Embolic strokes of undetermined source in young adults: baseline characteristics and long‐term outcome

Potential Embolic Sources Differ in Patients With Embolic Stroke of Undetermined Source According to Age: A 15-Year Study

Introduction

Understanding the potential embolic source in young patients with ESUS may improve the diagnosis and treatment of such patients.

Hypothesis

Potential embolic sources (PES) differ in young vs. older patients with ESUS, and, therefore, not all patients with ESUS have the same risk profile for stroke recurrence.

Methods

Young patients (age 18-49) with ESUS, who were admitted to our stroke center from 2006 to 2019, were identified retrospectively and matched with next consecutive older patients (age 50-99) with ESUS by admission date. PES were categorized as atrial cardiopathy, AFib diagnosed during follow-up, left ventricular disease (LVD), cardiac valvular disease (CVD), PFO or atrial septal aneurysm (ASA), and arterial disease. Patients, who had cancer or thrombophilia, were excluded. The type and number of PES and stroke recurrence rates were determined and compared between young and older patients.

Results

In young patients (55.3% women, median age 39 years), the most common PES was PFO/ASA, and the rate of other PES was low (2-7%). Half of the young patients (54.1%) had a single PES, only 10% had multiple PES, and 35.3% of young patients did not have any PES identified. In older patients (41.7% women, median age 74 years), the 3 most common PES were atrial cardiopathy (38.1%), LVD (35.7%), and arterial disease (23.8%). Nearly half of older patients (42.9%) had multiple PES. The rate of stroke recurrence tended to be lower in young patients as compared to older patients (4.9 vs. 11.4%, p = 0.29). During a median follow-up of 3 years, only 3 young patients (4.9%) had a recurrent stroke, and two of them had unclosed PFO. There were no recurrent strokes among young patients with no PES identified.

Conclusions

It was noted that PES differ in patients with ESUS according to age and differences in recurrence. PFO is the only common PES in young patients with ESUS. Future studies prospectively evaluating PES in both age groups are needed.

From cryptogenic to ESUS: Toward precision medicine?

Cryptogenic infarctions are infarctions without a defined cause, despite a complete work-up. They differ from infarctions of undetermined causes, which may involve overlapping causes or an incomplete investigation. It is also different from uncommon heritable and non-heritable causes. The term embolic stroke of undetermined source (ESUS) proposed in 2014 is defined as a non-lacunar brain infarct without proximal arterial stenosis or cardioembolic sources. The major advantage of this definition compared to cryptogenic definition is the proposition of a specific work-up. In a general population, frequent potential sources of embolism in patients with ESUS have been suggested since a long time and include: patent foramen ovale (PFO), covert atrial fibrillation (AF), complex aortic arch atheroma, large vessel atheroma with stenosis<50%, carotid web, atrial cardiomyopathy, thrombophilia associated with cancer. It took almost 30 years to show, in patients under 60 with a cryptogenic stroke and a PFO, that PFO occlusion was superior to medical treatment alone for recurrent stroke. PFO under 60 is therefore no longer a cryptogenic cause of infarction. The concept of cryptogenic stroke and its refinement in ESUS have been fruitful for the identification of PFO associated as a cause. Covert AF can be detected by different techniques but its risk significance for recurrent stroke might be different from the simple electrocardiographic detection of AF. With the development of direct oral anticoagulants (DOAs), randomized studies in patients with ESUS, were run for stroke prevention but no difference was observed between patients treated by DOA compared to aspirin. These studies showed however the heterogeneity of ESUS patients. Further ESUS classification should be considered as a tool to identify homogeneous groups. We propose to further split the ESUS group into different subgroups: ESU-PFO>60-year-old, ESUS-ATH with stenosis<50%, ESUS-AF (covert AF & atrial cardiomyopathy), ESUS-cancer and others. Precision medicine is the ability to make targeted healthcare decisions based on the specific risks of individual patients. One preliminary stage is therefore to identify homogeneous groups suitable in the future for new therapeutic trials and, at the end, for new specific treatments.

Etiology of Large Vessel Occlusion Posterior Circulation Stroke: Results of the MR CLEAN Registry

BACKGROUND

In patients with large vessel occlusion stroke of the anterior circulation, underlying cause is a determinant of outcome. Whether this is the case for posterior circulation large vessel occlusion stroke has yet to be determined. We aimed to report on cause in patients with posterior circulation stroke treated with endovascular thrombectomy and to analyze the association with functional outcome.

METHODS

We used data of patients with posterior circulation stroke included in the MR CLEAN (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) registry, a prospective multicenter observational study, between 2014 and 2018. Stroke cause was categorized into large artery atherosclerosis (LAA), cardioembolism, arterial dissection, embolic stroke of undetermined source (ESUS), other determined cause, or undetermined cause. For primary analysis on the association between cause and outcome, we used multivariable ordinal logistic regression analysis to estimate the adjusted common odds ratio for a shift towards a better functional outcome on the modified Rankin Scale at 90 days with LAA as a reference group. Secondary outcomes included favorable functional outcome (modified Rankin Scale score 0-3), National Institutes of Health Stroke Scale score at 24 to 48 hours, reperfusion on digital subtraction angiography, and stroke progression.

RESULTS

Of 264 patients with posterior circulation stroke, 84 (32%) had LAA, 48 (18%) cardioembolism, 31 (12%) dissection, and 14 (5%) ESUS. Patients with a dissection were younger (48 [interquartile range, 43-60] years) and had a lower National Institutes of Health Stroke Scale at baseline (12 [interquartile range, 6-31]) than patients with other cause. Functional outcome was better for patients with cardioembolism and ESUS compared to LAA (modified Rankin Scale adjusted common odds ratio, 2.4 [95% CI, 1.1-5.2], respectively adjusted common odds ratio, 3.1 [95% CI, 1.0-9.3]). Patients with a dissection had a lower chance of successful reperfusion compared with LAA (adjusted odds ratio, 0.20 [95% CI, 0.06-0.70]).

