Population based study of early risk of stroke after transient ischaemic attack or minor stroke: implications for public education and organ
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《英国医生杂志》
1 Stroke Prevention Research Unit, Department of Clinical Neurology, Radcliffe Infirmary, Oxford OX2 6HE
Correspondence to: P M Rothwell peter.rothwell@clneuro.ox.ac.uk
Abstract
Approximately 15% of ischaemic strokes are preceded by a transient ischaemic attack (TIA).1 This "warning" event provides an opportunity to prevent stroke, and guidelines highlight the need for rapid access clinics.2-4 However, although much work has been done on the causes and dangers of delayed assessment after acute major stroke,5 6 few studies of TIA or minor stroke have been done, and we do not know how urgently patients must be seen for these clinics to be effective. North American guidelines recommend that assessment and investigation should be completed within one week of a TIA or minor stroke,7 8 and British guidelines recommend assessment within two weeks,2 3 but routine practice varies widely.9 In the United Kingdom, the national service framework for older people requires that rapid access stroke prevention services are in place by April 2004.4 However, no guidance is given for how rapidly patients should be seen.
The danger of delaying investigation and treatment after a TIA or minor stroke depends on the early risk of subsequent stroke. Commonly quoted risks, of 1-2% at seven days and 4% at one month,1 8 10-13 are underestimates because patients were usually recruited several weeks after the TIA and any patients who had a major stroke during this period were excluded. A study of patients presenting to an emergency department within 24 hours of a TIA reported a risk of stroke of 5.3% at two days,14 but no recent data from population based studies exist, and no data are available on the risk of recurrence after a minor stroke, which is also usually investigated in "TIA" clinics.
We have studied the early risk of stroke after a TIA or minor stroke in a prospective population based study (the Oxford vascular study), in which patients are enrolled as soon as possible after their symptoms and detailed information is collected on the timing of onset of symptoms and early recurrent events.
Methods
We recruited 87 patients with a TIA and 87 patients with a minor stroke (table). We excluded 83 patients with major stroke (National Institutes of Health score > 3). All patients were followed up for 3 months. During this time 15 patients with TIA had a subsequent stroke, two of which were fatal and three of which resulted in an increased Rankin score at three months' follow up.19 The remaining 10 cases were minor strokes, and we therefore entered them into the minor stroke analysis from the date of the minor stroke onwards. Sixteen patients with minor stroke had a subsequent stroke, of which four were fatal and two resulted in increased disability at three months. The estimated stroke risks after a TIA were 8.0% (95% confidence interval 2.3% to 13.7%) at seven days, 11.5% (4.8% to 18.2%) at one month, and 17.3% (9.3% to 25.3%) at three months. The risks at the three time points were similar (log rank P = 0.8; figure) after a minor stroke: 11.5% (4.8% to 11.2%), 15.0% (7.5% to 22.5%), and 18.5% (10.3% to 26.7%).
Characteristics of patients included in the analyses. Values are numbers (percentages) unless stated otherwise
Cumulative risk of stroke after a transient ischaemic attack (TIA) or minor stroke
Five TIA patients and three minor stroke patients had their subsequent stroke before seeking medical attention after the initial event. If we exclude these patients to produce more conservative estimates, the seven day, one month, and three month stroke risks are 7.2% (1.7% to 12.8%), 8.4% (2.4% to 14.4%), and 13.3% (6.0% to 20.6%) after a TIA and 7.2% (1.7% to 12.8%), 10.9% (4.2% to 17.6%), and 14.6% (7.0% to 22.2%) after a minor stroke.
Discussion
Hankey GJ. Impact of treatment of people with transient ischaemic attack on stroke incidence and public health. Cerebrovasc Dis 1996;6(suppl 1): 26-33.
Intercollegiate Working Party for Stroke. National clinical guidelines for stroke. London: Royal College of Physicians, 2000.
Scottish Intercollegiate Guidelines Network. SIGN guidelines: management of patients with stroke. Edinburgh: SIGN, 1997.
Department of Health. National service framework for older people. London: Department of Health, 2001.
Evenson KR, Rosamond WD, Morris DL. Prehospital and in-hospital delays in acute stroke care. Neuroepidemiology 2001;20: 65-76.
Proceedings of a national symposium on rapid identification and treatment of acute stroke. Washington: National Institute of Neurological Disorders and Stroke, 1997.
Feinberg WM, Albers GW, Barnett HJ, Biller J, Caplan LR, Carter LP, et al. Guidelines for the management of transient ischemic attacks. Circulation 1994;89: 2950-65.
Wolf PA, Clagett GP, Easton JD, Goldstein LB, Gorelick PB, Kelly-Hayes M, et al. Preventing ischemic stroke in patients with prior stroke and transient ischemic attack: a statement for healthcare professionals from the Stroke Council of the American Heart Association. Stroke 1999;30: 1991-4.
Johnston SC, Smith WS. Practice variability in management of transient ischemic attacks. Eur Neurol 1999;42: 105-8.
