Chronic ischemic lesions and presence of patent foramen ovale in young adults with embolic stroke of undetermined source: Results of the young ESUS patient registry

BACKGROUND

Chronic ischemic lesions (CILs) are frequent findings in patients with acute ischemic stroke, but their phenotypes and relevance in young adults with embolic stroke of undetermined source (Y-ESUS) remains uncertain. We aimed to compare Y-ESUS patients with CIL to those without CIL and assessed the association of CIL and its phenotypes with the presence of patent foramen ovale (PFO).

METHODS

This prospective longitudinal, multicenter cohort study enrolled consecutive patients 50 years and younger with ESUS from October 2017 to October 2019 in 41 stroke research centers in 13 countries. Local investigators adjudicated presence and phenotypes of CIL on routine brain imaging (either magnetic resonance imaging (MRI) or computed tomography (CT)).

RESULTS

Overall, 535 patients were enrolled (mean age = 40.4 (standard deviation (SD) = 7.3) years, 238 (44%) female). CILs were present in 76/534 (14.2%) patients with a median count CIL count of 1.0 (interquartile range (IQR) = 1-2), 42/76 (55%) had at least one cortical phenotype and 38/76 (50%) at least one non-cortical phenotype. Y-ESUS with CIL were less often female (32% vs 47% in non-CIL Y-ESUS), were older (mean 43 vs 40 years), had more often hypertension (42% vs 19%), diabetes (17% vs 7%), and hyperlipidemia (34% vs 18%). CIL Y-ESUS were independently associated with lower stroke recurrence (relative risk (RR) = 0.17 (0.05-0.61)). In Y-ESUS with PFO, CILs were less frequent in probable pathogenic PFO than with probable non-pathogenic PFO (6.1% vs 30% p< 0.001).

CONCLUSION

One in seven Y-ESUS patients has additional CIL. CILs were associated with several vascular risk factors, lower probability of a pathogenic PFO, and lower stroke recurrence.

Study of Rivaroxaban for Cerebral Venous Thrombosis: A Randomized Controlled Feasibility Trial Comparing Anticoagulation With Rivaroxaban to Standard-of-Care in Symptomatic Cerebral Venous Thrombosis

BACKGROUND

Emerging data suggest that direct oral anticoagulants may be a suitable choice for anticoagulation for cerebral venous thrombosis (CVT). However, conducting high-quality trials in CVT is challenging as it is a rare disease with low rates of adverse outcomes such as major bleeding and functional dependence. To facilitate the design of future CVT trials, SECRET (Study of Rivaroxaban for Cerebral Venous Thrombosis) assessed (1) the feasibility of recruitment, (2) the safety of rivaroxaban compared with standard-of-care anticoagulation, and (3) patient-centered functional outcomes.

METHODS

This was a phase II, prospective, open-label blinded-end point 1:1 randomized trial conducted at 12 Canadian centers. Participants were aged ≥18 years, within 14 days of a new diagnosis of symptomatic CVT, and suitable for oral anticoagulation; they were randomized to receive rivaroxaban 20 mg daily, or standard-of-care anticoagulation (warfarin, target international normalized ratio, 2.0-3.0, or low-molecular-weight heparin) for 180 days, with optional extension up to 365 days. Primary outcomes were annual rate of recruitment (feasibility); and a composite of symptomatic intracranial hemorrhage, major extracranial hemorrhage, or mortality at 180 days (safety). Secondary outcomes included recurrent venous thromboembolism, recanalization, clinically relevant nonmajor bleeding, and functional and patient-reported outcomes (modified Rankin Scale, quality of life, headache, mood, fatigue, and cognition) at days 180 and 365.

RESULTS

Fifty-five participants were randomized. The rate of recruitment was 21.3 participants/year; 57% of eligible candidates consented. Median age was 48.0 years (interquartile range, 38.5-73.2); 66% were female. There was 1 primary event (symptomatic intracranial hemorrhage), 2 clinically relevant nonmajor bleeding events, and 1 recurrent CVT by day 180, all in the rivaroxaban group. All participants in both arms had at least partial recanalization by day 180. At enrollment, both groups on average reported reduced quality of life, low mood, fatigue, and headache with impaired cognitive performance. All metrics improved markedly by day 180.

CONCLUSIONS

Recruitment targets were reached, but many eligible participants declined randomization. There were numerically more bleeding events in patients taking rivaroxaban compared with control, but rates of bleeding and recurrent venous thromboembolism were low overall and in keeping with previous studies. Participants had symptoms affecting their well-being at enrollment but improved over time.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03178864.

Evaluating Rates of Recurrent Ischemic Stroke Among Young Adults With Embolic Stroke of Undetermined Source: The Young ESUS Longitudinal Cohort Study

Importance

Cryptogenic strokes constitute approximately 40% of ischemic strokes in young adults, and most meet criteria for the embolic stroke of undetermined source (ESUS). Two randomized clinical trials, NAVIGATE ESUS and RESPECT ESUS, showed a high rate of stroke recurrence in older adults with ESUS but the prognosis and prognostic factors among younger individuals with ESUS is uncertain.

Objective

To determine rates of and factors associated with recurrent ischemic stroke and death and new-onset atrial fibrillation (AF) among young adults.

