Acute coronary syndromes presentations and care outcomes in white, South Asian and Chinese patients: a cohort study.

OBJECTIVES: Successful treatment of acute coronary syndrome (ACS) relies on its rapid recognition. It is unclear whether the accepted presentation of chest pain applies to different ethnic groups. We thus examined potential ethnic variations in ACS symptoms and clinical care outcomes in white, South Asian and Chinese patients. DESIGN: Cross-sectional survey. SETTING: Participants were hospitalised at 1 of 12 Canadian centres across four provinces. PARTICIPANTS: 1334 patients with ACS (630 white; 488 South Asian; 216 Chinese). MAIN OUTCOME MEASURES: ACS presentation symptoms (classic/typical midsternal pain/discomfort with or without radiation to the left neck, shoulder or arm) were assessed by self-report. Clinical care outcomes (time to emergency room [ER] presentation, cardiac catheterisation; receipt of cardiac catheterisation, percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG]) were obtained by health record audit. RESULTS: The mean age of the sample was 62 years and 30% had ST-elevation myocardial infarction (STEMI). The most common presenting symptom was midsternal pain/discomfort of any intensity regardless of ethnic status. Yet, a substantial proportion of patients reported atypical symptoms (33% white, 19% South Asian, 20% Chinese; p<0.006). After adjustment for age, sex, education, current smoking, extent of coronary artery disease, presence of diabetes or chronic kidney disease and STEMI vs non-STEMI/unstable angina, South Asians were more likely to present with at least moderate intensity midsternal pain/discomfort (adjusted OR [AOR] 1.44; 95% CI 1.05 to 1.98), whereas Chinese were less likely to present with radiating symptoms (AOR 0.53; 95% CI 0.38 to 0.74) compared with whites. South Asians with atypical pain (relative to those with midsternal pain/discomfort) took significantly longer to present to the ER (p=0.037), and were less likely to receive PCI (p=0.008) or CABG (p=0.041). CONCLUSIONS: Atypical presentations were associated with greater delays in arrival to the emergency department and reduced invasive cardiovascular care in South Asians.

A 5-item prediction rule to identify severe renal dysfunction in patients with acute stroke.

BACKGROUND AND PURPOSE: Although patients with severe renal dysfunction who receive iodinated contrast are at high risk of CIN, contrast-enhanced CT scans are often obtained without prior knowledge of kidney function in patients with acute stroke. We aimed to develop a tool to identify patients with acute stroke at a high risk of CIN in the absence of a recent GFR. MATERIALS AND METHODS: We used the RCSN (9872 patients) and OSA (2544 patients) for our derivation and validation cohort, respectively. A multivariable logistic regression model was performed to develop a predictive tool to identify severe renal dysfunction (defined as a GFR < 30 mL/min/1.73 m(2)). RESULTS: The overall prevalence of severe renal dysfunction was 4.9% and 5.2% in the derivation and validation cohort, respectively. The prediction rule was designed as follows: (age in years) + (5 points for women) + (5 points for history of diabetes mellitus) + (15 points for preadmission insulin use) + (10 points for history of hypertension). The prevalence of severe renal dysfunction is negligible in patients with a total score of ≤70 (≤0.005%-0.7%) but increases with higher Renal Risk Scores (eg, scores 71-80: 2.1%-2.2%; scores 91-100: 6.6%-7.1%; scores 111-120: 15.9%-28.1%). CONCLUSIONS: The Renal Risk Score is a validated tool that helps clinicians select which patients with stroke can safely proceed to contrast-enhanced brain imaging without waiting for laboratory evidence of good renal function.

Care and outcomes in patients with ischemic stroke with and without preexisting dementia.

