Risk factors, quality of care and prognosis in South Asian, East Asian and White patients with stroke

Associated demographic factors for the recurrence and prognosis of stroke patients within a multiethnic Asian population

OBJECTIVE

There is a paucity of studies investigating the outcomes among Asian stroke patients. Identifying subgroups of stroke patients at risk of poorer outcomes could identify patients who would benefit from targeted interventions. Therefore, the aim of this study was to identify which ischemic stroke patients at high risk of recurrent events and mortality.

METHODS

This cohort study adhered to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) guidelines. We obtained data from the Singapore Stroke Registry (SSR) from 2005 to 2016 and cross referenced to the Death Registry and the Myocardial Infarction Registry. Outcome measures included recurrent stroke, acute myocardial infarction (AMI), and all-cause and stroke-related deaths. Multivariable Cox proportional hazards regression models were performed to determine risk factors for recurrent stroke, AMI, and all-cause and stroke-related deaths.

RESULTS

A total of 64,915 patients (6705 young, and 58,210 older) were included in our analysis. Older stroke patients were found to have an increased risk of recurrent stroke (hazard ratio (HR) = 1.21, 95% confidence interval (CI) = 1.12-1.30), AMI (HR = 1.73, 95% CI = 1.54-1.95), all-cause death (HR = 2.49, 95% CI = 2.34-2.64), and stroke-related death (HR = 176, 95% CI = 1.61-1.92). Among young stroke patients, males were at increased risk for recurrent stroke (HR = 1.18, 95% CI = 1.01-1.39) and AMI (HR = 1.41, 95% CI = 1.08-1.83), but at reduced risk for all-cause (HR = 0.78, 95% CI = 0.69-0.89) and stroke-related deaths (HR = 0.79, 95% CI = 0.67-0.94). Ethnicity appeared to influence outcomes, with Malay patients at increased risk of recurrent stroke (HR = 1.37, 95% CI = 1.14-1.65), AMI (HR = 2.45, 95% CI = 1.87-3.22), and all-cause (HR = 1.43, 95% CI = 1.24-1.66) and stroke-related deaths (HR = 1.34, 95% CI = 1.09-1.64). Indian patients were also at increased risk of AMI (HR = 1.96, 95% CI = 1.41-2.72). Similar findings were seen among the older stroke patients.

CONCLUSION

This study found that older stroke patients are at risk of poorer outcomes. Within the young stroke population specifically, males were predisposed to recurrent stroke and AMI but were protected against all-cause and stroke-related deaths. Males were also at reduced risk of all-cause and stroke-related deaths in the older stroke population. In addition, Malay and Indian patients experience poorer outcomes after first stroke. Further optimization of risk factors targeting these high-priority populations are needed to achieve high-quality care.

Exploring the Poststroke Experiences and Needs of South Asian Communities Living in High-Income Countries: Findings from a Scoping Review

Despite the high prevalence of stroke among South Asian communities in high-income countries, a comprehensive understanding of their unique experiences and needs after stroke is lacking. This study aimed to synthesize the literature examining the experiences and needs of South Asian community members impacted by stroke and their family caregivers residing in high-income countries. A scoping review methodology was utilized. Data for this review were identified from seven databases and hand-searching reference lists of included studies. Study characteristics, purpose, methods, participant characteristics, results, limitations, recommendations, and conclusions were extracted. Data were analyzed using descriptive qualitative analysis. In addition, a consultative focus group exercise with six South Asian community members who had experienced a stroke and a program facilitator was conducted to inform the review interpretations. A total of 26 articles met the inclusion criteria and were analyzed. Qualitative analysis identified four descriptive categories: (1) rationale for studying the South Asian stroke population (e.g., increasing South Asian population and stroke prevalence), (2) stroke-related experiences (e.g., managing community support versus stigma and caregiving expectations), (3) stroke service challenges (e.g., language barriers), and (4) stroke service recommendations to address stroke service needs (e.g., continuity of care). Several cultural factors impacted participant experiences, including cultural beliefs about illness and caregiving. Focus group participants from our consultation activity agreed with our review findings. The clinical and research recommendations identified in this review support the need for culturally appropriate services for South Asian communities across the stroke care continuum; however, more research is necessary to inform the design and structure of culturally appropriate stroke service delivery models.

Incidence of recurrent ischemic stroke and its associated factors in a tertiary care center in Thailand: a retrospective cohort study

BACKGROUND

Ischemic stroke (IS) is one of the leading causes of death among non-communicable diseases in Thailand. Patients who have survived an IS are at an increased risk of developing recurrent IS, which can result in worse outcomes and post-stroke complications.