CONCLUSIONS

Unlike the anterior circulation, most frequent cause in our posterior large vessel occlusion stroke cohort is LAA followed by cardioembolism, dissection, and ESUS. Patients with cardioembolism and ESUS have a better prognosis for functional outcome after endovascular thrombectomy than patients with LAA.

Review and update of the concept of embolic stroke of undetermined source

Ischaemic strokes have traditionally been classified according to the TOAST criteria, in which strokes with unclear aetiology are classified as cryptogenic strokes. However, the definition of cryptogenic stroke did not meet the operational criteria necessary to define patient populations for randomized treatment trials. To address this problem, the concept of embolic stroke of undetermined source (ESUS) was developed and published in 2014. A hypothesis that underpinned this concept was that most strokes in patients with ESUS are caused by embolic events, perhaps many cardioembolic, and that anticoagulation would prevent secondary ischaemic events. On this basis, two large randomized trials were conducted to compare the non-vitamin K antagonist oral anticoagulants (NOACs) dabigatran and rivaroxaban with aspirin. Neither NOAC was superior to aspirin in these trials, although subgroups of patients with ESUS seemed to benefit specifically from anticoagulation or antiplatelet therapy. The neutral results of the trials of anticoagulation and insights into ESUS from research conducted since the concept was introduced warrant reassessment of the ESUS construct as a research concept and a treatment target. In this Review, we discuss the evidence produced since the concept of ESUS was introduced, and propose updates to the criteria and diagnostic algorithm in light of the latest knowledge.

Endothelial Dysfunction is Associated With Early-Onset Cryptogenic Ischemic Stroke in Men and With Increasing Age

Background

The aim of this study was to assess the association between endothelial function and early‐onset cryptogenic ischemic stroke (CIS), with subgroup analyses stratified by sex and age groups.

Methods and Results

We prospectively enrolled 136 consecutive patients aged 18 to 49 years (median age, 41 years; 44% women) with a recent CIS and 136 age‐ and sex‐matched (±5 years) stroke‐free controls. Endothelial function was measured with an EndoPAT 2000 device and analyzed as tertiles of natural logarithm of reactive hyperemia index with lower values reflecting dysfunction. We used conditional logistic regression adjusting for age, education, hypertension, diabetes mellitus, dyslipidemia, current smoking, heavy drinking, obesity, and diet score to assess the independent association between endothelial function and CIS. Patients in the lowest tertile of natural logarithm of reactive hyperemia index were more often men and they more frequently had a history of dyslipidemia; they were also more often obese, had a lower diet score, and lower high‐density lipoprotein cholesterol. In the entire cohort, we found no association in patients with endothelial function and CIS compared with stroke‐free controls. In sex‐ and age‐specific analyses, endothelial dysfunction was associated with CIS in men (adjusted odds ratio [OR], 3.50 for lowest versus highest natural logarithm of reactive hyperemia index tertile; 95% CI, 1.22–10.07) and in patients ≥41 years (OR, 5.78; 95% CI, 1.52–21.95). These associations remained significant when dyslipidemia was replaced with the ratio of total to high‐density lipoprotein cholesterol.

Conclusions

Endothelial dysfunction appears to be an independent player in early‐onset CIS in men and patients approaching middle age.

Characteristics and prognosis of patients with embolic stroke of undetermined source in China

BACKGROUND AND PURPOSE

We aimed to explore the frequencies, risk factors, and natural history of embolic stroke of undetermined source (ESUS) through a national prospective registry in China.

METHODS

Between August 2015 and March 2018, the Third China National Stroke Registry recruited consecutive patients with ischemic stroke or transient ischemic attack in China. The baseline characteristics, risks of stroke, and prognosis in patients with embolic stroke of undetermined source were described and compared with that in patients with other causative subtypes.

RESULTS

A total of 15,166 transient ischemic attack and ischemic stroke patients were enrolled in the Third China National Stroke Registry. Among 8528 ischemic stroke with standard diagnostic work-up, 2415 (28.3%) patients were diagnosed with embolic stroke of undetermined source. The mean age was 61 years and 70% of them were male. Compared to patients with cardioembolic strokes and small vessel disease, patients with embolic stroke of undetermined source had higher prevalence of nonstenosing large artery atherosclerosis (37.93% vs. 31.26%, P = 0.008 and 37.93% vs. 34.40%, P = 0.044 respectively). The cumulative probability of stroke recurrence in patients with embolic stroke of undetermined source at three months and one year was 5.59% and 8.74%. Compared with embolic stroke of undetermined source patients (0.70% and 1.99%), patients with the large artery atherosclerosis and cardioembolic strokes had higher cumulative probability of death at three months (1.94% and 3.22%) and one year (4.17% and 7.39%).

CONCLUSIONS

Embolic stroke of undetermined source is a common cause of ischemic stroke in Chinese population with a higher stroke recurrence than previously reported. It was more likely to have nonstenosing large artery atherosclerosis in patients with embolic stroke of undetermined source than with cardioembolic strokes and small vessel disease.

Transesophageal echocardiogram in the evaluation of acute ischemic stroke of young adults

INTRODUCTION:

Acute ischemic stroke (AIS) in the young age (≤50 years) is a major cause of disability. The underlying mechanism of AIS in this age group is usually different from elderly. Transthoracic echocardiography (TTE) is used to detect the potential cardiac sources of embolism in AIS patients. Transthoracic echocardiogram (TEE) is superior to detect specific underlying cardio-aortic source of embolism when compared to TTE. We aim to evaluate the diagnostic yield and therapeutic impact of TEE in AIS of young adults.

METHODS:

We retrospectively reviewed the consecutive patients with AIS in our comprehensive center in a 5-year period from our prospectively collected registry. We selected patients with age ≤50 years who had acute infarcts on brain magnetic resonance imaging or head computed tomography and underwent TEE as part of their diagnostic workup. Demographic details including, age, gender, body mass index, cardiovascular risk factors profile, and TEE findings were collected.

