, because it remains unclear whether patients with persistent AF are at higher risk compared with paroxysmal AF, particularly in secondary prevention. We aimed to assess the differences in clinical outcomes between mostly anticoagulated patients with persistent vs. paroxysmal AF who had ischemic stroke or TIA.

Methods: Using interim data of 1192 nonvalvular AF (NVAF) patients with acute ischemic stroke or TIA who were registered in the SAMURAI-NVAF study (an ongoing prospective, multicenter, observational study) to determine choice of anticoagulantion therapy and clinical outcomes, we divided patients into those with paroxysmal AF and those with persistent AF. We compared clinical outcomes between the 2 groups.

Results: The median follow-up period was 1.0 year (IQR 0.3-2.0). Of the 1192 patients, 434 (191 women, 77.3±10.0 y.o.) and 758 (336, 77.9±9.9) were assigned to the paroxysmal AF group and persistent AF group, respectively. Of each group, 220 (50.7%) and 442 (58.3%) were anticoagulated with warfarin and 199 (45.9%) and 276 (36.4%) were so with non-vitamin K antagonist oral anticoagulant (NOAC) (p=0.004). As for primary outcomes, 30 (6.2%/person-year) and 78 (9.9) ischemic events, respectively [hazard ratio adjusted for sex, age, initial NIHSS, CHADS2 score, creatinine clearance, anticoagulation with warfarin (vs. NOAC) (HR) 0.65; 95% CI 0.42-0.98], and 18 (4.9%/person-year) and 31 (3.8) hemorrhagic events, respectively (HR 0.97, 0.52-1.75), occurred during follow-up. As for secondary outcomes, the person-year rate of ischemic stroke or TIA was 3.9% and 8.4%, respectively (HR 0.46, 0.27-0.76), that of intracranial hemorrhage was 1.6% and 1.7%, respectively (HR 0.97, 0.36-2.37), and that of death was 11.1% and 15.7%, respectively (HR 0.90, 0.64-1.26).

Conclusions: Among patients with prior ischemic stroke or TIA, those with persistent AF had a higher risk of ischemic events, and ischemic stroke or TIA compared with those with paroxysmal AF. The prevention of progress to persistent AF from paroxysmal AF may be beneficial for secondary prevention in patients with NVAF.

Abstract TP42: Early Neurological Deterioration in Patients With Single Infarct in the Territory of Lenticulostriate Artery Territory

Purpose: Early neurological deterioration (END) in the acute phase of penetrating artery infarction is not uncommon. Recently, atherosclerotic status has been reported to contribute to END. Considering such findings, we further explored factors associated with END in patients with single infarctions in the lenticulostriate artery territory (LSA).

Methods: We studied 523 consecutive patients with LSA who entered our hospital within 24 hours after onset. We categorized subjects into 3 groups: no END, minor END and major END. Minor END was defined as worsening or fluctuation by 1-2 points in the National Institutes of Health Stroke Scale (NIHSS) but recovered afterward. Major END was worsening by 2 or more points in the NIHSS and afterwards thoroughly progressed. LSA infarcts on the first DWI were divided into proximal and distal types. The proximal type was further divided into anterior and posterior type based on the intermediate point in the corona radiating adjacent to the lateral ventricle. Systolic blood pressures in an emergency room (SBP) were categorized into 5 groups as follows: G1; < 140mmHg, G2; 140-159, G3; 160-179; G4; 180-200 and G5; > 200. NIHSS on admission was dichotomized and higher NIHSS was defined as ≥4. Atherosclerotic diseases of the intracranial middle cerebral artery were assessed on MRA as follows: normal, mild stenosis (< 50%) and severe stenosis (> 50%). Central values of modified Rankin scale one month after ictus in 3 END groups were no END (n=302): 1, minor END (n=112): 1 and major END (n=109): 4, respectively. We then calculated the odds ratios (OR) of predictive factors for major END.