Gubitz G, Phillips S, Dwyer V. What is the cost of admitting patients with transient ischaemic attacks to hospital? Cerebrovasc Dis 1999;9: 210-4.
Warlow CP, Dennis MS, van Gijn J, Sandercock PAG, Bamford JM, Wardlaw JM. Preventing recurrent stroke and other serious vascular events. In: Stroke: a practical guide to management. Oxford: Blackwell Science, 2001.
Gubitz G, Sandercock P. Prevention of ischaemic stroke. BMJ 2000;321: 1455-9.
Hankey GJ, Dennis MS, Slattery JM, Warlow CP. Why is the outcome of transient ischaemic attacks different in different groups of patients? BMJ 1993;306: 1107-11.
Johnston SC, Gress DR, Browner WS, Sidney S. Short-term prognosis after emergency department diagnosis of TIA. JAMA 2000;284: 2901-6.
Schulz UG, Rothwell PM. Differences in vascular risk factors between etiological subtypes of ischemic stroke: importance of population-based studies. Stroke 2003;34: 2050-9.
Bamford J, Sandercock P, Dennis M, Burn J, Warlow C. A prospective study of acute cerebrovascular disease in the community: the Oxfordshire Community Stroke Project—1981-86. 2: incidence, case fatality rates and overall outcome at one year of cerebral infarction, primary intracerebral and subarachnoid haemorrhage. J Neurol Neurosurg Psychiatry 1990;53: 16-22.
Dennis MS, Bamford JM, Sandercock PA, Warlow CP. Incidence of transient ischemic attacks in Oxfordshire, England. Stroke 1989;20: 333-9.
Goldstein LB, Bertels C, Davis JN. Interrater reliability of the NIH stroke scale. Arch Neurol 1989;46: 660-2.
Van Swieten JC, Koudstaal PJ, Visser MC, Schouten HJ, van Gijn J. Interobserver agreement for the assessment of handicap in stroke patients. Stroke 1988;19: 604-7.
Lovett JK, Dennis MS, Sandercock PAG, Bamford J, Warlow CP, Rothwell PM. The very early risk of stroke after a transient ischaemic attack. Stroke 2003; 138-40e.
EAFT (European Atrial Fibrillation Trial) Study Group. Secondary prevention in non-rheumatic atrial fibrillation after transient ischaemic attack or minor stroke. Lancet 1993;342: 1255-62.
Rothwell PM, Eliasziw M, Gutnikov SA, Warlow CP, Barnett HJM, for the Carotid Endarterectomy Trialists' Collaboration. Effect of endarterectomy for symptomatic carotid stenosis in relation to clinical subgroups and to the timing of surgery. Lancet 2004 (in press).(A J Coull, clinical resea)
Correspondence to: P M Rothwell peter.rothwell@clneuro.ox.ac.uk
Abstract
Approximately 15% of ischaemic strokes are preceded by a transient ischaemic attack (TIA).1 This "warning" event provides an opportunity to prevent stroke, and guidelines highlight the need for rapid access clinics.2-4 However, although much work has been done on the causes and dangers of delayed assessment after acute major stroke,5 6 few studies of TIA or minor stroke have been done, and we do not know how urgently patients must be seen for these clinics to be effective. North American guidelines recommend that assessment and investigation should be completed within one week of a TIA or minor stroke,7 8 and British guidelines recommend assessment within two weeks,2 3 but routine practice varies widely.9 In the United Kingdom, the national service framework for older people requires that rapid access stroke prevention services are in place by April 2004.4 However, no guidance is given for how rapidly patients should be seen.
The danger of delaying investigation and treatment after a TIA or minor stroke depends on the early risk of subsequent stroke. Commonly quoted risks, of 1-2% at seven days and 4% at one month,1 8 10-13 are underestimates because patients were usually recruited several weeks after the TIA and any patients who had a major stroke during this period were excluded. A study of patients presenting to an emergency department within 24 hours of a TIA reported a risk of stroke of 5.3% at two days,14 but no recent data from population based studies exist, and no data are available on the risk of recurrence after a minor stroke, which is also usually investigated in "TIA" clinics.
We have studied the early risk of stroke after a TIA or minor stroke in a prospective population based study (the Oxford vascular study), in which patients are enrolled as soon as possible after their symptoms and detailed information is collected on the timing of onset of symptoms and early recurrent events.
Methods
We recruited 87 patients with a TIA and 87 patients with a minor stroke (table). We excluded 83 patients with major stroke (National Institutes of Health score > 3). All patients were followed up for 3 months. During this time 15 patients with TIA had a subsequent stroke, two of which were fatal and three of which resulted in an increased Rankin score at three months' follow up.19 The remaining 10 cases were minor strokes, and we therefore entered them into the minor stroke analysis from the date of the minor stroke onwards. Sixteen patients with minor stroke had a subsequent stroke, of which four were fatal and two resulted in increased disability at three months. The estimated stroke risks after a TIA were 8.0% (95% confidence interval 2.3% to 13.7%) at seven days, 11.5% (4.8% to 18.2%) at one month, and 17.3% (9.3% to 25.3%) at three months. The risks at the three time points were similar (log rank P = 0.8; figure) after a minor stroke: 11.5% (4.8% to 11.2%), 15.0% (7.5% to 22.5%), and 18.5% (10.3% to 26.7%).
