Fiona C. Cuthbertson

Effect of urgent treatment of transient ischaemic attack and minor stroke on early recurrent stroke (EXPRESS study): a prospective population-based sequential comparison.

BACKGROUND The risk of recurrent stroke is up to 10% in the week after a transient ischaemic attack (TIA) or minor stroke. Modelling studies suggest that urgent use of existing preventive treatments could reduce the risk by 80-90%, but in the absence of evidence many health-care systems make little provision. Our aim was to determine the effect of more rapid treatment after TIA and minor stroke in patients who are not admitted direct to hospital. METHODS We did a prospective before (phase 1: April 1, 2002, to Sept 30, 2004) versus after (phase 2: Oct 1, 2004, to March 31, 2007) study of the effect on process of care and outcome of more urgent assessment and immediate treatment in clinic, rather than subsequent initiation in primary care, in all patients with TIA or minor stroke not admitted direct to hospital. The study was nested within a rigorous population-based incidence study of all TIA and stroke (Oxford Vascular Study; OXVASC), such that case ascertainment, investigation, and follow-up were complete and identical in both periods. The primary outcome was the risk of stroke within 90 days of first seeking medical attention, with independent blinded (to study period) audit of all events. FINDINGS Of the 1278 patients in OXVASC who presented with TIA or stroke (634 in phase 1 and 644 in phase 2), 607 were referred or presented direct to hospital, 620 were referred for outpatient assessment, and 51 were not referred to secondary care. 95% (n=591) of all outpatient referrals were to the study clinic. Baseline characteristics and delays in seeking medical attention were similar in both periods, but median delay to assessment in the study clinic fell from 3 (IQR 2-5) days in phase 1 to less than 1 (0-3) day in phase 2 (p<0.0001), and median delay to first prescription of treatment fell from 20 (8-53) days to 1 (0-3) day (p<0.0001). The 90-day risk of recurrent stroke in the patients referred to the study clinic was 10.3% (32/310 patients) in phase 1 and 2.1% (6/281 patients) in phase 2 (adjusted hazard ratio 0.20, 95% CI 0.08-0.49; p=0.0001); there was no significant change in risk in patients treated elsewhere. The reduction in risk was independent of age and sex, and early treatment did not increase the risk of intracerebral haemorrhage or other bleeding. INTERPRETATION Early initiation of existing treatments after TIA or minor stroke was associated with an 80% reduction in the risk of early recurrent stroke. Further follow-up is required to determine long-term outcome, but these results have immediate implications for service provision and public education about TIA and minor stroke.

Population-based study of event-rate, incidence, case fatality, and mortality for all acute vascular events in all arterial territories (Oxford Vascular Study).

BACKGROUND Acute coronary, cerebrovascular, and peripheral vascular events have common underlying arterial pathology, risk factors, and preventive treatments, but they are rarely studied concurrently. In the Oxford Vascular Study, we determined the comparative epidemiology of different acute vascular syndromes, their current burdens, and the potential effect of the ageing population on future rates. METHODS We prospectively assessed all individuals presenting with an acute vascular event of any type in any arterial territory irrespective of age in a population of 91 106 in Oxfordshire, UK, in 2002-05. FINDINGS 2024 acute vascular events occurred in 1657 individuals: 918 (45%) cerebrovascular (618 stroke, 300 transient ischaemic attacks [TIA]); 856 (42%) coronary vascular (159 ST-elevation myocardial infarction, 316 non-ST-elevation myocardial infarction, 218 unstable angina, 163 sudden cardiac death); 188 (9%) peripheral vascular (43 aortic, 53 embolic visceral or limb ischaemia, 92 critical limb ischaemia); and 62 unclassifiable deaths. Relative incidence of cerebrovascular events compared with coronary events was 1.19 (95% CI 1.06-1.33) overall; 1.40 (1.23-1.59) for non-fatal events; and 1.21 (1.04-1.41) if TIA and unstable angina were further excluded. Event and incidence rates rose steeply with age in all arterial territories, with 735 (80%) cerebrovascular, 623 (73%) coronary, and 147 (78%) peripheral vascular events in 12 886 (14%) individuals aged 65 years or older; and 503 (54%), 402 (47%), and 105 (56%), respectively, in the 5919 (6%) aged 75 years or older. Although case-fatality rates increased with age, 736 (47%) of 1561 non-fatal events occurred at age 75 years or older. INTERPRETATION The high rates of acute vascular events outside the coronary arterial territory and the steep rise in event rates with age in all territories have implications for prevention strategies, clinical trial design, and the targeting of funds for service provision and research.

