Embolic strokes of undetermined source: a clinical consensus statement of the ESC Council on Stroke, the European Association of Cardiovascular Imaging and the European Heart Rhythm Association of the ESC.

One in six ischaemic stroke patients has an embolic stroke of undetermined source (ESUS), defined as a stroke with unclear aetiology despite recommended diagnostic evaluation. The overall cardiovascular risk of ESUS is high and it is important to optimize strategies to prevent recurrent stroke and other cardiovascular events. The aim of clinicians when confronted with a patient not only with ESUS but also with any other medical condition of unclear aetiology is to identify the actual cause amongst a list of potential differential diagnoses, in order to optimize secondary prevention. However, specifically in ESUS, this may be challenging as multiple potential thromboembolic sources frequently coexist. Also, it can be delusively reassuring because despite the implementation of specific treatments for the individual pathology presumed to be the actual thromboembolic source, patients can still be vulnerable to stroke and other cardiovascular events caused by other pathologies already identified during the index diagnostic evaluation but whose thromboembolic potential was underestimated. Therefore, rather than trying to presume which particular mechanism is the actual embolic source in an ESUS patient, it is important to assess the overall thromboembolic risk of the patient through synthesis of the individual risks linked to all pathologies present, regardless if presumed causally associated or not. In this paper, a multi-disciplinary panel of clinicians/researchers from various backgrounds of expertise and specialties (cardiology, internal medicine, neurology, radiology and vascular surgery) proposes a comprehensive multi-dimensional assessment of the overall thromboembolic risk in ESUS patients through the composition of individual risks associated with all prevalent pathologies.

Prevalence and Factors Associated with Carotid Stenosis in Acute Ischemic Stroke Patients with Atrial Fibrillation.

INTRODUCTION: Among stroke patients with atrial fibrillation (AF), it is not uncommon to identify carotid atherosclerosis. This study aimed to estimate the prevalence of, and factors associated with, carotid atherosclerosis among patients with AF and acute ischemic stroke. PATIENTS AND METHODS: Prospectively collected data from consecutive patients with anterior ischemic stroke and AF who underwent carotid imaging from 10 stroke registries were categorized retrospectively according to the degree of stenosis in: no atherosclerosis, stenosis <50%, stenosis ≥50%, and occlusion. Logistic regression analysis was used to identify factors associated with ipsilateral carotid atherosclerosis. RESULTS: Among 2,955 patients with ischemic stroke and AF, carotid atherosclerosis was evident in 1,022 (34.6%) patients, while carotid stenosis ≥50% and occlusion were identified in 204 (6.9%) and 168 (5.7%) patients, respectively. Ipsilateral carotid stenosis ≥50% or occlusion was associated with higher age (OR: 1.15, 95% CI: 1.01-1.32, per decade), previous ischemic stroke or transient ischemic attack (OR: 1.70, 95% CI: 1.29-2.25), peripheral artery disease (OR: 1.85, 95% CI: 1.23-2.78), coronary artery disease (OR: 1.53, 95% CI: 1.16-2.04), and statin treatment on admission (OR: 1.30, 95% CI: 1.01-1.67). Patients with lacunar stroke had a lower likelihood of stenosis ≥50% or occlusion (OR: 0.29, 95% CI: 0.13-0.68). Compared to the absence of atherosclerotic disease, atherosclerosis in one and two arterial beds was associated with the identification of ipsilateral carotid stenosis (OR: 1.49, 95% CI: 1.22-2.98 and OR: 3.18, 95% CI: 1.85-5.49, respectively). CONCLUSION: Among acute ischemic stroke patients with AF, 1 out of 3 had ipsilateral carotid atherosclerosis, and 1 out of 8 had ipsilateral carotid stenosis ≥50% or occlusion. Atherosclerosis in two arterial beds was the most important predictor for the identification of ipsilateral carotid stenosis. Among ischemic stroke patients with AF, carotid atherosclerosis is common, while carotid imaging should not be overlooked, especially in those with coronary or/and peripheral artery disease.

Incidence of Stroke in Randomized Trials of COVID-19 Therapeutics: A Systematic Review and Meta-Analysis.