Characteristics of patients included in the analyses. Values are numbers (percentages) unless stated otherwise
Cumulative risk of stroke after a transient ischaemic attack (TIA) or minor stroke
Five TIA patients and three minor stroke patients had their subsequent stroke before seeking medical attention after the initial event. If we exclude these patients to produce more conservative estimates, the seven day, one month, and three month stroke risks are 7.2% (1.7% to 12.8%), 8.4% (2.4% to 14.4%), and 13.3% (6.0% to 20.6%) after a TIA and 7.2% (1.7% to 12.8%), 10.9% (4.2% to 17.6%), and 14.6% (7.0% to 22.2%) after a minor stroke.
Discussion
Hankey GJ. Impact of treatment of people with transient ischaemic attack on stroke incidence and public health. Cerebrovasc Dis 1996;6(suppl 1): 26-33.
Intercollegiate Working Party for Stroke. National clinical guidelines for stroke. London: Royal College of Physicians, 2000.
Scottish Intercollegiate Guidelines Network. SIGN guidelines: management of patients with stroke. Edinburgh: SIGN, 1997.
Department of Health. National service framework for older people. London: Department of Health, 2001.
Evenson KR, Rosamond WD, Morris DL. Prehospital and in-hospital delays in acute stroke care. Neuroepidemiology 2001;20: 65-76.
Proceedings of a national symposium on rapid identification and treatment of acute stroke. Washington: National Institute of Neurological Disorders and Stroke, 1997.
Feinberg WM, Albers GW, Barnett HJ, Biller J, Caplan LR, Carter LP, et al. Guidelines for the management of transient ischemic attacks. Circulation 1994;89: 2950-65.
Wolf PA, Clagett GP, Easton JD, Goldstein LB, Gorelick PB, Kelly-Hayes M, et al. Preventing ischemic stroke in patients with prior stroke and transient ischemic attack: a statement for healthcare professionals from the Stroke Council of the American Heart Association. Stroke 1999;30: 1991-4.
Johnston SC, Smith WS. Practice variability in management of transient ischemic attacks. Eur Neurol 1999;42: 105-8.
Gubitz G, Phillips S, Dwyer V. What is the cost of admitting patients with transient ischaemic attacks to hospital? Cerebrovasc Dis 1999;9: 210-4.
Warlow CP, Dennis MS, van Gijn J, Sandercock PAG, Bamford JM, Wardlaw JM. Preventing recurrent stroke and other serious vascular events. In: Stroke: a practical guide to management. Oxford: Blackwell Science, 2001.
Gubitz G, Sandercock P. Prevention of ischaemic stroke. BMJ 2000;321: 1455-9.
Hankey GJ, Dennis MS, Slattery JM, Warlow CP. Why is the outcome of transient ischaemic attacks different in different groups of patients? BMJ 1993;306: 1107-11.
Johnston SC, Gress DR, Browner WS, Sidney S. Short-term prognosis after emergency department diagnosis of TIA. JAMA 2000;284: 2901-6.
Schulz UG, Rothwell PM. Differences in vascular risk factors between etiological subtypes of ischemic stroke: importance of population-based studies. Stroke 2003;34: 2050-9.
Bamford J, Sandercock P, Dennis M, Burn J, Warlow C. A prospective study of acute cerebrovascular disease in the community: the Oxfordshire Community Stroke Project—1981-86. 2: incidence, case fatality rates and overall outcome at one year of cerebral infarction, primary intracerebral and subarachnoid haemorrhage. J Neurol Neurosurg Psychiatry 1990;53: 16-22.
Dennis MS, Bamford JM, Sandercock PA, Warlow CP. Incidence of transient ischemic attacks in Oxfordshire, England. Stroke 1989;20: 333-9.
Goldstein LB, Bertels C, Davis JN. Interrater reliability of the NIH stroke scale. Arch Neurol 1989;46: 660-2.
Van Swieten JC, Koudstaal PJ, Visser MC, Schouten HJ, van Gijn J. Interobserver agreement for the assessment of handicap in stroke patients. Stroke 1988;19: 604-7.
Lovett JK, Dennis MS, Sandercock PAG, Bamford J, Warlow CP, Rothwell PM. The very early risk of stroke after a transient ischaemic attack. Stroke 2003; 138-40e.
EAFT (European Atrial Fibrillation Trial) Study Group. Secondary prevention in non-rheumatic atrial fibrillation after transient ischaemic attack or minor stroke. Lancet 1993;342: 1255-62.
Rothwell PM, Eliasziw M, Gutnikov SA, Warlow CP, Barnett HJM, for the Carotid Endarterectomy Trialists' Collaboration. Effect of endarterectomy for symptomatic carotid stenosis in relation to clinical subgroups and to the timing of surgery. Lancet 2004 (in press).(A J Coull, clinical resea)