Results: Predictive factors found significant by uni-variate analysis were female, anterior and posterior proximal type, mild stenosis, higher NIHSS and G4 and G5 of SBP. Multivariate analysis revealed that anterior proximal type (OR and 95% p&lt 0.0001), posterior proximal type (156.1, p&lt 0.0001), mild stenosis (3.0, p=0.014) and higher NIHSS (4.3, p=0.0002) were found to be independently associated with major END.

Conclusions: Posterior rather than anterior proximal type was strongly associated with major END probably due to the anatomical fact that corticospinal tracts crossed the LSA territory at the postero-superior quadrant.

Abstract WP168: The Impact of Intracardiac Thrombi on Recurrent Ischemic Events in Acute Ischemic Stroke Patients With Non-valvular Atrial Fibrillation the Samurai-nvaf Study

Objective: The intracardiac thrombus is associated with an increase in the risks of stroke and thromboembolism for primary prevention. However, it remains unclear in the setting of early management of patients with acute ischemic stroke/TIA. The purpose of this study was to clarify the impact of intracardiac thrombi on recurrent ischemic events in acute ischemic stroke/TIA patients with nonvalvular atrial fibrillation (NVAF).

Methods: In the SAMURAI-NVAF study (an ongoing prospective, multicenter, observational study), 1192 acute ischemic stroke/TIA patients with NVAF were registered. Of these, the patients who underwent transesophageal echocardiography (TEE) and/or transthoracic echocardiography (TTE) during acute hospitalization were included. We evaluated the association between the prevalence of intracardiac thrombi and recurrent ischemic events (composite of ischemic stroke/TIA and systemic embolism) during hospital stay (median 29 days).

Results: A total of 1091 patients (474 women, 77.6±9.9 y.o) were studied. Of these, 48 patients had intracardiac thrombus (4.4% [95% CI, 3.3-5.7%]). In acute hospital stay, 29 recurrent ischemic events (2.7% [1.9-3.8%]; 24 ischemic stroke, 3 TIA, and 2 systemic embolism) occurred. Patients with intracardiac thrombi had higher incidence of recurrent ischemic events than those without (12.5% versus 2.2%, p<0.001). The thrombus was an independent predictor for ischemic events after adjusted for age, sex and platelet count (OR 6.5; 95% CI 2.28-16.36, p=0.002). Detectability of thrombi increased when only patients undergoing both TEE and TTE were studied (34/216, 16%).

Conclusion: In acute ischemic stroke/TIA patients with NVAF, intracardiac thrombi are associated with risk of recurrent ischemic events. The evaluation of intracardiac thrombus should be considered in acute phase of ischemic stroke/TIA.

Diffuse large B-cell lymphoma presenting with central pontine myelinolysis: a case report

Introduction

The most common cause of central pontine myelinolysis is an overly rapid correction of hyponatremia, although it can also occur in patients with any condition leading to nutritional or electrolyte stress. We report a case of diffuse large B-cell lymphoma with central pontine myelinolysis developing at the onset of disease. To the best of our knowledge, hematological malignancies presenting with central pontine myelinolysis have been rarely reported, especially in previously untreated patients, as in our case report.

Case presentation

A 78-year-old Japanese woman presented to a neighborhood clinic with persistent high fever, edema, and general weakness. Despite the absence of specific neurological findings, brain magnetic resonance imaging showed an abnormal lesion in the central pons area of her brain (hyperintense on T2-weighted and hypointense on T1-weighted sequences), compatible with central pontine myelinolysis. She was admitted to our emergency department in a state of shock one month later. The results of her blood tests showed greatly elevated C-reactive protein and lactate dehydrogenase levels. She had severe hypoalbuminemia and mild hyponatremia, and showed signs of disseminated intravascular coagulation. Mild bilateral pleural effusion, prominent subcutaneous edema, and splenomegaly were detected on her systemic computed tomography scan. Her body fluid cultures did not show signs of infection and her spinal aspiration did not show pleocytosis or abnormal cells. A diagnosis of diffuse large B-cell lymphoma was made based on the results of her bone marrow examination. As she was critically ill before the diagnosis was made, she was treated with methylprednisolone pulse therapy, followed by systemic chemotherapy (rituximab with modified THP-COP regimen, including cyclophosphamide, pirarubicin, vindesine, and prednisolone), which resulted in complete remission and recovery without any neurological defects, and resolution of her abnormal findings on magnetic resonance imaging.