Underestimation of Cognitive Impairment by Mini-Mental State Examination Versus the Montreal Cognitive Assessment in Patients With Transient Ischemic Attack and Stroke A Population-Based Study

Background and Purpose— The Mini-Mental State Examination (MMSE) is insensitive to mild cognitive impairment and executive function. The more recently developed Montreal Cognitive Assessment (MoCA), an alternative, brief 30-point global cognitive screen, might pick up more cognitive abnormalities in patients with cerebrovascular disease. Methods— In a population-based study (Oxford Vascular Study) of transient ischemic attack and stroke, the MMSE and MoCA were administered to consecutive patients at 6-month or 5-year follow-up. Accepted cutoffs of MMSE <27 and MoCA <26 were taken to indicate cognitive impairment. Results— Of 493 patients, 413 (84%) were testable. Untestable patients were older (75.5 versus 69.9 years, P<0.001) and often had dysphasia (24%) or dementia (15%). Although MMSE and MoCA scores were highly correlated (r2=0.80, P<0.001), MMSE scores were skewed toward higher values, whereas MoCA scores were normally distributed: median and interquartile range 28 (26 to 29) and 23 (20 to 26), respectively. Two hundred ninety-one of 413 (70%) patients had MoCA <26 of whom 162 had MMSE ≥27, whereas only 5 patients had MoCA ≥26 and MMSE <27 (P<0.0001). In patients with MMSE ≥27, MoCA <26 was associated with higher Rankin scores (P=0.0003) and deficits in delayed recall, abstraction, visuospatial/executive function, and sustained attention. Conclusion— The MoCA picked up substantially more cognitive abnormalities after transient ischemic attack and stroke than the MMSE, demonstrating deficits in executive function, attention, and delayed recall.

Population-Based Study of Disability and Institutionalization After Transient Ischemic Attack and Stroke 10-Year Results of the Oxford Vascular Study

Background and Purpose— Long-term outcome information after transient ischemic attack (TIA) and stroke is required to help plan and allocate care services. We evaluated the impact of TIA and stroke on disability and institutionalization over 5 years using data from a population-based study. Methods— Patients from a UK population-based cohort study (Oxford Vascular Study) were recruited from 2002 to 2007 and followed up to 2012. Patients were followed up at 1, 6, 12, 24, and 60 months postevent and assessed using the modified Rankin scale. A multivariate regression analysis was performed to assess the predictors of disability postevent. Results— A total of 748 index stroke and 440 TIA cases were studied. For patients with TIA, disability levels increased from 14% (63 of 440) premorbidly to 23% (60 of 256) at 5 years (P=0.002), with occurrence of subsequent stroke being a major predictor of disability. For stroke survivors, the proportion disabled (modified Rankin scale >2) increased from 21% (154 of 748) premorbidly to 43% (273 of 634) at 1 month (P<0.001), with 39% (132 of 339) of survivors disabled 5 years after stroke. Five years postevent, 70% (483 of 690) of patients with stroke and 48% (179 of 375) of patients with TIA were either dead or disabled. The 5-year risk of care home institutionalization was 11% after TIA and 19% after stroke. The average 5-year cost per institutionalized patient was

Lack of reproducibility of assessment of aspirin responsiveness by optical aggregometry and two platelet function tests

99 831 (SD, 67 020) for TIA and

Telephone assessment of cognition after transient ischemic attack and stroke: modified telephone interview of cognitive status and telephone Montreal Cognitive Assessment versus face-to-face Montreal Cognitive Assessment and neuropsychological battery.

