Economic evaluation of the Very Early Rehabilitation in SpEech (VERSE) intervention

INTRODUCTION

There is limited evidence on the costs and outcomes of patients with aphasia after stroke. The aim of this study was to estimate costs in patients with aphasia after stroke according to the aphasia therapies provided.

METHODS

A three-arm, prospective, randomized, parallel group, open-label, blinded endpoint assessment trial conducted in Australia and New Zealand. Usual ward-based care (Usual Care) was compared to additional usual ward-based therapy (Usual Care Plus) and a prescribed and structured aphasia therapy program in addition to Usual Care (the VERSE intervention). Information about healthcare utilization and productivity were collected to estimate costs in Australian dollars for 2017-18. Multivariable regression models with bootstrapping were used to estimate differences in costs and outcomes (clinically meaningful change in aphasia severity measured by the WAB-R-AQ).

RESULTS

Overall, 202/246 (82%) participants completed follow-up at 26 weeks. Median costs per person were $23,322 (Q1 5,367, Q3 52,669, n = 63) for Usual Care, $26,923 (Q1 7,303, Q3 76,174, n = 70) for Usual Care Plus and $31,143 (Q1 7,001. Q3 62,390, n = 69) for VERSE. No differences in costs and outcomes were detected between groups. Usual Care Plus was inferior (i.e. more costly and less effective) in 64% of iterations, and in 18% was less costly and less effective compared to Usual Care. VERSE was inferior in 65% of samples and less costly and less effective in 12% compared to Usual Care.

CONCLUSION

There was limited evidence that additional intensively delivered aphasia therapy within the context of usual acute care provided was worthwhile in terms of costs for the outcomes gained.

Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation

BACKGROUND

The prevalence of type 2 diabetes is increasing rapidly, particularly among younger age groups. Estimates suggest that people with diabetes die, on average, 6 years earlier than people without diabetes. We aimed to provide reliable estimates of the associations between age at diagnosis of diabetes and all-cause mortality, cause-specific mortality, and reductions in life expectancy.

METHODS

For this observational study, we conducted a combined analysis of individual-participant data from 19 high-income countries using two large-scale data sources: the Emerging Risk Factors Collaboration (96 cohorts, median baseline years 1961-2007, median latest follow-up years 1980-2013) and the UK Biobank (median baseline year 2006, median latest follow-up year 2020). We calculated age-adjusted and sex-adjusted hazard ratios (HRs) for all-cause mortality according to age at diagnosis of diabetes using data from 1 515 718 participants, in whom deaths were recorded during 23·1 million person-years of follow-up. We estimated cumulative survival by applying age-specific HRs to age-specific death rates from 2015 for the USA and the EU.

FINDINGS

For participants with diabetes, we observed a linear dose-response association between earlier age at diagnosis and higher risk of all-cause mortality compared with participants without diabetes. HRs were 2·69 (95% CI 2·43-2·97) when diagnosed at 30-39 years, 2·26 (2·08-2·45) at 40-49 years, 1·84 (1·72-1·97) at 50-59 years, 1·57 (1·47-1·67) at 60-69 years, and 1·39 (1·29-1·51) at 70 years and older. HRs per decade of earlier diagnosis were similar for men and women. Using death rates from the USA, a 50-year-old individual with diabetes died on average 14 years earlier when diagnosed aged 30 years, 10 years earlier when diagnosed aged 40 years, or 6 years earlier when diagnosed aged 50 years than an individual without diabetes. Using EU death rates, the corresponding estimates were 13, 9, or 5 years earlier.

INTERPRETATION

Every decade of earlier diagnosis of diabetes was associated with about 3-4 years of lower life expectancy, highlighting the need to develop and implement interventions that prevent or delay the onset of diabetes and to intensify the treatment of risk factors among young adults diagnosed with diabetes.

FUNDING

British Heart Foundation, Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

Hearing Impairment and Incident Frailty in Later Life: The Health in Men Study (HIMS)

OBJECTIVES

This study is designed to determine if hearing loss is associated with increased risk of frailty in later life.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

We retrieved data of a community sample of men aged 70 years and above living in the metropolitan region of Perth, Western Australia. 3,285 participants who were free of frailty at the beginning of the study were followed for up to 17 years. Data were retrieved from the Health in Men Study (HIMS) and the Western Australian Data Linkage System (WADLS).

MEASUREMENTS

Hearing loss was defined by self-report or by diagnosis recorded in the WADLS. Incident frailty was assessed using the Hospital Frailty Risk Score (HFRS).

RESULTS

A total of 2,348 (71.5%) men developed frailty during follow up. The adjusted hazard ratio was 1.03 (95% CI: 0.95-1.12). The majority of the participants became frail by age 90 regardless of hearing condition. The time point where half of the group become frail was delayed by 14.4 months for men without hearing loss compared with hearing impaired men.

CONCLUSIONS

Hearing loss is not associated with incident frailty in men aged 70 years or older when frailty was measured by HFRS. However, this statistically non-significant result could be due to the low sensitivity of study measures. Also, we found a trend that men with hearing loss were more likely to develop frailty compared with their normal-hearing peers, suggesting a potential association between hearing loss and frailty.