Conclusions

Central pontine myelinolysis is a serious condition that may result in neuropathological sequelae and mortality, and clinicians should be aware of its potential presence in patients with malignancies.

Abstract W P203: Early Recurrence or Worsening of Transient Ischemic Attack or Minor Ischemic Stroke

Purpose: The present study aimed to assess the rate of and predictors for early recurrence or worsening after transient ischemic attack (TIA) or minor ischemic stroke (MIS). Methods: From 1806 consecutive patients with acute ischemic stroke, 474 patients with TIA or MIS have been studied. MIS was defined by an NIH Stroke Scale (NIHSS) score ≤3. The primary outcome was total events that include new-onset stroke or TIA and early worsening in patients with MIS in the first 90 days. Worsening was defined as clinical deterioration by ≥2 points on the NIHSS. Patients were classified into 6 stroke subtypes, i.e., G1: Intracranial atherothrombotic (ATB) (n=53), G2: Extracranial ATB (34), G3: Cardioembolic (85), G4: Penetrating artery (PA) disease (200), G5: Coagulopathy (9), and G6: Other embolism included paradoxical (22), aortogenic (31) and cryptogenic (44) embolism. Patients were also classified into 4 groups in terms of diffusion weighted image (DWI) pattern, i.e., D1: Single cortical and subcortical (n=53), D2: Multiple cortical and subcortical (108), D3: Penetrating artery territory (209) and D4: None (90). Results: Penetrating artery disease as stroke subtype is most prevalent (42.1%). There were 83 total events, of those 65% were worsening. Higher NIHSS (≥2) at admission and positive DWI were significantly higher in the group with events than without (OR: 1.67, 2.39, respectively). Most worsening occurred within 6 days. The incidence of total events/ worsening in different stroke subtypes were G1: 13 (24.5%)/8 (15.0%), G2: 8 (23.4)/4 (11.7), G3: 13 (15.2)/ 8 (9.4), G4: 41 (20.5)/32 (16.0), G5: 2 (22.2) /1 (11.1), and G6: 6 (6.4) /3 (3.2). Total event were higher in G1, G2 and G4, and worsening were higher in G1 (60% of total events) and G4 (80%). The incidence of total events/ worsening in different DWI patterns were D1: 8 (11.9%)/5 (7.4%), D2: 21 (19.4)/14 (12.9), D3: 46 (22.0)/ 36 (17.2), D4: 8 (8.8)/0 (0). Total events were higher in D2 and D3, of those worsening was 66.6% in D2 and 78.2% in D3. Conclusions: A majority of events after TIA/MIS was worsening that is prevalent especially in the patients with intracranial ATB and PA disease and those with high DWI signals of multiple cortical and PA territory. A strategy to halt progressive stroke should be tailored.

Abstract W P375: Prior Antithrombotic Therapy, Initial Neurological Severity And 3-month Outcome In Acute Ischemic Stroke Patients With Non-valvular Atrial Fibrillation: The Samurai-nvaf Study

Background and Purpose: We aimed to assess whether prior antithrombotic therapy affects initial neurological severity and functional outcome in acute ischemic stroke patients with non-valvular atrial fibrillation (NVAF).