Design, Setting, and Participants

This multicenter longitudinal cohort study with enrollment from October 2017 to October 2019 and a mean follow-up period of 12 months ending in October 2020 included 41 stroke research centers in 13 countries. Consecutive patients 50 years and younger with a diagnosis of ESUS were included. Of 576 screened, 535 participants were enrolled after 1 withdrew consent, 41 were found to be ineligible, and 2 were excluded for other reasons. The final follow-up visit was completed by 520 patients.

Main Outcomes and Measures

Recurrent ischemic stroke and/or death, recurrent ischemic stroke, and prevalence of patent foramen ovale (PFO).

Results

The mean (SD) age of participants was 40.4 (7.3) years, and 297 (56%) participants were male. The most frequent vascular risk factors were tobacco use (240 patients [45%]), hypertension (118 patients [22%]), and dyslipidemia (109 patients [20%]). PFO was detected in 177 participants (50%) who had transthoracic echocardiograms with bubble studies. Following initial ESUS, 468 participants (88%) were receiving antiplatelet therapy, and 52 (10%) received anticoagulation. The recurrent ischemic stroke and death rate was 2.19 per 100 patient-years, and the ischemic stroke recurrence rate was 1.9 per 100 patient-years. Of the recurrent strokes, 9 (64%) were ESUS, 2 (14%) were cardioembolic, and 3 (21%) were of other determined cause. AF was detected in 15 participants (2.8%; 95% CI, 1.6-4.6). In multivariate analysis, the following were associated with recurrent ischemic stroke: history of stroke or transient ischemic attack (hazard ratio, 5.3; 95% CI, 1.8-15), presence of diabetes (hazard ratio, 4.4; 95% CI, 1.5-13), and history of coronary artery disease (hazard ratio, 10; 95% CI, 4.8-22).

Conclusions and Relevance

In this large cohort of young adult patients with ESUS, there was a relatively low rate of subsequent ischemic stroke and a low frequency of new-onset AF. Most recurrent strokes also met the criteria for ESUS, suggesting the need for future studies to improve our understanding of the underlying stroke mechanism in this population.

Oral anticoagulation versus antiplatelet therapy for secondary stroke prevention in patients with embolic stroke of undetermined source: A systematic review and meta-analysis

Purpose

We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of direct oral anticoagulation (DOAC) compared with antiplatelet therapy for secondary stroke prevention in adult patients with embolic stroke of undetermined source (ESUS).

Method

We searched major databases (Embase, MEDLINE, CINAHL, CENTRAL, and Web of Science) for RCTs published until March 2021. The primary outcome was recurrent stroke, and the main safety outcomes were major bleeding and clinically relevant non-major bleeding (CRNB). We assessed risk of bias using the Cochrane Risk of Bias tool. We used a random-effects model to determine pooled risk ratios and 95% confidence intervals in the datasets and key subgroups.

Findings

Our search identified two RCTs, involving a total of 12,603 patients with ESUS. Anticoagulation with dabigatran or rivaroxaban compared with aspirin did not reduce the risk of recurrent stroke (RR, 0.96 [0.76–1.20]) or increase major bleeding (RR, 1.77 [0.80–3.89]) but significantly increased the composite of major or clinically relevant non-major bleeding (RR, 1.57 [1.26–1.97]). Prespecified subgroup analysis demonstrated consistent results according to age and sex. Additional post-hoc subgroup analyses demonstrated consistent results according to prior stroke and presence of a patent foramen ovale but suggested that DOACs reduced recurrent stroke in patients with an estimated glomerular filtration rate (eGFR) <50 and 50-80 ml/min but not in those with eGFR >80 ml/min (interaction P = 0.0234).

Discussion/conclusion

Direct oral anticoagulations are not more effective than aspirin in preventing stroke recurrence in patients with ESUS and increase bleeding.

Registration

PROSPERO ID: CRD42019138593

Rivaroxaban versus aspirin for prevention of covert brain infarcts in patients with embolic stroke of undetermined source: NAVIGATE ESUS MRI substudy

Background

Covert brain infarcts are associated with important neurological morbidity. Their incidence in patients with embolic stroke of undetermined source (ESUS) is unknown.

Aims

To assess the incidence of covert brain infarcts and cerebral microbleeds using MRI in a prospective substudy of the NAVIGATE ESUS randomized trial and to evaluate the effects of antithrombotic therapies.

Methods

At 87 sites in 15 countries, substudy participants were randomly assigned to receive rivaroxaban 15 mg daily or aspirin 100 mg daily and underwent brain MRI near randomization and after study termination. The primary outcome was incident brain infarct (clinical ischemic stroke or covert brain infarct). Brain infarcts and microbleeds were ascertained centrally by readers unaware of treatment. Treatment effects were estimated using logistic regression.