OBJECTIVE: To describe clinical characteristics and evaluate processes of care and outcomes at discharge in patients with ischemic stroke with and without preexisting dementia. METHODS: Retrospective cohort study using the Registry of the Canadian Stroke Network including patients presenting with an acute ischemic stroke between 2003 and 2008. Preexisting dementia was defined as any type of dementia that was present prior to the index stroke case. Palliative patients were excluded. Demographic information, clinical presentation, selected process measures (e.g., thrombolysis, admission to stroke unit, carotid imaging, stroke prevention), pneumonia, death, disability, and disposition at discharge were analyzed. RESULTS: Among 9,304 eligible patients with an acute ischemic stroke, 702 (9.1%) had a history of dementia. Patients with dementia were older (mean age 81 vs 70 years; p < 0.001), had more severe strokes (Canadian Neurological Scale score <4, 20.7% vs 10.5%; p < 0.001), and were more likely to have atrial fibrillation (22.8% vs 15.3%; p < 0.001) than those without dementia. Patients with dementia were slightly less likely to be admitted to a stroke unit (63% vs 67.6%; odds ratio [OR] 0.82, 95% confidence interval [CI] 0.70-0.96) or to receive thrombolysis (10.5% vs 15.7%; OR 0.63, 95% CI 0.49-0.81). There were no differences in other performance measures. Patients with preexisting dementia had higher disability at discharge (OR 3.20, 95% CI 2.64-3.87) and were less likely to be discharged to their prestroke place of residence (24% vs 45%; p < 0.001). CONCLUSIONS: In patients with stroke, preexisting dementia is associated with high rates of disability and institutionalization, representing an increasing challenge for the health care system.

Do all ischemic stroke subtypes benefit from organized inpatient stroke care?

BACKGROUND: There are limited data on the effectiveness of organized stroke care in different ischemic stroke subtypes in the real-world setting. We analyzed the effect of organized stroke care in all stroke subtypes in a longitudinal cohort study using data from the Registry of the Canadian Stroke Network. METHODS: Between July 2003 and September 2007, there were 6,223 consecutive patients with ischemic stroke subtype information by Trial of Org 10172 in Acute Stroke Treatment criteria. Subtypes were categorized as large artery atherosclerotic disease, lacunar, cardioembolic, or other. The amount of organized stroke care was quantified using the previously published organized care index (OCI), graded 0-3 based on the presence or absence of occupational therapy or physiotherapy, stroke team assessment, and admission to a stroke unit. RESULTS: Mortality at 30 days was associated with both stroke subtype and OCI. Higher OCI (defined as score 2-3 compared to 0-1) was strongly associated with lower odds of 30-day mortality in each ischemic stroke subtype (adjusted odds ratio estimates ranged from 0.16 to 0.43, p < 0.001, controlling for age, gender, stroke severity, and medical comorbidities by logistic regression). These estimates were essentially unchanged after excluding patients treated with palliative care. Numbers needed to treat, to prevent 1 death at 30 days, ranged from 4 to 9 across the subtypes. CONCLUSIONS: A strong association between higher OCI and lower 30-day mortality was apparent in each ischemic stroke subtype. These data suggest that organized stroke care should be provided to stroke patients regardless of stroke subtype.

Differences in stroke outcome based on sex.

OBJECTIVE: Stroke thrombolysis may have a differential effect by sex. We sought to examine the relationship between sex and outcome after thrombolysis. METHODS: This is a retrospective cohort study of stroke patients from the Registry of Canadian Stroke Network phase 1 (June 2001-February 2002) and phase 2 (June 2002-December 2002). Variables including demographics, history, clinical data, process measures, and outcome were analyzed. The primary outcomes were the Stroke Impact Scale-16 score (SIS-16) and mortality at 6 months. We compared the outcomes of the thrombolyzed and nonthrombolyzed cohorts and examined the data for a tissue plasminogen activator (tPA)-by-sex interaction on the 2 primary outcomes. RESULTS: The overall proportion of patients who achieved an excellent outcome (SIS-16 >75) was not different by gender. However, the proportion of patients achieving an excellent outcome in the non-tPA cohort was much greater in males, with an absolute risk difference of 11.8%. A multiplicative treatment by sex interaction was evident (p = 0.054). This interaction was not present for stroke case fatality. CONCLUSIONS: Women fared poorly compared to men in the placebo groups, but this negative prognostic sex effect was neutralized by thrombolysis.

