Very Early Risk of Stroke After a First Transient Ischemic Attack

Abstract

Background and Purpose-The commonly quoted early risks of stroke after a first transient ischemic attack (TIA)-1% to 2% at 7 days and 2% to 4% at 1 month-are likely to be underestimates because of the delay before inclusion into previous studies and the exclusion of patients who had a stroke during this time. Therefore, it is uncertain how urgently TIA patients should be assessed. We used data from the Oxford Community Stroke Project (OCSP) to estimate the very early stroke risk after a TIA and investigated the potential effects of the delays before specialist assessment. Methods-All OCSP patients who had a first-ever definite TIA during the study period (nϭ209) were included. Three analyses were used to estimate the early stroke risk after a first TIA starting from 3 different dates: assessment by a neurologist, referral to the TIA service, and onset of first TIA. Results-The stroke risk from assessment by a neurologist was 1.9% [95% confidence interval (CI), 0.1 to 3.8] at 7 days and 4.4% (95% CI, 1.6 to 7.2) at 30 days. The 7-and 30-day stroke risks from referral were 2.4% (95% CI, 0.3 to 4.5) and 4.9% (95% CI, 1.9 to 7.8), respectively, and from onset of first-ever TIA were 8.6% (95% CI, 4.8 to 12.4) and 12.0% (95% CI, 7.6 to 16.4), respectively. Conclusions-The early risk of stroke from date of first-ever TIA is likely to be higher than commonly quoted. Public education about the symptoms of TIA is needed so that medical attention is sought more urgently and stroke prevention strategies are implemented sooner. (Stroke. 2003;34:e138-e142.)Key Words: cerebral ischemia, transient Ⅲ stroke Ⅲ stroke prevention A pproximately 15% of ischemic strokes are preceded by a transient ischemic attack (TIA). 1 Guidelines highlight the need for rapid-access TIA clinics, 2-4 but it is uncertain how urgently patients must be seen, and there is great variation in practice. 5 The danger of delaying investigation and treatment after a TIA depends on the early risk of stroke. Risks of 1% to 2% at 7 days and 2% to 4% at 1 month are usually quoted. 1,4 However, these are likely to be underestimates because of the delay before patients were included into previous hospital-based studies and clinical trials. Any patients who had a major stroke during this period were excluded.A recent study of patients presenting to an emergency department, almost all of whom were enrolled within 24 hours of the TIA, reported a stroke risk of 5.3% at 2 days. 6 However, this population was self-selected, and there are no equivalent data from populationbased studies. In contrast to stroke incidence and prognosis studies, population-based studies of TIA are scarce. 7 One early populationbased TIA incidence study provided some information on the risk of stroke from the date of TIA, but the analysis was based on retrospective case-note review, and some patients did not come under observation until several years after their TIA. 8 The only population-based prospective TIA incidence study that followed up patients and that satisfies the criteria for a hig...

2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS Guideline on the Management of Patients With Extracranial Carotid and Vertebral Artery Disease: Executive summary

“…[99][100][101][102][103][104][105][106] In patients with ischemia in the territory of a stenotic carotid artery, CEA within the first 2 weeks reduces the risk of stroke, 35,93 but the benefit of surgery diminishes with time after the initial event. 107 Transient monocular blindness (amaurosis fugax) is caused by temporary reduction of blood flow to an eye.…”

The Importance of Early Carotid Endarterectomy in Symptomatic Patients

“…12 The estimated risk of repeat cerebral events observed in this study was slightly higher than the risk of recurrent stroke observed in previous studies. 5,6 Furthermore, the risk factor analysis in the current study showed that elderly patients waiting longer for surgery are more likely to suffer from repeat cerebral events. This supports the view that repeat events are likely to have different predictive factors and early recognition of these may be useful in preventing any delays in carotid intervention.…”

“…5 The Oxford Community Stroke Project (OCSP) reported a stroke risk of 8.6% at 7 days and 12% at 1 month after first-ever TIA and 2.4% in the first week after referral rising to 4.9% at 1 month. 6 As a result, timing of carotid endarterectomy following cerebral ischaemic event has been a topic of considerable interest. [7][8][9][10][11] Carotid endarterectomy is beneficial in reducing risk of stroke in the presence of > 70% carotid stenosis, 3,4 with greater absolute risk reduction seen if surgery is carried out within 1-2 weeks of the ischaemic event.…”

National survey of emergency physicians for transient ischemic attack (TIA) risk stratification consensus and appropriate treatment for a given level of risk

“…Previous studies have estimated this risk to be 4%-10% within 7 days of TIA, and increases to 8%-12% by 90 days. [3][4][5][6][7][8][9][10][11][12] Stroke is a serious and significant health and economic burden, because it is the leading cause of adult disability, the second leading cause of dementia, and the third leading cause of death. [13][14][15] In addition, it results in the use of large amounts of health care system resources.…”