Results

Among the 718 substudy participants with interpretable, paired MRIs, the mean age was 67 years and 61% were men with a median of 52 days between the qualifying ischemic stroke and randomization and a median of seven days between randomization and baseline MRI. During the median (IQR) 11 (12) month interval between scans, clinical ischemic strokes occurred in 27 (4%) participants, while 60 (9%) of the remaining participants had an incident covert brain infarct detected by MRI. Assignment to rivaroxaban was not associated with reduction in the incidence of brain infarct (OR 0.77, 95% CI 0.49, 1.2) or of covert brain infarct among those without clinical stroke (OR 0.85, 95% CI 0.50, 1.4). New microbleeds were observed in 7% and did not differ among those assigned rivaroxaban vs. aspirin (HR 0.95, 95% CI 0.52–1.7).

Conclusions

Incident covert brain infarcts occurred in twice as many ESUS patients as a clinical ischemic stroke. Treatment with rivaroxaban compared with aspirin did not significantly reduce the incidence of covert brain infarcts or increase the incidence of microbleeds, but the confidence intervals for treatment effects were wide.

Registration:https://www.clinicaltrials.gov. Unique identifier: NCT 02313909

Frequency and Patterns of Brain Infarction in Patients With Embolic Stroke of Undetermined Source: NAVIGATE ESUS Trial

BACKGROUND AND PURPOSE

The spectrum of brain infarction in patients with embolic stroke of undetermined source (ESUS) has not been well characterized. Our objective was to define the frequency and pattern of brain infarcts detected by magnetic resonance imaging (MRI) among patients with recent ESUS participating in a clinical trial.

METHODS

In the NAVIGATE ESUS trial (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source), an MRI substudy was carried out at 87 sites in 15 countries. Participants underwent an MRI using a specified protocol near randomization. Images were interpreted centrally by those unaware of clinical characteristics.

RESULTS

Among the 918 substudy cohort participants, the mean age was 67 years and 60% were men with a median (interquartile range) of 64 (26-115) days between the qualifying ischemic stroke and MRI. On MRI, 855 (93%) had recent or chronic brain infarcts that were multiple in 646 (70%) and involved multiple arterial territories in 62% (401/646). Multiple brain infarcts were present in 68% (510/755) of those without a history of stroke or transient ischemic attack before the qualifying ESUS. Prior stroke/transient ischemic attack (P<0.001), modified Rankin Scale score >0 (P<0.001), and current tobacco use (P=0.01) were associated with multiple infarcts. Topographically, large and/or cortical infarcts were present in 89% (757/855) of patients with infarcts, while in 11% (98/855) infarcts were exclusively small and subcortical. Among those with multiple large and/or cortical infarcts, 57% (251/437) had one or more involving a different vascular territory from the qualifying ESUS.

CONCLUSIONS

Most patients with ESUS, including those without prior clinical stroke or transient ischemic attack, had multiple large and/or cortical brain infarcts detected by MRI, reflecting a substantial burden of clinical stroke and covert brain infarction. Infarcts most frequently involved multiple vascular territories.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02313909.

Association Between Low-Dose Rivaroxaban With or Without Aspirin and Ischemic Stroke Subtypes: A Secondary Analysis of the COMPASS Trial

Importance

The COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) randomized clinical trial was stopped early owing to the efficacy of low-dose rivaroxaban plus aspirin in preventing major cardiovascular events. The main reason for early trial termination was the effect of combination therapy on reducing ischemic strokes.

Objective

To analyze the association between low-dose rivaroxaban with or without aspirin and different ischemic stroke subtypes.

Design, Setting, and Participants

This is a secondary analysis of a multicenter, double-blind, randomized, placebo-controlled study that was performed in 33 countries from March 12, 2013, to May 10, 2016. Patients with stable atherosclerotic vascular disease were eligible, and a total of 27 395 participants were randomized and followed up to February 6, 2017. All first ischemic strokes and uncertain strokes that occurred by this date were adjudicated using TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. The analysis of ischemic stroke subtypes was evaluated using an intention-to-treat principle. Statistical analysis was performed from March 12, 2013, to February 6, 2017.

Interventions

Participants received rivaroxaban (2.5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban (5 mg twice a day), or aspirin (100 mg once a day).

Main Outcomes and Measures

Risk of ischemic stroke subtypes during follow-up.

Results

A total of 291 patients (66 women; mean [SD] age, 69.4 [8.5] years; 43 [14.8%] had a previous nonlacunar stroke) experienced an ischemic stroke. During the study, 49 patients (16.8%) received a diagnosis of atrial fibrillation. Applying TOAST criteria, 59 strokes (20.3%) were cardioembolic, 54 strokes (18.6%) were secondary to greater than 50% stenosis of the ipsilateral internal carotid artery, 42 strokes (14.4%) had a negative evaluation that met criteria for embolic stroke of undetermined source, and 21 strokes (7.2%) were secondary to small vessel disease. There were significantly fewer cardioembolic strokes (hazard ratio [HR], 0.40 [95% CI, 0.20-0.78]; P = .005) and embolic strokes of undetermined source (HR, 0.30 [95% CI, 0.12-0.74]; P = .006) in the combination therapy group compared with the aspirin-only group. A trend for reduction in strokes secondary to small vessel disease (HR, 0.36 [95% CI, 0.12-1.14]; P = .07) was not statistically significant. No significant difference was observed between the 2 groups in strokes secondary to greater than 50% carotid artery stenosis (HR, 0.85 [95% CI, 0.45-1.60]; P = .61). Rivaroxaban, 5 mg, twice daily showed a trend for reducing cardioembolic strokes compared with aspirin (HR, 0.57 [95% CI, 0.31-1.03]; P = .06) but was not associated with reducing other stroke subtypes.

