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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.

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., ((c) 2009 S. Karger AG, Basel.)

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.

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.