Methods: Patients with NVAF who were admitted within 7 days after ischemic stroke onset from 2011 to 2014 were enrolled from the register of a prospective, multicenter, observational study (the SAMURAI-NVAF study). Patients receiving novel oral anticoagulants at onset were excluded from the study. They were classified into 3 groups: the non-WF group, patients without prior warfarin; the iWF group, those on warfarin with initial PT-INR below the target range; the sWF group, those on warfarin with initial PT-INR within or above the target range. They were also divided into patients without prior antiplatelet agents (the non-AP group) and those with (the AP group). Initial neurological severity was measured by NIHSS score. Poor functional outcome was defined by mRS 3-6 at 3 months of onset.

Results: Of 1000 patients studied, 713, 221 and 66 were assigned to the non-WF group, the iWF group and the sWF group, respectively. Of all, 245 were assigned to the AP group, mainly taking aspirin (202 patients). On multivariate analysis, the sWF group (vs. the non-WF group) (standardized regression coefficient [β], -0.23; p<0.001) was inversely associated with initial NIHSS score, but the iWF group (vs. the non-WF group) (β, -0.03; p=0.327) and the AP group (vs. the non-AP group) (β, 0.02; p=0.580) were not. The sWF group (vs. the non-WF group) (OR, 0.41; 95% CI, 0.21-0.77; p=0.005) was inversely associated with poor functional outcome, but the iWF group (vs. the non-WF group) (OR, 0.81; 95% CI, 0.55-1.18; p=0.267) and the AP group (vs. the non-AP group) (OR, 1.17; 95% CI, 0.80-1.71; p=0.413) were not.

Conclusions: Prior sufficient warfarinization was associated with mild neurological severity and favorable outcome in acute ischemic stroke patients with NVAF, whereas prior insufficient warfarinization and prior antiplatelet therapy were not.

Abstract 63: Three-month Outcomes in Japanese Stroke /TIA Patients With Non-valvular Atrial Fibrillation After Initiating Oral Anticoagulants: The SAMURAI-NVAF Study

Backgound and Purpose: Recently, three non-vitamin K antagonist oral anticoagulants (NOACs) became available for patients with nonvalvular atrial fibrillation (NVAF) in Japan. We aimed to determine 3-month outcomes in ischemic stroke/TIA patients receiving NOACs or warfarin from a multicenter prospective registry (SAMURAI-NVAF registry, NCT01581502).

Methods: Among 1,191 acute ischemic stroke /TIA patients enrolled between September 2011 and March 2014, we studied 916 patients (389 women, 77±10 y) who took oral anticoagulants (OACs) after index stroke and completed 3-month follow-up survey. Primary outcome measures were ischemic events, including recurrent stroke/TIA and thromboembolism, and major bleedings events, such as fatal bleeding and/or symptomatic bleeding in a critical area or organ according to the International Society on Thrombosis and Haemostasis statement. We assessed the incidence and clinical factors associated with primary outcomes within 90 days after initiating OACs.

Results: NOACs were given for 370 patients (126 women, 74±9 y; dabigatran 168, rivaroxaban 183 and apixaban 19) and warfarin for 546 (263 women, 79±10 y). NOAC users had lower scores of CHADS2 (median 3 in NOAC, 4 in warfarin, p<0.001) and HAS-BLED (3, 3, p<0.001) than warfarin users. Ischemic events occurred in 14 NOAC users (3.8%; 2 women, 76±6 y, including 8 lower dose users between two approved dose for each NOAC) and 25 warfarin users (4.6%; 13 women, 81±9 y). Of these, 13 NOAC users (3.5%) and 16 warfarin users (2.9%) developed ischemic stroke/TIA. Among NOAC users, patients with ischemic events had lower body weights (53±11 vs 60±11kg, p= 0.017), more frequently had congestive heart failure (36 vs 10%, p = 0.003) and intracardiac thrombus (27 vs 4%, p < 0.001) than those without. Major bleeding events occurred in 5 NOAC users (1.4%, all using lower dose), and 14 warfarin users (2.6%). Of these, one NOAC user (0.3%) and 4 warfarin users (0.7%) developed intracranial hemorrhage.