RESULTS:

Among a total 7,930 patients, 876 (11.04%) were found to be ≤50 years old. Among those, TEE was done in 113 patients (12.8%) in addition to TTE. Those who underwent TEE had a mean age of 40.4 ± 7.9 years, 60 were male (53%), 7 (6.2%) had a history of coronary artery disease, 38 (33%) had a history of diabetes, and 45 (40%) had a history of smoking. TEE showed new abnormal findings in a total of 15 patients (13.2%) that were not reported in their TTEs. Out of these, left atrial appendage thrombus was found in 5, infective endocarditis in 4, atrial septal aneurysms associated with patent foramen ovale (PFO) in 3, and spontaneous mobile echo density in three patients. Overall, new findings from TEE resulted in change in the secondary stroke prevention strategy in 14 patients of those who underwent TEE (12.3%). TEE also confirmed the presence of PFO, which was present on TTE with bubble study in 20 (17.6%) patients.

CONCLUSION:

TEE may provide additional information in the evaluation of the AIS in young adults, which could lead to change of the secondary stroke prevention strategy.

Large disparities in 28-day case fatality by stroke subtype: data from a French stroke registry between 2008 and 2017

BACKGROUND AND PURPOSE

The objectives of the present analysis were to assess 28-day stroke case fatality according to the stroke aetiology and to identify associated factors.

METHODS

All stroke events in adults aged ≥35 years between 2008 and 2017 were collected in a population-based stroke registry in northern France.

RESULTS

Out of a total of 2933 strokes, there were 479 (16%) haemorrhagic strokes and 2454 (84%) ischaemic strokes; the 28-day case fatality rates were 48% and 15%, respectively. Three-quarters of the 28-day case fatalities occurred within 6 days of the event for haemorrhagic strokes and within 16.5 days for ischaemic strokes. After an ischaemic stroke, the case fatality rate was higher for women (18%) than for men (12%, p < 0.0001); however, this difference disappeared after adjustment for age. Cardioembolic strokes (34%) and strokes of undetermined cause (33%) were the most common ischaemic subtypes, with case fatality rates of 16% and 18%, respectively. Large artery atherosclerosis (11%) and lacunar strokes (10%) were less common, and both types had a case fatality rate of 3%. Age at the time of the event and stroke severity were both significantly associated with case fatality. For some types of stroke, a history of cardiovascular events and residence in a nursing home were associated with a poor prognosis. Medical care in a neurology ward was inversely associated with case fatality, for all stroke subtypes.

CONCLUSIONS

In northern France, post-stroke case fatality remains high, especially for haemorrhagic stroke. Being treated in a neurology ward improved survival by around 80%.

Sex- related differences in the factors associated with outcomes among patients with strokes of undetermined source: a hospital-based follow-up study

Objective: Sex-related differences are well established among stroke patients, including the incidence and prevalence of stroke being higher among men than among women. However, the sex-related factors for differences in the outcomes of strokes of undetermined source (SUSs) have not been well described, especially in the Chinese population. We assessed the sex-related differences in the factors associated with outcomes among patients with SUSs in China.Method: Between January 2011 and December 2018, we recruited 205 patients diagnosed with SUSs from Kailuan General Hospital (China). The clinical features, risk factors, and outcome data were collected for the patients at 3 and 12 months after their strokes.Results: There were higher frequencies of hyperlipidemia (27.8% vs. 26.4%), smoking (41.4% vs. 5.6%), and alcohol consumption (21.8% vs. 0%) for male patients than for female patients. However, women were more likely than men to have hypertension (63.9% vs. 46.6%), diabetes (27.8% vs. 20.3%), and atrial fibrillation (9.7% vs. 5.3%); they were also more likely to be obese (16.7% vs. 12.0%). There were no significant differences in outcome between the sexes. Among men, severe strokes were associated with higher case fatality and disability risks at 12 months after stroke onset; hyperlipidemia was a risk factor for recurrence within 3 months of the initial stroke. Among women, severe strokes also increased the risk of disability; in women, high total cholesterol (TC) and age were associated with poor outcomes.Conclusion: The factors associated with outcomes in SUS differed by sex. For male patients, more severe stroke and hyperlipidemia were associated with poor outcomes in SUS. Risk factors for poor outcomes in female patients were stroke severity, age, and TC level. These findings suggest that taking measures to manage blood lipid levels and severe stroke among patients with SUS is important for both male and female patients and is crucial for reducing the burden of stroke in China.

Associating cryptogenic ischemic stroke in the young with cardiovascular risk factor phenotypes

Acute Ischemic Stroke (AIS) in the young is increasing in prevalence and the largest subtype within this cohort is cryptogenic. To curb this trend, new ways of defining cryptogenic stroke and associated risk factors are needed. We aimed to gain insights into the presence or absence of cardiovascular risk factors in cases of cryptogenic stroke. We conducted a retrospective cohort study of patients aged 18-49 who presented to an urban tertiary care center with AIS. We manually collected predefined demographic, clinical, laboratory and radiological variables. Clinical risk phenotypes were determined using these variables through multivariate analysis of patients with the small and large vessel disease subtypes (vascular phenotype) and cardioembolic subtype (cardiac phenotype). The resultant phenotype models were applied to cases deemed cryptogenic. Within the 449 patients who met criteria, patients with small and large vessel disease (vascular phenotype) had higher rates of hypertension, intracranial atherosclerosis, and diabetes mellitus, and higher admission glucose, HbA1c, admission blood pressure, and cholesterol compared to the patients with cardioembolic AIS. The cardioembolic subgroup (cardiac phenotype) had significantly higher rates of congestive heart failure (CHF), rheumatic heart disease, atrial fibrillation, clotting disorders, left ventricular hypertrophy, larger left atrial sizes, lower ejection fractions, and higher B-type natriuretic peptide and troponin levels. Adjusted multivariate analysis produced six variables independently associated with the vascular phenotype (age, male sex, hemoglobin A1c, ejection fraction (EF), low-density lipoprotein (LDL) cholesterol, and family history of AIS) and five independently associated with the cardiac phenotype (age, female sex, decreased EF, CHF, and absence of intracranial atherosclerosis). Applying these models to cryptogenic stroke cases yielded that 51.5% fit the vascular phenotype and 3.1% fit the cardiac phenotype. In our cohort, half of young patients with cryptogenic stroke fit the risk factor phenotype of small and large vessel strokes.

