Causality assessment between reported fatal cerebral haemorrhage and suspected drugs: developing a new algorithm based on the analysis of the Japanese Adverse Event Report (JADER) database and literature review.

PURPOSE: Cerebral haemorrhage is a life-threatening event with various causes including adverse drug reactions (ADRs). Several methods have been proposed for the causality assessment of ADRs, but none specific for cerebral haemorrhage. The purpose of this study was to develop an algorithm for causality assessment between drugs and fatal cerebral haemorrhage, based on the analysis of data from the Japanese Adverse Drug Event Report (JADER) database and literature review. METHODS: All fatal ADRs reported in the JADER database between April 2004 and March 2020 were searched, and literature on drug-related cerebral haemorrhage or general causality assessment was reviewed to summarise the information on causality between cerebral haemorrhage and ADRs. RESULTS: Of the 50,095 cases identified in the JADER database, cerebral haemorrhage was the fifth most reported cause of fatal ADRs, but the causality of >80% of the events was published as 'Unassessable'. The literature review identified articles on drug-related cerebral haemorrhage and causality assessment methods in general. Based on these articles, information on five categories (temporal relationship, previous knowledge about the relationship between drug action and ADRs, alternative aetiological candidate, appropriateness of drug use, and the relationship between death and ADRs) was determined for causality assessment between a suspected drug and fatal cerebral haemorrhage; a new algorithm was created using this information. CONCLUSION: In this study, the information considered necessary for causality assessment between drugs and fatal cerebral haemorrhage was reviewed and an assessment algorithm was developed. Future studies are needed to validate the usefulness of this method.

Bleeding risk assessment for stroke patients on antithrombotic therapy. / Evaluación del riesgo hemorrágico de la terapia antitrombótica en pacientes con ictus.

INTRODUCTION: After an ischemic cerebrovascular event the risk of new ischemic events is high, therefore antithrombotic therapy are indicated to prevent stroke recurrence. DISCUSSION: Despite its clear benefit, these therapies increase the risk of bleeding. Therefore, it is essential to identify high hemorrhagic risk patients. There are different predictive models of hemorrhage, in particular of intracranial hemorrhage, associated with the use of antiaggregants in patients who have presented an ischemic stroke or TIA, such as the CCSC, intracranial scales -B2LEED3S score or S2TOP-BLEED. However, though main international guidelines recommend the use of scales, in particular, the HAS-BLED score, to assess the risk of bleeding in anticoagulated patients, there is no specific recommendation in the case of the use of antiplatelet drugs. CONCLUSIONS: In this review we present the main models currently available for the prediction of bleeding of antithrombotic therapy in patients who have had a stroke or TIA.

Personalizing Bridging Anticoagulation in Patients with Nonvalvular Atrial Fibrillation-a Microsimulation Analysis.

BACKGROUND: Bridging anticoagulation is commonly prescribed to patients with atrial fibrillation who are initiating warfarin or require interruption of anticoagulation. Current guidelines recommend bridging for patients at high risk of stroke. Among patients with atrial fibrillation and one or more risk factors for ischemic stroke, the recently published BRIDGE trial found forgoing bridging during interruption to be, on average, noninferior to bridging with respect to ischemic complications, with significantly fewer hemorrhagic complications. OBJECTIVE: We sought to examine the benefits and harms of bridging anticoagulation across the spectrum of ischemic and hemorrhagic stroke risk and thereby enable more nuanced, risk-stratified decision-making when bridging is considered during initiation or interruption of vitamin K antagonists. DESIGN: A Monte Carlo simulation, using a combination of literature-derived estimates, registry data, and trial data. MAIN MEASURES: Net clinical benefit, weighting for ischemic strokes, intracranial hemorrhages, and extracranial major hemorrhages. KEY RESULTS: The benefits and harms of bridging anticoagulation vary according to underlying patient risk profiles for both thromboembolic stroke and major intracranial bleeding. Patients at high risk of ischemic stroke and low risk of hemorrhage derive benefit from bridging during initiation or interruption of warfarin therapy. Patients at similarly high or low risk of both outcomes may receive benefit from bridging during initiation and bridging during interruption, but this was sensitive to underlying assumptions. The need for stratification along both axes of risk was robust to a wide range of parameters. CONCLUSIONS: Bridging anticoagulation may provide benefit to patients at high risk of ischemic stroke and low risk of intracranial hemorrhage who are initiating or interrupting warfarin therapy, while patients at high or low risk of both complications may be harmed. The use of bridging anticoagulation in patients with non-valvular atrial fibrillation should be considered only after stratification by risk of ischemic and hemorrhagic complications.