BACKGROUND: COVID-19 has been frequently associated with an increased risk of thrombotic complications. There have also been reports of an increased likelihood of stroke, although its true incidence in patients with COVID-19 is currently unknown. METHODS: Electronic databases PubMed and Scopus were searched from inception up to July 30, 2021 to identify randomized controlled studies in patients with confirmed COVID-19 undergoing one or more interventions. Studies were screened for eligibility using a predefined inclusion criterion and selected using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A random-effects model meta-analysis was conducted, and heterogeneity was assessed using I-squared test. RESULTS: Out of 3960 potentially eligible articles, 77 randomized studies (38 732 patients) were included. Mean age of the study population was 55±9.3 years. Females constituted 38% of the study population and mean duration of follow-up after study enrollment was 23±12.9 days. Cumulative incidence of stroke in the overall study population was 0.001 (95% CI, 0.001-0.002) with a total of 65 events in 38 732 patients, corresponding to an absolute incidence of 0.168%. Incidence of stroke in the inpatient population was 0.001 (95% CI, 0.001-0.002; 65 events in 37 069 patients), corresponding to an absolute incidence of 0.175%. No strokes were observed in the outpatient setting. CONCLUSIONS: The overall incidence of stroke in patients with COVID-19 appears to be lower than that reported in previous observational reports.

Late-onset hematological complications post COVID-19: An emerging medical problem for the hematologist.

Coronavirus disease 19 (COVID-19) is considered a multisystemic disease. Several studies have reported persistent symptoms or late-onset complications after acute COVID-19, including post-COVID-19 hematological disorders. COVID-19-induced coagulopathy, an immunothrombotic state, has been linked to thromboembolic and hemorrhagic events. Late-onset thrombocytopenia related to immune system dysregulation has also been reported as a rare manifestation post COVID-19. Close monitoring of laboratory dynamics is considered essential to identify timely abnormal values that need further investigation, providing supportive care whenever indicated. The role of hematologists is essential in terms of the multidisciplinary approach of long COVID-19. This review summarizes all the available evidence on post-acute COVID-19 hematological complications.

Ischemic stroke in oral anticoagulated patients with atrial fibrillation.

BACKGROUND: Ischemic strokes in orally anticoagulated patients pose challenges for acute management and secondary prevention but the characteristics of these strokes are poorly understood. We examined the clinical and imaging features, the presumed underlying etiology and the subsequent antithrombotic management. METHODS: We analyzed a consecutive series of patients enrolled into the EIDASAF study, a single center, observational study of ischemic stroke patients with a diagnosis atrial fibrillation (AF) prior to the index event who had been admitted to the Hyperacute Stroke Unit of Imperial College London between 2010 and 2017. We compared patients with oral anticoagulation therapy prior admission (OACprior ) with those without anticoagulation (OACnaive ). Brain imaging was analyzed centrally. RESULTS: 763 patients were included in the analysis. 481 (63%) were OACnaive while 282 (37%) were OACprior . Patients with OACprior were younger, more often had a previous history of stroke or transient ischemic attack (TIA), and more often suffered from hypertension and diabetes. In OACnaive, patients, large and deep middle cerebral artery infarcts occurred more often than in OACprior patients. The groups differed significantly in the distribution of competing etiologies underlying their stroke. At discharge, OACprior more frequently were (re)-anticoagulated compared to OACnaive patients. Within the OACprior group, patients with recurrent strokes did not differ from those with a first stroke regarding clinical characteristics and pattern of cerebral infarction but they were less frequently anticoagulated. CONCLUSIONS: Ischemic strokes on OAC represent a significant proportion of AF-related strokes. There is an unmet need to better understand the causes underlying these strokes and to optimize the medical management.

Comparative kinetics of SARS-CoV-2 anti-spike protein RBD IgGs and neutralizing antibodies in convalescent and naïve recipients of the BNT162b2 mRNA vaccine versus COVID-19 patients.