Risk factors, etiology, and outcome of ischemic stroke in young adults: A Japanese multicenter prospective study

PURPOSE

This study aimed to evaluate the risk factors, etiology, and outcomes of ischemic stroke (IS) in Japanese young adults.

METHODS

This was a prospective multicenter study. We enrolled patients aged 16 to 55 years with IS within seven days of the onset of symptoms. We assessed the demographic data, risk factors, stroke etiology, and outcome at discharge. The clinical characteristics were compared between sexes and among age groups.

RESULTS

We prospectively enrolled 519 patients (median age, 48 years: 139 females). The mean National Institute of Health Stroke Scale score was 3.6 ± 0.2. The most common risk factors were hypertension (HT) (55%), dyslipidemia (DL) (47%), and current smoking (42%). Body mass index, incidence of current smoking, and heavy alcohol consumption were higher in males. The prevalence of current smoking, HT, DL, and diabetes mellitus increased with aging. The most common etiologic subgroup of IS was small vessel disease (145/510, 28%). Intracranial arterial dissection (IAD) was the most common among the other determined causes (56/115, 49%). The outcome at discharge was relatively good (mRS 0-1, 71.7%); however, poor outcome (mRS ≥ 4) was observed at an incidence of 9.5%.

CONCLUSIONS

Most young adults with IS had modifiable risk factors, of which prevalence increased with age. This emphasizes lifestyle improvement to prevent IS in the young population. Furthermore, we indicated that the incidence rate of IAD was high among the other determined causes.

Risk of recurrent ischemic stroke in young cryptogenic patients with embolic stroke of undetermined source

INTRODUCTION

Elderly cryptogenic ischemic stroke (IS) patients with embolic stroke of undetermined source (ESUS) have a high risk of recurrent IS (RIS) compared to other stroke subtypes. In young ESUS patients, different sources of embolism may be a cause and the risk of RIS remains not enough established. The aim was to assess and compare risk of RIS between ESUS and non ESUS patients <50 years.

METHODS

The study set consisted of young acute IS patients <50 years enrolled in the prospective HISTORY (Heart and Ischemic STrOke Relationship studY) study registered on ClinicalTrials.gov (NCT01541163). In all analyzed patients, the brain ischemia was confirmed on CT or MRI. All patients underwent identical diagnostic protocol including TEE and long-term ECG-Holter. Cause of IS was assessed according to the ASCOD classification.

RESULTS

Of 320 enrolled patients <50 years, 219 (68.4%) were identified as cryptogenic (119 males, mean age 41.4 ± 7.2 years) and 122 (38.1%) patients fulfilled the ESUS criteria. During the follow-up with a median of 34 months, three (2.5%) ESUS and 5 (5.2%) non-ESUS patients suffered from RIS (p = .471). One-year risk of RIS was 0.008 (95% CI: 0-0.025) for ESUS and 0.036 (95% CI: 0-0.076) for non-ESUS patients (p = .262).

CONCLUSION

The risk of RIS was very low in ESUS patients and did not differ from those with non-ESUS. Our finding may indicate that antiplatelet therapy can be effective in the secondary prevention in young ESUS patients if high-risk sources of embolization are excluded extensively.

Characteristics and Outcomes of Younger Adults with Embolic Stroke of Undetermined Source (ESUS): A Retrospective Study

Introduction

Embolic stroke of undetermined source (ESUS) in younger adults may have different risk factors compared with ESUS in elderly, and the approach to ESUS in young adults may require new therapies. We aimed to investigate the characteristics and outcomes in younger adults with ESUS at a single centre in Saudi Arabia.

Patients and Methods

A retrospective study was conducted using the medical records of younger adults with ESUS according to the criteria of the Cryptogenic Stroke/ESUS International Working Group. Younger adults (aged ≤50 years) with ESUS were compared with older patients, on admission and discharge from hospital, using the modified Rankin scale (mRS) and the National Institute of Health Stroke Scale (NIHSS).

Results

Among 147 patients with ESUS, 39 (26.5%) were younger adults. Younger adults compared with older adults with ESUS had fewer vascular risk factors, including lower rates of hypertension (43.6% vs. 70.3%; P = 0.004), diabetes (35.9% vs. 57.4%; P = 0.03), and dyslipidaemia (12.8% vs. 28.7%; P = 0.05). There was no significant difference in poor outcome at discharge (defined as mRS > 2), which was observed in 17.9% of younger adults and 28.7% of older adults. Further, there were no significant differences in stroke severity at discharge (NIHSS score ≤5) or median length of stay.

Discussion

Although the outcomes of ESUS do not differ between younger and older patients, younger patients have fewer identified risk factors.

Conclusion

This study showed that 26.5% of patients with ESUS were aged ≤50  years. Although younger adults with ESUS had fewer risk factors, there were no significant differences in neurologic disability or mortality at discharge, stroke severity, or median length of stay.

Risk Factors for Early-Onset Ischemic Stroke: A Case-Control Study

Background

Recent studies have shown an increasing prevalence of vascular risk factors in young adults with ischemic stroke (IS). However, the strength of the association between all vascular risk factors and early‐onset IS has not been fully established.

Methods and Results

We compared 961 patients with a first‐ever IS at 25 to 49 years to 1403 frequency‐matched stroke‐free controls from a population‐based cohort study (FINRISK). Assessed risk factors included an active malignancy, atrial fibrillation, cardiovascular disease, current smoking status, a family history of stroke, high low‐density lipoprotein cholesterol, high triglycerides, low high‐density lipoprotein cholesterol, hypertension, and type 1 and type 2 diabetes mellitus. We performed subgroup analyses based on age, sex, and IS etiology. In a fully adjusted multivariable logistic regression analysis, significant risk factors for IS consisted of atrial fibrillation (odds ratio [OR], 10.43; 95% confidence interval [CI], 2.33–46.77], cardiovascular disease (OR, 8.01; 95% CI, 3.09–20.78), type 1 diabetes mellitus (OR, 6.72; 95% CI, 3.15–14.33), type 2 diabetes mellitus (OR, 2.31; 95% CI, 1.35–3.95), low high‐density lipoprotein cholesterol (OR, 1.81; 95% CI, 1.37–2.40), current smoking status (OR, 1.81; 95% CI, 1.50–2.17), hypertension (OR, 1.43; 95% CI, 1.17–1.75), and a family history of stroke (OR, 1.37; 95% CI, 1.04–1.82). High low‐density lipoprotein cholesterol exhibited an inverse association with IS. In the subgroup analyses, the most consistent associations appeared for current smoking status and type 1 diabetes mellitus.