Gender differences in carotid imaging and revascularization following stroke.

BACKGROUND: Carotid endarterectomy is performed less often in women than in men, but it is unknown whether this reflects differences in screening rates, disease prevalence, or other factors. METHODS: This was a cohort study of consecutive patients with acute stroke or TIA admitted to 11 Ontario stroke centers participating in the Registry of the Canadian Stroke Network between July 1, 2003, and September 30, 2007. We compared rates of carotid imaging, the severity of carotid stenosis, and rates of carotid endarterectomy or angioplasty within 6 months of the index event in women vs men. RESULTS: We studied 6,389 patients (48% women) with ischemic stroke or TIA. Women were less likely than men to undergo carotid imaging (81% vs 86%, p < 0.0001); however, when the analysis was limited to patients without apparent contraindications to surgery, 92% received carotid imaging, with no difference between women and men. Women were less likely than men to have severe carotid stenosis (7.4% vs 11.5%, p < 0.0001). Women were half as likely as men to undergo carotid revascularization within 6 months of the index event (odds ratio 0.51, 95% confidence interval 0.37 to 0.70), but this gender difference was no longer significant in the subgroup with severe carotid stenosis (odds ratio 0.75, 95% confidence interval 0.49 to 1.15). CONCLUSIONS: Although women with ischemic stroke or TIA are less likely than men to undergo carotid screening and revascularization, this difference is largely explained by potential contraindications to surgery and by sex differences in the severity of carotid disease.

In-hospital myocardial infarction following acute ischaemic stroke: an observational study.

BACKGROUND AND PURPOSE: Acute myocardial infarction is expected to be an important medical complication following ischaemic stroke. We sought to describe the frequency and clinical impact of in-hospital myocardial infarction following acute ischaemic stroke. METHODS: Consecutive patients with acute ischaemic stroke were identified from the Registry of the Canadian Stroke Network (2003-2006). Stroke severity was measured using the Canadian Neurological Scale (CNS). Functional status at discharge was measured with the modified-Rankin Scale, and categorized into strokes with no or mild-moderate dependency (m-Rankin 0-3) and those with severe dependence or death (m-Rankin 4-6). Multivariable logistic regression was used to determine the association between myocardial infarction and clinical outcome (death or severe dependence at hospital discharge and 1 year mortality), independent of co-morbidities and in-hospital medical complications. RESULTS: In total, 9180 patients with acute ischaemic stroke were included. The mean age was 72 years (SD 13.9) and 48% were female. Overall, 211 (2.3%) patients were reported to have myocardial infarction during hospitalization. At hospital discharge, 64.9% of patients with in-hospital myocardial infarction had died or were severely disabled, compared with 35.8% in the entire cohort. Mortality at 1 year after ischaemic stroke was 56.4% in patients with myocardial infarction and 21.9% in the entire cohort. On multivariable analyses, myocardial infarction was also associated with death or severe dependence at discharge (OR 2.51; 95%CI 1.75-3.59) and mortality within 1 year (HR 1.83; 95%CI 1.51-2.23). Previous history of myocardial infarction (OR 1.50; 95%CI 1.05-2.15), diabetes mellitus (OR 1.55; 95%CI 1.42-2.10), stroke severity (OR 1.13; 95% CI 1.09-1.17) and peripheral vascular disease (OR 1.61; 95%CI 1.04-2.49) were independently associated with myocardial infarction during hospitalization. CONCLUSIONS: Myocardial infarction is an important medical complication after acute ischaemic stroke.

Risk factors for posterior compared to anterior ischemic stroke: an observational study of the Registry of the Canadian Stroke Network.