BACKGROUND: Coronavirus SARS-CoV-2, the causative agent of COVID-19, has caused a still evolving global pandemic. Given the worldwide vaccination campaign, the understanding of the vaccine-induced versus COVID-19-induced immunity will contribute to adjusting vaccine dosing strategies and speeding-up vaccination efforts. METHODS: Anti-spike-RBD IgGs and neutralizing antibodies (NAbs) titers were measured in BNT162b2 mRNA vaccinated participants (n = 250); we also investigated humoral and cellular immune responses in vaccinated individuals (n = 21) of this cohort 5 months post-vaccination and assayed NAbs levels in COVID-19 hospitalized patients (n = 60) with moderate or severe disease, as well as in COVID-19 recovered patients (n = 34). RESULTS: We found that one (boosting) dose of the BNT162b2 vaccine triggers robust immune (i.e., anti-spike-RBD IgGs and NAbs) responses in COVID-19 convalescent healthy recipients, while naïve recipients require both priming and boosting shots to acquire high antibody titers. Severe COVID-19 triggers an earlier and more intense (versus moderate disease) immune response in hospitalized patients; in all cases, however, antibody titers remain at high levels in COVID-19 recovered patients. Although virus infection promotes an earlier and more intense, versus priming vaccination, immune response, boosting vaccination induces antibody titers significantly higher and likely more durable versus COVID-19. In support, high anti-spike-RBD IgGs/NAbs titers along with spike (vaccine encoded antigen) specific T cell clones were found in the serum and peripheral blood mononuclear cells, respectively, of vaccinated individuals 5 months post-vaccination. CONCLUSIONS: These findings support vaccination efficacy, also suggesting that vaccination likely offers more protection than natural infection.

COVID-19 and ischemic stroke.

Since the onset of the COVID-19 pandemic, a substantial proportion of COVID-19 patients had documented thrombotic complications and ischemic stroke. Several mechanisms related to immune-mediated thrombosis, the renin angiotensin system and the effect of SARS-CoV-2 in cardiac and brain tissue may contribute to the pathogenesis of ischemic stroke in patients with COVID-19. Simultaneously, significant strains on global healthcare delivery, including ischemic stroke management, have made treatment of stroke in the setting of COVID-19 particularly challenging. In this review, we summarize the current knowledge on epidemiology, clinical manifestation, and pathophysiology of ischemic stroke in patients with COVID-19 to bridge the gap from bench to bedside and clinical practice during the most challenging global health crisis of the last decades.

Development of a novel risk score for the prediction of critical illness amongst COVID-19 patients.

OBJECTIVES: Coronavirus disease-19 (COVID-19) is associated with various clinical manifestations, ranging from asymptomatic infection to critical illness. The aim of this study is to evaluate the clinical and laboratory characteristics of hospitalised COVID-19 patients and construct a predictive model for the discrimination of patients at risk of disease progression. METHODS: A single-centre cohort study was conducted including consecutively patients with COVID-19. Demographic, clinical and laboratory findings were prospectively collected at admission. The primary outcome of interest was the intensive care unit admission. A risk model was constructed by applying a Cox's proportional hazard's model with elastic net penalty. Its diagnostic performance was assessed by receiver operating characteristic analysis and was compared with conventional pneumonia severity scores. RESULTS: From a total of 67 patients 15 progressed to critical illness. The risk score included patients' gender, presence of hypertension and diabetes mellitus, fever, shortness of breath, serum glucose, aspartate aminotransferase, lactate dehydrogenase, C-reactive protein and fibrinogen. Its predictive accuracy was estimated to be high (area under the curve: 97.1%), performing better than CURB-65, CRB-65 and PSI/PORT scores. Its sensitivity and specificity were estimated to be 92.3% and 93.3%, respectively, at the optimal threshold of 1.6. CONCLUSIONS: A10-variable risk score was constructed based on clinical and laboratory characteristics in order to predict critical illness amongst hospitalised COVID-19 patients, achieving better discrimination compared with traditional pneumonia severity scores. The proposed risk model should be externally validated in independent cohorts in order to ensure its prognostic efficacy.

Machine-Learning-Derived Model for the Stratification of Cardiovascular risk in Patients with Ischemic Stroke.

Background Stratification of cardiovascular risk in patients with ischemic stroke is important as it may inform management strategies. We aimed to develop a machine-learning-derived prognostic model for the prediction of cardiovascular risk in ischemic stroke patients. MATERIALS AND METHODS: Two prospective stroke registries with consecutive acute ischemic stroke patients were used as training/validation and test datasets. The outcome assessed was major adverse cardiovascular event, defined as non-fatal stroke, non-fatal myocardial infarction, and cardiovascular death during 2-year follow-up. The variables selection was performed with the LASSO technique. The algorithms XGBoost (Extreme Gradient Boosting), Random Forest and Support Vector Machines were selected according to their performance. The evaluation of the classifier was performed by bootstrapping the dataset 1000 times and performing cross-validation by splitting in 60% for the training samples and 40% for the validation samples. RESULTS: The model included age, gender, atrial fibrillation, heart failure, peripheral artery disease, arterial hypertension, statin treatment before stroke onset, prior anticoagulant treatment (in case of atrial fibrillation), creatinine, cervical artery stenosis, anticoagulant treatment at discharge (in case of atrial fibrillation), and statin treatment at discharge. The best accuracy was measured by the XGBoost classifier. In the validation dataset, the area under the curve was 0.648 (95%CI:0.619-0.675) and the balanced accuracy was 0.58 ± 0.14. In the test dataset, the corresponding values were 0.59 and 0.576. CONCLUSIONS: We propose an externally validated machine-learning-derived model which includes readily available parameters and can be used for the estimation of cardiovascular risk in ischemic stroke patients.

