Peter M. Rothwell

Very Early Risk of Stroke After a First Transient Ischemic Attack

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 (n=209) 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.

Addition of Brain Infarction to the ABCD2 Score (ABCD2I) A Collaborative Analysis of Unpublished Data on 4574 Patients

Background and Purpose— The ABCD system was developed to predict early stroke risk after transient ischemic attack. Incorporation of brain imaging findings has been suggested, but reports have used inconsistent methods and been underpowered. We therefore performed an international, multicenter collaborative study of the prognostic performance of the ABCD2 score and brain infarction on imaging to determine the optimal weighting of infarction in the score (ABCD2I). Methods— Twelve centers provided unpublished data on ABCD2 scores, presence of brain infarction on either diffusion-weighted imaging or CT, and follow-up in cohorts of patients with transient ischemic attack diagnosed by World Health Organization criteria. Optimal weighting of infarction in the ABCD2I score was determined using area under the receiver operating characteristic curve analyses and random effects meta-analysis. Results— Among 4574 patients with TIA, acute infarction was present in 884 (27.6%) of 3206 imaged with diffusion-weighted imaging and new or old infarction was present in 327 (23.9%) of 1368 imaged with CT. ABCD2 score and presence of infarction on diffusion-weighted imaging or CT were both independently predictive of stroke (n=145) at 7 days (after adjustment for ABCD2 score, OR for infarction=6.2, 95% CI=4.2 to 9.0, overall; 14.9, 7.4 to 30.2, for diffusion-weighted imaging; 4.2, 2.6 to 6.9, for CT; all P<0.001). Incorporation of infarction in the ABCD2I score improved predictive power with an optimal weighting of 3 points for infarction on CT or diffusion-weighted imaging. Pooled areas under the curve increased from 0.66 (0.53 to 0.78) for the ABCD2 score to 0.78 (0.72 to 0.85) for the ABCD2I score. Conclusions— In secondary care, incorporation of brain infarction into the ABCD system (ABCD2I score) improves prediction of stroke in the acute phase after transient ischemic attack.

Predictors of risk of intracerebral haemorrhage in patients with a history of TIA or minor ischaemic stroke

We developed a model identifying patients with previous cerebral ischaemia at increased risk of intracerebral haemorrhage (ICH). Based on data from eight cohorts, 107 ICHs were found to have occurred among 12u200a648 patients. Multivariate Cox regression analysis identified the following predictors: age (⩾60 years, hazard ratio (HR) 2.07), blood glucose level (⩾7 mmol/l, HR 0.33), systolic blood pressure (⩾140 mm Hg, HR 2.17), and antihypertensive drugs (HR 1.53). The highest risk quartile was associated with five times more ICHs than the lowest quartile.

Why the US Center for Medicare and Medicaid Services should not extend reimbursement indications for carotid artery angioplasty/stenting.

Why the US Center for Medicare and Medicaid Services Should Not Extend Reimbursement Indications for Carotid Artery Angioplasty/Stenting

Response to Letter by Sanders et al

Response:nnWe thank Sanders and colleagues for their interest in the recent systematic review and pooled analysis of validations of the ABCD and ABCD2 scores.1 Various points were raised about the interpretation and application of the area under the curve (AUC) statistic, the search methods, and the comparison of the ABCD and ABCD2 scores, which we will attempt to address in order.nnThe ABCD system is designed for use as a triage tool between primary or emergency care and specialist care settings and is therefore based on clinical information that is available at the early stage of the patient pathway. We would argue that an AUC of 0.72 does indicate “good predictive value” given that it is based on elements obtained …

SIMPLE FUNCTIONAL SCALES MISS SIGNIFICANT COGNITIVE IMPAIRMENT: IMPLICATIONS FOR ASSESSING OUTCOME AFTER STROKE

Background About 10% of patients develop new dementia after first stroke and about 30% after recurrent stroke, and milder cognitive impairment is probably even more prevalent. There is some evidence that optimal acute stroke care may reduce these risks. We aimed to determine whether measures of dependency and disability commonly used in assessing stroke outcome adequately reflect cognitive burden. Methods In a population-based study of consecutive strokes, functional outcome was assessed with the Rankin and Barthel scores and cognitive outcome with the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) at least 6u2005months after index event. Standard cut-offs of MMSE≥27 (normal cognitive function), and MoCA≥26 (normal cognitive function) were used. Results Among 808 patients (mean age 72.3, 50% male), 591 were nondependent according to the Rankin score (0–2), of whom 181 (31%) had MMSE<27 and 58 (10%) had MMSE<24. Of 512 patients with normal Barthel (20), 144 (28%) had MMSE<27 and 45 (9%) had MMSE<24. In 349 patients who received the MoCA, 256 were nondependent on Rankin score, of whom 174 (68%) had MoCA<26, and 234 had a normal Barthel score, of whom 151 (64%) had MoCA<26. Conclusion Up to 60% of stroke patients defined as nondependent on standard functional outcome scales have some degree of cognitive impairment indicating that such functional outcome scales alone may be inadequate to assess the full effects of interventions in acute stroke.

IMPAIRMENT ON MONTREAL COGNITIVE ASSESSMENT IN TRANSIENT ISCHAEMIC ATTACK AND STROKE PATIENTS WITH NORMAL MINI-MENTAL STATE EXAMINATION SCORE IS CLINICALLY RELEVANT

Background We have shown that over 50% of transient ischaemic attack (TIA) and stroke patients with MMSE≥27, score below the cut-off for normal cognitive function on the Montreal Cognitive Assessment (MoCA). However, it is uncertain whether these patients have clinically relevant cognitive problems. We therefore aimed to determine the clinical, functional and neuropsychological characteristics of this group. Methods Consecutive patients with transient ischaemic attack (TIA) or stroke had the MMSE, MoCA, Rankin score, Addenbrookes cognitive examination-revised (ACE-R) and neuropsychological battery (trail test, Hopkins verbal learning test (HVLT), digit symbol substitution test (DSST), Boston naming test) at least 6u2005months after the index event. Patients with MMSE≥27 were grouped as MoCA-normal (MoCA≥26), or MoCA-impaired (MoCA<26). Results The MoCA-impaired group (n=162) were more likely than the MoCA-normal group (n=122) to have had a stroke rather than a transient ischaemic attack (TIA) (97/162 vs 50/122, OR 2.15, p=0.0016) and had higher Rankin scores (p<0.0001). All neuropsychological battery test scores and total ACE-R score were significantly (p<0.01) worse in the MoCA-impaired group than in the MoCA-normal group. Differences were greatest for the DSST (executive function/attention) and the HVLT (memory). Conclusion In patients with normal MMSE, impairment on the MoCA is associated with stroke vs TIA, with greater dependency, and with worse performance on neuropsychological battery.