Conclusions

Our study establishes the associations between 11 vascular risk factors and early‐onset IS, among which atrial fibrillation, cardiovascular disease, and both type 1 and 2 diabetes mellitus in particular showed strong associations.

A tool to identify patients with embolic stroke of undetermined source at high recurrence risk

OBJECTIVE

A tool to stratify the risk of stroke recurrence in patients with embolic stroke of undetermined source (ESUS) could be useful in research and clinical practice. We aimed to determine whether a score can be developed and externally validated for the identification of patients with ESUS at high risk for stroke recurrence.

METHODS

We pooled the data of all consecutive patients with ESUS from 11 prospective stroke registries. We performed multivariable Cox regression analysis to identify predictors of stroke recurrence. Based on the coefficient of each covariate of the fitted multivariable model, we generated an integer-based point scoring system. We validated the score externally assessing its discrimination and calibration.

RESULTS

In 3 registries (884 patients) that were used as the derivation cohort, age, leukoaraiosis, and multiterritorial infarct were identified as independent predictors of stroke recurrence and were included in the final score, which assigns 1 point per every decade after 35 years of age, 2 points for leukoaraiosis, and 3 points for multiterritorial infarcts (acute or old nonlacunar). The rate of stroke recurrence was 2.1 per 100 patient-years (95% confidence interval [CI] 1.44-3.06) in patients with a score of 0-4 (low risk), 3.74 (95% CI 2.77-5.04) in patients with a score of 5-6 (intermediate risk), and 8.23 (95% CI 5.99-11.3) in patients with a score of 7-12 (high risk). Compared to low-risk patients, the risk of stroke recurrence was significantly higher in intermediate-risk (hazard ratio [HR] 1.78, 95% CI 1.1-2.88) and high-risk patients (HR 4.67, 95% CI 2.83-7.7). The score was well-calibrated in both derivation and external validation cohorts (8 registries, 820 patients) (Hosmer-Lemeshow test χ²: 12.1 [p = 0.357] and χ²: 21.7 [p = 0.753], respectively). The area under the curve of the score was 0.63 (95% CI 0.58-0.68) and 0.60 (95% CI 0.54-0.66), respectively.

CONCLUSIONS

The proposed score can assist in the identification of patients with ESUS at high risk for stroke recurrence.

Use of Statins After Ischemic Stroke in Young Adults and Its Association With Long-Term Outcome

Background and Purpose—

Knowledge of the use of secondary preventive medication in young adults is limited. We studied the use of statins and its association with subsequent vascular events in young adults with ischemic stroke—a patient group with a known low burden of atherosclerosis.

Methods—

The study population included 935 first-ever 30-day ischemic stroke survivors aged 15 to 49 years from the Helsinki Young Stroke Registry, 1994 to 2007. Follow-up data until 2012 were obtained from the Social Insurance Institution of Finland (Drug Prescription Register), the Finnish Care Register, and Statistics Finland. The association of the use of statins (defined as at least 2 purchases) with all-cause mortality, recurrent stroke, and other recurrent vascular events was assessed through adjusted Cox regression analyses. We further compared propensity score–matched statin users with nonusers.

Results—

Of our 935 patients, 46.8% used statins at some point during follow-up. Higher age, dyslipidemia, heavy alcohol use, and hypertension were significantly associated with purchasing statins. Statin users exhibited lower risk of all-cause mortality (hazard ratio, 0.38 [95% CI, 0.25–0.58]) and recurrent stroke (hazard ratio, 0.29 [95% CI, 0.19–0.44]) than nonusers, after adjustment for dyslipidemia, stroke subtype, and other confounders. These results remained unchanged after propensity score–matched comparison.

Conclusions—

Less than half of young ischemic stroke patients used statins; use was affected by age and risk factor profile. Statin use was independently associated with lower risk of all-cause mortality and recurrent stroke.

Long-term (>10-year) clinical follow-up after young embolic stroke/TIA of undetermined source

Background

To date, the pathophysiology of first-ever and recurrent stroke/TIA still remains unclear in young patients with embolic stroke/TIA of undetermined source (ESUS). Clinical studies with long-term follow-up in young ESUS patients are necessary to investigate the underlying pathophysiology of first-ever and recurrent stroke/TIA in this patient population, in particular the role of new-onset atrial fibrillation.

Aims

Our aim was to study the long-term (>10-year) clinical outcome of young patients (<50 years) with ESUS.

Methods

This cohort study included all patients aged ≤ 50 years who underwent transoesophageal echocardiography for diagnostic work-up of ESUS during 1996–2008 from one tertiary center. All patients were contacted by telephone between September–November 2018 to update clinical information from medical records. The clinical outcomes of this study were incidence rates of all-cause and cardiovascular mortality, recurrent stroke/TIA, new-onset clinical AF, and ischemic vascular events.

Results

In total, 108 patients (57% female, mean age 40 ± 7.2 years [range 19–50 years], n = 72 stroke) were included. Across clinical follow-up (median 13[IQR 10–16] years), 24 patients died (n = 14 cardiovascular). The 15-year incidence rate of recurrent stroke/TIA was 15% (incidence rate = 1.09[95%CI 0.54–1.65]/100 patient-years) and a 5.5% incidence of new-onset clinical AF (incidence rate = 0.44[95%CI 0.09–0.79]/100 patient-years) following ESUS.