Effect of apixaban on brain infarction and microbleeds: AVERROES-MRI assessment study.

BACKGROUND: Clinical and subclinical (covert) stroke is a cause of cognitive loss and functional impairment. In the AVERROES trial, we performed serial brain magnetic resonance imaging (MRI) scans in a subgroup to explore the effect of apixaban, compared with aspirin, on clinical and covert brain infarction and on microbleeds in patients with atrial fibrillation. METHODS: We performed brain MRI (T1, T2, fluid-attenuated inversion recovery, and T2* gradient echo sequences) in 1,180 at baseline and in 931 participants at follow-up. Mean interval from baseline to follow-up MRI scans was 1.0 year. The primary outcome was a composite of clinical ischemic stroke and covert embolic pattern infarction (defined as infarction >1.5 cm, cortical-based infarction, or new multiterritory infarction). Secondary outcomes included new MRI-detected brain infarcts and microbleeds and change in white matter hyperintensities. RESULTS: Baseline MRI scans revealed brain infarct(s) in 26.2% and microbleed(s) in 10.5%. The rate of the primary outcomes was 2.0% in the apixaban group and 3.3% in the aspirin group (hazard ratio [HR] 0.55; 0.27-1.14) from baseline to follow-up MRI scan (mean duration of follow-up: 1 year). In those who completed baseline and follow-up MRI scans, the rate of new infarction detected on MRI was 2.5% in the apixaban group and 2.2% in the aspirin group (HR 1.09; 0.47-2.52), but new infarcts were smaller in the apixaban group (P = .03). There was no difference in proportion with new microbleeds on follow-up MRI (HR 0.92; 0.53-1.60) between treatment groups. CONCLUSIONS: Apixaban treatment was associated with a nonsignificant trend toward reduction in the composite of clinical ischemic stroke and covert embolic-pattern infarction and did not increase the number of microbleeds in patients with atrial fibrillation compared with aspirin.

Estimating the Quantitative Demand of NOAC Antidote Doses on Stroke Units.

BACKGROUND: The first specific antidote for non-vitamin K antagonist oral anticoagulants (NOAC) has recently been approved. NOAC antidotes will allow specific treatment for 2 hitherto problematic patient groups: patients with oral anticoagulant therapy (OAT)-associated intracerebral hemorrhage (ICH) and maybe also thrombolysis candidates presenting on oral anticoagulation (OAT). We aimed to estimate the frequency of these events and hence the quantitative demand of antidote doses on a stroke unit. METHODS: We extracted data of patients with acute ischemic stroke and ICH (<24 h after symptom onset) in the years 2012-2015 from a state-wide prospective stroke inpatient registry. We selected 8 stroke units and determined the mode of OAT upon admission in 2012-2013. In 2015, the mode of OAT became a mandatory item of the inpatient registry. From the number of anticoagulated patients and the NOAC share, we estimated the current and future demand for NOAC antidote doses on stroke units. RESULTS: Eighteen percent of ICH patients within 6 h of symptom onset or an unknown symptom onset were on OAT. Given a NOAC share at admission of 40%, about 7% of all ICH patients may qualify for NOAC reversal therapy. Thirteen percent of ischemic stroke patients admitted within 4 h presented on anticoagulation. Given the availability of an appropriate antidote, a NOAC share of 50% could lead to a 6.1% increase in thrombolysis rate. CONCLUSIONS: Stroke units serving populations with a comparable demographic structure should prepare to treat up to 1% of all acute ischemic stroke patients and 7% of all acute ICH patients with NOAC antidotes. These numbers may increase with the mounting prevalence of atrial fibrillation and an increasing use of NOAC.

