Summary Background The decision of whether to treat incidental intracranial saccular aneurysms is complicated by limitations in current knowledge of their natural history. We combined individual ...patient data from prospective cohort studies to determine predictors of aneurysm rupture and to construct a risk prediction chart to estimate 5-year aneurysm rupture risk by risk factor status. Methods We did a systematic review and pooled analysis of individual patient data from 8382 participants in six prospective cohort studies with subarachnoid haemorrhage as outcome. We analysed cumulative rupture rates with Kaplan-Meier curves and assessed predictors with Cox proportional-hazard regression analysis. Findings Rupture occurred in 230 patients during 29 166 person-years of follow-up. The mean observed 1-year risk of aneurysm rupture was 1·4% (95% CI 1·1–1·6) and the 5-year risk was 3·4% (2·9–4·0). Predictors were age, hypertension, history of subarachnoid haemorrhage, aneurysm size, aneurysm location, and geographical region. In study populations from North America and European countries other than Finland, the estimated 5-year absolute risk of aneurysm rupture ranged from 0·25% in individuals younger than 70 years without vascular risk factors with a small-sized (<7 mm) internal carotid artery aneurysm, to more than 15% in patients aged 70 years or older with hypertension, a history of subarachnoid haemorrhage, and a giant-sized (>20 mm) posterior circulation aneurysm. By comparison with populations from North America and European countries other than Finland, Finnish people had a 3·6-times increased risk of aneurysm rupture and Japanese people a 2·8-times increased risk. Interpretation The PHASES score is an easily applicable aid for prediction of the risk of rupture of incidental intracranial aneurysms. Funding Netherlands Organisation for Health Research and Development.
Summary Background Aspirin is recommended for secondary prevention after transient ischaemic attack (TIA) or ischaemic stroke on the basis of trials showing a 13% reduction in long-term risk of ...recurrent stroke. However, the risk of major stroke is very high for only the first few days after TIA and minor ischaemic stroke, and observational studies show substantially greater benefits of early medical treatment in the acute phase than do longer-term trials. We hypothesised that the short-term benefits of early aspirin have been underestimated. Methods Pooling the individual patient data from all randomised trials of aspirin versus control in secondary prevention after TIA or ischaemic stroke, we studied the effects of aspirin on the risk and severity of recurrent stroke, stratified by the following time periods: less than 6 weeks, 6–12 weeks, and more than 12 weeks after randomisation. We compared the severity of early recurrent strokes between treatment groups with shift analysis of modified Rankin Scale (mRS) score. To understand possible mechanisms of action, we also studied the time course of the interaction between effects of aspirin and dipyridamole in secondary prevention of stroke. In a further analysis we pooled data from trials of aspirin versus control in which patients were randomised less than 48 h after major acute stroke, stratified by severity of baseline neurological deficit, to establish the very early time course of the effect of aspirin on risk of recurrent ischaemic stroke and how this differs by severity at baseline. Findings We pooled data for 15 778 participants from 12 trials of aspirin versus control in secondary prevention. Aspirin reduced the 6 week risk of recurrent ischaemic stroke by about 60% (84 of 8452 participants in the aspirin group had an ischaemic stroke vs 175 of 7326; hazard ratio HR 0·42, 95% CI 0·32–0·55, p<0·0001) and disabling or fatal ischaemic stroke by about 70% (36 of 8452 vs 110 of 7326; 0·29, 0·20–0·42, p<0·0001), with greatest benefit noted in patients presenting with TIA or minor stroke (at 0–2 weeks, two of 6691 participants in the aspirin group with TIA or minor stroke had a disabling or fatal ischaemic stroke vs 23 of 5726 in the control group, HR 0·07, 95% CI 0·02–0·31, p=0·0004; at 0–6 weeks, 14 vs 60 participants, 0·19, 0·11–0·34, p<0·0001). The effect of aspirin on early recurrent ischaemic stroke was due partly to a substantial reduction in severity (mRS shift analysis odds ratio OR 0·42, 0·26–0·70, p=0·0007). These effects were independent of dose, patient characteristics, or aetiology of TIA or stroke. Some further reduction in risk of ischaemic stroke accrued for aspirin only versus control from 6–12 weeks, but there was no benefit after 12 weeks (stroke risk OR 0·97, 0·84–1·12, p=0·67; severity mRS shift OR 1·00, 0·77–1·29, p=0·97). By contrast, dipyridamole plus aspirin versus aspirin alone had no effect on risk or severity of recurrent ischaemic stroke within 12 weeks (OR 0·90, 95% CI 0·65–1·25, p=0·53; mRS shift OR 0·90, 0·37–1·72, p=0·99), but dipyridamole did reduce risk thereafter (0·76, 0·63–0·92, p=0·005), particularly of disabling or fatal ischaemic stroke (0·64, 0·49–0·84, p=0·0010). We pooled data for 40 531 participants from three trials of aspirin versus control in major acute stroke. The reduction in risk of recurrent ischaemic stroke at 14 days was most evident in patients with less severe baseline deficits, and was substantial by the second day after starting treatment (2–3 day HR 0·37, 95% CI 0·25–0·57, p<0·0001). Interpretation Our findings confirm that medical treatment substantially reduces the risk of early recurrent stroke after TIA and minor stroke and identify aspirin as the key intervention. The considerable early benefit from aspirin warrants public education about self-administration after possible TIA. The previously unrecognised effect of aspirin on severity of early recurrent stroke, the diminishing benefit with longer-term use, and the contrasting time course of effects of dipyridamole have implications for understanding mechanisms of action. Funding Wellcome Trust, the National Institute of Health Research (NIHR) Biomedical Research Centre, Oxford.