OBJECTIVES

The study aimed to investigate the incidence of recurrent IS among patients with first-ever IS during a one-year follow-up period and to determine its associated risk factors.

METHODS

Adult patients (aged ≥ 18 years) who were hospitalized at the Stroke Center, King Chulalongkorn Memorial Hospital (KCMH) in Bangkok, Thailand, due to first-ever IS between January and December 2019 and had at least one follow-up visit during the one-year follow-up period were included in this retrospective cohort study. IS diagnosis was confirmed by neurologists and imaging. The log-rank test was used to determine the event-free survival probabilities of recurrent IS in each risk factor.

RESULTS

Of 418 patients hospitalized due to first-ever IS in 2019, 366 (87.6%) were included in the analysis. During a total of 327.2 person-years of follow-up, 25 (6.8%) patients developed recurrent IS, accounting for an incidence rate of 7.7 per 100 person-year (95% confidence interval [CI] 5.2-11.3). The median (interquartile range) time of recurrence was 35 (16-73) days. None of the 47 patients with atrial fibrillation developed recurrent IS. The highest incidence rate of recurrent IS occurred within 1 month after the first episode (34 per 100 person-years) compared to other follow-up periods. Patients with small vessel occlusion and large-artery atherosclerosis (LAA) constituted the majority of patients in the recurrent IS episode (48% and 40%, respectively), with LAA exhibiting a higher recurrence rate (13.5%). Additionally, smoking status was found to be associated with an increased risk of recurrence.

CONCLUSION

The incidence rate of the recurrence was moderate in our tertiary care setting, with a decreasing trend over time after the first episode. The various subtypes of IS and smoking status can lead to differences in event-free survival probabilities.

Ethnic differences between South Asians and White Caucasians in cardiovascular disease-related mortality in developed countries: a systematic literature review

BACKGROUND

Cardiovascular disease is the leading cause of death worldwide, with significantly worse mortality-related outcomes in ethnic minorities in developed countries. A systematic literature review and meta-analysis of observational studies was conducted to investigate cardiovascular disease-related mortality inequalities between South Asian and White Caucasian ethnic groups.

METHODS

Published studies on mortality between South Asians and Whites in developed countries were retrieved from MEDLINE, PubMed, Embase, Web of Science, and grey literature sources (inception-April 2021) and critically appraised using the Quality in Prognosis Studies tool. Bayesian random-effects meta-analyses were performed for both primary and secondary outcomes. Heterogeneity was determined using the I² statistic.

RESULTS

Of the 9879 studies screened originally, 41 were deemed eligible. A further 3 studies were included via the later search. Of these, 15 reported cardiovascular disease-related mortality, 23 reported all-cause mortality, and 6 reported both. The meta-analysis results showed that South Asians had a significantly increased risk of cardiovascular disease mortality compared to Whites (risk ratio = 1.32; 95% credible interval = 1.14 to 1.54) and a decreased risk of all-cause mortality (risk ratio = 0.95; 95% credible interval = 0.83 to 1.12).

DISCUSSION

South Asians had statistically significantly higher odds of cardiovascular disease-related mortality compared to Whites, but not for all-cause mortality. Risk of bias was a serious concern mainly due to a lack of confounders being reported.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42021240865.

High-resolution MR vessel wall imaging in determining the stroke aetiology and risk stratification in isolated middle cerebral artery disease

PURPOSE

High-resolution MR vessel wall imaging (HRVWI) can characterise vessel wall pathology affecting intracranial circulation and helps in differentiating intracranial vasculopathies. The aim was to differentiate intracranial pathologies involving middle cerebral artery (MCA) in patients with ischemic stroke and characterise the high-risk plaques in intracranial atherosclerotic disease (ICAD) using HRVWI.

METHODS

Patients with ischemic stroke with isolated MCA disease with ≥ 50% luminal narrowing by vascular imaging were enrolled within 2 weeks of onset and underwent high-resolution (3 T) intracranial vessel wall imaging (VWI). The pattern of vessel wall thickening, high signal on T1-weighted images, juxtaluminal hyperintensity, pattern and grade of enhancement were studied. The TOAST classification before and after HRVWI and the correlation of the recurrence of ischemic events at 3 months with imaging characteristics were analysed.

RESULTS

Of the 36 patients, the mean age was 49.53 ± 15.61 years. After luminal imaging, by TOAST classification, 12 of 36 patients had stroke of undetermined aetiology. After vessel wall imaging, lesions in MCA were analysed. Of them, 23 patients had ICAD, 8 had vasculitis, and 2 had partially occlusive thrombus in MCA. The ability of HRVWI to bring a change in diagnosis was significant (p = 0.031). Of the 23 patients with ICAD, 12 patients had recurrent strokes within 3 months. The presence of grade 2 contrast enhancement (p = 0.02) and type 2 wall thickening (p = 0.03) showed a statistically significant association with recurrent ischemic events.