Conclusions

The incidence of recurrent stroke/TIA is relatively high during long-term clinical follow-up of young patients with ESUS. In contrast, new-onset clinical AF is relatively low and therefore may not play an important part in the pathophysiology of first-ever and recurrent stroke/TIA of these patients.

Embolic Stroke of Undetermined Source in Saudi Arabia: Prevalence, Patient Characteristics, and Outcomes

BACKGROUND

Embolic stroke of undetermined source (ESUS) is a newly introduced clinical construct to better characterize cryptogenic stroke. It is associated with considerable morbidity and mortality and a high recurrence rate. It has not previously been investigated in Saudi stroke patients. We aimed to conduct a descriptive analysis of ESUS in Saudi Arabia, including its frequency among patients with acute stroke, characteristics, and outcomes.

METHODS

We reviewed all ischemic stroke patients admitted to the stroke unit at King Abdulaziz Medical City-Riyadh, Saudi Arabia, from February 2016 to July 2018. We applied the criteria proposed by the Cryptogenic Stroke/ESUS International Working Group, which defines ESUS as a radiologically confirmed nonlacunar brain infarct without (a) extracranial or intracranial atherosclerosis causing ≥50% stenosis in arteries supplying the ischemic area, (b) a major-risk cardioembolic source, (c) any other specific cause of stroke. We compared ESUS patients with the other stroke patients. Study was approved by local institutional review board.

RESULTS

Of the 736 patients admitted with ischemic stroke, 147 (20%) had ESUS. Patients with ESUS had fewer vascular risk factors compared to patients without ESUS. Nearly third were either dead or dependent at discharge. There were no significant differences between ESUS and other types of ischemic strokes in mortality rate and independence at discharge.

CONCLUSION

ESUS is common in Saudi stroke patients. Despite of the lack of definite etiology, it is associated with considerable morbidity and mortality.

Renal Function and Risk Stratification of Patients With Embolic Stroke of Undetermined Source

Background and Purpose- We aimed to assess if renal function can aid in risk stratification for ischemic stroke or transient ischemic attack (TIA) recurrence and death in patients with embolic stroke of undetermined source (ESUS). Methods- We pooled 12 ESUS datasets from Europe and America. Renal function was evaluated using the estimated glomerular filtration rate (eGFR) and analyzed in continuous, binary, and categorical way. Cox-regression analyses assessed if renal function was independently associated with the risk for ischemic stroke/TIA recurrence and death. The Kaplan-Meier product limit method estimated the cumulative probability of ischemic stroke/TIA recurrence and death. Results- In 1530 patients with ESUS followed for 3260 patient-years, there were 237 recurrences (15.9%) and 201 deaths (13.4%), corresponding to 7.3 ischemic stroke/TIA recurrences and 5.6 deaths per 100 patient-years, respectively. Renal function was not associated with the risk for ischemic stroke/TIA recurrence when forced into the final multivariate model, regardless if it was analyzed as continuous (hazard ratio, 1.00; 95% CI, 0.99-1.00 for every 1 mL/min), binary (hazard ratio, 1.27; 95% CI, 0.87-1.73) or categorical covariate (likelihood-ratio test 2.59, P=0.63 for stroke recurrence). The probability of ischemic stroke/TIA recurrence across stages of renal function was 11.9% for eGFR ≥90, 16.6% for eGFR 60-89, 21.7% for eGFR 45-59, 19.2% for eGFR 30-44, and 24.9% for eGFR <30 (likelihood-ratio test 2.59, P=0.63). The results were similar for the outcome of death. Conclusions- The present study is the largest pooled individual patient-level ESUS dataset, and does not provide evidence that renal function can be used to stratify the risk of ischemic stroke/TIA recurrence or death in patients with ESUS.

Clinical and Neuroimaging Characteristics in Embolic Stroke of Undetermined versus Cardioembolic Origin: A Population-Based Study

BACKGROUND AND PURPOSE

Evidence suggests that cardioembolism represents the underlying mechanism in the minority of embolic strokes of undetermined source (ESUS). In this population-based study, we sought to compare the clinical and imaging characteristics as well as outcomes in patients with ESUS and cardioembolic stroke (CE).

METHODS

We included consecutive patients with first-ever ischemic stroke (IS) from the previously published population-based Evros-Stroke-Registry identified as ESUS or CE according to standardized criteria. Baseline characteristics, admission NIHSS scores, cerebral edema, hemorrhagic transformation, stroke recurrence, functional outcomes (determined by modified Rankin Scale [mRS] scores), and mortality rates were recorded during the 1-year follow-up period.

RESULTS

We identified 21 ESUS (3.7% of IS) and 211 CE (37.1% of IS) cases. Patients with ESUS were younger (median age: 68 years [interquartile range [IQR]: 61-75] vs 80 years [IQR: 75-84]; P < .001), had lower median admission NIHSS scores (4 points [IQR: 2-8] vs 10 points [IQR: 5-17]; P < .001), and lower prevalence of cerebral edema on neuroimaging studies (0 vs. 33.3%, P = .002). Functional outcomes were more favorable in ESUS at 28 (median mRS score: 2 [IQR: 1-3] vs 4 [IQR: 4-5]; P < .001), 90 (median mRS score: 1 [IQR: 0-2] vs 4 [IQR: 3-5]; P < .001), and 365 days (median mRS score: 1 [IQR: 0-2] vs 4 [IQR: 2-4]; P < 0.001). At 1-year, the mortality rate was lower in ESUS (0% [95% confidence interval [CI]: 0-13.5%] vs 34.6% [95% CI: 28.2-41.0%]; P < .001); the 1-year recurrent rate was also lower numerically (0% [95% CI: 0-13.5%] vs 9.5% [95% CI: 5.5-13.4%]; P = .140) but this difference failed to reach statistical significance due to the small study population.

CONCLUSIONS

The clinical and neuroimaging profiles as well as clinical outcomes vary substantially between ESUS and CE indicating different underlying mechanisms.

Effect of coexisting vascular disease on long-term risk of recurrent events after TIA or stroke

OBJECTIVE

To determine whether patients with TIA or ischemic stroke with coexisting cardiovascular disease (i.e., history of coronary or peripheral artery disease) are still at high risk of recurrent ischemic events despite current secondary prevention guidelines.