A comparison of the safety and effectiveness of dabigatran and warfarin in non-valvular atrial fibrillation patients in a large healthcare system.

Dabigatran is approved for stroke risk reduction in patients with nonvalvular atrial fibrillation (NVAF). Data from diverse clinical practice settings will help establish whether the risk:benefit ratio seen in clinical trials is comparable with routine clinical care. This study aimed to compare the safety and effectiveness of dabigatran and warfarin in clinical practice. We undertook a propensity score-matched (PSM) cohort study (N=12,793 per group; mean age 74) comparing treatment with dabigatran or warfarin in the US Department of Defense claims database, October 2009 to July 2013. Treatment-naïve patients with first prescription claim for dabigatran (either FDA-approved dose) or warfarin between October 2010 and July 2012 (index) and a diagnosis of NVAF during the 12 months before index date were included. Primary outcomes were stroke and major bleeding. Secondary outcomes included ischaemic and haemorrhagic stroke, major gastrointestinal (GI), urogenital or other bleeding, myocardial infarction (MI) and death. Time-to-event was investigated using Kaplan-Meier survival analyses. Outcomes comparisons were made utilising Cox-proportional hazards models of PSM groups. Dabigatran users experienced fewer strokes (adjusted hazard ratio [95 % confidence intervals] 0.73 [0.55-0.97]), major intracranial (0.49 [0.30-0.79]), urogenital (0.36 [0.18-0.74]) and other (0.38 [0.22-0.66]) bleeding, MI (0.65 [0.45-0.95]) and deaths (0.64 [0.55-0.74]) than the warfarin group. Major bleeding (0.87 [0.74-1.03]) and major GI bleeding (1.13 [0.94-1.37]) was similar between groups and major lower GI bleeding events were more frequent (1.30 [1.04-1.62]) with dabigatran. In conclusion, compared with warfarin, dabigatran treatment was associated with a lower risk of stroke and most outcomes measured, but increased incidence of major lower GI bleeding.

Safety and effectiveness of dabigatran and warfarin in routine care of patients with atrial fibrillation.

The RE-LY study demonstrated the safety and efficacy of dabigatran relative to warfarin for stroke prevention in non-valvular atrial fibrillation. It is important to further evaluate safety and effectiveness of drugs in routine care. This study used a sequential cohort design with propensity score matching to compare dabigatran with warfarin among patients in two commercial health insurance databases. New users of these anticoagulants were followed from initiation until discontinuation, the end of the study, or the occurrence of a study outcome (primary study outcomes were stroke and major bleeding). Proportional hazards regression was conducted separately within each data source and results were pooled. Among 19,189 matched dabigatran and warfarin initiators (mean age: 68 years, 36 % female), as-treated follow-up (average of 5 months for dabigatran, 4 months for warfarin) identified 62 and 69 strokes, respectively (pooled HR = 0.77; 95 % CI = 0.54 to 1.09), and 354 and 395 major haemorrhages, respectively (HR = 0.75; 0.65 to 0.87). No meaningful heterogeneity was identified across subgroups, but numeric trends suggest more pronounced stroke prevention by dabigatran relative to warfarin among patients age 75+ (HR = 0.57; 0.33 to 0.97) or with < 6 months of use (HR = 0.51; 0.19 to 1.42). Major bleeds were reduced more by dabigatran among patients aged < 55 (HR = 0.51; 0.30 to 0.87) and with CHADS2 < 2 (HR = 0.58; 0.44 to 0.77). In conclusion, in routine care of patients with non-valvular atrial fibrillation, dabigatran treatment resulted in improved health outcomes compared with warfarin.

Randomized assessment of rapid endovascular treatment of ischemic stroke.