CONCLUSION

High-resolution MRVWI can help in identifying the aetiology of stroke. The HRVWI characteristics in ICAD can help in risk stratification.

Evidence-Based Disparities in Stroke Care Metrics and Outcomes in the United States: A Systematic Review

Stroke disproportionately affects racial minorities, and the level to which stroke treatment practices differ across races is understudied. Here, we performed a systematic review of disparities in stroke treatment between racial minorities and White patients. A systematic literature search was performed on PubMed to identify studies published from January 1, 2010, to April 5, 2021 that investigated disparities in access to stroke treatment between racial minorities and White patients. A total of 30 studies were included in the systematic review. White patients were estimated to use emergency medical services at a greater rate (59.8%) than African American (55.6%), Asian (54.7%), and Hispanic patients (53.2%). A greater proportion of White patients (37.4%) were estimated to arrive within 3 hours from onset of stroke symptoms than African American (26.0%) and Hispanic (28.9%) patients. A greater proportion of White patients (2.8%) were estimated to receive tPA (tissue-type plasminogen activator) as compared with African American (2.3%), Hispanic (2.6%), and Asian (2.3%) patients. Rates of utilization of mechanical thrombectomy were also lower in minorities than in the White population. As shown in this review, racial disparities exist at key points along the continuum of stroke care from onset of stroke symptoms to treatment. Beyond patient level factors, these disparities may be attributed to other provider and system level factors within the health care ecosystem.

Relationship between platelet aggregation and stroke risk after percutaneous coronary intervention: a PENDULUM analysis

In patients undergoing percutaneous coronary intervention (PCI) with a stent, high on-treatment platelet reactivity may be associated with an increased risk of stroke. This post hoc analysis of the PENDULUM registry compared the risk of post-PCI stroke according to on-treatment P2Y₁₂ reaction unit (PRU) values. Patients aged ≥ 20 years who underwent PCI were stratified by baseline PRU (at 12 and 48 h post-PCI) as either high (HPR, > 208), optimal (OPR, > 85 to ≤ 208), or low on-treatment platelet reactivity (LPR, ≤ 85). The incidences of non-fatal ischemic and non-ischemic stroke through to 12 months post-PCI were recorded. Almost all enrolled patients (6102/6267 [97.4%]) had a risk factor for ischemic stroke, and most were receiving dual antiplatelet therapy. Of the 5906 patients with PRU data (HPR, n = 2227; OPR, n = 3002; LPR, n = 677), 47 had a non-fatal stroke post-PCI (cumulative incidence: 0.68%, ischemic; 0.18%, non-ischemic stroke). Patients with a non-fatal ischemic stroke event had statistically significantly higher post-PCI PRU values versus those without an event (P = 0.037). The incidence of non-fatal non-ischemic stroke was not related to PRU value. When the patients were stratified by PRU ≤ 153 versus > 153 at 12–48 h post-PCI, a significant difference was observed in the cumulative incidence of non-fatal stroke at 12 months (P = 0.044). We found that patients with ischemic stroke tended to have higher PRU values at 12–48 h after PCI versus those without ischemic stroke.

Clinical trial registration: UMIN000020332.

Management characteristics and prognosis after stroke in China: findings from a large nationwide stroke registry

BACKGROUND AND PURPOSE

There is limited nationwide evidence about the standard management characteristics of stroke types and prognosis in China. This study aimed to assess clinical characteristics, in-hospital and after-discharge management characteristics and prognosis for stroke types in China.

METHODS

A nationwide registry recruited 14 244 imaging-confirmed first-ever incident strokes from 132 hospitals across 31 provinces of China during 2007-2008, recording presenting characteristics, diagnostic procedures and in-hospital treatment. After hospital discharge, patients were followed up for 6 months. Conventional statistical methods were used to examine the patterns of management and prognosis.

RESULTS

Overall, 68.7%, 26.9% and 4.4% were ischaemic stroke (IS), intracerebral haemorrhage (ICH), and subarachnoid haemorrhage (SAH), respectively. Only 20% were managed in a dedicated stroke unit. Among IS, 1.3% received thrombolysis within 3 hours after symptom onset, whereas the proportions of receiving in-hospital antiplatelet therapy, neuroprotective agents and traditional Chinese medicines (TCM) were 88.4%, 69.7% and 70.6%, respectively. For ICH, 63.3% and 36.3% received neuroprotective agents and TCM in hospital, respectively. At discharge, 70.7% and 38.0% of the patients with IS were given antiplatelet and statin therapies, respectively, decreasing to 64.8% and 23.9%, respectively, at 6 months. In-hospital mortality was 3.2%, 9.3% and 10.1% for IS, ICH and SAH, respectively, with a further 8.6%, 18.2% and 22.0%, respectively, died by 6 month. Meanwhile, in-hospital recurrence rate was 2.6%, 1.9% and 7.2% for IS, ICH and SAH, respectively, with a further 8.0%, 5.1% and 7.5%, respectively, recurred by 6 month.