Conclusions and Relevance

For patients with systemic atherosclerosis, low-dose rivaroxaban plus aspirin was associated with large, significant reductions in cardioembolic strokes and embolic strokes of undetermined source. However, these results of exploratory analysis need to be independently confirmed before influencing clinical practice.

Trial Registration

ClinicalTrials.gov identifier: NCT01776424.

Oral factor Xa inhibitors and risk of subdural hematoma

Objective

Subdural hematomas (SDHs) are an uncommon, but important, complication of anticoagulation therapy. We hypothesized that the risks of SDH would be similar during treatment with oral factor Xa inhibitors compared with aspirin.

Methods

We assessed the frequency and the effects of antithrombotic treatments on SDHs in the recent international Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) randomized trial comparing aspirin 100 mg daily, rivaroxaban 5 mg twice daily, and rivaroxaban 2.5 mg twice daily plus aspirin. A systematic review/meta-analysis of randomized trials comparing oral factor Xa inhibitors vs aspirin on SDH risk was undertaken.

Results

Among 27,395 COMPASS participants, 28 patients with SDHs were identified (mean age 72 years). SDH-associated mortality was 7%. Incidence was 0.06 per 100 patient-years (11 SDH/17,492 years observation) during the mean 23-month follow-up among aspirin-assigned patients and did not differ significantly between treatments. Three additional randomized controlled trials including 16,177 participants reported a total of 14 SDHs with an incidence ranging from 0.06 to 0.1 per 100 patient-years. Factor Xa inhibitor use was not associated with an increased risk of SDH compared to aspirin (odds ratio, 0.97; 95% confidence interval, 0.52–1.81; I2 = 0%).

Conclusion

The frequency of SDH was similar in all 3 treatment arms of the COMPASS trial. The COMPASS trial results markedly increase the available evidence from randomized comparisons of oral factor Xa inhibitors with aspirin regarding SDH. From available, albeit limited, evidence from 4 randomized trials, therapeutic dosages of factor Xa inhibitors do not appear to increase the risk of SDH compared with aspirin.

Clinical trial identifier number:

NCT01776424.

Rivaroxaban versus aspirin for secondary prevention of ischaemic stroke in patients with cancer: a subgroup analysis of the NAVIGATE ESUS randomized trial

BACKGROUND AND PURPOSE

Cancer is a frequent finding in ischaemic stroke patients. The frequency of cancer amongst participants in the NAVIGATE ESUS randomized trial and the distribution of outcome events during treatment with aspirin and rivaroxaban were investigated.

METHODS

Trial participation required a recent embolic stroke of undetermined source. Patients' history of cancer was recorded at the time of study entry. During a mean follow-up of 11 months, the effects of aspirin and rivaroxaban treatment on recurrent ischaemic stroke, major bleeding and all-cause mortality were compared between patients with cancer and patients without cancer.

RESULTS

Amongst 7213 randomized patients, 543 (7.5%) had cancer. Of all patients, 3609 were randomized to rivaroxaban [254 (7.0%) with cancer] and 3604 patients to aspirin [289 (8.0%) with cancer]. The annual rate of recurrent ischaemic stroke was 4.5% in non-cancer patients in the rivaroxaban arm and 4.6% in the aspirin arm [hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.78-1.24]. In cancer patients, the rate of recurrent ischaemic stroke was 7.7% in the rivaroxaban arm and 5.4% in the aspirin arm (HR 1.43, 95% CI 0.71-2.87). Amongst cancer patients, the annual rate of major bleeds was non-significantly higher for rivaroxaban than aspirin (2.9% vs. 1.1%; HR 2.57, 95% CI 0.67-9.96; P for interaction 0.95). All-cause mortality was similar in both groups.

CONCLUSIONS

Our exploratory analyses show that patients with embolic stroke of undetermined source and a history of cancer had similar rates of recurrent ischaemic strokes and all-cause mortality during aspirin and rivaroxaban treatments and that aspirin appeared safer than rivaroxaban in cancer patients regarding major bleeds. www.clinicaltrials.gov (NCT02313909).

Abstract TP217: Longitudinal Study of Young Patients With Embolic Stroke of Undetermined Source (ESUS)

Introduction: Stroke in young adults is not rare, and can have a devastating, lasting impact. Up to 20% of patients with Embolic Stroke of Undetermined Source (ESUS) are under 50 years of age; thus, determining potential causes and outcomes in this younger cohort may significantly impact clinical practice. We aim to describe clinical, laboratory and imaging characteristics of patients between 21 and 50 years of age with ESUS; determine rates of new-onset atrial fibrillation; and investigate predictors of recurrent stroke in this unique population.

Methods: This is an ongoing multi-center, international registry, which plans to prospectively enroll 500 patients between the ages of 21-50 years with ESUS 1 within 60 days. Clinical, laboratory and imaging data are documented at enrollment. Patients will be followed prospectively at 6, 12 and 18 months post-stroke via telephone interview to determine treatment and outcomes. End of enrollment is anticipated in mid-2019.