125 359 (SD, 91 121) for stroke. Conclusions— Our results show that 70% of patients with stroke are either dead or disabled 5 years after the event. Thus, there remains considerable scope for improvements in acute treatment and secondary prevention to reduce postevent disability and institutionalization.

Quality of life after TIA and stroke Ten-year results of the Oxford Vascular Study

The term aspirin-resistance describes the failure of aspirin to inhibit thromboxane A2 production. Many new tests have become available for potentially measuring aspirin responses but some are non-specific and do not isolate COX-1 activity. We previously demonstrated that agreement between two tests (PFA-100® and VerifyNow®-ASA) and light transmission aggregation (LTA) was no greater than would be expected by chance. In this study we re-tested the same patients using identical methods after 1 year to determine whether poor agreement might have been due to assessment in the acute phase and whether the results of the individual tests are consistent over time. Platelet function by all three tests was re-tested in the 72 patients who were alive and still receiving low dose ASA therapy one year after the first tests were performed. On re-testing the prevalence of ASA non-responsiveness compared with baseline was 10% vs 17% by the VerifyNow®-ASA test, 25% vs 22% by the PFA-100®, and 1% vs 5% by LTA. Agreement between the tests at 1 year remained poor (kappas: 0.02–0.17) and only one patient was identified as a non-responder by all three tests, in keeping with the theoretical differences between the tests. Within test comparisons of baseline vs 1 year showed moderate agreement for the PFA-100® (kappa = 0.44, 95% CI 0.19–0.68, p = 0.0006), a fair agreement for VerifyNow®-ASA (kappa = 0.34, 0.04–0.64, p = 0.12) and poor agreement for LTA (kappa = 0.14, −0.11 −0.39, p = 0.24 for ADP; kappa = 0.09, −0.21–0.39, p = 0.41 for arachidonic acid). Agreement between the three tests in identifying aspirin non-responsiveness remained poor in patients who had been taking aspirin for at least 1 year follow-up. Reproducibility over time was no greater than chance for LTA and only moderate for VerifyNow®-ASA and PFA-100®. Lack of consistency over time in identification of apparently non-responsiveness individuals is likely to substantially undermine any ability of these tests to predict risk of recurrent vascular events.

Methodological Factors in Determining Risk of Dementia After Transient Ischemic Attack and Stroke (II) Effect of Attrition on Follow-Up

Background and Purpose— Face-to-face cognitive testing is not always possible in large studies. Therefore, we assessed the telephone Montreal Cognitive Assessment (T-MoCA: MoCA items not requiring pencil and paper or visual stimulus) and the modified Telephone Interview of Cognitive Status (TICSm) against face-to-face cognitive tests in patients with transient ischemic attack (TIA) or stroke. Methods— In a population-based study, consecutive community-dwelling patients underwent the MoCA and neuropsychological battery >1 year after TIA or stroke, followed by T-MoCA (22 points) and TICSm (39 points) at least 1 month later. Mild cognitive impairment (MCI) was diagnosed using modified Petersen criteria and the area under the receiver-operating characteristic curve (AUC) determined for T-MoCA and TICSm. Results— Ninety-one nondemented subjects completed neuropsychological testing (mean±SD age, 72.9±11.6 years; 54 males; stroke 49%) and 73 had telephone follow-up. MoCA subtest scores for repetition, abstraction, and verbal fluency were significantly worse (P<0.02) by telephone than during face-to-face testing. Reliability of diagnosis for MCI (AUC) were T-MoCA of 0.75 (95% confidence interval [CI], 0.63–0.87) and TICSm of 0.79 (95% CI, 0.68–0.90) vs face-to-face MoCA of 0.85 (95% CI, 0.76–0.94). Optimal cutoffs were 18 to 19 for T-MoCA and 24 to 25 for TICSm. Reliability of diagnosis for MCI (AUC) was greater when only multi-domain impairment was considered (T-MoCA=0.85; 95% CI, 0.75–0.96 and TICSm=0.83, 95% CI, 0.70–0.96) vs face-to-face MoCA=0.87; 95% CI, 0.76–0.97). Conclusions— Both T-MoCA and TICSm are feasible and valid telephone tests of cognition after TIA and stroke but perform better in detecting multi-domain vs single-domain impairment. However, T-MoCA is limited in its ability to assess visuoexecutive and complex language tasks compared with face-to-face MoCA.