CONCLUSIONS

In China, the mortality rate of stroke is lower than that reported from west populations, though most strokes are not managed in specialised stroke unit. There is widespread use of some unproven therapies but limited proven treatments, especially after discharge, leading to unnecessary recurrent risks.

Efficacy and Safety of Left Atrial Appendage Closure With WATCHMAN in Japanese Nonvalvular Atrial Fibrillation Patients - Final 2-Year Follow-up Outcome Data From the SALUTE Trial

BACKGROUND

The SALUTE trial was a prospective, multicenter, single-arm trial to confirm the safety and efficacy of the WATCHMAN left atrial appendage closure (LAAC) device for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in Japan.

METHODS AND RESULTS

A total of 54 subjects (including 12 roll-in subjects) with a WATCHMAN implant procedure were followed in 10 investigational centers. Follow-up visits were performed up to 2 years post-implant. The baseline CHA2DS2-VASc score was 3.6±1.6 and the baseline HAS-BLED score was 3.0±1.1. All 42 subjects in the intention to treat (ITT) cohort underwent successful implantation of the LAAC device without any serious complications, achieving the prespecified performance goal. The effective LAAC rate was maintained at 100% from 45 days to 12 months post-implant, achieving the prespecified performance goal. During follow-up, 1 subject died of heart failure, and 3 had ischemic strokes, but there were no cases of hemorrhagic stroke or systemic embolism. All events were adjudicated as unrelated to the WATCHMAN device/procedure by the independent Clinical Events Committee. All 3 ischemic strokes were classified as nondisabling based on no change in the modified Rankin scale score.

CONCLUSIONS

Final results of the SALUTE trial demonstrated that the WATCHMAN LAAC device is an effective and safe alternative nonpharmacological therapy for stroke risk reduction in Japanese NVAF patients who are not optimal candidates for lifelong anticoagulation. (Trial Registration: clinicaltrials.gov Identifier NCT03033134).

Genetic Etiology Shared by Multiple Sclerosis and Ischemic Stroke

Although dramatic progress has been achieved in the understanding and treatment of multiple sclerosis (MS) and ischemic stroke (IS), more precise and instructive support is required for further research. Recent large-scale genome-wide association studies (GWASs) have already revealed risk variants for IS and MS, but the common genetic etiology between MS and IS remains an unresolved issue. This research was designed to overlapping genes between MS and IS and unmask their transcriptional features. We designed a three-section analysis process. Firstly, we computed gene-based analyses of MS GWAS and IS GWAS data sets by VGEAS2. Secondly, overlapping genes of significance were identified in a meta-analysis using the Fisher’s procedure. Finally, we performed gene expression analyses to confirm transcriptional changes. We identified 24 shared genes with Bonferroni correction (P_combined < 2.31E-04), and five (FOXP1, CAMK2G, CLEC2D, LBH, and SLC2A4RG) had significant expression differences in MS and IS gene expression omnibus data sets. These meaningful shared genes between IS and MS shed light on the underlying genetic etiologies shared by the diseases. Our results provide a basis for in-depth genomic studies of associations between MS and IS.

Comparison of Risk Factors, Treatment, and Outcome in Patients with Symptomatic Intracranial Atherosclerotic Disease in India and the United States

BACKGROUND AND AIMS

Intracranial atherosclerotic disease (ICAD) is common in the Asian population, but less studied in South Asians compared to East Asians. We compared risk factors, treatments, and outcomes among consecutive patients with symptomatic ICAD from India with a mixed-ethnic cohort from Chicago, Illinois.

METHODS

Consecutive patients with symptomatic ICAD were enrolled at 2 academic medical centers in Kerala, India and Chicago, United States. Data on demographics, risk factors, initial stroke severity (National Institute of Health Stroke Scale score [NIHSS]), recurrent stroke, and 3-month functional outcome (modified Rankin Scale [mRS]) were prospectively collected. Recurrent stroke was defined as symptomatic recurrence of focal neurologic deficits associated with radiographic evidence of new cerebral infarction within 3 months of index admission.