Results: Majority of patients are male (63.7%), and males had a higher median age at stroke than females (43 versus 41 years, range 21-50). Figure 1 shows the geographical breakdown of recruited patients. Intravenous recombinant tissue plasminogen activator (tPA) was given to 26/146 (17.8%). Median modified Rankin Score at time of stroke was 1.0 (range 0-5.0). Table 1 contains baseline characteristics and diagnostic workup of 146/187 patients enrolled thus far.

Conclusion: Demographics, stroke risk factors and recurrence rates may differ for younger patients with ESUS; thus, findings of this study could potentially shape clinical practice and ultimately improve outcomes for this at-risk population.

Abstract 21: Effect of Oral Factor Xa Inhibitors on the Risk of Subdural Hematoma: COMPASS trial Results and Systematic Review

Background: Subdural Hematomas (SDHs) are an uncommon but important complication of anticoagulation therapy. Data on SDHs has been underreported from major randomized trials testing novel oral anticoagulants, and the risk of SDHs relative to aspirin has not been defined.

Methods: We assessed the frequency and the effects of antithrombotic treatments on SDHs in the recent international COMPASS randomized trial comparing aspirin 100mg daily, Rivaroxaban 5mg twice daily, and Rivaroxaban 2.5mg twice daily plus aspirin. A systematic literature review of randomized trials comparing factor Xa inhibitors versus aspirin on SDH risk was undertaken.

Results: A total of 28 SDHs among 27,395 COMPASS participants were identified. The incidence was 0.04 -0.06 per 100 patient-years during the mean 23-month follow-up. The frequency of SDH according to assigned antithrombotic therapy was 11 for Aspirin, 7 for Rivaroxaban and 10 for combined antithrombotic therapy. The rates of SDHs did not differ per treatment groups. Three RCTs comparing Factor Xa inhibitors versus Aspirin and reporting data on SDHs were identified. They involved 16,177 participants (mean age 65) with a total of 11 SDHs. The incidence of SDHs ranged from 0.06 to 0.1 per 100-patient-years (HR 1.51 in one study).

Conclusions: The frequency of SDH was similar in all three treatment arms of the COMPASS trial. Based on available evidence from four randomized trials, therapeutic dosages of factor Xa inhibitors do not appear to increase the risk of SDH compared to aspirin. The COMPASS trial results triple the available evidence from randomized comparisons of oral factor Xa inhibitors with aspirin.

Stroke type and severity in patients with subclinical atrial fibrillation: An analysis from the Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial (ASSERT)

BACKGROUND

The Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the Atrial Fibrillation Reduction Atrial Pacing Trial (ASSERT) demonstrated that subclinical atrial fibrillation (SCAF) was associated with a 2.5-fold increased risk of stroke. However, the absolute stroke rate was only 1.7% per year and fewer than 20% patients with stroke had SCAF in the preceding 30 days. This raises the possibility that SCAF is merely a risk marker for stroke rather than the cause. Systematic characterization of stroke subtypes among patients with SCAF would help clarify this issue.

METHODS

All ischemic strokes that occurred in the ASSERT trial were blindly adjudicated by stroke neurologists, classified as cortical versus subcortical, and subtyped using modified TOAST criteria. Stroke severity was measured using the modified Rankin Score.

RESULTS

Of the 44 participants who had an ischemic stroke, 14 had SCAF before stroke. Among patients with SCAF who had stroke, 57% of strokes (n = 8) were judged to be cardioembolic, 36% to be lacunar (n = 5), and 7% (n = 1) to be large artery disease. However, of 5 patients who had SCAF detected within 30 days before their index stroke, 4 patients had a cardioembolic stroke. The average duration of SCAF in these 4 patients was 6.0 ± 6.1 h/d. The modified Rankin score at 30 days was similar between patients with (2.7 ± 2.3) and without SCAF (2.3 ± 2.0; P = .68).

CONCLUSIONS

In patients with SCAF and stroke, SCAF seems probably causal in many cases; however, in more than 40%, it seems to be acting only as a risk marker.

Frequency and features of embolic stroke of undetermined source in young adults

INTRODUCTION

The sources of emboli in those with embolic stroke of undetermined source may differ in old and young. We assessed the frequency, features and potential embolic sources of younger vs. older embolic stroke of undetermined source patients in the embolic stroke of undetermined source Global Registry.

PATIENTS AND METHODS

Cross-sectional study of consecutive patients over age 18 years, with recent ischaemic strokes at 19 centres conducted in 2013-2014. Characteristics of embolic stroke of undetermined source patients who aged ≤50 years were analysed and compared with embolic stroke of undetermined source patients who aged >50 years.

RESULTS

Among 2144 patients with ischaemic stroke, 323 (15.1%, 95% confidence interval: 13.6-16.7%) were ≤50 years old and, 1821 >50 years. 24% (n = 78) of young vs. 15% (n = 273) of older patients met embolic stroke of undetermined source criteria. The mean age of young embolic stroke of undetermined source patients was 40 years (standard deviation +/-9), 33% were women and the most prevalent vascular risk factor was hypertension (38%). Conventional vascular risk factors were less frequent in younger embolic stroke of undetermined source patients. Fewer young embolic stroke of undetermined source patients (63%) had potential minor risk embolic sources identified vs. older embolic stroke of undetermined source patients (77%) (p = 0.02). Stroke severity on admission was similar in younger vs. older patients (National Institute of Health Stroke Scale (NIHSS) 3 vs. 4, p = 0.06).

