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One-Year Risk of Stroke after Transient Ischemic Attack or Minor Stroke
Abstracts Gregory L. Moneta, MD, SECTION EDITOR One-Year Risk of Stroke after Transient Ischemic Attack or Minor Stroke Amarenco P, Lavallee PC, Labreuche J, et al. N Engl J Med 2016;374:1533-42. Conclusions: There is a lower risk of cardiovascular events after transient ischemic attack (TIA) than previously reported. The ABCD2 score, findings and brain imaging, and presence of large-artery atherosclerosis help stratify the risk of recurrent stroke within 1 year after a TIA or minor stroke. Summary: Studies conducted between 1997 and 2003 estimate the risk of stroke or an acute coronary syndrome following TIA or minor stroke to be 12% to 20% during the first 3 months (Johnston SC et al, JAMA 2000;284:2901-6). However, over the last decade there have been major changes in management of TIA including more frequent urgent management in specialized stroke units, implementation of immediate investigations, and rapid treatment with antithrombotic agents and other stroke prevention strategies. Therefore, the current prognosis of patients who have had a TIA and the role of risk-scoring systems in patients receiving urgent care are unclear. The TIA registry.org project was designed to describe the contemporary profile, etiologic factors, and short-term (1-year) and long-term (5-year) outcomes in patients with TIA or minor ischemic stroke, and to redefine risk in the context of modern stroke prevention and management. The current paper consists of 1-year data. Patients recruited were those who had a TIA or minor stroke within the previous 7 days. Sites were selected for inclusion in this study if they had systems dedicated to urgent evaluation of patients with TIA. The 1-year risk of stroke, and a composite outcome of stroke, and acute coronary syndrome, or death from cardiovascular causes was estimated. The authors also examined the association of ABCD2 score with the risk of stroke (range, 0 [lowest risk] to 7 [highest risk]), findings on brain imaging, and cause of TIA or minor stroke with the risk of recurrent stroke over a 1-year period. From 2009 to 2011, there were 4789 patients at 61 sites in 21 countries enrolled in this study. A total of 78.4% of the patients were evaluated by stroke specialists within 24 hours after symptom onset. There were 33.4% of patients that had an acute brain infarction, 23.2% that had at least one extracranial or intracranial stenosis of $50%, and 10.4% that had atrial fibrillation. The Kaplan-Meier estimate of the 1year event rate of the composite cardiovascular outcome was 6.2% (95% confidence interval, 5.5-7.0). Kaplan-Meier estimates of the stroke rate at day 2, 7, 30, 90, and 365 were 1.5%, 2.1%, 2.8%, 3.7% and 5.1%, respectively. Multiple infarctions on brain imaging, large-artery atherosclerosis, and ABCD2 score of 6 or 7 in multivariable analyses were each associated with more than doubling the risk of stroke. Comment: The data suggest that stroke is a disease in retreat. Lower risk of stroke reported by single center registries for patients with TIA or minor stroke that received care by dedicated strokes specialists and organized fast-track evaluation has also been previously reported. Patients in this study were not at low risk, more than two thirds had an ABCD2 score of $4. Despite this, clearly aggressive treatment of TIA or minor stroke can help prevent later stroke. However, 22% of recurrent strokes occurred in patients with ABCD2 scores <4 and with preventable causes such as atrial fibrillation and ipsilateral internal-carotid-artery stenosis of >50%. Multiple infarctions, neuroimaging and large-artery atherosclerotic disease were strong independent predictors of recurrent vascular events and may also help guide therapy in these patients.