RESULTS

329 patients (117 from Kerala, 212 from Chicago) were included. Indian patients were younger (61 vs. 68, P < 0.001), less frequently had prior stroke history (15.4 vs. 32.5%, P = 0.001) and coronary artery disease (11.1 vs. 22.2%, P = 0.013) but had higher initial NIHSS score (median 6 vs. 3, P < 0.001). Both groups received reperfusion therapy in similar proportions (8.5 vs. 7.1%, P = 0.630) but at discharge, 90.6% of Indian patients compared to 59.0% of Chicago patients were treated with dual antiplatelet therapy. More recurrent strokes occurred in Chicago patients (21.7 vs. 1.9%, P < 0.001) but functional outcome did not differ significantly.

CONCLUSION

Compared to patients in US with symptomatic ICAD, Indian patients were younger and had more severe strokes. However, Indian patients had lower rates of recurrent stroke, perhaps due to greater use of dual antiplatelet therapy.

Association Between Immigration Status and Acute Stroke Care

Background and Purpose—

Immigrants to high-income countries have a lower incidence of stroke compared with long-term residents; however, little is known about the care and outcomes of stroke in immigrants.

Methods—

We used linked clinical and administrative data to conduct a retrospective cohort study of adults seen in the emergency department or hospitalized with ischemic stroke or transient ischemic attack between July 1, 2003, and April 1, 2013, and included in the provincial stroke registry. We ascertained immigration status using immigration records and compared processes of stroke care delivery between immigrants (defined as those immigrating after 1985) and long-term residents. In the subgroup with ischemic stroke, we calculated inverse probability treatment weight (IPTW)–adjusted risk ratios for disability on discharge (modified Rankin Scale score of 3 to 5), accounting for demographic characteristics and comorbid conditions to compare outcomes between immigrants and long-term residents.

Results—

We included 34 987 patients with ischemic stroke or transient ischemic attack, of whom 2649 (7.6%) were immigrants. Immigrants were younger than long-term residents at the time of stroke/transient ischemic attack (median age 67 years versus 76 years; P <0.001). In the subgroup with ischemic stroke, there were no differences in stroke care delivery, except that a higher proportion of immigrants received thrombolysis than long-term residents (21.2% versus 15.5%; P <0.001). Immigrants with ischemic stroke had a higher adjusted risk of being disabled on discharge (adjusted risk ratio, 1.18; 95% CI, 1.13–1.22) compared to long-term residents.

Conclusions—

Stroke care is similar in Canadian immigrants and long-term residents. Future research is needed to confirm the observed association between immigration status and disability after stroke and to identify factors underlying the association.

Shared Gene Expression Between Multiple Sclerosis and Ischemic Stroke

Patients with multiple sclerosis (MS) appear to have an increased risk of ischemic stroke (IS). Although MS and IS have very different phenotypes, gene-based and pathway-based analyses of large-scale genome-wide association studies (GWAS) have increasingly enhanced our understanding of these two diseases. Whether there are common molecular mechanisms connecting MS and IS is still unclear. Here, we describe the outcome of gene-based test and pathway-based analysis of GWAS datasets that explored potential gene expression links between MS and IS. After identifying significant gene sets individually of MS and IS, we performed pathway-based analysis in four biological pathway databases (KEGG, PANTHER, REACTOME, and WikiPathways) and GO categories. We discovered that there were 9 shared pathways between MS and IS in KEGG, 2 in PANTHER, 14 in REACTOME, 1 in WikiPathways, and 194 in GO annotations (p < 0.05). These results provide an improved understanding about possible shared mechanisms and treatments strategies for MS and IS. They also provide some basis for further studies of how these two diseases are linked at the molecular level.

Care and Discharge Outcome of Acute Stroke in Lebanon: A Hospital-Based Study

The present study was conducted to assess stroke care and outcomes in two Lebanese hospitals. Patients admitted in 2012 and 2013 were retrospectively selected. Data were extracted from medical records for time to hospital arrival, stroke severity, management, and discharge outcomes. A Cox regression analysis was then conducted to predict time to in-hospital death. A total of 201 patients were included (mean age = 69.2 years), among whom 50% arrived within a delay of 3.75 hours. Half underwent brain imaging in the first hour, and nine patients received an acute intervention. Forty-four patients died at the hospital; 142 were discharged home, among whom 98 patients were dependent in their daily activities. Stroke severity on admission and time from onset to arrival were found to be significantly associated to the time to in-hospital death (adjusted hazard ratio [HRa] = 1.13 and HRa = 0.98 respectively; p < 0.05). The study sheds light on high case fatality and dependency rates at discharge among stroke patients in Lebanese hospitals.