Carotid Atherosclerosis and Patent Foramen Ovale in Embolic Stroke of Undetermined Source.

BACKGROUND: Carotid atherosclerosis and likely pathogenic patent foramen ovale (PFO) are two potential embolic sources in patients with embolic stroke of undetermined source (ESUS). The relationship between these two mechanisms among ESUS patients remains unclear. AIM: To investigate the relation between carotid atherosclerosis and likely pathogenic PFO in patients with ESUS. We hypothesized that ipsilateral carotid atherosclerotic plaques are less prevalent in ESUS with likely pathogenic PFO compared to patients with likely incidental PFO or without PFO. METHODS: The presence of PFO was assessed with transthoracic echocardiography with microbubble test and, when deemed necessary, through trans-oesophageal echocardiography. The presence of PFO was considered as likely incidental if the RoPE (Risk of Paradoxical Embolism) score was 0-6 and likely pathogenic if 7-10. RESULTS: Among 374 ESUS patients (median age: 61years, 40.4% women), there were 63 (49.6%) with likely incidental PFO, 64 (50.4%) with likely pathogenic PFO and 165 (44.1%) with ipsilateral carotid atherosclerosis. The prevalence of ipsilateral carotid atherosclerosis was lower in patients with likely pathogenic PFO (7.8%) compared to patients with likely incidental PFO (46.0%) or patients without PFO (53.0%) (p<0.001). After adjustment for multiple confounders, the prevalence of ipsilateral carotid atherosclerosis remained lower in patients with likely pathogenic PFO compared to patients with likely incidental PFO or without PFO (adjusted OR=0.32, 95%CI:0.104-0.994, p=0.049). CONCLUSIONS: The presence of carotid atherosclerosis is inversely related to the presence of likely pathogenic PFO in patients with ESUS.

Searching for Atrial Fibrillation Poststroke: A White Paper of the AF-SCREEN International Collaboration.

Cardiac thromboembolism attributed to atrial fibrillation (AF) is responsible for up to one-third of ischemic strokes. Stroke may be the first manifestation of previously undetected AF. Given the efficacy of oral anticoagulants in preventing AF-related ischemic strokes, strategies of searching for AF after a stroke using ECG monitoring followed by oral anticoagulation (OAC) treatment have been proposed to prevent recurrent cardioembolic strokes. This white paper by experts from the AF-SCREEN International Collaboration summarizes existing evidence and knowledge gaps on searching for AF after a stroke by using ECG monitoring. New AF can be detected by routine plus intensive ECG monitoring in approximately one-quarter of patients with ischemic stroke. It may be causal, a bystander, or neurogenically induced by the stroke. AF after a stroke is a risk factor for thromboembolism and a strong marker for atrial myopathy. After acute ischemic stroke, patients should undergo 72 hours of electrocardiographic monitoring to detect AF. The diagnosis requires an ECG of sufficient quality for confirmation by a health professional with ECG rhythm expertise. AF detection rate is a function of monitoring duration and quality of analysis, AF episode definition, interval from stroke to monitoring commencement, and patient characteristics including old age, certain ECG alterations, and stroke type. Markers of atrial myopathy (eg, imaging, atrial ectopy, natriuretic peptides) may increase AF yield from monitoring and could be used to guide patient selection for more intensive/prolonged poststroke ECG monitoring. Atrial myopathy without detected AF is not currently sufficient to initiate OAC. The concept of embolic stroke of unknown source is not proven to identify patients who have had a stroke benefitting from empiric OAC treatment. However, some embolic stroke of unknown source subgroups (eg, advanced age, atrial enlargement) might benefit more from non-vitamin K-dependent OAC therapy than aspirin. Fulfilling embolic stroke of unknown source criteria is an indication neither for empiric non-vitamin K-dependent OAC treatment nor for withholding prolonged ECG monitoring for AF. Clinically diagnosed AF after a stroke or a transient ischemic attack is associated with significantly increased risk of recurrent stroke or systemic embolism, in particular, with additional stroke risk factors, and requires OAC rather than antiplatelet therapy. The minimum subclinical AF duration required on ECG monitoring poststroke/transient ischemic attack to recommend OAC therapy is debated.