METHODS

In a population-based study in Oxfordshire, UK (Oxford Vascular Study), we studied consecutive patients with TIA or ischemic stroke for 2002-2014. Patients were treated according to current secondary prevention guidelines and we determined risks of coronary events, recurrent ischemic stroke, and major bleeding stratified by the presence of coexisting cardiovascular disease.

RESULTS

Among 2,555 patients (9,148 patient-years of follow-up), those (n = 640; 25.0%) with coexisting cardiovascular disease (449 coronary only; 103 peripheral only; 88 both) were at higher 10-year risk of coronary events than those without (22.8%, 95% confidence interval 17.4-27.9; vs 7.1%, 5.3-8.8; p < 0.001; age- and sex-adjusted hazard ratio [HR] 3.07, 2.24-4.21) and of recurrent ischemic stroke (31.5%, 25.1-37.4; vs 23.4%, 20.5-26.2; p = 0.0049; age- and sex-adjusted HR 1.23, 0.99-1.53), despite similar rates of use of antithrombotic and lipid-lowering medication. However, in patients with noncardioembolic TIA/stroke, risk of extracranial bleeds was also higher in those with coexisting cardiovascular disease, particularly in patients aged <75 years (8.1%, 2.8-13.0; vs 3.4%, 1.6-5.3; p = 0.0050; age- and sex-adjusted HR 2.71, 1.16-6.30), although risk of intracerebral hemorrhage was not increased (age- and sex-adjusted HR 0.36, 0.04-2.99).

CONCLUSIONS

As in older studies, patients with TIA/stroke with coexisting cardiovascular disease remain at high risk of recurrent ischemic events despite current management. More intensive lipid-lowering might therefore be justified, but benefit from increased antithrombotic treatment might be offset by the higher risk of extracranial bleeding.

Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome (SECRETO): echocardiography performance protocol

Background

The incidence of ischemic stroke in young patients is increasing and associated with unfavorable prognosis due to high risk of recurrent cardiovascular events. In many young patients the cause of stroke remains unknown, referred to as cryptogenic stroke. Neuroimaging frequently suggests a proximal source of embolism in these strokes. We developed a comprehensive step-by-step echocardiography protocol for a prospective study with centralized reading to characterize preclinical cardiac changes associated with cryptogenic stroke.

Methods and study design

SECRETO (Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome; NCT01934725) is an ongoing multicenter case–control study enrolling patients (target n = 600) aged 18–49 years hospitalized due to first-ever ischemic stroke of undetermined etiology and age- and sex-matched controls (target n = 600). A comprehensive assessment of cardiovascular risk factors and extensive cardiac imaging with transthoracic and transesophageal echocardiography, electrocardiography and neurovascular imaging is performed. Transthoracic and transesophageal echocardiograms will be centrally read, following an extensive protocol particularly emphasizing the characteristics of left atrium, left atrial appendage and interatrial septum.

Conclusions

A detailed assessment of both conventional and unconventional vascular risk factors and cardiac imaging with transthoracic and transesophageal echocardiography are implemented in SECRETO, aiming to establish indirect and direct risk factors and causes for cryptogenic stroke and novel pathophysiological brain–heart pathways. This may ultimately enable more personalized therapeutic options for these patients.

Embolic strokes of undetermined source: theoretical construct or useful clinical tool?

In 2014, the definition of embolic strokes of undetermined source (ESUS) emerged as a new clinical construct to characterize cryptogenic stroke (CS) patients with complete vascular workup to determine nonlacunar, nonatherosclerotic strokes of presumable embolic origin. NAVIGATE ESUS, the first phase III randomized-controlled, clinical trial (RCT) comparing rivaroxaban (15 mg daily) with aspirin (100 mg daily), was prematurely terminated for lack of efficacy after enrollment of 7213 patients. Except for the lack of efficacy in the primary outcome, rivaroxaban was associated with increased risk of major bleeding and hemorrhagic stroke compared with aspirin. RE-SPECT ESUS was the second phase III RCT that compared the efficacy and safety of dabigatran (110 or 150 mg, twice daily) to aspirin (100 mg daily). The results of this trial have been recently presented and showed similar efficacy and safety outcomes between dabigatran and aspirin. Indirect analyses of these trials suggest similar efficacy on the risk of ischemic stroke (IS) prevention, but higher intracranial hemorrhage risk in ESUS patients receiving rivaroxaban compared to those receiving dabigatran (indirect HR = 6.63, 95% CI: 1.38-31.76). ESUS constitute a heterogeneous group of patients with embolic cerebral infarction. Occult AF represents the underlying mechanism of cerebral ischemia in the minority of ESUS patients. Other embolic mechanisms (paradoxical embolism via patent foramen ovale, aortic plaque, nonstenosing unstable carotid plaque, etc.) may represent alternative mechanisms of cerebral embolism in ESUS, and may mandate different management than oral anticoagulation. The potential clinical utility of ESUS may be challenged since the concept failed to identify patients who would benefit from anticoagulation therapy. Compared with the former diagnosis of CS, ESUS patients required thorough investigations; more comprehensive diagnostic work-up than is requested in current ESUS diagnostic criteria may assist clinicians in uncovering the source of brain embolism in CS patients and individualize treatment approaches.