Carotid Atherosclerotic Plaque Characteristics on Magnetic Resonance Imaging Relate With History of Stroke and Coronary Heart Disease Selwaness M, Bos D, van den Bouwhuijsen Q, et al. Stroke 2016;47:1542-7. Conclusion: Carotid plaque thickness and stenosis are associated with a history of ischemic stroke and coronary heart disease (CHD). Carotid intraplaque hemorrhage is associated with ischemic stroke but not with CHD. Summary: CHD and ischemic stroke are the most important clinical manifestations of atherosclerotic vascular disease. Data has suggested that vulnerability of atherosclerotic plaque depends on plaque composition rather than on thickness or severity of stenosis (Little WC, Am J
Cardiol 1990;66:44G-7G). Ultrasound allows for accurate assessment of carotid plaque thickness however, magnetic resonance imaging (MRI) may allow better characterization of plaque composition. Plaque components reliably assessed with MRI include lipid deposits with or without a necrotic core, calcification and intraplaque hemorrhage (IPH). The presence of atherosclerosis in one particular vascular bed may predict presence of atherosclerotic disease in other locations. For example, intima media thickness of the carotid artery has been used to assess risk of CHD (Chambles KE et al, Am J Epidemiol 1997;146:483-94). It may also be that systemic risk factors lead to a systemic pre deposition to plaque irregularity and rupture of atherosclerotic plaques and plaque composition in carotid arteries could be related not only to stroke but to other events such as CHD. In this study, the authors investigated the association of the carotid plaque composition with a history of ischemic stroke and CHD in a population-based cohort study. The authors utilized subjects from the Rotterdam Study; 1731 asymptomatic participants (mean age, 72.4 6 9.1 years; 55% male) underwent MRI of both carotid arteries. Carotid wall thickness, stenosis and plaque composition as well as presence of IPH, lipid and calcification were assessed. History of ischemic stroke and CHD was assessed until the day of MRI imaging. Logistic regression analysis adjusted for age and traditional cardiovascular risk factors was used to study sex specific associations between plaque characteristics and clinical events. It was found that carotid stenosis and IPH were associated with ischemic stroke in men but not in women (men odds ratio [OR] for stenosis [per 10% increase], 1.71 [95% confidence interval (CI), 1.06-1.30] and for IPH, 2.39 [95% CI, 1.32-4.35]). In both men and women carotid stenosis was associated with CHD (men: OR per 10% increase, 1.12 [95% CI, 1.04-1.21] and woman: OR, 1. 17 [95% CI, 1.031.34]). Carotid wall thickness was associated with CHD (men: OR 1.20 [95% CI, 1.03-1.39] and women: OR 1.21 [95% CI, 0.88-1.65]). None of the plaque components was associated with CHD. Comment: The data provide some insight into the pathogenesis of cardiovascular events in that plaque characteristics are differentially related to ischemic stroke and CHD. Whereas plaque thickness or stenosis is associated both with ischemic stroke and CHD, plaque composition, specifically IPH, seems to be associated with the history of stroke only and not CHD and these associations were primarily present in men and less prominent in women. Overall burden of atherosclerosis is reflected by carotid stenosis and plaque thickness while plaque composition has artery and disease specific implications.
Effects of Intensive Blood Pressure Lowering on Cardiovascular and Renal Outcomes: Updated Systematic Review and Meta-Analysis Xie X, Atkins E, Lv J, et al. Lancet 2016;387:435-43. Conclusion: Intensive blood pressure lowering provides greater vascular protection than standard regimes. This applies to even patients who have systolic blood pressures <140 mm Hg. Summary: Guidelines recommending target blood pressure levels of around 130/85 mm Hg previously have been in place for patients with cerebral vascular, coronary, and renal disease as well as diabetes. However, some guidelines now recommend target levels of 140/90 mm Hg in these patient populations. The 8th joint national community guideline raised the target blood pressure level for individuals >60 years of age to 150/ 90 mm Hg (James PA et al, JAMA 2014;311:507-20). Globally, just under about half of the total blood pressure-attributable disease burden occurs in people with systolic blood pressures <140 mm Hg and most cardiovascular events occur in people who have not had a previous event (Rodgers A et al, PLoS Med 2004;1:e27, and Kerr AJ et al, Heart 2009;95:125-9). Recommendations for treatment initiation, intensification or maintenance of high-risk patients who have systolic blood pressure levels <140 mm Hg have potentially large substantial clinical and public health importance. There is, however, considerable controversy as to these recommendations. The ACCORD trial did not report a significant difference in overall cardiovascular event rates associated with systolic blood pressure in patients with diabetes (ACCORD Study Group, N Engl J Med 2010;362:1575). However, a systematic review of trials of more vs less blood pressure lowering did notice significant reduction in major vascular events with lower blood pressure (Lv JC et al, PLoS Med 2012; 9:e1001293). The authors therefore sought in this paper to undertake an updated systematic review of all trials comparing different blood