Summary More and more patients survive aneurysmal subarachnoid haemorrhage (aSAH), with case fatality decreasing by 17% in absolute terms over the past three decades and incidence remaining ...relatively stable at nine per 100 000 patient-years. The mean age at which aSAH occurs is reasonably young at 55 years, and people of this age in the general population have a good life expectancy. However, there are few data for life expectancy after aSAH, and the risks of late recurrent aSAH and other vascular diseases are unclear. The course of associated long-term physical and cognitive deficits after aSAH is not well established, leading to questions about potential outcomes to quality of life and working capacity, as well as best clinical practices.
Stroke is a major cause of death and disability worldwide. Without improvements in prevention, the burden will increase during the next 20 years because of the ageing population, especially in ...developing countries. Major advances have occurred in secondary prevention during the past three decades, which demonstrate the broader potential to prevent stroke. We review the main medical treatments that should be considered for most patients with transient ischaemic attack or ischaemic stroke in the acute phase and the long term, and draw attention to recent developments.
The use of thromboprophylaxis to prevent clinically apparent venous thromboembolism after knee arthroscopy or casting of the lower leg is disputed. We compared the incidence of symptomatic venous ...thromboembolism after these procedures between patients who received anticoagulant therapy and those who received no anticoagulant therapy.
We conducted two parallel, pragmatic, multicenter, randomized, controlled, open-label trials with blinded outcome evaluation: the POT-KAST trial, which included patients undergoing knee arthroscopy, and the POT-CAST trial, which included patients treated with casting of the lower leg. Patients were assigned to receive either a prophylactic dose of low-molecular-weight heparin (for the 8 days after arthroscopy in the POT-KAST trial or during the full period of immobilization due to casting in the POT-CAST trial) or no anticoagulant therapy. The primary outcomes were the cumulative incidences of symptomatic venous thromboembolism and major bleeding within 3 months after the procedure.
In the POT-KAST trial, 1543 patients underwent randomization, of whom 1451 were included in the intention-to-treat population. Venous thromboembolism occurred in 5 of the 731 patients (0.7%) in the treatment group and in 3 of the 720 patients (0.4%) in the control group (relative risk, 1.6; 95% confidence interval CI, 0.4 to 6.8; absolute difference in risk, 0.3 percentage points; 95% CI, -0.6 to 1.2). Major bleeding occurred in 1 patient (0.1%) in the treatment group and in 1 (0.1%) in the control group (absolute difference in risk, 0 percentage points; 95% CI, -0.6 to 0.7). In the POT-CAST trial, 1519 patients underwent randomization, of whom 1435 were included in the intention-to-treat population. Venous thromboembolism occurred in 10 of the 719 patients (1.4%) in the treatment group and in 13 of the 716 patients (1.8%) in the control group (relative risk, 0.8; 95% CI, 0.3 to 1.7; absolute difference in risk, -0.4 percentage points; 95% CI, -1.8 to 1.0). No major bleeding events occurred. In both trials, the most common adverse event was infection.
The results of our trials showed that prophylaxis with low-molecular-weight heparin for the 8 days after knee arthroscopy or during the full period of immobilization due to casting was not effective for the prevention of symptomatic venous thromboembolism. (Funded by the Netherlands Organization for Health Research and Development; POT-KAST and POT-CAST ClinicalTrials.gov numbers, NCT01542723 and NCT01542762 , respectively.).