Plasma Dimethylarginine Levels and Carotid Intima-Media Thickness are related to Atrial Fibrillation in Patients with Embolic Stroke

A relevant part of embolic strokes of undetermined source (ESUS) is assumed to be due to non-detected atrial fibrillation (AF). In this study, we aimed to investigate if markers of endothelial dysfunction and damage may indicate AF risk in embolic stroke. Eighty-eight patients with ischemic stroke confirmed by imaging were assigned to one of three groups: ESUS, AF, or micro-/macroangiopathy. ESUS patients underwent prolonged Holter electrocardiography scheduled for three days. The National Institutes of Health Stroke Scale (NIHSS), the CHA₂DS₂VASC score, and the carotid intima–media thickness (CIMT) were obtained. Markers of endothelial (dys)function (L-arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA)) were measured at day seven after stroke. ESUS patients were younger and had fewer cardiovascular risk factors than patients with determined stroke etiology. Compared with AF patients, ESUS patients showed significantly lower values of SDMA (p = 0.004) and higher values of L-arginine (p = 0.031), L-arginine/ADMA ratio (p = 0.006), L-arginine/SDMA ratio (p = 0.002), and ADMA/SDMA ratio (p = 0.013). Concordant differences could be observed comparing ESUS patients with those with newly diagnosed AF (p = 0.026; p = 0.03; p = 0.009; p = 0.004; and p = 0.046, respectively). CIMT was significantly larger in AF than in ESUS patients (p < 0.001), and was identified as an AF risk factor independent from CHA₂DS₂VASC in the regression analysis (p = 0.014). These findings may support future stratification for AF risk in patients who have suffered embolic stroke.

Features of Patients Aged 80 Years or Older with Embolic Stroke of Undetermined Source

BACKGROUND

Embolic stroke of undetermined source has not been thoroughly investigated in older patients. In this study, we investigated the features of this condition in patients greater than or equal to 80 years of age.

METHODS

All patients with acute ischemic stroke in our hospital underwent diffusion-weighted imaging, magnetic resonance angiography, T2-weighted imaging, and fluid-attenuated inversion recovery sequence imaging. Embolic stroke of undetermined source was defined as a radiologically confirmed nonlacunar brain infarct on diffusion-weighted imaging without (1) extracranial or intracranial atherosclerosis causing greater than or equal to 50% luminal stenosis in arteries supplying the ischemic area, (2) major-risk cardioembolic source, and (3) any other specific cause of stroke. We retrospectively identified consecutive patients hospitalized for acute ischemic stroke who met the embolic stroke of undetermined source diagnostic criteria and investigated patients' baseline and diagnostic findings.

RESULTS

We divided 122 consecutive embolic stroke of undetermined source patients (median age: 73 years; 49 men, 73 women) into 2 groups by age at admission. Patients aged greater than or equal to 80 years had higher D-dimer and brain natriuretic peptide levels, more frequent premature atrial complexes/day in 24-hour Holter electrocardiography, and thicker maximum intima media thickness on ultrasound compared with patients aged less than 80 years (P < .05, U test).

CONCLUSIONS

Our results suggest that high admission D-dimer and brain natriuretic peptide levels are associated with age of onset in patients with embolic stroke of undetermined source. Patients aged greater than or equal to 80 years tended to have more frequent premature atrial complexes and thicker maximum intima media thickness compared with patients aged less than 80 years.

Use of antihypertensive medication after ischemic stroke in young adults and its association with long-term outcome

BACKGROUND

Knowledge on the use of secondary preventive medication in young adults is limited.

METHODS

We included 936 first-ever ischemic stroke 30-day survivors aged 15-49, enrolled in the Helsinki Young Stroke Registry, 1994-2007. Follow-up data until 2012 came from Finnish Care Register, Statistics Finland, and Social Insurance Institution of Finland. Usage thresholds were defined as non-users, low (prescription coverage <30%), intermediate (30-80%) and high users (>80%). Adjusted Cox regression allowed assessing the association of usage with all-cause mortality and recurrent vascular events.

RESULTS

Of our patients, 40.5% were non-users, 7.8% had low usage, 11.8% intermediate usage and 40.0% high usage. Median follow-up was 8.3 years. Compared to non-users, risk of mortality and recurrent stroke or TIA was lower for patients with low-intermediate (HR 0.40, 95% CI 0.22-0.65; HR 0.31, 95% CI 0.18-0.53) and high usage (HR 0.25, 95% CI 0.15-0.42; HR 0.30, 95% CI 0.19-0.46), after adjustment for confounders.

CONCLUSIONS

Use of antihypertensives was suboptimal in one-third of patients in whom antihypertensives were initially prescribed. Users were at lower risk of mortality and recurrent stroke or TIA compared to non-users. Key Messages The use of antihypertensive medication is suboptimal in one-third of patients in whom antihypertensive medication was initially prescribed after ischemic stroke at young age. The risk of mortality and recurrent stroke or TIA is lower for users of antihypertensive medication after ischemic stroke at young age compared to non-users, after adjustment for relevant confounders including pre-existing hypertension and prior use of antihypertensive medication. Specific guidelines on antihypertensive medication use after ischemic stroke at young age are lacking. However, our results may motivate doctors and patients in gaining better usage of antihypertensive medication, since better usage was associated with more favorable outcome in this study.

Embolic strokes of undetermined source in a cohort of Polish stroke patients

We aimed to provide a descriptive analysis of embolic stroke of undetermined etiology (ESUS) population based on a long-term prospective stroke registry. We retrospectively analyzed data collected in a detailed registry regarding consecutive patients admitted for first-ever ischemic stroke (IS) between January 2001 and December 2015. We used Org 10172 in Acute Stroke Treatment classification supplemented with ESUS criteria proposed by the Cryptogenic Stroke/ESUS International Working Group. Within the ESUS group, we additionally compared patients ≤ 60 and > 60 years of age. During the study period, there was a total of 3008 (1615 females and 1393 males) admissions of first-ever strokes. The most frequent cause was undetermined (38.7%), followed by cardioembolic (27.7%), large artery atherosclerosis (18.2%), small vessel disease (11.9%), and other determined (3.6%). We identified 326 patients as ESUS, which accounted for 10.8% of all strokes and 28% of strokes of undetermined etiology. ESUS patients were the youngest. Compared to all types of stroke but for those with small vessel disease, ESUS patients were most often independent before stroke and had the least severe neurological deficit at admission and the best outcome at discharge. ESUS patients ≤ 60 years were more frequently independent at discharge than ESUS patients > 60 years. Approximately 11% of patients from our registry met ESUS criteria. ESUS patients were younger when compared to all other stroke etiologies, suffered less severe strokes, and had more favorable outcome at discharge than other groups except for those with small vessel disease strokes.