Relationship between race and outcome in Asian, Black, and Caucasian patients with spontaneous intracerebral hemorrhage: Data from the Virtual International Stroke Trials Archive and Efficacy of Nitric Oxide in Stroke trial

Background and purpose Although poor prognosis after intracerebral hemorrhage relates to risk factors and hematoma characteristics, there is limited evidence for the effect of race-ethnicity. Methods Data from 1011 patients with intracerebral hemorrhage enrolled into hyperacute trials and randomized to control were obtained from the Virtual International Stroke Trials Archive and Efficacy of Nitric Oxide in Stroke Trial. Clinical characteristics and functional outcome were compared among three racial groups - Asians, Blacks, and Caucasians. Results The majority of patients were Caucasian (78.1%) followed by Asians (14.5%) and Blacks (5.5%). At baseline, Caucasians were older and had larger hematoma volumes; Blacks had lower Glasgow Coma Scale and higher systolic blood pressure (all p < 0.05). Although the primary outcome of modified Rankin Scale did not differ at 90 days (p = 0.14), there were significant differences in mortality (p < 0.0001) and quality of life (EQ-5D p < 0.0001; EQ-VAS p 0.015). In test of multiple comparisons, Caucasians were more likely to die (p = 0.0003) and had worse quality of life (EQ-5D p = 0.003; EQ-VAS p < 0.0001) as compared to Asians. Conclusion Race-ethnicity appears to explain some of the variation in clinical characteristics and outcomes after acute intracerebral hemorrhage. Factors that explain this variation need to be identified.

Secondary prevention treatment after acute stroke in older South Asian, Chinese and other Canadians: a retrospective data analysis

BACKGROUND

Little is known about whether there are differences in medication use between older patients of Chinese descent, those of South Asian descent and other Canadian patients after acute ischemic or primary intracerebral hemorrhagic stroke. The aim of this population-based study was to evaluate potential ethnic differences in secondary prevention pharmacotherapy after acute stroke.

METHODS

Using health administrative data, we conducted a retrospective analysis of all patients aged 66 years or more admitted to hospital with acute stroke in Ontario (1997-2011) and British Columbia (1997-2009). We compared prescriptions filled for statins, warfarin, any antihypertensive agent, the recommended combination of angiotensin-converting-enzyme (ACE) inhibitor and diuretic, and the combination of ACE inhibitor, diuretic and statin within 1 year after ischemic or primary intracerebral hemorrhagic stroke.

RESULTS

There were 118 362 patients with acute stroke (3430 Chinese, 2075 South Asian and 112 857 other Canadians). Among those with ischemic stroke (n = 108 699), Chinese patients were less likely than other Canadian patients to fill prescriptions for the combination of ACE inhibitor, diuretic and statin (adjusted odds ratio [OR] 0.64 [95% confidence interval (CI) 0.55-0.74]) and, in those with atrial fibrillation, for warfarin (adjusted OR 0.75 [95% CI 0.59-0.95]). There were no differences in filling of prescriptions for antihypertensive therapy overall between the 3 groups. Among patients with intracerebral hemorrhagic stroke (n = 9663), Chinese patients were less likely than other Canadian patients to fill prescriptions for the combination of ACE inhibitor and diuretic (adjusted OR 0.51 [95% CI 0.38-0.69]), and South Asians were more likely than other Canadian patients to fill prescriptions for any antihypertensive agent (adjusted OR 1.73 [95% CI 1.21-2.49]).

INTERPRETATION

We identified ethnic differences in filling of prescriptions for several secondary prevention medications after acute stroke. The reasons underlying these differences need to be investigated.

An Examination of Stroke Risk and Burden in South Asians

BACKGROUND

South Asians (India, Pakistan, Sri Lanka, Bangladesh, Nepal, and Bhutan) are at a disproportionately higher risk of stroke and heart disease due to their cardiometabolic profile. Despite evidence for a strong association between diabetes and stroke, and growing stroke risk in this ethnic minority-notwithstanding reports of higher stroke mortality irrespective of country of residence-the explanation for the excess risk of stroke remains unknown.

METHODS

We have used extensive literature review, epidemiologic studies, morbidity and mortality records, and expert opinions to examine the burden of stroke among South Asians, and the risk factors identified thus far.

RESULTS

We summarize existing evidence and indicate gaps in current knowledge of stroke epidemiology among South Asian natives and immigrants.

CONCLUSIONS

This research focuses attention on a looming epidemic of stroke mainly due to modifiable risk factors, but also new determinants that might aggravate the effect of vascular risk factors in South Asians causing more disabling strokes and death.