Population-Based Study of Disability and Institutionalization After Transient Ischemic Attack and Stroke

Objective: To evaluate the 5-year impact of stroke and TIA on utility and quality-adjusted survival. Methods: TIA and stroke patients from a UK population-based study (Oxford Vascular Study) were recruited from 2002 to 2007, and followed up until 2012. Quality of life was assessed over 5 years using the EQ-5D (EuroQol-5 Dimensions), with responses converted into utilities ranging from −0.59 (worse than death) to 1 (perfect health), using UK population valuations. Utilities for stroke and TIA patients were compared with those in matched controls obtained from the 2006 Health Survey for England. Five-year quality-adjusted life years were estimated by combining utility and survival information. Results: Four hundred forty TIA and 748 stroke patients were ascertained and included. Utility remained constant at approximately 0.78 over the 5 years after TIA. Utility improved from 0.64 one month after stroke to 0.70 at 6 months (p = 0.006), remaining at approximately 0.70 thereafter. Matched controls had considerably higher utility levels than stroke/TIA patients (0.85, p < 0.001). Event severity and recurrent stroke were significant predictors of decreased long-term utility. Five-year quality-adjusted life expectancy was 3.32 (95% confidence interval: 3.22–3.48) quality-adjusted life years after TIA and 2.21 (2.15–2.37) after stroke, varying considerably by severity (minor: 2.94; moderate: 1.65; and severe: 0.70). Conclusion: Quality-adjusted survival is low over the 5 years after stroke and TIA, with severity and recurrent stroke being major predictors. There remains considerable scope for improvements in acute treatment and secondary prevention to improve the quality of life after TIA and stroke.

A population-based study of disability and institutionalisation after TIA and stroke: 10-year results of the Oxford Vascular Study

Background and Purpose— Cognitive outcomes in cohorts and trials are often based only on face-to-face clinic assessment. However, cognitive impairment is strongly associated with increased morbidity and mortality, leading to substantial loss to clinic follow-up. In the absence of previous population-based data, we determined the effect of such attrition on measured risk of dementia after transient ischemic attack and stroke. Methods— Patients with transient ischemic attack or stroke prospectively recruited (2002–2007) into the Oxford Vascular (OXVASC) study had baseline clinical/cognitive assessment and follow-up to 2014. Dementia was diagnosed through face-to-face clinic interview, supplemented by home visits and telephone assessment in patients unable to attend clinic and by hand-searching of primary care records in uncontactable patients. Results— Of 1236 patients (mean age/SD, 75.2/12.1 years; 582 men), 527 (43%) died by 5-year follow-up. Follow-up assessment rates (study clinic, home visit, or telephone) of survivors were 947 in 1026 (92%), 857 in 958 (89%), 792 in 915 (87%), and 567 in 673 (84%) at 1, 6, 12 months and 5 years. Dementia developed in 260 patients, of whom 110 (42%; n=50 primary care records, n=49 home visit, and n=11 telephone follow-up) had not been available for face-to-face clinic follow-up at the time of diagnosis. The 5-year cumulative incidence of postevent dementia was 29% (26%–32%) overall but was only 17% (14% to 19%) in clinic assessed versus 45% (39%–51%) in nonclinic-assessed patients (P difference<0.001). Conclusions— Exclusion of patients unavailable for clinic follow-up reduces the measured risk of postevent dementia. Use of multiple follow-up methods, including home visits, telephone assessments, and consent, to access primary care records substantially increases ascertainment of longer-term dementia outcomes.