Summary Background Unruptured intracranial aneurysms (UIAs) are increasingly detected and are an important health-care burden. We aimed to assess the prevalence of UIAs according to family history, ...comorbidity, sex, age, country, and time period. Methods Through searches of PubMed, Embase, and Web of Science we updated our 1998 systematic review up to March, 2011. We calculated prevalences and prevalence ratios (PRs) with random-effects binomial meta-analysis. We assessed time trends with year of study as a continuous variable. Findings We included 68 studies, which reported on 83 study populations and 1450 UIAs in 94 912 patients from 21 countries. The overall prevalence was estimated as 3·2% (95% CI 1·9–5·2) in a population without comorbidity, with a mean age of 50 years, and consisting of 50% men. Compared with populations without the comorbidity, PRs were 6·9 (95% CI 3·5–14) for autosomal dominant polycystic kidney disease (ADPKD), 3·4 (1·9–5·9) for a positive family history of intracranial aneurysm of subarachnoid haemorrhage, 3·6 (0·4–30) for brain tumour, 2·0 (0·9–4·6) for pituitary adenoma, and 1·7 (0·9–3·0) for atherosclerosis. The PR for women compared with men was 1·61 (1·02–2·54), with a ratio of 2·2 (1·3–3·6) in study populations with a mean age of more than 50 years. Compared with patients older than 80 years, we found no differences by age, except for patients younger than 30 years (0·01, 0·00–0·12). Compared with the USA, PRs were similar for other countries, including Japan (0·8, 0·4–1·7) and Finland (1·0, 0·4–2·4). There was no statistically significant time trend. Interpretation The prevalence of UIAs is higher in patients with ADPKD or a positive family history of intracranial aneurysm of subarachnoid haemorrhage than in people without comorbidity. In Finland and Japan, the higher incidence of subarachnoid haemorrhage is not explained by a higher prevalence of UIAs, implicating higher risks of rupture. Funding Julius Centre for Health Sciences and Primary Care and Department of Neurology and Neurosurgery, University Medical Centre, Utrecht.
Summary Background Arterial thrombosis is a major clinical manifestation of the antiphospholipid syndrome, which is an autoimmune disease found mostly in young women. Although the presence of ...circulating antiphospholipid antibodies in individuals who have a thrombotic event is a prerequisite for the diagnosis of the antiphospholipid syndrome, the risk of arterial thrombosis associated with antiphospholipid antibodies in the general population is unclear. Methods In RATIO (Risk of Arterial Thrombosis In relation to Oral contraceptives), a large multicentre population-based case-control study, we enrolled women aged under 50 years who were admitted to hospital at 16 centres with first ischaemic stroke or myocardial infarction between January, 1990, and October, 1995. An additional 59 women who presented with ischaemic stroke at the University Medical Centre Utrecht between 1996 and 2001 were also enrolled. Information on cardiovascular risk factors (such as oral contraceptive use, smoking, and hypertension) were assessed with a standard questionnaire. During the second phase (1998–2002), blood samples were taken to measure antiphospholipid antibody profiles (lupus anticoagulant, anticardiolipin IgG, anti-β2 -glycoprotein I IgG, and antiprothrombin IgG) and to determine genetic prothrombotic risk factors (factor V G1691A variant, prothrombin G20210A variant, and factor XIII 204Phe allele). Findings 175 patients with ischaemic stroke, 203 patients with myocardial infarction, and 628 healthy controls were included. Patients were frequency matched with controls for age, residence area, and index year. Lupus anticoagulant was found in 30 (17%) patients with ischaemic stroke, six (3%) patients with myocardial infarction, and four (0·7%) in the control group. The odds ratio for myocardial infarction was 5·3 (95% CI 1·4–20·8), which increased to 21·6 (1·9–242·0) in women who used oral contraceptives and 33·7 (6·0–189·0) in those who smoked. The odds ratio for ischaemic stroke was 43·1 (12·2–152·0), which increased to 201·0 (22·1–1828·0) in women who used oral contraceptives and 87·0 (14·5–523·0) in those who smoked. In women who had anti-β2 -glycoprotein I antibodies, the risk of ischaemic stroke was 2·3 (1·4–3·7), but the risk of myocardial infarction was not increased (0·9, 0·5–1·6). Neither anticardiolipin nor antiprothrombin antibodies affected the risk of myocardial infarction or ischaemic stroke. Interpretation Our results suggest that lupus anticoagulant is a major risk factor for arterial thrombotic events in young women, and the presence of other cardiovascular risk factors increases the risk even further. Funding Netherlands Heart Foundation and Leducq Foundation.