BACKGROUND: Among patients with a proximal vessel occlusion in the anterior circulation, 60 to 80% of patients die within 90 days after stroke onset or do not regain functional independence despite alteplase treatment. We evaluated rapid endovascular treatment in addition to standard care in patients with acute ischemic stroke with a small infarct core, a proximal intracranial arterial occlusion, and moderate-to-good collateral circulation. METHODS: We randomly assigned participants to receive standard care (control group) or standard care plus endovascular treatment with the use of available thrombectomy devices (intervention group). Patients with a proximal intracranial occlusion in the anterior circulation were included up to 12 hours after symptom onset. Patients with a large infarct core or poor collateral circulation on computed tomography (CT) and CT angiography were excluded. Workflow times were measured against predetermined targets. The primary outcome was the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. A proportional odds model was used to calculate the common odds ratio as a measure of the likelihood that the intervention would lead to lower scores on the modified Rankin scale than would control care (shift analysis). RESULTS: The trial was stopped early because of efficacy. At 22 centers worldwide, 316 participants were enrolled, of whom 238 received intravenous alteplase (120 in the intervention group and 118 in the control group). In the intervention group, the median time from study CT of the head to first reperfusion was 84 minutes. The rate of functional independence (90-day modified Rankin score of 0 to 2) was increased with the intervention (53.0%, vs. 29.3% in the control group; P<0.001). The primary outcome favored the intervention (common odds ratio, 2.6; 95% confidence interval, 1.7 to 3.8; P<0.001), and the intervention was associated with reduced mortality (10.4%, vs. 19.0% in the control group; P=0.04). Symptomatic intracerebral hemorrhage occurred in 3.6% of participants in intervention group and 2.7% of participants in control group (P=0.75). CONCLUSIONS: Among patients with acute ischemic stroke with a proximal vessel occlusion, a small infarct core, and moderate-to-good collateral circulation, rapid endovascular treatment improved functional outcomes and reduced mortality. (Funded by Covidien and others; ESCAPE ClinicalTrials.gov number, NCT01778335.).

Racial disparities in methamphetamine-associated intracerebral hemorrhage.

OBJECTIVE: To assess racial disparities in the prevalence of methamphetamine-associated intracerebral hemorrhage (Meth-ICH) among Native Hawaiians and other Pacific Islanders (NHOPI). METHODS: Prospectively collected data from an ongoing, multiethnic, single-center cohort study were analyzed. The inclusion criteria for the cohort study required that patients be adult (age 18 years or older) residents of Hawaii with nontraumatic spontaneous intracerebral hemorrhage (ICH). Patients of race other than white, Asian, or NHOPI were excluded. Determination of Meth-ICH was made prospectively by positive urine toxicology result and lack of other clinically suspected ICH etiology. Prevalence of Meth-ICH among NHOPI was compared with that of white and Asian patients. RESULTS: A total of 193 patients (white 16%, Asian 61%, NHOPI 23%) were analyzed. NHOPI were younger than white (54 ± 15 vs 68 ± 15 years, respectively, p = 0.0001) and Asian (vs 65 ± 16 years, p = 0.0001) patients. Overall, 25 (13%) Meth-ICHs (mean age: 49 ± 6 years, range: 33-56 years) were identified. NHOPI had higher prevalence of Meth-ICH compared with white (24% vs 0%, respectively, p = 0.003) and Asian (vs 12%, p = 0.046) patients. The observed age differences between the racial groups persisted even after excluding the Meth-ICH group (p < 0.01 for all comparison). CONCLUSIONS: NHOPI have higher prevalence of Meth-ICH compared with white and Asian patients. However, the age disparity is not entirely driven by methamphetamine abuse.

Does warfarin-related intracerebral haemorrhage lead to higher costs of management?