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Carotid Atherosclerotic Plaque Characteristics on Magnetic Resonance Imaging Relate With History of Stroke and Coronary Heart Disease Selwaness M, Bos D, van den Bouwhuijsen Q, et al. Stroke 2016;47:1542-7. Conclusion: Carotid plaque thickness and stenosis are associated with a history of ischemic stroke and coronary heart disease (CHD). Carotid intraplaque hemorrhage is associated with ischemic stroke but not with CHD. Summary: CHD and ischemic stroke are the most important clinical manifestations of atherosclerotic vascular disease. Data has suggested that vulnerability of atherosclerotic plaque depends on plaque composition rather than on thickness or severity of stenosis (Little WC, Am J
Cardiol 1990;66:44G-7G). Ultrasound allows for accurate assessment of carotid plaque thickness however, magnetic resonance imaging (MRI) may allow better characterization of plaque composition. Plaque components reliably assessed with MRI include lipid deposits with or without a necrotic core, calcification and intraplaque hemorrhage (IPH). The presence of atherosclerosis in one particular vascular bed may predict presence of atherosclerotic disease in other locations. For example, intima media thickness of the carotid artery has been used to assess risk of CHD (Chambles KE et al, Am J Epidemiol 1997;146:483-94). It may also be that systemic risk factors lead to a systemic pre deposition to plaque irregularity and rupture of atherosclerotic plaques and plaque composition in carotid arteries could be related not only to stroke but to other events such as CHD. In this study, the authors investigated the association of the carotid plaque composition with a history of ischemic stroke and CHD in a population-based cohort study. The authors utilized subjects from the Rotterdam Study; 1731 asymptomatic participants (mean age, 72.4 6 9.1 years; 55% male) underwent MRI of both carotid arteries. Carotid wall thickness, stenosis and plaque composition as well as presence of IPH, lipid and calcification were assessed. History of ischemic stroke and CHD was assessed until the day of MRI imaging. Logistic regression analysis adjusted for age and traditional cardiovascular risk factors was used to study sex specific associations between plaque characteristics and clinical events. It was found that carotid stenosis and IPH were associated with ischemic stroke in men but not in women (men odds ratio [OR] for stenosis [per 10% increase], 1.71 [95% confidence interval (CI), 1.06-1.30] and for IPH, 2.39 [95% CI, 1.32-4.35]). In both men and women carotid stenosis was associated with CHD (men: OR per 10% increase, 1.12 [95% CI, 1.04-1.21] and woman: OR, 1. 17 [95% CI, 1.031.34]). Carotid wall thickness was associated with CHD (men: OR 1.20 [95% CI, 1.03-1.39] and women: OR 1.21 [95% CI, 0.88-1.65]). None of the plaque components was associated with CHD. Comment: The data provide some insight into the pathogenesis of cardiovascular events in that plaque characteristics are differentially related to ischemic stroke and CHD. Whereas plaque thickness or stenosis is associated both with ischemic stroke and CHD, plaque composition, specifically IPH, seems to be associated with the history of stroke only and not CHD and these associations were primarily present in men and less prominent in women. Overall burden of atherosclerosis is reflected by carotid stenosis and plaque thickness while plaque composition has artery and disease specific implications.
Effects of Intensive Blood Pressure Lowering on Cardiovascular and Renal Outcomes: Updated Systematic Review and Meta-Analysis Xie X, Atkins E, Lv J, et al. Lancet 2016;387:435-43. Conclusion: Intensive blood pressure lowering provides greater vascular protection than standard regimes. This applies to even patients who have systolic blood pressures <140 mm Hg. Summary: Guidelines recommending target blood pressure levels of around 130/85 mm Hg previously have been in place for patients with cerebral vascular, coronary, and renal disease as well as diabetes. However, some guidelines now recommend target levels of 140/90 mm Hg in these patient populations. The 8th joint national community guideline raised the target blood pressure level for individuals >60 years of age to 150/ 90 mm Hg (James PA et al, JAMA 2014;311:507-20). Globally, just under about half of the total blood pressure-attributable disease burden occurs in people with systolic blood pressures <140 mm Hg and most cardiovascular events occur in people who have not had a previous event (Rodgers A et al, PLoS Med 2004;1:e27, and Kerr AJ et al, Heart 2009;95:125-9). Recommendations for treatment initiation, intensification or maintenance of high-risk patients who have systolic blood pressure levels <140 mm Hg have potentially large substantial clinical and public health importance. There is, however, considerable controversy as to these recommendations. The ACCORD trial did not report a significant difference in overall cardiovascular event rates associated with systolic blood pressure in patients with diabetes (ACCORD Study Group, N Engl J Med 2010;362:1575). However, a systematic review of trials of more vs less blood pressure lowering did notice significant reduction in major vascular events with lower blood pressure (Lv JC et al, PLoS Med 2012; 9:e1001293). The authors therefore sought in this paper to undertake an updated systematic review of all trials comparing different blood
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