Risks of recurrent stroke and all serious vascular events after spontaneous intracerebral haemorrhage: pooled analyses of two population-based studies.

BACKGROUND: Patients with stroke due to spontaneous (non-traumatic) intracerebral haemorrhage (ICH) are at risk of recurrent ICH, ischaemic stroke, and other serious vascular events. We aimed to analyse these risks in population-based studies and compare them with the risks in RESTART, which assessed antiplatelet therapy after ICH. METHODS: We pooled individual patient data from two prospective, population-based inception cohort studies of all patients with an incident firs-in-a-lifetime ICH in Oxfordshire, England (Oxford Vascular Study; April 1, 2002, to Sept 28, 2018) and Lothian, Scotland, UK (Lothian Audit of the Treatment of Cerebral Haemorrhage; June 1, 2010, to May 31, 2013). We quantified the absolute and relative risks of recurrent ICH, ischaemic stroke, or any serious vascular event (non-fatal stroke, non-fatal myocardial infarction, or vascular death), stratified by ICH location (lobar vs non-lobar) and comorbid atrial fibrillation (AF). We compared pooled event rates with those after allocation to avoid antiplatelet therapy in RESTART. FINDINGS: Among 674 patients (mean age 74·7 years [SD 12·6], 320 [47%] men) with 1553 person-years of follow-up, 46 recurrent ICHs (event rate 3·2 per 100 patient-years, 95% CI 2·0-5·1) and 25 ischaemic strokes (1·7 per 100 patient-years, 0·8-3·3) were reported. Patients with lobar ICH (n=317) had higher risk of recurrent ICH (5·1 per 100 patient-years, 95% CI 3·6-7·2) than patients with non-lobar ICH (n=355; 1·8 per 100 patient-years, 1·0-3·3; hazard ratio [HR] 3·2, 95% CI 1·6-6·3; p=0·0010), but there was no evidence of a difference in the risk of ischaemic stroke (1·8 per 100 patient-years, 1·0-3·2, vs 1·6 per 100 patient-years, 0·6-4·4; HR 1·1, 95% CI 0·5-2·8). Conversely, there was no evidence of a difference in recurrent ICH rate in patients with AF (n=147; 3·3 per 100 patient-years, 95% CI 1·0-10·7) compared with those without (n=526; 3·2 per 100 patient-years, 2·2-4·7; HR 0·9, 95% CI 0·4-2·1), but the risk of ischaemic stroke was higher with AF (6·3 per 100 patient-years, 3·7-10·9, vs 0·7 per 100 patient-years, 0·1-5·6; HR 8·2, 3·3-20·3; p<0·0001), resulting in patients with AF having a higher risk of all serious vascular events than patients without AF (15·5 per 100 patient-years, 10·0-24·1, vs 6·8 per 100 patient-years, 3·6-12·5; HR 1·78, 95% CI 1·16-2·74; p=0·0090). Only for patients with lobar ICH without comorbid AF was the risk of recurrent ICH greater than the risk of ischaemic stroke (5·2 per 100 patient-years, 95% CI 3·6-7·5, vs 0·9 per 100 patient-years, 0·2-4·8; p=0·00034). Comparing data from the pooled population-based studies with that from patients allocated to not receive antiplatelet therapy in RESTART, there was no evidence of a difference in the rate of recurrent ICH (3·5 per 100 patient-years, 95% CI 1·9-6·0, vs 4·4 per 100 patient-years, 2·6-6·1) or ischaemic stroke (3·4 per 100 patient-years, 1·9-5·9, vs 5·3 per 100 patient-years, 3·3-7·2). INTERPRETATION: The risks of recurrent ICH, ischaemic stroke, and all serious vascular events after ICH differ by ICH location and comorbid AF. These data enable risk stratification of patients in clinical practice and ongoing randomised trials. FUNDING: UK Medical Research Council, Stroke Association, British Heart Foundation, Wellcome Trust, and the National Institute for Health Research Oxford Biomedical Research Centre.

Sensitivity of Administrative Coding in Identifying Inpatient Acute Strokes Complicating Procedures or Other Diseases in UK Hospitals.