Conclusion: The 3-month incidence of ischemic events in stroke/TIA patients with NVAF was approximately 4% in both NOAC and warfarin users. Intracranial hemorrhage was relatively infrequent in NOAC users.

Abstract T P158: Albuminuria Is Associated With Neurological Deterioration and Poor Outcome in Acute Stroke Patients With Non-valvular Atrial Fibrillation: The SAMURAI-NVAF Study

Background and purpose: The impact of albuminuria on clinical outcomes in acute cardioembolic stroke is not fully investigated. We assessed whether high spot urine albumin/creatinine ratio (ACR) was associated with clinical outcomes in acute stroke with non-valvular atrial fibrillation (NVAF).

Methods: From 2011 to 2014, we enrolled acute ischemic stroke/TIA patients with NVAF in the SAMURAI-NVAF study, which is a multicenter, observational study. Patients with complete ACR values were included in the analysis. They were divided into the N (normal, ACR < 30mg/g) and the H (high, ACR ≥ 30mg/g) groups. Clinical outcomes were neurological deterioration (an increase of NIHSS ≥1 point during the initial 7 days) and poor outcome (mRS of 4-6 at 3 months).

Results: Of 558 patients (328 men, 77±10 y) who were included, 271 and 287 were assigned to the H group and the N group, respectively. As compared with patients in the N group, those in the H group were more frequently female (52 vs 31%, p < 0.001) and older (80±10 vs 75±10 y, p < 0.001). On admission, patients in the H group more frequently had diabetes (28 vs 17%, p = 0.003), less frequently had paroxysmal AF (68 vs 57%, p = 0.009), had higher levels of SBP (157±28 vs 151±24 mmHg, p = 0.003), NIHSS score (11 vs 5, p < 0.001), CHA2DS2-VASc score (6 vs 5, p < 0.001), plasma glucose (141±62 vs 132±41 mg/dL, p = 0.04), and brain natriuretic peptide (348±331 vs 259±309 pg/mL, p = 0.002), and had lower levels of hemoglobin (13±2 vs 14±2 g/dL, p = 0.02), and estimated glomerular filtration ratio (eGFR) (60±24 vs 66±20 mL/min/1.73m2 p = 0.002). On imaging studies, patients in the H group more frequently had large infarct (29 vs 20 %, p = 0.02) and culprit artery occlusion (64 vs 48%, p < 0.001). Neurological deterioration (14 vs 4%, p < 0.001) and poor outcome (49 vs 24%, p < 0.001) were more frequently observed in the H group. On multivariate regression analysis adjusted for significant confounders and reperfusion therapy, the H group was associated with neurological deterioration (OR 2.43; 95% CI 1.14-5.5; p = 0.02) and poor outcome (OR 2.75; 95% CI 1.45-5.2; p = 0.002), although eGFR was not significantly related to either.

Conclusion: High ACR, a marker of albuminuria, was independently associated with unfavorable outcomes in acute stroke patients with NVAF.

Trends in oral anticoagulant choice for acute stroke patients with nonvalvular atrial fibrillation in Japan: the SAMURAI-NVAF study

BACKGROUND

Large clinical trials are lack of data on non-vitamin K antagonist oral anticoagulants for acute stroke patients.

AIM

To evaluate the choice of oral anticoagulants at acute hospital discharge in stroke patients with nonvalvular atrial fibrillation and clarify the underlying characteristics potentially affecting that choice using the multicenter Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-NVAF registry (ClinicalTrials.gov NCT01581502).

METHOD

The study included 1192 acute ischemic stroke/transient ischemic attack patients with nonvalvular atrial fibrillation (527 women, 77·7 ± 9·9 years old) between September 2011 and March 2014, during which three nonvitamin K antagonist oral anticoagulant oral anticoagulants were approved for clinical use. Oral anticoagulant choice at hospital discharge (median 23-day stay) was assessed.