Potential Embolic Sources and Outcomes in Embolic Stroke of Undetermined Source in the NAVIGATE-ESUS Trial.

Background and Purpose- Emboli in embolic stroke of undetermined source (ESUS) may originate from various potential embolic sources (PES), some of which may respond better to anticoagulation, whereas others to antiplatelets. We analyzed whether rivaroxaban is associated with reduction of recurrent stroke compared with aspirin in patients with ESUS across different PES and by number of PES. Methods- We assessed the presence/absence of each PES (atrial cardiopathy, atrial fibrillation, arterial atherosclerosis, left ventricular dysfunction, cardiac valvulopathy, patent foramen ovale, cancer) in NAVIGATE-ESUS (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source) participants. Prevalence of each PES, as well as treatment effect and risk of event for each PES were determined. Results by number of PES were also determined. The outcomes were ischemic stroke, all-cause mortality, cardiovascular mortality, and myocardial infarction. Results- In 7213 patients (38% women, mean age 67years) followed for a median of 11 months, the 3 most prevalent PES were atrial cardiopathy (37%), left ventricular disease (36%), and arterial atherosclerosis (29%). Forty-one percent of all patients had multiple PES, with 15% having ≥3 PES. None or a single PES was present in 23% and 36%, respectively. Recurrent ischemic stroke risk was similar for rivaroxaban- and aspirin-assigned patients for each PES, except for those with cardiac valvular disease which was marginally higher in rivaroxaban-assigned patients (hazard ratio, 1.8 [95% CI, 1.0-3.0]). All-cause mortality risks were similar across treatment groups for each PES while too few myocardial infarctions and cardiovascular deaths occurred for meaningful assessment. Increasing number of PES was not associated with increased stroke recurrence nor all-cause mortality, and outcomes did not vary between rivaroxaban- and aspirin-assigned patients by number of PES. Conclusions- A large proportion of patients with ESUS had multiple PES which could explain the neutral results of NAVIGATE-ESUS. Recurrence rates between rivaroxaban- and aspirin-assigned patients were similar across the spectrum of PES. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02313909.

Automated Continuous Electrocardiogram Monitoring Accelerates the Detection of Atrial Fibrillation after Ischemic Stroke or Transient Ischemic Attack on a Hyper Acute Stroke Unit.

BACKGROUND AND AIM: Rapid and sensitive detection of atrial fibrillation (AF) is of paramount importance for initiation of adequate preventive therapy after stroke. Stroke Unit care includes continuous electrocardiogram monitoring (CEM) but the optimal exploitation of the recorded ECG traces is controversial. In this retrospective single-center study, we investigated whether an automated analysis of continuous electrocardiogram monitoring (ACEM), based on a software algorithm, accelerates the detection of AF in patients admitted to our Stroke Unit compared to the routine CEM. METHODS: Patients with acute ischemic stroke or transient ischemic attack were consecutively enrolled. After a 12-channel ECG on admission, all patients received CEM. Additionally, in the second phase of the study the CEM traces of the patients underwent ACEM analysis using a software algorithm for AF detection. Patients with history of AF or with AF on the admission ECG were excluded. RESULTS: The CEM (n = 208) and ACEM cohorts (n= 114) did not differ significantly regarding risk factors, duration of monitoring and length of admission. We found a higher rate of newly-detected AF in the ACEM cohort compared to the CEM cohort (15.8% versus 10.1%, P < .001). Median time to first detection of AF was shorter in the ACEM compared to the CEM cohort [10 hours (IQR 0-23) versus 46.50 hours (IQR 0-108.25), P < .001]. CONCLUSIONS: ACEM accelerates the detection of AF in patients with stroke compared with the routine CEM. Further evidences are required to confirm the increased rate of AF detected using ACEM.