BACKGROUND AND PURPOSE: Warfarin-related intracerebral haemorrhage is associated with significant morbidity but long term treatment costs are unknown. Our study aimed to assess the cost of warfarin-related intracerebral haemorrhage. METHODS: We included all patients with intracerebral haemorrhage between July 2006 and December 2011 at a single centre. We collected data on anticoagulant use, baseline clinical variables, discharge destinations, modified Rankin Scale at discharge and in-hospital costings. First year costings were extracted from previous studies. Multiple linear regression for treatment cost was performed with stratified analysis to assess for effect modification. RESULTS: There were 694 intracerebral haemorrhage patients, with 108 (15.6%) previously on warfarin. Mean age (SD) of participants was 70.3 (13.6) and 58.5% were male. Patients on warfarin compared to those not on warfarin had significantly lower rates of discharge home (12.0% versus 18.9%, p=0.013). Overall total costs between groups were similar, $AUD 25,767 for warfarin-related intracerebral haemorrhage and $AUD 27,388 for non-warfarin intracerebral haemorrhage (p=0.353). Stratified analysis showed survivors of warfarin-related intracerebral haemorrhage had higher costs compared to those without warfarin ($AUD 33,419 versus $AUD 30,193, p<0.001) as well as increased length of stay (12 days versus 8 days, p<0.001). Inpatient mortality of patients on warfarin was associated with a shorter length of stay (p=0.001) and lower costs. CONCLUSION: Survival of initial haemorrhage on warfarin was associated with increased treatment cost and length of stay but this was discounted by higher rates and earlier nature of mortality in warfarinised patients.

Inhibition of serotonin reuptake by antidepressants and cerebral microbleeds in the general population.

BACKGROUND AND PURPOSE: Serotonin reuptake inhibiting antidepressants decrease platelet aggregation. This may cause an increased risk of intracerebral hemorrhage. However, the risk of subclinical microbleeds, which are highly prevalent in middle-aged and elderly people, is unknown. We studied whether serotonin reuptake inhibiting antidepressants increase the frequency of cerebral microbleeds and secondarily whether they lower the presence of ischemic vascular damage. METHODS: Within the population-based Rotterdam Study, information on antidepressant use was obtained from continuously monitored pharmacy records. Brain MRI was available in 4945 participants (55% women, mean age 64 years) between 2005 and 2011. We categorized antidepressants based on affinity for the serotonin transporter: high, intermediate, or low. Microbleeds (presence and location) and ischemic lesions (lacunes, white matter lesions) were rated on MRI. Logistic and linear regression, adjusted for age, sex, depressive symptoms, and cardiovascular risk were used to study the association of antidepressants with microbleeds and ischemic vascular lesions. RESULTS: Antidepressant use with strong serotonin reuptake inhibition was not associated with microbleed presence (odds ratio compared with nonuse, 1.03; confidence interval, 0.75-1.39) irrespective of microbleed location in the brain. Exclusion of antithrombotic users or persons with cortical infarcts did not change our results. Furthermore, serotonin reuptake inhibition was not related to ischemic vascular brain damage. CONCLUSIONS: In the general population, use of serotonin reuptake inhibiting antidepressants is not related to presence of cerebral microbleeds. This strengthens the idea that the platelet inhibitor effects of antidepressant drugs with affinity for serotonin are minimal and further supports the safety of selective serotonin reuptake inhibitors for nongastrointestinal bleedings.

[How to properly use warfarin and new anticoagulants].

Warfarin has unmet medical needs such as blood coagulation monitoring, limitation of vitamin K intake, and interaction with other drugs, while novel oral anticoagulants (NOACs) do not have such kind of unmet medical needs. Therefore, NOACs are recommended to busy patients or patients far from hospitals, or who do not want to limit vitamin K or use many other drugs concomitantly. NOACs are also recommended to patients with low time in therapeutic range (TTR). NOACs are also recommended to warfarin-naïve patients. Warfarin is recommended to patients with economical difficulty because it is much cheaper than NOACs. If needed, warfarin should be selected in patients with renal insufficiency or under hemodialysis because NOACs are contraindicated. New guidelines by the European Society of Cardiology recommend NOACs to low risk patients with CHA2DS2-VASc score 1, and also as the first line to those with CHA2DS2-VASc 2 or more. Finally, drug should be determined by patients' preference. Doctors should give adequate information helpful for patients' selection.