DISCUSSION

Young embolic stroke of undetermined source patients comprise an important subset of ischaemic stroke patients around the world. Severity of stroke on admission and 30-day mortality rates are similar among young and older patients. However, there are important differences between younger vs. older embolic stroke of undetermined source patients with respect to risk factors, and potential embolic sources that could affect response to anticoagulants vs. antiplatelet therapies.

CONCLUSION

This study provides a benchmark for the global frequency and characteristics of young embolic stroke of undetermined source patients and shows consistent high frequency of embolic stroke of undetermined source in young adults.

Predictors of Mortality in Patients With Atrial Fibrillation (from the Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events [ACTIVE A])

The mortality rate of most patients with atrial fibrillation (AF) exceeds the stroke rate, but predictors of mortality have not been well defined. The Atrial Fibrillation Clopidogrel Trial With Irbesartan for Prevention of Vascular Events (ACTIVE A) recruited patients with AF who were unsuitable to receive vitamin K-antagonists and were randomized to aspirin alone versus aspirin plus clopidogrel. We investigated independent predictors of all-cause mortality by multivariable Cox regression analysis and explored interactions with assigned antiplatelet therapy. Of the 7,554 patients enrolled with a mean age of 71 years, 1,687 (22%) patients died during the median follow-up of 3.7 years (annualized mortality rate 6.4%/year). Assignment to dual antiplatelet therapy had no effect on mortality (hazard ratio [HR] 0.99, 95% confidence interval [CI] 0.90 to 1.1) or on vascular and nonvascular death. Independent predictors of all-cause mortality were advancing age, lower body mass index (HR 1.4 < 25 kg/m², 95% CI 1.3 to 1.6), diabetes mellitus, Latin American ethnicity (HR 1.4, 95% CI 1.1 to 1.6), previous stroke or transient ischemic attack, peripheral artery disease, increased resting heart rate (HR 1.3, 95% CI 1.1 to 1.4 per 30 bpm), lower diastolic blood pressure, coronary artery disease, heart failure, left ventricular systolic dysfunction, hemoglobin level of <13 mg/dl, and reduced estimated glomerular filtration rate. In conclusion, in this large clinical trial cohort of patients with AF, treatment with clopidogrel plus aspirin versus aspirin monotherapy did not affect all-cause mortality, vascular death, or nonvascular death. Novel independent predictors of increased mortality included lower diastolic blood pressure and Latin American ethnicity.

Embolic Stroke of Undetermined Source: A Systematic Review and Clinical Update

BACKGROUND AND PURPOSE

Embolic stroke of undetermined source (ESUS) designates patients with nonlacunar cryptogenic ischemic strokes in whom embolism is the likely stroke mechanism. It has been hypothesized that anticoagulation is more efficacious than antiplatelet therapy for secondary stroke prevention in ESUS patients. We review available information about ESUS.

METHODS

Systematic literature review to assess the frequency of ESUS, patient features, and prognosis using PubMed from 2014 to present, unrestricted by language.

RESULTS

On the basis of 9 studies, the reported frequency of ESUS ranged from 9% to 25% of ischemic strokes, averaging 17%. From 8 studies involving 2045 ESUS patients, the mean age was 65 years and 42% were women; the mean NIH stroke score was 5 at stroke onset (4 studies, 1772 ESUS patients). Most (86%) ESUS patients were treated with antiplatelet therapy during follow-up, with the annualized recurrent stroke rate averaging 4.5% per year during a mean follow-up of 2.7 years (5 studies, 1605 ESUS patients).

CONCLUSIONS

ESUS comprises about 1 ischemic stroke in 6. Patients with ischemic stroke meeting criteria for ESUS were relatively young compared with other ischemic stroke subtypes and had, on average, minor strokes, consistent with small emboli. Retrospective methods of available studies limit confidence in stroke recurrence rates but support a substantial (>4% per year) rate of stroke recurrence during (mostly) antiplatelet therapy. There is an important need to define better antithrombotic prophylaxis for this frequently occurring subtype of ischemic stroke.

Global Survey of the Frequency of Atrial Fibrillation–Associated Stroke

Background and Purpose—

Atrial fibrillation (AF) is increasingly recognized as the single most important cause of disabling ischemic stroke in the elderly. We undertook an international survey to characterize the frequency of AF-associated stroke, methods of AF detection, and patient features.

Methods—

Consecutive patients hospitalized for ischemic stroke in 2013 to 2014 were surveyed from 19 stroke research centers in 19 different countries. Data were analyzed by global regions and World Bank income levels.