Summary Background High-dose aspirin (≥500 mg daily) reduces long-term incidence of colorectal cancer, but adverse effects might limit its potential for long-term prevention. The long-term ...effectiveness of lower doses (75–300 mg daily) is unknown. We assessed the effects of aspirin on incidence and mortality due to colorectal cancer in relation to dose, duration of treatment, and site of tumour. Methods We followed up four randomised trials of aspirin versus control in primary (Thrombosis Prevention Trial, British Doctors Aspirin Trial) and secondary (Swedish Aspirin Low Dose Trial, UK-TIA Aspirin Trial) prevention of vascular events and one trial of different doses of aspirin (Dutch TIA Aspirin Trial) and established the effect of aspirin on risk of colorectal cancer over 20 years during and after the trials by analysis of pooled individual patient data. Results In the four trials of aspirin versus control (mean duration of scheduled treatment 6·0 years), 391 (2·8%) of 14 033 patients had colorectal cancer during a median follow-up of 18·3 years. Allocation to aspirin reduced the 20-year risk of colon cancer (incidence hazard ratio HR 0·76, 0·60–0·96, p=0·02; mortality HR 0·65, 0·48–0·88, p=0·005), but not rectal cancer (0·90, 0·63–1·30, p=0·58; 0·80, 0·50–1·28, p=0·35). Where subsite data were available, aspirin reduced risk of cancer of the proximal colon (0·45, 0·28–0·74, p=0·001; 0·34, 0·18–0·66, p=0·001), but not the distal colon (1·10, 0·73–1·64, p=0·66; 1·21, 0·66–2·24, p=0·54; for incidence difference p=0·04, for mortality difference p=0·01). However, benefit increased with scheduled duration of treatment, such that allocation to aspirin of 5 years or longer reduced risk of proximal colon cancer by about 70% (0·35, 0·20–0·63; 0·24, 0·11–0·52; both p<0·0001) and also reduced risk of rectal cancer (0·58, 0·36–0·92, p=0·02; 0·47, 0·26–0·87, p=0·01). There was no increase in benefit at doses of aspirin greater than 75 mg daily, with an absolute reduction of 1·76% (0·61–2·91; p=0·001) in 20-year risk of any fatal colorectal cancer after 5-years scheduled treatment with 75–300 mg daily. However, risk of fatal colorectal cancer was higher on 30 mg versus 283 mg daily on long-term follow-up of the Dutch TIA trial (odds ratio 2·02, 0·70–6·05, p=0·15). Interpretation Aspirin taken for several years at doses of at least 75 mg daily reduced long-term incidence and mortality due to colorectal cancer. Benefit was greatest for cancers of the proximal colon, which are not otherwise prevented effectively by screening with sigmoidoscopy or colonoscopy. Funding None.
Summary Background Treatment strategies for acute basilar artery occlusion (BAO) are based on case series and data that have been extrapolated from stroke intervention trials in other cerebrovascular ...territories, and information on the efficacy of different treatments in unselected patients with BAO is scarce. We therefore assessed outcomes and differences in treatment response after BAO. Methods The Basilar Artery International Cooperation Study (BASICS) is a prospective, observational registry of consecutive patients who presented with an acute symptomatic and radiologically confirmed BAO between November 1, 2002, and October 1, 2007. Stroke severity at time of treatment was dichotomised as severe (coma, locked-in state, or tetraplegia) or mild to moderate (any deficit that was less than severe). Outcome was assessed at 1 month. Poor outcome was defined as a modified Rankin scale score of 4 or 5, or death. Patients were divided into three groups according to the treatment they received: antithrombotic treatment only (AT), which comprised antiplatelet drugs or systemic anticoagulation; primary intravenous thrombolysis (IVT), including subsequent intra-arterial thrombolysis; or intra-arterial therapy (IAT), which comprised thrombolysis, mechanical thrombectomy, stenting, or a combination of these approaches. Risk ratios (RR) for treatment effects were adjusted for age, the severity of neurological deficits at the time of treatment, time to treatment, prodromal minor stroke, location of the occlusion, and diabetes. Findings 619 patients were entered in the registry. 27 patients were excluded from the analyses because they did not receive AT, IVT, or IAT, and all had a poor outcome. Of the 592 patients who were analysed, 183 were treated with only AT, 121 with IVT, and 288 with IAT. Overall, 402 (68%) of the analysed patients had a poor outcome. No statistically significant superiority was found for any treatment strategy. Compared with outcome after AT, patients with a mild-to-moderate deficit (n=245) had about the same risk of poor outcome after IVT (adjusted RR 0·94, 95% CI 0·60–1·45) or after IAT (adjusted RR 1·29, 0·97–1·72) but had a worse outcome after IAT compared with IVT (adjusted RR 1·49, 1·00–2·23). Compared with AT, patients with a severe deficit (n=347) had a lower risk of poor outcome after IVT (adjusted RR 0·88, 0·76–1·01) or IAT (adjusted RR 0·94, 0·86–1·02), whereas outcomes were similar after treatment with IAT or IVT (adjusted RR 1·06, 0·91–1·22). Interpretation Most patients in the BASICS registry received IAT. Our results do not support unequivocal superiority of IAT over IVT, and the efficacy of IAT versus IVT in patients with an acute BAO needs to be assessed in a randomised controlled trial. Funding Department of Neurology, University Medical Center Utrecht.
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