RESULTS

Warfarin was chosen for 650 patients, dabigatran for 203, rivaroxaban for 238, and apixaban for 25. Over the three 10-month observation periods, patients taking warfarin gradually decreased to 46·5% and those taking nonvitamin K antagonist oral anticoagulants increased to 48·0%. As compared with warfarin users, patients taking nonvitamin K antagonist oral anticoagulants included more men, were younger, more frequently had small infarcts, and had lower scores for poststroke CHADS2 , CHA2 DS2 -VASc, and HAS-BLED, admission National Institutes of Health stroke scale, and discharge modified Rankin Scale. Nonvitamin K antagonist oral anticoagulants were started at a median of four-days after stroke onset without early intracranial hemorrhage. Patients starting nonvitamin K antagonist oral anticoagulants earlier had smaller infarcts and lower scores for the admission National Institutes of Health stroke scale and the discharge modified Rankin Scale than those starting later. Choice of nonvitamin K antagonist oral anticoagulants was independently associated with 20-day or shorter hospitalization (OR 2·46, 95% CI 1·87-3·24).

CONCLUSIONS

Warfarin use at acute hospital discharge was still common in the initial years after approval of nonvitamin K antagonist oral anticoagulants, although nonvitamin K antagonist oral anticoagulant users increased gradually. The index stroke was milder and ischemia-risk indices were lower in nonvitamin K antagonist oral anticoagulant users than in warfarin users. Early initiation of nonvitamin K antagonist oral anticoagulants seemed safe.

Abstract T P179: Atrial Fibrillation Unidentified Prior to Stroke/tia: Background Features, Stroke Severity and Outcome - The Samurai-nvaf Study

Purpose: Atrial fibrillation (AF) is often detected after embolic events occur, and it is an obstacle to effective preventive anticoagulation. We aimed to determine a percentage of patients with nonvalvular AF (NVAF) unidentified prior to stroke in the overall stroke patients with NVAF, as well as background features, stroke severity and outcome of such occult NVAF patients.

Methods: A total of 743 acute ischemic stroke/TIA patients with NVAF (344 women, 78±10 years old) were enrolled between Sep 2011 and Jun 2013 from a multicenter prospective registry (the SAMURAI-NVAF study, NCT01581502). Patients were divided into two groups; those with identified AF before stroke/TIA (Group I) and those with unidentified AF that was documented at emergent visit or later (Group U). Favorable outcome was defined as mRS 0-2 at hospital discharge (for 710 patients, median 23 days) and at 3 months (for 565 patients).

Results: 285 patients belonged to the Group U (38%; 138 women, 78±11 years old). Although both median CHADS 2 (2 vs. 2, p<0.001) and CHA 2 DS 2 -VASc (3 vs. 4, p<0.001) were lower in the Group U than the Group I, patients with the high ischemic risk category (≥2 in each score) accounted for 68% according to CHADS 2 and 91% according to CHA 2 DS 2 -VASc in the Group U. After multivariate adjustment, paroxysmal AF (OR 1.91, 95% CI 1.24-2.75) was more common and congestive heart failure (0.63, 0.40-0.99) and premorbid use of oral anticoagulants (0.08, 0.04-0.13) were less common in the Group U than the Group I. The median initial NIHSS was higher in the Group U (11 [IQR 4-19]) than in the Group I (6 [2-17], p<0.001). Favorable outcome was less common in the Group U than the Group I both at discharge (41% vs. 51%, p=0.011) and at 3 months (46% vs. 56%, p=0.036). Unidentified AF was independently associated with mRS 3-6 after adjustment for sex and age both at discharge (OR 1.57, 95% CI 1.13-2.18) and at 3 months (1.60, 1.10-2.32), but was no longer associated with mRS 3-6 after further adjustment for the initial NIHSS.