BACKGROUND: Traditional vascular risk factors appear to exert varying magnitudes of risk for different major vascular events. For example, hypercholesterolemia is a much stronger risk factor for myocardial infarction than ischemic stroke. Limited evidence also suggests that vascular risk factors may exert differing magnitudes of risk for ischemic stroke within different cerebral arterial territories. We sought to determine the association between traditional vascular risk factors and the location of ischemic stroke (posterior versus anterior). METHODS: Consecutive patients with acute ischemic stroke who were admitted to 11 regional stroke centers within the Registry of the Canadian Stroke Network were included in the study sample. The Oxfordshire Community Stroke Project classification was used to distinguish posterior from anterior circulation ischemic stroke. Multivariable logistic regression was applied to determine the association between risk factors (age, gender, diabetes mellitus, hypercholesterolemia, hypertension, atrial fibrillation and smoking history) and posterior (compared to anterior) circulation ischemic stroke. RESULTS: In total, 8,489 patients with acute ischemic stroke were included. On multivariable analysis, diabetes mellitus (OR = 1.14; 95% CI = 1.02-1.27) was associated with an increased odds of posterior circulation ischemic stroke, whereas age (OR = 0.86; 95% CI = 0.83-0.90), female sex (OR = 0.84; 95% CI = 0.76-0.93), atrial fibrillation (OR = 0.83; 95% CI = 0.74-0.94) and pulmonary edema (OR = 0.74; 95% CI = 0.62-0.88) were related to a reduced odds of posterior compared with anterior circulation ischemic stroke. CONCLUSIONS: Some traditional vascular risk factors for ischemic stroke appear to exert different magnitudes of risk for posterior compared to anterior circulation ischemic stroke.

Gastrointestinal bleeding after acute ischemic stroke.

OBJECTIVE: Recent studies report that major bleeding is associated with a significant increase in mortality after acute coronary syndrome. Major bleeding has also been reported to be common after ischemic stroke, most often gastrointestinal, but its association with clinical outcome is less certain. We sought to describe the incidence, risk factors, and association with clinical outcomes of gastrointestinal bleeding following acute ischemic stroke. METHODS: Consecutive patients with acute ischemic stroke, who were admitted to 11 Ontario hospitals, were identified from the Registry of the Canadian Stroke Network (2003-2006). Stroke severity was measured using the Canadian Neurological Scale. Dependence was measured with the modified Rankin Scale (mRS), and categorized into strokes with no or mild-moderate dependency (mRS 0-3) and those with severe dependence or death (mRS 4-6). Multivariable logistic regression was used to determine the association between gastrointestinal bleeding and clinical outcome (death or severe dependence at hospital discharge and 6-month mortality), independent of comorbidities and in-hospital medical complications. RESULTS: In total, 6,853 patients with acute ischemic stroke were included. One hundred (1.5%) patients experienced gastrointestinal hemorrhage during hospitalization, of which 36 (0.5%) required blood transfusion. On multivariable analyses, previous history of peptic ulcer disease, cancer, and stroke severity were independent predictors of gastrointestinal bleeding. Gastrointestinal hemorrhage was independently associated with death or severe dependence at discharge (OR 3.3; 95% CI 1.9-5.8) and mortality at 6 months (HR 1.5; 95% CI 1.1-2.0). CONCLUSIONS: Gastrointestinal hemorrhage is relatively uncommon after acute ischemic stroke but is associated with increased odds of death and severe dependence.

Hospital volume and stroke outcome: does it matter?