Cardiometabolic disease in South Asians: A global health concern in an expanding population

Cardiovascular disease (CVD) is one of the main causes of mortality and morbidity worldwide. As an emerging population, South Asians (SAs) bear a disproportionately high burden of CVD relative to underlying classical risk factors, partly attributable to a greater prevalence of insulin resistance and diabetes and distinct genetic and epigenetic influences. While the phenotypic distinctions between SAs and other ethnicities in CVD risk are becoming increasingly clear, the biology of these conditions remains an area of active investigation, with emerging studies involving metabolism, genetic variation and epigenetic modifiers (e.g., extracellular RNA). In this review, we describe the current literature on prevalence, prognosis and CVD risk in SAs, and provide a landscape of translational research in this field toward ameliorating CVD risk in SAs.

Overcoming global challenges in stroke prophylaxis in atrial fibrillation: The role of non-vitamin K antagonist oral anticoagulants

Atrial fibrillation is the world's most common sustained cardiac arrhythmia and is associated with a significantly increased risk of stroke. The global burden of atrial fibrillation is rising, commensurate with the ageing population. Well-controlled vitamin K antagonist-based anticoagulation has been shown to reduce the risk of stroke secondary to atrial fibrillation by two-thirds. However, patients with atrial fibrillation have frequently been denied anticoagulation because of a variety of perceived risks related to bleeding, falls, chronological age, and poor compliance. Even when vitamin K antagonists are used, maximum benefit and safety are only delivered when high quality control of therapy (TTR > 70%) is achieved, which has proven remarkably difficult in many health-care systems and amongst many patient groups. The non-vitamin K antagonist oral anticoagulants (NOACs) offer solutions to many of the challenges of achieving widespread, safe, and effective anticoagulation for stroke prophylaxis in atrial fibrillation, yet their uptake into routine clinical practice remains variable. The evidence supporting their more widespread use to overcome the challenges of stroke prophylaxis for atrial fibrillation is reviewed in this article.

Traditional Risk Factors for Stroke in East Asia

Stroke is one of the leading causes of death and morbidity worldwide. The occurrence of stroke is strongly dependent on well-known vascular risk factors. After rapid modernization, urbanization, and mechanization, East Asian countries have experienced growth in their aged populations, as well as changes in lifestyle and diet. This phenomenon has increased the prevalence of vascular risk factors among Asian populations, which are susceptible to developing cardiovascular risk factors. However, differing patterns of stroke risk factor profiles have been noted in East Asian countries over the past decades. Even though the prevalence of vascular risk factors has changed, hypertension is still prevalent and the burden of diabetes and hypercholesterolemia will continue to increase. Asia remains a high tobacco-consuming area. Although indicators of awareness and management of vascular risk factors have increased in many East Asian countries, their rates still remain low. Here we review the burdens of traditional risk factors, such as hypertension, diabetes, hypercholesterolemia, and smoking in East Asia. We will also discuss the different associations between these vascular risk factors and stroke in Asian and non-Asian populations.

Stroke recurrence among South Asians with diabetes in Ontario, Canada

Background South Asians have more vascular risk factors, earlier cardiovascular disease onset, and higher stroke mortality than non-South Asians. However, ethnic differences in long-term outcomes post-stroke in diabetics are unclear. Aims We compared cardiovascular outcome risk after first ischemic stroke between South Asian and non-South Asian diabetics. Methods Using population-based health care databases in Ontario, Canada, we selected all patients with diabetes hospitalized with first ischemic stroke between 1 April 2002 and 31 March 2012, and assigned South Asian versus non-South Asian ethnicity using a validated surname algorithm. Kaplan-Meier survival analysis estimated survival functions, and competing risk models estimated hazards of death, stroke, and myocardial infarction. The primary predictor was ethnicity, and models were adjusted for demographics and vascular risk factors. Sensitivity analysis including adjustment for medication use was performed in those aged ≥65 years. Results There were 25,495 diabetics with first ischemic stroke; 840 were South Asian. South Asians were younger, more often male, had lower income, and had shorter Ontario residency compared to non-South Asians. South Asians had higher incidence and cumulative risk of recurrent stroke. In fully adjusted competing risk models, recurrent stroke rate was increased among South Asians compared to non-South Asians (HR 1.17 [95% CI 1.00-1.38]) in the whole cohort and in those aged ≥65 years, both with adjustment for medication use (HR 1.23 [1.01-1.50]) and without (1.27 [1.04-1.54]). Conclusions In this large population-based study, South Asian diabetic stroke patients had higher recurrent stroke rates compared to non-South Asians, despite a younger age profile. Further research is needed to reduce stroke burden in South Asians.