Conclusion: Two fifth of the stroke/TIA patients with NVAF were not diagnosed as having AF prior to the attack, though their ischemia-risk indices were generally high. Patients with such occult NVAF had severer stroke and worse outcome than those with identified AF.

Abstract T P57: Length of Stay and Hospital Charges in Japanese NVAF Inpatients with Acute Stroke/TIA: The SAMURAI-NVAF Study

Purpose: Warfarin needs several days to reach the steady anticoagulative state, however novel oral anticoagulants (NOACs) does not. It may cause differences in acute hospital stay for stroke and hospital charges between NVAF patients taking warfarin and those taking NOACs. We aimed to determine the association of OAC choice after stroke with length of hospital stay and hospital charges from a multicenter prospective registry (the SAMURAI-NVAF, NCT01581502) involving 18 hospitals.

Methods: 634 acute ischemic stroke/TIA survivors with NVAF (277 women, 77±10 years old) who was taking OACs at discharge between Sep 2011 and Jun 2013 were studied; three NOACs were approved for clinical use in NVAF patients in Japan just before or during the periods (dabigatran in Jan 2011, rivaroxaban in Jan 2012, apixaban in Dec 2012). Hospital charges were analyzed using 217 patients in the first author’s hospital where the Diagnosis Procedure Combination, a Japanese diagnosis-dominant case-mix system was used for charges.

Results: Warfarin was chosen for 420 patients (66%), dabigatran for 143 (23%), and rivaroxaban for 71 (11%) at hospital discharge. Warfarin users were older (warfarin 79±10, dabigatran 73±9, rivaroxaban 74±10 years old, p<0.001) and more female (47%, 34%, 41%, p=0.021), and had higher scores of admission NIHSS (median 10, 3, 6, p<0.001) and discharge mRS (3.5, 1, 2, p<0.001) than the others. Median hospital stay was longer in warfarin users (28 [IQR 18-36] days) than dabigatran users (15 [12-22] days) and rivaroxaban users (18 [13-26] days, p<0.001). As compared to NOAC use, warfarin use was independently associated with longer stay both after adjustment for sex, age, and initial NIHSS score (p<0.001) and after adjustment for sex, age, and discharge mRS (p<0.001). Median hospital charges were 1,623*10 3 [IQR 980-2141] JPY for warfarin users (n=137), 967*10 3 [IQR 716-1240] JPY for dabigatran users (n=43), and 1,354*10 3 [IQR 944-2063] JPY for rivaroxaban users (n=137, p<0.001). There was no independent association of OAC choice with hospital charges after multivariate adjustment.

Conclusion: Use of NOACs for secondary prevention shortened acute hospital stay after stroke/TIA independently from stroke severity.

Abstract W P344: Choice of Warfarin and Novel Oral Anticoagulants for Secondary Prevention of Stroke/TIA in Japanese NVAF Patients: The SAMURAI-NVAF Study

Purpose: We aimed to determine choice of oral anticoagulants (OACs) at acute hospital discharge in stroke patients with NVAF and clarify their underlying characteristics potentially influencing the choice from a multicenter prospective registry (the SAMURAI-NVAF, NCT01581502).

Methods: 668 acute ischemic stroke/TIA survivors with NVAF (298 women, 77±10 years old) between Sep '11 and Jun '13 were studied; dabigatran (Jan '11), rivaroxaban (Jan '12), and apixaban (Dec '12) were approved for clinical use in NVAF patients in Japan just before or during the periods. OAC choice at hospital discharge (median 23 days) was assessed.