Background Administrative hospital diagnostic coding data are increasingly used in "big data" research and to assess complication rates after surgery or acute medical conditions. Acute stroke is a common complication of several procedures/conditions, such as carotid interventions, but data are lacking on the sensitivity of administrative coding in identifying acute stroke during inpatient stay. Methods and Results Using all acute strokes ascertained in a population-based cohort (2002-2017) as the reference, we determined the sensitivity of hospital administrative diagnostic codes ( International Classification of Diseases, Tenth Revision; ICD-10) for identifying acute strokes that occurred during hospital admission for other reasons, stratified by coding strategies, study periods, and stroke severity (National Institutes of Health Stroke Score

Medical Attention Seeking After Transient Ischemic Attack and Minor Stroke Before and After the UK Face, Arm, Speech, Time (FAST) Public Education Campaign: Results From the Oxford Vascular Study.

Importance: Risk of major stroke is high during the hours and days after transient ischemic attack (TIA) and minor stroke but is substantially reduced by urgent medical treatment. Public education campaigns have improved the response after major stroke, but their association with behavior after TIA and minor stroke is uncertain. The number of potentially preventable early recurrent strokes in patients who delay or fail to seek medical attention is unknown. Objective: To investigate the association of public education with delays and failure in seeking medical attention after TIA and minor stroke. Design, Setting, and Participants: Prospective population-based study of all patients with TIA or stroke who sought medical attention between April 1, 2002, and March 31, 2014, registered at 9 general practices in Oxfordshire, United Kingdom. Data analysis took place from July 1, 2013, to March 2, 2015. Exposures: Face, Arm, Speech, Time (FAST) public education campaign in the United Kingdom. Main Outcomes and Measures: Number of early recurrent strokes in patients who delayed or failed to seek medical attention, as well as the odds of seeking urgent attention after TIA and minor stroke before vs after initiation of the public education campaign. Results: Among 2243 consecutive patients with first TIA or stroke (mean [SD] age, 73.6 [13.4] years; 1126 [50.2%] female; 96.3% of white race/ethnicity), 1656 (73.8%) had a minor stroke or TIA. After the FAST campaign, patients with major stroke more often sought medical attention within 3 hours (odds ratio [OR], 2.56; 95% CI, 1.11-5.90; P = .03). For TIA and minor stroke, there was no improvement in use of emergency medical services (OR, 0.79; 95% CI, 0.50-1.23; P for interaction = .03 vs major stroke) or time to first seeking medical attention within 24 hours (OR, 0.75; 95% CI, 0.48-1.19; P for interaction = .006 vs major stroke). Patient perception of symptoms after TIA and minor stroke was associated with more urgent behavior, but correct perception declined after the FAST campaign (from 37.3% [289 of 774] to 27.6% [178 of 645]; OR, 0.64; 95% CI, 0.51-0.80; P < .001). One hundred eighty-eight patients had a stroke within 90 days of their initial TIA or stroke, of whom 93 (49.5%) followed unheeded TIAs for which no medical attention was sought, similar before and after the FAST campaign (43 of 538 [8.0%] before vs 50 of 615 [8.1%] after, P = .93). Conclusions and Relevance: This study suggests that in contrast to major stroke, extensive FAST-based public education has not improved the response to TIA and minor stroke in the United Kingdom, emphasizing the need for campaigns that are tailored to transient and less severe symptoms.

Late functional improvement after lacunar stroke: a population-based study.