Lateralization of Insular Ischemic Stroke is Not Associated With Any Stroke Clinical Outcomes: The Athens Stroke Registry.

BACKGROUND: Controversial evidence suggests that right insular stroke may be associated with worse outcomes compared to the left insular ischemic lesion. OBJECTIVES: We investigated whether lateralization of insular stroke is associated with early and late outcome in terms of in-hospital complications, stroke recurrence, cardiovascular events, and death. METHODS: Data were prospectively collected from the Athens Stroke Registry. Insular cortex involvement was identified based on brain CT scans or MRI images. Patients were followed up prospectively at 1, 3, 6 months after hospital discharge and yearly thereafter up to 5-years or until death. The assessed outcomes were in-hospital complications, functional outcome assessed by the modified Rankin Scale, stroke recurrence, cardiovascular events, and death. Cox-regression analysis was performed to estimate the cumulative probability of each outcome according to the lateralization of insular strokes. RESULTS: Among the 1212 patients, 650 had left insular stroke involvement and 562 had right. New onset of in-hospital atrial fibrillation was similar between right and left insular strokes (11.6% versus 12.9%, P = .484). During the 5-year follow-up sudden death occurred in 21 (3.7%) patients with right insular compared to 30 (4.6%) with left insular stroke (P = .476). There was no difference between left and right insular strokes regarding mortality (adjusted odds ratio [OR]: .92, 95% confidence interval [CI]: .80-1.06), stroke recurrence (4.3% versus 4.9%; adjusted OR: .81 95% CI: .58-1.13), cardiovascular events, and sudden death (adjusted OR: .99, 95% CI: .76-1.29) and on death and dependency (adjusted OR: .88, 95% CI: .75-1.02) during a 5-year follow up. CONCLUSIONS: Lateralization of insular ischemic stroke involvement is not associated with stroke outcomes.

Antithrombotic Treatment in Cryptogenic Stroke Patients With Patent Foramen Ovale: Systematic Review and Meta-Analysis.

Background and Purpose- It is unclear whether treatment with anticoagulants or antiplatelets is the optimal strategy in patients with stroke or transient ischemic attack of undetermined cause and patent foramen ovale that is not percutaneously closed. We aimed to perform a systematic review and meta-analysis of randomized controlled trials to compare anticoagulant or antiplatelet treatment in this population. Methods- We searched PubMed until July 16, 2019 for trials comparing anticoagulants and antiplatelet treatment in patients with stroke/transient ischemic attack and medically treated patent foramen ovale using the terms: "cryptogenic or embolic stroke of undetermined source" and "stroke or cerebrovascular accident or transient ischemic attack" and "patent foramen ovale or patent foramen ovale or paradoxical embolism" and "trial or study" and "antithrombotic or anticoagulant or antiplatelet." The outcomes assessed were stroke recurrence, major bleeding, and the composite end point of stroke recurrence or major bleeding. We used 3 random-effects models: (1) a reference model based on the inverse variance method with the Sidik and Jonkman heterogeneity estimator; (2) a strict model, implementing the Hartung and Knapp method; and (3) a commonly used Bayesian model with a prior that assumes moderate to large between-study variance. Results- Among 112 articles identified in the literature search, 5 randomized controlled trials were included in the meta-analysis (1720 patients, mean follow-up 2.3±0.5 years). Stroke recurrence occurred at a rate of 1.73 per 100 patient-years in anticoagulant-assigned patients and 2.39 in antiplatelet-assigned patients (hazard ratio, 0.68; 95% CI, 0.32-1.48 for the Sidik and Jonkman estimator). Major bleeding occurred at a rate of 1.16 per 100 patient-years in anticoagulant-assigned patients and 0.68 in antiplatelet-assigned patients (hazard ratio, 1.61; 95% CI, 0.72-3.59 for the Sidik and Jonkman estimator). The composite outcome occurred in 52 anticoagulant-assigned and 54 antiplatelet-assigned patients (odds ratio, 1.05; 95% CI, 0.65-1.70 for the Sidik and Jonkman estimator). Conclusions- We cannot exclude a large reduction of stroke recurrence in anticoagulant-assigned patients compared with antiplatelet-assigned, without significant differences in major bleeding. An adequately powered randomized controlled trial of a non-vitamin K antagonist versus aspirin is warranted.

Efficacy and Safety of Rivaroxaban Versus Aspirin in Embolic Stroke of Undetermined Source and Carotid Atherosclerosis.