Results—

Of 2144 patients with ischemic stroke, 590 (28%; 95% confidence interval, 25.6–29.5) had AF-associated stroke, with highest frequencies in North America (35%) and Europe (33%) and lowest in Latin America (17%). Most had a history of AF before stroke (15%) or newly detected AF on electrocardiography (10%); only 2% of patients with ischemic stroke had unsuspected AF detected by poststroke cardiac rhythm monitoring. The mean age and 30-day mortality rate of patients with AF-associated stroke (75 years; SD, 11.5 years; 10%; 95% confidence interval, 7.6–12.6, respectively) were substantially higher than those of patients without AF (64 years; SD, 15.58 years; 4%; 95% confidence interval, 3.3–5.4; P <0.001 for both comparisons). There was a strong positive correlation between the mean age and the frequency of AF ( r =0.76; P =0.0002).

Conclusions—

This cross-sectional global sample of patients with recent ischemic stroke shows a substantial frequency of AF-associated stroke throughout the world in proportion to the mean age of the stroke population. Most AF is identified by history or electrocardiography; the yield of conventional short-duration cardiac rhythm monitoring is relatively low. Patients with AF-associated stroke were typically elderly (>75 years old) and more often women.

Age disparity in diagnostic evaluation of stroke patients: Embolic Stroke of Undetermined Source Global Registry Project

Introduction: Incomplete evaluation of stroke patients may result in an unclear diagnosis. Our objective was to determine if older stroke patients more often undergo incomplete diagnostic evaluations versus younger patients in an international cohort. Patients and methods: The Embolic Stroke of Undetermined Source Global Registry was a retrospective cohort of consecutive stroke patients evaluated at 19 stroke centers in 19 countries. Diagnostic evaluation was considered as complete if the patient had, at a minimum, brain computed tomography or magnetic resonance imaging with evidence of infarction, extracranial and intracranial vascular imaging, electrocardiography, ≥24 h of cardiac rhythm monitoring, and echocardiography. Patients were diagnosed with Embolic Stroke of Undetermined Source if brain imaging confirmed a nonlacunar infarction and no stroke etiology was determined after complete evaluation. Completeness of evaluation was compared between patients ≥75 versus <75 years old. Results: The registry included 2132 patients with recent ischemic stroke during 2013-2014, of which 349 were diagnosed with Embolic Stroke of Undetermined Source. Embolic Stroke of Undetermined Source patients ≥75 years were less likely to undergo brain magnetic resonance imaging (74% versus 89%, p = 0.001), transesophageal echocardiography (22% versus 39%, p = 0.005), and combination transthoracic and transesophageal echocardiography (16% versus 32%, p = 0.005) compared with Embolic Stroke of Undetermined Source patients <75 years. Discussion: Our study has identified an international age disparity in fundamental diagnostic testing for older patients with stroke of unknown etiology. Some testing biases were affected by geographic location (e.g., brain MRI was less frequently used in European ESUS patients), whereas other testing was implemented less frequently in the elderly regardless of location (e.g., transesophageal echocardiogram). Conclusion: Older patients in this international cohort had less sophisticated diagnostic testing for stroke, despite advanced age being well established as an independent risk factor for recurrent stroke. This was a global problem and further investigations are warranted to explore the cause.

Embolic strokes of undetermined source: Prevalence and patient features in the ESUS Global Registry

Background

Recent evidence supports that most non-lacunar cryptogenic strokes are embolic. Accordingly, these strokes have been designated as embolic strokes of undetermined source (ESUS).

Aims

We undertook an international survey to characterize the frequency and clinical features of ESUS patients across global regions.

Methods

Consecutive patients hospitalized for ischemic stroke were retrospectively surveyed from 19 stroke research centers in 19 different countries to collect patients meeting criteria for ESUS.

Results

Of 2144 patients with recent ischemic stroke, 351 (16%, 95% CI 15% to 18%) met ESUS criteria, similar across global regions (range 16% to 21%), and an additional 308 (14%) patients had incomplete evaluation required for ESUS diagnosis. The mean age of ESUS patients (62 years; SD = 15) was significantly lower than the 1793 non-ESUS ischemic stroke patients (68 years, p ≤ 0.001). Excluding patients with atrial fibrillation ( n = 590, mean age = 75 years), the mean age of the remaining 1203 non-ESUS ischemic stroke patients was 64 years ( p = 0.02 vs. ESUS patients). Among ESUS patients, hypertension, diabetes, and prior stroke were present in 64%, 25%, and 17%, respectively. Median NIHSS score was 4 (interquartile range 2–8). At discharge, 90% of ESUS patients received antiplatelet therapy and 7% received anticoagulation.

Conclusions

This cross-sectional global sample of patients with recent ischemic stroke shows that one-sixth met criteria for ESUS, with additional ESUS patients likely among those with incomplete diagnostic investigation. ESUS patients were relatively young with mild strokes. Antiplatelet therapy was the standard antithrombotic therapy for secondary stroke prevention in all global regions.

Abstract TP222: Frequency of Intracranial Arterial Imaging and its Yield in Consecutive Patients with Non-lacunar Cryptogenic Ischemic Stroke: ESUS Global Registry

Background: Atherosclerotic stenosis of large IC arteries is an important cause of stroke. The prevalence of ICS in stroke population differs by ethnicity.We report the frequency of ICS among a global sample of patients with non-lacunar cryptogenic ischemic stroke (NLCIS) who did not have another identifiable cause for stroke i.e. cardioembolic, extracranial LAD, or other specific causes.