Results: Warfarin was chosen for 420 patients (63%), dabigatran for 143 (21%), rivaroxaban for 72 (11%), and OACs were not chosen for 33 (5%). Of 204 prestroke warfarin users, 160 (78%) continued to take warfarin, 27 changed to dabigatran, and 17 to rivaroxaban. Among three 7-month parts of observation period, warfarin users decreased (70%, 69%, 48%), dabigatran users unchanged (23%, 21%, 19%), and rivaroxaban users increased (0.5%, 7%, 26%). Warfarin users had higher scores of CHADS 2 (median 4 in warfarin, 4 in dabigatran, 3 in rivaroxaban, same orders in the following parentheses, p<0.001) and CHA 2 DS 2 -VASc (6, 5, 5, p<0.001). Of components for CHA 2 DS 2 VASc, congestive heart failure (27%, 12%, 13%, p<0.001), stroke history (29%, 15%, 15%, p=0.001), vascular disease (18%, 11%, 7%, p=0.019), and women (47%, 34%, 40%, p=0.020) were more common in warfarin users than the others. Age (79±10, 73±9, 74±10 years old, p<0.001), body weight (54±12, 62±11, 59±12 kg, p<0.001), admission creatinine clearance (52±26, 72±23, 67±25 ml/min, p<0.001), and concomitant antiplatelet use (12%, 10%, 1%, p=0.020) were also different. As features of index stroke, infarcts >33% in size of the culprit arterial territory were more common (29%, 8%, 13%) and scores of admission NIHSS (median 10, 3, 6), 7-day NIHSS (5, 1, 1) and discharge mRS (3.5, 1, 2, p<0.001 for all) were higher in warfarin users.

Conclusion: In the initial two years after approval of novel OACs (NOACs), warfarin use at acute hospital discharge was still common, although NOAC users gradually increased. Index stroke was milder and ischemia-risk indices were lower in NOAC users than warfarin users.

Abstract T P58: Early Anticoagulant Therapy for Secondary Stroke Prevention in Japanese NVAF Patients With TIA/minor Stroke: The SAMURAI-NVAF Study

Objective: Early anticoagulant therapy is commonly used for acute cardioembolic stroke in Japan, although its usefulness remains undetected. The purpose of this study was to estimate the efficacy and safety of early anticoagulation for the treatment of acute stroke/TIA patients with nonvalvular atrial fibrillation (NVAF).

Methods: From September 2011 through June 2013, 697 acute ischemic stroke/TIA patients with NVAF were registered from a multicenter prospective registry (the SAMURAI-NVAF study including 18 Japanese stroke centers, NCT01581502). Of those, the patients who started anticoagulant therapy within 48 hours after the onset were assessed for the incidence of ischemic and hemorrhagic events during the first 30 days.

Results: A total of 438 patients (62.8%; 247 men, 77.4±9.8 years old) was evaluated. Of these, 292 patients (66.7%) started anticoagulation with intravenous unfractionated heparin (UFH) mono-therapy, 87 patients (19.9%) with UFH and warfarin, and 2 patients (0.5%) with UFH switched to novel oral anticoagulants (NOACs). As oral anticoagulants mono-therapy, 34 patients (7.8%) started with warfarin, and 23 (5.3%) with NOAC. Ischemic events were developed in 11 patients (2.5%: 11 recurrent ischemic strokes), and hemorrhagic events in 11 patients (2.5%: 6 symptomatic intracranial hemorrhages during the first 7days and 5 extracranial hemorrhages). Patients with major artery occlusion had higher incidence of hemorrhagic events than those without (4.0% versus 0.6%, p=0.02), whereas ischemic events were similar in both groups (2.4% versus 2.7%, p=0.82). In multivariable analysis, major artery occlusion was independently associated with higher rate of major hemorrhagic events (OR 6.19; 95% CI 1.01-119.75) adjusted for age, sex, BMI, HAS-BLED score before index TIA/stroke, and NIHSS on admission.

Conclusion: In our cohort, early initiation of anticoagulant therapy is often performed in patients with acute stroke/TIA with NVAF patient, and the frequency of ischemic and hemorrhagic events seems to be low compared with previous reports. Early anticoagulant therapy can be safe for patients without major artery occlusion.