BACKGROUND: Recovery in function after stroke involves neuroplasticity and adaptation to impairments. Few studies have examined differences in late functional improvement beyond 3 months among stroke subtypes, although interventions for late restorative therapies are often studied in lacunar stroke. Therefore, we compared rates of functional improvement beyond 3 months in patients with lacunar versus non-lacunar strokes. METHODS: In a prospective, population-based cohort of 3-month ischaemic stroke survivors (Oxford Vascular Study; 2002-2014), we examined changes in functional status (modified Rankin Scale (mRS), Rivermead Mobility Index (RMI), Barthel Index (BI)) in patients with lacunar versus non-lacunar strokes from 3 to 60 months poststroke, stratifying by age. We used logistic regression adjusted for age, sex and baseline disability to compare functional improvement (≥1 mRS grades, ≥1 RMI points and/or ≥2 BI points), particularly from 3 to 12 months. RESULTS: Among 1425 3-month survivors, 234 patients with lacunar stroke did not differ from others in 3-month outcome (adjusted OR (aOR) for 3-month mRS >2 adjusted for age/sex/National Institutes of Health Stroke Scale score/prestroke disability: 1.14, 95% CI 0.75 to 1.74, p=0.55), but were more likely to demonstrate further improvement between 3 months and 1 year (aOR (mRS) adjusted for age/sex/3-month mRS: 1.64, 1.17 to 2.31, p=0.004). The results were similar on restricting analyses to patients with 3-month mRS 2-4 and excluding recurrent events (aOR (mRS): 2.28, 1.34 to 3.86, p=0.002), or examining BI and RMI (aOR (RMI) adjusted for age/sex/3-month RMI: 1.78, 1.20 to 2.64, p=0.004). CONCLUSION: Patients with lacunar strokes have significant potential for late functional improvement from 3 to 12 months, which should motivate patients and clinicians to maximise late improvements in routine practice. However, since late recovery is common, intervention studies enrolling patients with lacunar strokes should be randomised and controlled.

Time course of blood pressure control prior to lacunar TIA and stroke: Population-based study.

OBJECTIVE: To determine the age-specific temporal trends in blood pressure (BP) before acute lacunar vs nonlacunar TIA and stroke. METHODS: In a population-based study of TIA/ischemic stroke (Oxford Vascular Study), we studied 15-year premorbid BP readings from primary care records in patients with lacunar vs nonlacunar events (Trial of Org 10172 in Acute Stroke Treatment [TOAST]) stratified by age (<65, ≥65 years). RESULTS: Of 2,085 patients (1,250 with stroke, 835 with TIA), 309 had lacunar events. In 493 patients <65 years of age, the prevalence of diagnosed hypertension did not differ between lacunar and nonlacunar events (46 [48.4%] vs 164 [41.2%], p = 0.20), but mean/SD premorbid BP (44,496 BP readings) was higher in patients with lacunar events (15-year records: systolic BP [SBP] 138.5/17.7 vs 133.3/15.0 mm Hg, p = 0.004; diastolic BP [DBP] 84.1/9.6 vs 80.9/8.4 mm Hg, p = 0.001), mainly because of higher mean BP during the 5 years before the event (SBP 142.6/18.8 vs 134.6/16.6 mm Hg, p = 0.0001; DBP 85.2/9.7 vs 80.6/9.0 mm Hg, p < 0.0001), with a rising trend (ptrend = 0.006) toward higher BP leading up to the event (<30-day pre-event SBP: 152.7/16.1 vs 135.3/23.1 mm Hg, p = 0.009; DBP 87.9/9.4 vs 80.8/12.8 mm Hg, p = 0.05; mean BP ≤1 year before the event 145.8/22.0 vs 134.7/16.1 mm Hg, p = 0.001; 86.1/10.7 vs 80.4/9.8 mm Hg, p = 0.0001). Maximum BP in the 5 years before the event was also higher in patients with lacunar events (SBP 173.7/26.6 vs 158.6/23.2 mm Hg, p = 0.0001; DBP 102.3/12.9 vs 94.2/11.2 mm Hg, p < 0.0001), as was persistently elevated BP (≥50% SBP >160 mm Hg, odd ratio 4.95, 95% confidence interval 1.99-12.31, p = 0.0002). However, no similar differences in BP were observed in patients ≥65 years of age. CONCLUSION: Recent premorbid BP control is strongly temporarily related to acute lacunar events at younger ages, suggesting a direct role of BP in accelerating causal pathology and highlighting the need to control hypertension quickly.

Time Course of Evolution of Disability and Cause-Specific Mortality After Ischemic Stroke: Implications for Trial Design.