BACKGROUND: Although hospital-outcome relationships have been explored for a variety of procedures and interventions, little is known about the association between annual stroke admission volumes and stroke mortality. Our aim was to determine whether facility type and hospital volume was associated with stroke mortality. METHODS: All hospital admissions for ischemic stroke were identified from the Hospital Morbidity database (HMDB) from April 2003 to March 2004. The HMDB is a national database that contains patient-level sociodemographic, diagnostic, procedural, and administrative information across Canada. Ischemic stroke was identified through patient's principal diagnosis recorded using the International Classification of Diseases (9 and 10). Multivariable analysis was performed with generalized estimating equations with adjustment for demographic characteristics, provider specialty, facility type, hospital volume, and clustering of observations at institutions. RESULTS: Overall, 26,676 patients with ischemic stroke were admitted to 606 hospitals. Seven-day stroke mortality was 7.6% and mortality at discharge was 15.6%. Adverse outcomes were more frequent in patients treated in low-volume facilities (<50 strokes/year) than in those treated in high volume facilities (100 to 199 and >200 strokes patients/year) (for 7-day mortality: 9.5 vs 7.3%, p < 0.001; 9.5 vs 6.0%, p < 0.001; for discharge mortality: 18.2 vs 15.2%, p < 0.001; 18.2 vs 12.8%, p < 0.001). The difference persisted after multivariable adjustment or when hospital volume was divided into quartiles. CONCLUSIONS: High annual hospital volume was consistently associated with lower stroke mortality. Our study encourages further research to determine whether this is due to differences in case mix, more organized care in high-volume facilities, or differences in the performance or in the processes of care among facilities.

Carotid endarterectomy for women and men.

Carotid endarterectomy is the standard of care for people with severe symptomatic carotid stenosis. We analyzed population administrative data and clinical trial data to determine whether sex differences exist in the use and outcomes of this surgical procedure. We studied patients in Ontario who underwent carotid endarterectomy between 1982 and 1994 (n = 12,949) and patients with severe carotid stenosis who were enrolled in two randomized trials of endarterectomy (n = 1646). We compared the proportion of men and women who underwent carotid endarterectomy in each group, over time, and after adjustment for demographic factors. Men were twice as likely as women to receive carotid endarterectomy in the administrative analysis (65% versus 35%, p < 0.001) and in the clinical trial analysis (70% versus 30%, p < 0.001). The relatively lower use in women was consistent in every age group and in every year studied. Men in the administrative database were somewhat less likely than women to die or be institutionalized after surgery (5% versus 6%, p = 0.007). Men in the clinical trial database were also less likely than women to experience perioperative stroke or death, although the results were not statistically significant (6% versus 7%, p = 0.32). Patients who were assigned to surgical therapy, compared with those assigned to medical therapy, had a significant decrease in the risk of adverse events at 1 year, and the net benefit appeared similar in women and men. Carotid endarterectomy is performed relatively infrequently on women despite their similar lifetime burden of disease and similar short-term perioperative risks compared with men.

Sex differences and similarities in the management and outcome of stroke patients.

BACKGROUND AND PURPOSE: Previous studies have documented sex differences in the management and outcome of patients with cardiovascular disease. However, little data exist on whether similar sex differences exist in stroke patients. We conducted a study to determine whether sex differences exist in patients with acute stroke admitted to Ontario hospitals. METHODS: Using linked administrative databases, we performed a population-based cohort study. The databases contained information on all 44 832 patients discharged from acute-care hospitals in Ontario between April 1993 and March 1996 with a most responsible diagnosis of acute stroke. The main outcomes measured consisted of sex differences in comorbidities, the use of rehabilitative services, the use of antiplatelet therapy and anticoagulants (in elderly stroke survivors aged > or =65 years only), discharge destination, and mortality. RESULTS: Male stroke patients were more likely than female stroke patients to have a history of ischemic heart disease (18.1% versus 15.3%, respectively; P<0.001) and diabetes mellitus (20.1% versus 18. 7%, respectively; P<0.001), whereas female patients were more likely than male patients to have hypertension (33.8% versus 30.0%, respectively; P<0.001) and atrial fibrillation (12.9% versus 10.2%, respectively; P<0.001). There were no sex differences in the usage of in-hospital rehabilitative services. The overall 90-day postdischarge use of aspirin and ticlopidine was similar in stroke survivors aged 65 to 84 years. However, among stroke survivors aged > or =85 years, men were more likely than women to receive aspirin (36. 0% versus 30.7%, respectively; P<0.001) and ticlopidine (9.2% versus 6.8%, respectively; P=0.007). Use of warfarin was similar for the two sexes. Men were more likely than women to be discharged home (50. 6% versus 40.9%, respectively; P<0.001) and less likely to be discharged to chronic care facilities (16.8% versus 25.2%, respectively; P<0.001). The risk of death 1 year after stroke was somewhat lower in women than men (adjusted odds ratio 0.939, 95% CI 0.899 to 0.980; P=0.004). The mortality differences were greatest among elderly stroke patients. CONCLUSIONS: Elderly men are more likely than elderly women to receive aspirin and ticlopidine and equally like to receive warfarin after a stroke. Despite these differences, elderly women have a better 1-year survival after a stroke.