Hyperglycemia exacerbates intracerebral hemorrhage via the downregulation of aquaporin-4: temporal assessment with magnetic resonance imaging.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) is associated with high mortality and neurological deficits, and concurrent hyperglycemia usually worsens clinical outcomes. Aquaporin-4 (AQP-4) is important in cerebral water movement. Our aim was to investigate the role of AQP-4 in hyperglycemic ICH. METHODS: Hyperglycemia was induced by intraperitoneal injection of streptozotocin (STZ; 60 mg/kg) in adult Sprague-Dawley male rats. ICH was induced by stereotaxic infusion of collagenase/heparin into the right striatum. One set of rats was repeatedly monitored by MRI at 1, 4, and 7 days after ICH induction so as to acquire information on the formation of hematoma and edema. Another set of rats was killed and brains were examined for differences in the degree of hemorrhage and edema, water content, blood-brain barrier destruction, and AQP-4 expression. RESULTS: Hyperglycemia ICH rats exhibited increased brain water content, more severe blood-brain barrier destruction, and greater vasogenic edema as seen on diffusion-weighted MRI. Significant downregulation of AQP-4 was observed in STZ-treated rats after ICH as compared with non-STZ-treated rats. Apoptosis was greater on day 1 after ICH in STZ-treated rats. CONCLUSIONS: The expression of AQP-4 in the brain is downregulated in hyperglycemic rats as compared with normoglycemic rats after ICH. This change is accompanied by increased vasogenic brain edema and more severe blood-brain barrier destruction.

The bradykinesia assessment task: an automated method to measure forelimb speed in rodents.

Bradykinesia in upper extremities is associated with a wide variety of motor disorders; however, there are few tasks that assay forelimb movement speed in rodent models. This study describes the bradykinesia assessment task, a novel method to quantitatively measure forelimb speed in rats. Rats were trained to reach out through a narrow slot in the cage and rapidly press a lever twice within a predefined time window to receive a food reward. The task provides measurement of multiple parameters of forelimb function, including inter-press interval, number of presses per trial, and success rate. The bradykinesia assessment task represents a significant advancement in evaluating bradykinesia in rat models because it directly measures forelimb speed. The task is fully automated, so a single experimenter can test multiple animals simultaneously with typically in excess of 300 trials each per day, resulting in high statistical power. Several parameters of the task can be modified to adjust difficulty, which permits application to a broad spectrum of motor dysfunction models. Here we show that two distinct models of brain damage, ischemic lesions of primary motor cortex and hemorrhagic lesions of the dorsolateral striatum, cause impairment in all facets of performance measured by the task. The bradykinesia assessment task provides insight into bradykinesia and motor dysfunction in multiple disease models and may be useful in assessing therapies that aim to improve forelimb function following brain damage.

Low-dose intravenous recombinant tissue-type plasminogen activator therapy for patients with stroke outside European indications: Stroke Acute Management with Urgent Risk-factor Assessment and Improvement (SAMURAI) rtPA Registry.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the safety and efficacy of intravenous recombinant tissue-type plasminogen activator (0.6 mg/kg alteplase) within 3 hours of stroke onset in Japanese patients outside the indications in the European license. METHODS: Of the 600 patients who were treated with recombinant tissue-type plasminogen activator, 422 met the inclusion criteria of the European license (IN group) and 178 did not (OUT group). RESULTS: The OUT group was inversely associated with any intracerebral hemorrhage (adjusted OR, 0.50; 95% CI, 0.29-0.84), positively associated with an unfavorable outcome (2.48; 1.55-3.94) and mortality (2.04; 1.02-4.04), and not associated with symptomatic intracerebral hemorrhage (0.53; 0.11-1.79) or complete independency (0.65; 0.40-1.03) after multivariate adjustment. CONCLUSIONS: Functional and vital outcomes 3 months after low-dose recombinant tissue-type plasminogen activator in patients outside the European indications were less favorable compared with those included in the indications; however, the risk of intracerebral hemorrhage was not.