Background and Purpose- The sources of emboli in patients with embolic stroke of undetermined source (ESUS) are multiple and may not respond uniformly to anticoagulation. In this exploratory subgroup analysis of patients with carotid atherosclerosis in the NAVIGATE (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism)-ESUS trial, we assessed whether the treatment effect in this subgroup is consistent with the overall trial population and investigated the association of carotid atherosclerosis with recurrent ischemic stroke. Methods- Carotid atherosclerosis was analyzed either as the presence of mild (ie, 20%-49%) atherosclerotic stenosis or, separately, as the presence of carotid plaque. Primary efficacy outcome was ischemic stroke recurrence. Safety outcomes were major bleeding and symptomatic intracerebral bleeding. Results- Carotid plaque was present in 40% of participants and mild carotid stenosis in 11%. There was no significant difference in ischemic stroke recurrence between rivaroxaban- and aspirin-treated patients among 490 patients with carotid stenosis (5.0 versus 5.9/100 patient-years, respectively, hazard ratio [HR], 0.85; 95% CI, 0.39-1.87; P for interaction of treatment effect with patients without carotid stenosis 0.78) and among 2905 patients with carotid plaques (5.9 versus 4.9/100 patient-years, respectively, HR, 1.20; 95% CI, 0.86-1.68; P for interaction of treatment effect with patients without carotid stenosis 0.2). Among patients with carotid plaque, major bleeding was more frequent in rivaroxaban-treated patients compared with aspirin-treated (2.0 versus 0.5/100 patient-years, HR, 3.75; 95% CI, 1.63-8.65). Patients with carotid stenosis had similar rate of ischemic stroke recurrence compared with those without (5.4 versus 4.9/100 patient-years, respectively, HR, 1.11; 95% CI, 0.73-1.69), but there was a strong trend of higher rate of ischemic stroke recurrence in patients with carotid plaque compared with those without (5.4 versus 4.3/100 patient-years, respectively, HR, 1.23; 95% CI, 0.99-1.54). Conclusions- In ESUS patients with carotid atherosclerosis, we found no difference in efficacy between rivaroxaban and aspirin for prevention of recurrent stroke, but aspirin was safer, consistent with the overall trial results. Carotid plaque was much more often present ipsilateral to the qualifying ischemic stroke than contralateral, supporting an important etiological role of nonstenotic carotid disease in ESUS. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT02313909.

Comparison of Risk Scores for the Prediction of the Overall Cardiovascular Risk in Patients with Ischemic Stroke: The Athens Stroke Registry.

BACKGROUND: Stratification of overall vascular risk in patients with ischemic stroke is important as it may guide management decisions. Currently available schemes have only modest prognostic accuracy. The TRA2°P score aids in vascular risk stratification in patients with previous myocardial infarction (MI). AIM: We investigated whether the prognostic performance of TRA2°P can be extended in patients with ischemic stroke and whether it can improve the risk stratification made by CHA2DS2VASc and Essen-Stroke-Risk-Score (ESRS). METHODS: We analyzed the Athens Stroke Registry using Kaplan-Meier survival and Cox-regression analyses to assess if TRA2°P (in different categorizations) predicts the composite endpoint of stroke recurrence, MI or cardiovascular death. We compared its incremental predictive value over CHA2DS2-VASc and ESRS and calculated continuous net reclassification indices (cNRI). RESULTS: In 2833 patients (followed for 9278 patient-years) and 776 events, there was decreased survival probability for TRA2°P-based high-risk patients compared to low-risk (log-rank-test P < .001), but the discriminatory power for the occurrence of the composite endpoint was only modest (Harrell's-C:.566, 95% CI:.545-.587). Combined with ESRS, TRA2°P conferred incremental discrimination (Harrell's-C:.544, 95% CI:.513-.574 versus .574, 95% CI:.543-.605 respectively, P = .049) and reclassification value (cNRI = 9.8%, P = .02). Combined with CHA2DS2-VASc, TRA2°P did not improve discrimination (Harell's-C:.578, 95% CI: .547-.608 versus .585, 95% CI:.554-.616, P = .738). CONCLUSION: The currently available prognostic scores have generally low performance to predict the overall cardiovascular risk in ischemic stroke patients. Further research is needed to improve vascular risk stratification in ischemic stroke patients.