Preventive health care, 1999 update: 2. Echocardiography for the detection of a cardiac source of embolus in patients with stroke. Canadian Task Force on Preventive Health Care.

OBJECTIVE: To develop guidelines for the use of echocardiography in the investigation of patients with stroke. OPTIONS: (1) Routine transthoracic echocardiography (TTE); (2) routine transesophageal echocardiography (TEE); (3) routine TTE followed by TEE if the TTE findings are noncontributory; (4) selective TTE or TEE in patients with cardiac disease who would not otherwise receive anticoagulant therapy. OUTCOMES: This article reviews the available evidence on the yield of TTE and TEE in detecting cardiac sources of cerebral emboli in patients with stroke, the effectiveness of treatment for cardiac sources of emboli and the effectiveness of screening echocardiography for secondary stroke prevention. EVIDENCE: MEDLINE was searched for relevant articles published from January 1966 to April 1998; also reviewed were additional articles identified from the bibliographies and citations obtained from experts. BENEFITS, HARMS AND COSTS: Echocardiography can detect intracardiac masses (thrombus, vegetation or tumour) in about 4% (with TTE) to 11% (with TEE) of stroke patients. The yield is lower among patients without clinical evidence of cardiac disease by history, physical examination, electrocardiography or chest radiography (less than 2%) than among patients with clinical evidence of cardiac disease (less than 19%). The risks of echocardiography to patients are small. TTE has virtually no risks, and TEE is associated with cardiac, pulmonary and bleeding complications in 0.18%. Patients with an identified intracardiac thrombus are at increased risk for embolic events (absolute risk uncertain, range 0%-38%), and this appears to be reduced with anticoagulant therapy (absolute risk reduction uncertain). Anticoagulant therapy carries a risk of major hemorrhage of 1% to 3% per year. The overall effectiveness of echocardiography in the prevention of recurrent stroke is unknown. VALUES: The strength of evidence was evaluated using the methods of the Canadian Task Force on Preventive Health Care. RECOMMENDATIONS: There is fair evidence to recommend echocardiography in patients with stroke and clinical evidence of cardiac disease by history, physical examination, electrocardiography or chest radiography (grade B recommendation). There is insufficient evidence to recommend for or against TEE in patients with normal results of TTE (grade C recommendation). There is insufficient evidence to recommend for or against routine echocardiography in patients (including young patients) without clinical cardiac disease (grade C recommendation). Routine echocardiography is not recommended for patients with clinical cardiac disease who have independent indications for or contraindications to anticoagulant therapy (grade D recommendation). There is fair evidence to recommend anticoagulant therapy in patients with stroke and intracardiac thrombus (grade B recommendation). There is insufficient (no) evidence to recommend for or against any specific therapy for patent foramen ovale (grade C recommendation). VALIDATION: The findings of this analysis were reviewed through an iterative process by the members of the Canadian Task Force on Preventive Health Care.