BACKGROUND: Outcome in stroke trials is often based on a 3-month modified Rankin scale (mRS). How 3-month mRS relates to longer-term outcomes will depend on late recovery, delayed stroke-related deaths, recurrent strokes, and nonstroke deaths. We evaluated 3-month mRS and death/disability at 1 and 5 years in a population-based cohort study. METHODS AND RESULTS: In 3-month survivors of ischemic stroke (Oxford Vascular Study; 2002-2014), we related 3-month mRS to disability (defined as mRS >2) at 1 and 5 years and/or death rates (age/sex adjusted). Accrual of disability and index-stroke-related and nonstroke deaths in each poststroke year was categorized according to 3-month mRS. Among 1606 patients with acute ischemic stroke, 181 died within 3 months, but 126 index-stroke-related deaths and 320 other deaths occurred during the subsequent 4866 patient-years of follow-up up to 5 years. Although 69/126 (54.8%) post-3-month index-stroke-related deaths occurred after 1 year, mRS>2 at 1 year strongly predicted these deaths (adjusted hazard ratio=21.94, 95%CI 7.88-61.09, P<0.0001). Consequently, a 3-month mRS >2 was a strong independent predictor of death at both 1 year (adjusted hazard ratio=6.67, 95%CI 4.16-10.69, P<0.0001) and 5 years (adjusted hazard ratio=2.93, 95%CI 2.38-3.60, P<0.0001). Although mRS improved by ≥1 point from 3 months to 1 year in 317/1266 (25.0%) patients with 3-month mRS ≥1, improvement in mRS after 1 year was limited (improvement by ≥1 point: 91/858 [10.6%]; improvement to mRS ≤2: 13/353 [3.7%]). CONCLUSIONS: Our results reaffirm use of the 3-month mRS outcome in stroke trials. Although later recovery does occur, extending follow-up to 1 year would capture most long-term stroke-related disability. However, administrative mortality follow-up beyond 1 year has the potential to demonstrate translation of early disability gains into additional reductions in long-term mortality without much erosion by non-stroke-related deaths.

Age-specific incidence, outcome, cost, and projected future burden of atrial fibrillation-related embolic vascular events: a population-based study.

BACKGROUND: Prevalence of atrial fibrillation (AF) is >10% at age ≥80 years, but the impact of population aging on rates of AF-related ischemic events is uncertain. METHODS AND RESULTS: We studied age-specific incidence, outcome, and cost of all AF-related incident strokes and systemic emboli from 2002 to 2012 in the Oxford Vascular Study (OXVASC). We determined time trends in incidence of AF-related stroke in comparison with a sister study in 1981 to 1986, extrapolated numbers to the UK population and projected future numbers. Of 3096 acute cerebral or peripheral vascular events in the 92 728 study population, 383 incident ischemic strokes and 71 systemic emboli were related to AF, of which 272 (59.9%) occurred at ≥80 years. Of 597 fatal or disabling incident ischemic strokes, 262 (43.9%) were AF-related. Numbers of AF-related ischemic strokes at age ≥80 years increased nearly 3-fold from 1981-1986 to 2002-2012 (extrapolated to the United Kingdom: 6621 to 18 176 per year), due partly to increased age-specific incidence (relative rate 1.52, 95% confidence interval 1.31-1.77, P=0.001), with potentially preventable AF-related events at age ≥80 years costing the United Kingdom £374 million per year. At current incidence rates, numbers of AF-related embolic events at age ≥80 years will treble again by 2050 (72 974/year), with 83.5% of all events occurring in this age group. CONCLUSIONS: Numbers of AF-related incident ischemic strokes at age ≥80 years have trebled over the last 25 years, despite the introduction of anticoagulants, and are projected to treble again by 2050, along with the numbers of systemic emboli. Improved prevention in older people with AF should be a major public health priority.

Hospitalization resource use and costs before and after TIA and stroke: results from a population-based cohort study (OXVASC).