Hypothesis: We hypothesized that the prevalence rates of ICS will differ according to global regions.

Methods: Consecutive patients with recent ischemic stroke were retrospectively surveyed at 19 stroke centers in 19 countries to identify the frequency of IC imaging and its yield. Countries were grouped by World Bank regions. ICS was considered to be significant if there was >50% stenosis in the arteries proximal to the index stroke evidenced by MRA, CTA or TCD.

Results: We identified a total of 2145 consecutive ischemic stroke patients among which 475 had NLCIS. IC arterial imaging was carried-out,on average, in 87% of patients. Of these 414 patients, 15% had stenosis proximal to the area of brain ischemia. The frequency of ICS among NLCIS patients was highest in East Asia (27%) and lowest in Pacific (4%). Patients with ICS in Latin America were significantly younger when compared to other 4 regions.

Conclusion: IC arterial imaging is carried out in majority of stroke centers in patients with NLCIS, among whom the fraction of IS associated with ICS is substantial throughout the world, averaging about 15%. MRA / CTA had a higher yield than TCD. On average these patients have traditional vascular risk factors except for Latin American patients who are significantly younger with no vascular risk factors.

What's new in stroke? Phase III randomized clinical trials of 2012-2014

BACKGROUND

Randomized clinical trials provide the most reliable evidence to guide the management of stroke and threatened stroke and reflect the interests of the stroke research community. The spectrum of phase III randomized clinical trials in stroke has not been previously characterized.

METHODS

Phase III stroke randomized clinical trials published between 2012 and 2014 were identified by search of the Cochrane Central Register of Controlled Trials supplemented by recent publications known to the co-authors.

RESULTS

Thirty-four randomized clinical trials were included involving 85 770 participants: 20 acute stroke randomized clinical trials (32 590 patients), 11 stroke prevention randomized clinical trials (28 964 patients), and three randomized clinical trials in which stroke was a major component of a composite primary outcome involving nonstroke patients (24 216 patients). Twenty-two (65%) trials were international, and eight (24%) were industry sponsored. Drugs were tested in 21 (62%) randomized clinical trials, with devices (n = 9), surgery (n = 3), and diet (n = 1) in the remainder. Thirteen (38%) randomized clinical trials were stopped early: seven for futility, three for efficacy, two for harm, and one for budget/administrative reasons. Overall, the results of seven (21%) randomized clinical trials were positive, five (15%) equivocal, 18 (53%) negative, and four (12%) inconclusive. Considering positive and definitively negative randomized clinical trials testing currently used interventions, 11 (32%) randomized clinical trials have direct implications for clinical management.

CONCLUSIONS

The diversity of interventions, high-quality, and worldwide origins of recently published phase III randomized clinical trials reflects a vibrant international stroke research community. The current generation of stroke randomized clinical trials provides important guidance for stroke prevention and acute stroke care.

Effect of season and stage of lactation on plasma insulin and glucose following glucose injection in Holstein cattle

Changes in plasma glucose and insulin concentrations following glucose injection in dairy cows (six per stage of lactation per season) were characterized during early, middle, and late lactation in winter, spring, and summer. Blood samples were collected 60, 45, 30, 20, 15, 10, 5, and 0 min (period 1) before glucose injection (.1 g/kg body weight) and at 5, 10, 15, 20, 30, 45, and 60 min (period 2) after injection. Plasma insulin concentrations were affected by season, period, season by period interaction, and time within period. Plasma glucose was affected by period, time within period, and stage of lactation by period interaction. Insulin was lowest in summer. Magnitude of insulin response to glucose was highest in spring. Both plasma glucose and insulin increased significantly 5 min following glucose injection. Peak glucose concentrations increased with advancing lactation. Results indicate alterations in glucose metabolism as well as changes in insulin sensitivity to glucose in various seasons and stages of lactation.

Utilization of primary health care workers for early detection of oral cancer and precancer cases in Sri Lanka

Oral cancer presents a serious public health problem in south-east Asian countries. In Sri Lanka and India 35-40% of all cancers are reported to be oral cancers, which are curable if detected in the early stages. The idea that, in developing countries, one of the few practical approaches to early detection of these cases could be through the utilization of primary health care workers was tested in a field study carried out in Sri Lanka. In a control area the subjects with oral lesions were identified by medical/dental officers. In the study, 34 primary health care workers were able, alongside their routine duties, to examine the oral cavity of 28 295 subjects during a period of 52 weeks; 1220 subjects were detected with lesions needing re-examination. The performance of these primary health care workers was very satisfactory in terms of the number of cases detected and the accuracy of their diagnoses, which were verified by re-examination at a specially designated referral centre. The clinical diagnoses of the three categories of lesions detected were as follows: stage 1 lesions for observation (homogeneous or ulcerated leukoplakia), stage 2 lesions for investigation (speckled leukoplakia, erythroplakia, or submucous fibrosis), and stage 3 lesions for treatment (cancer). There was 89% correspondence between the stage 1-3 diagnoses by the health workers and the clinical diagnoses made at the referral centre. However, compliance by patients was low because only 50% of the cases detected in the field attended the referral centre. The cost-effectiveness of this approach to cancer control has been demonstrated.