Identification of PTCSC3 as a Novel Locus for Large-Vessel Ischemic Stroke: A Genome-Wide Association Study

Background

Ischemic stroke is a major cause of death and disability in the world. A major ischemic stroke subtype, large‐vessel ischemic stroke (large artery atherosclerosis; LAA), has been shown to have some genetic components in individuals of European ancestry. However, it is not clear whether the genetic predisposition to LAA stroke varies among ethnicities. We sought to identify genetic factors that contribute to LAA stroke in 2 independent samples of Han Chinese individuals.

Methods and Results

Novel genetic variants that predispose individuals to LAA stroke were identified using a genome‐wide association study (GWAS) of 444 individuals with LAA stroke and 1727 controls in a Han Chinese population residing in Taiwan. The study was replicated in an independent Han Chinese population comprising an additional 319 cases and 1802 controls. We identified 5 single‐nucleotide polymorphisms, including rs2415317 (P=3.10×10⁻⁸), rs934075 (P=4.00×10⁻⁹), rs944289 (P=3.57×10⁻⁸), rs2787417 (P=1.76×10⁻⁸), and rs1952706 (P=2.92×10⁻⁸), at one novel locus on chromosome 14q13.3 within PTCSC3 (encoding papillary thyroid carcinoma susceptibility candidate 3) that were associated with LAA stroke at genome‐wide significance (P<5×10⁻⁸).

Conclusions

Our data provide strong support for future studies on the role of PTCSC3 in the pathogenesis of LAA stroke and the association between LAA stroke development and thyroid function. In addition, these findings provide insights into the genetic basis of LAA stroke and identify a novel pathway that might be applicable for future therapeutic intervention.

Individualized approaches to thromboprophylaxis in atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide. The prevalence of AF in persons older than 55 years is at least 33.5 million globally and is predicted to more than double in the next half-century. Anticoagulation, heart rate control, and heart rhythm control comprise the 3 main treatment strategies in AF. Anticoagulation is aimed at preventing debilitating stroke, systemic embolism, and associated mortality. Historically, anticoagulation in AF was achieved with a vitamin K antagonist such as warfarin, which is supported by evidence demonstrating reduced incident stroke and all-cause mortality. However, warfarin has unpredictable pharmacokinetics with many drug-drug interactions that require regular monitoring to ensure patients remain in the therapeutic anticoagulant range. Non-vitamin K antagonist oral anticoagulants including dabigatran, rivaroxaban, apixaban, and edoxaban provide a possible solution to these issues with their more predictable pharmacokinetics, rapid onset of action, and greater specificity. Results from large randomized, controlled trials indicate that these agents are at least noninferior to warfarin in prevention of stroke. These trials also demonstrate a consistently lower incidence of intracranial hemorrhage, almost always all life-threatening bleeds, and many forms of major bleeds with the possible exception of gastrointestinal and some other forms of mucosal bleeding, compared with warfarin. Patients with AF are a heterogeneous population with diverse risk of stroke and bleeding, and different subgroups respond differently to anticoagulation. Important clinical questions have arisen regarding optimal anticoagulation drug selection in distinct populations such as those with renal impairment, older age, coronary artery disease, and heart failure as well as those at particularly high risk for bleeding or thromboembolism. In this review, treatment strategies in AF management are discussed in the context of different individual subgroups of patients.

Cardiovascular Disease in South Asian Migrants

Cardiovascular disease (CVD) represents a significant cause of global mortality and morbidity. South Asians (SAs) have a particularly high burden of coronary artery disease (CAD). This review describes current literature regarding the prevalence, incidence, etiology, and prognosis of CVD in SA migrants to high-income nations. We conducted a narrative review of CVD in the SA diaspora through a search of MEDLINE and PubMed. We included observational studies, randomized clinical trials, nonsystematic reviews, systematic reviews, and meta-analyses written in English. Of 15,231 articles identified, 827 articles were screened and 124 formed the basis for review. SA migrants have a 1.5-2 times greater prevalence of CAD than age- and sex-adjusted Europids. Increased abdominal obesity and body fat and increased burden of type 2 diabetes mellitus and dyslipidemia appear to be primary drivers of the excess CAD burden in SAs. Sedentary lifestyle and changes in diet after immigration are important contributors to weight gain and adiposity. Early life factors, physical activity patterns and, in some cases, reduced adherence to medical therapy may contribute to increased CVD risks in SAs. Novel biomarkers like leptin and adipokines may show distinct patterns in SAs and provide insights into cardiometabolic risk determinants. In conclusion, SAs have distinct CVD risk predispositions, with a complex relationship to cultural, innate, and acquired factors. Although CVD risk factor management and treatment among SAs is improving, opportunities exist for further advances.