OBJECTIVES: High hospitalization rates, prolonged length of stay, and increased risks of subsequent events mean a steep increase in health care usage after stroke. No study, however, has examined to what extent increased costs after transient ischemic attack (TIA) or stroke are due to hospitalizations for the initial event, recurrent events, and/or nonvascular hospitalizations, and how costs compare with the year prior to the event. METHODS: We studied patients in a population-based cohort study (Oxford Vascular Study) in the United Kingdom from 2003 to 2007. Hospitalization and cost details were obtained from patients' individualized Hospital Episode Statistics records. RESULTS: A total of 295 incident TIA and 439 incident stroke patients were included. For patients with stroke, average costs increased from £1437 in the year pre-event to £6629 in the year post-event (P<0.0001). Sixty-four percent (£4224) of poststroke costs were due to hospitalizations linked to the index stroke, more than 30% of which were given nonvascular primary diagnoses on Hospital Episode Statistics, and £653 (10%) were due to hospitalizations linked to subsequent vascular events. For patients with TIA, costs increased from £876 1 year before the event to £2410 in the year post-event (P<0.0001). Patients with TIA incurred nonsignificantly higher costs due to hospitalizations linked to subsequent vascular events (£774) than for hospitalizations linked to the index TIA (£720). CONCLUSIONS: Hospital costs increased after TIA or stroke, primarily because of increased initial cerebrovascular hospitalizations. The finding that costs due to nonvascular diagnoses also increased after TIA or stroke appears, in part, to be explained by the miscoding of TIA/stroke-related hospitalizations in electronic information systems.

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.

Treating individuals 3: from subgroups to individuals: general principles and the example of carotid endarterectomy.

Clinicians often have to make treatment decisions based on the likelihood that an individual patient will benefit. In this article we consider the relevance of relative and absolute risk reductions, and draw attention to the importance of expressing the results of trials and subgroup analyses in terms of absolute risk. We describe the limitations of univariate subgroup analysis in situations in which there are several determinants of treatment effect, and review the potential for targeting treatments with risk models, especially when benefit is probably going to be dependent on the absolute risk of adverse outcomes with or without treatment. The ability to systematically take into account the characteristics of an individual patient and their interactions, to consider the risks and benefits of interventions separately if needed, and to provide patients with personalised estimates of their likelihood of benefit is shown using the example of endarterectomy for symptomatic carotid stenosis.

Fibrinogen concentration and risk of ischemic stroke and acute coronary events in 5113 patients with transient ischemic attack and minor ischemic stroke.

BACKGROUND AND PURPOSE: Fibrinogen is an independent risk factor for coronary events in population-based studies and in patients with coronary heart disease, but there is uncertainty about prediction of stroke, particularly in secondary prevention. METHODS: We studied unpublished data from 3 prospective studies of patients with recent transient ischemic attack (TIA) or minor ischemic stroke: the United Kingdom TIA Aspirin (UK-TIA) trial (n=1860); the Dutch TIA trial (n=2960); and the Oxford TIA Study (n=293). By separate and pooled analysis, we used Cox models to determine the relationship between fibrinogen and risk of ischemic stroke and other vascular events during 23,272 patient-years of follow-up and adjusted for other risk factors. RESULTS: There was no significant heterogeneity in fibrinogen risk associations between studies. Fibrinogen predicted subsequent ischemic stroke, with a pooled hazard ratio (HR) for values above the median of 1.34 (95% CI, 1.13 to 1.60; P=0.001). The association tended to be stronger in patients with nonlacunar (HR=1.42; 95% CI, 1.13 to 1.78; P=0.002) than lacunar syndromes (HR=1.09; 95% CI, 0.80 to 1.49; P=0.58), but was not significantly so (P=0.18). There was no association with hemorrhagic stroke (adjusted HR=1.09; 95% CI, 0.55 to 2.17; P=0.81). Fibrinogen predicted acute coronary events (adjusted HR=1.42; 95% CI, 1.18 to 1.70; P<0.001) and all ischemic vascular events (adjusted HR=1.31; 95% CI, 1.15 to 1.49; P<0.001), but not nonvascular death (adjusted HR=1.24; 95% CI, 0.90 to 1.70; P=0.19). CONCLUSIONS: In patients with a previous TIA or ischemic stroke, risks of recurrent ischemic stroke and acute coronary events increase linearly with fibrinogen levels, but the relationships are weaker than in some previous population-based studies.