Risk of prevalent and incident dementia associated with insulin-like growth factor and insulin-like growth factor-binding protein 3

Insulin-like growth factor 1 (IGF-1) influences cell proliferation and survival. In the extracellular environment, IGF-1 circulates bound to proteins (IGF-binding proteins; IGFBP), some of which have physiological effects that seem independent of IGF-1, including the brain (for example, IGFBP-3). We completed a systematic review of the association between dementia and IGF-1 and IGFBP-3, and a cross-sectional and longitudinal study designed to investigate if lower plasma concentration of these proteins increased the risk of prevalent and incident dementia. A total of 3967 men aged 71-89 years joined the study, of whom 535 (13.5%) showed evidence of prevalent cognitive impairment. The plasma concentrations of IGF-1 and IGFBP-3 were similar for men with and without cognitive impairment. The 3432 men free of cognitive impairment were then followed for up to 13 years. During this time 571 (16.6%) developed dementia. The plasma concentration of IGF-1 had no association with incident dementia. The doubling of the plasma concentration of IGFBP-3 decreased the hazard ratio of dementia by 23% (95% confidence interval=5-37%). The results were not affected by age, body mass index and history of smoking, diabetes, hypertension, coronary heart disease or stroke. If these findings are confirmed by others, the plasma concentration of IGFBP-3 could be used to improve the accuracy of predictive models of dementia and as a potential new factor to assist in the development of prevention and treatment strategies.

Beyond Stroke Prevention in Atrial Fibrillation: Exploring Further Unmet Needs with Rivaroxaban

With improved life expectancy and the aging population, the global burden of atrial fibrillation (AF) continues to increase, and with AF comes an estimated fivefold increased risk of ischaemic stroke. Prophylactic anticoagulant therapy is more effective in reducing the risk of ischaemic stroke in AF patients than acetylsalicylic acid or dual-antiplatelet therapy combining ASA with clopidogrel. Non-vitamin K antagonist oral anticoagulants are the standard of care for stroke prevention in patients with non-valvular AF. The optimal anticoagulant strategy to prevent thromboembolism in AF patients who are undergoing percutaneous coronary intervention and stenting, those who have undergone successful transcatheter aortic valve replacement and those with embolic stroke of undetermined source are areas of ongoing research. This article provides an update on three randomized controlled trials of rivaroxaban, a direct, oral factor Xa inhibitor, that are complete or are ongoing, in these unmet areas of stroke prevention: oPen-label, randomized, controlled, multicentre study explorIng twO treatmeNt stratEgiEs of Rivaroxaban and a dose-adjusted oral vitamin K antagonist treatment strategy in patients with Atrial Fibrillation who undergo Percutaneous Coronary Intervention (PIONEER AF-PCI) trial; the New Approach riVaroxaban Inhibition of factor Xa in a Global trial vs Aspirin to prevenT Embolism in Embolic Stroke of Undetermined Source (NAVIGATE ESUS) trial and the Global study comparing a rivAroxaban-based antithrombotic strategy to an antipLatelet-based strategy after transcatheter aortIc vaLve rEplacement to Optimize clinical outcomes (GALILEO) trial. The data from these studies are anticipated to help address continuing challenges for a range of patients at risk of stroke.

Determinants of post-stroke cognitive impairment: analysis from VISTA

BACKGROUND

Post-stroke cognitive impairment (PSCI) occurs commonly and is linked with development of dementia. We investigated the relationship between demographic, clinical and stroke symptoms at stroke onset and the presence of PSCI at 1 and 3 years after stroke.

METHODS

We accessed anonymized data from the Virtual International Stroke Trial Archive (VISTA), including demographic and clinical variables. Post-stroke cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score of ≤26. We assessed univariate relationships between baseline stroke symptoms and PSCI at 1 and 3 years following stroke, retaining the significant and relevant clinical factors as covariates in a final adjusted logistic regression model.

RESULTS

We analysed data on 5435 patients with recent (median 33 days) stroke or transient ischaemic attack (TIA). Mean (±SD) age was 62.6 (±12.6) years; 3476 (65%) patients were male. Follow-up data were available for 2270 and 1294 patients at 1 and 3 years, respectively. At 1 year, 781 (34%) patients had MMSE≤26; at 3 years, 391 (30%) had MMSE≤26. After adjusting for age, stroke severity, hypertension, diabetes and type of qualifying event, initial stroke impairment (leg paralysis) was associated with increased rate of PSCI at 1 year (OR=1.62; 95% CI=1.20-2.20) and at 3 years (OR=1.95; 95% CI=1.23-3.09). Associations were consistent on subgroup analysis restricted to ischaemic stroke and transient ischaemic attack (N=4992).

CONCLUSIONS

Besides well-known determinants of PSCI such as age, stroke severity and the presence of vascular risk factors, also leg paralysis is associated with subsequent of PSCI up to 3 years after stroke.

Profile of diabetes in men aged 79-97 years: the Western Australian Health in Men Study

AIMS

To investigate behavioural, physical and biochemical characteristics associated with diabetes in the oldest age group of elderly men.

METHODS

We conducted a cross-sectional analysis of community-dwelling men aged 79-97 years from Perth, Western Australia. Lifestyle behaviours, self-rated health, physical function, and fasting glucose and HbA_1c levels were assessed.

RESULTS

Of 1426 men, 315 had diabetes (22%). Men with diabetes were of similar age to men without (84.9 vs 84.5 years; P = 0.14). Only 26.5% of men with diabetes self-rated their health as excellent or very good, compared with 40.6% of men without diabetes (P < 0.001). Diabetes was associated with less involvement with recreational walking (32.7 vs 41.0%; P < 0.01) and leisure activities (19.0 vs 26.5%; P < 0.01). Men with diabetes had poorer physical function on multiple measures, including longer times for the Timed Up-and-Go test (15.0 ± 6.9 s vs 13.4 ± 5.3 s; P < 0.001) and weaker knee extension (20.2 vs 21.9 kg; P < 0.001). In multivariate analyses, diabetes was associated with an increased prevalence of myocardial infarction (odds ratio 1.80, 95% CI 1.25-2.60; P < 0.001) and falls resulting in injury (odds ratio 1.55, 95% CI 1.06-2.26; P = 0.02). Average HbA_1c was 49 ± 8 mmol/mol (6.6 ± 0.8%) in men with diabetes, with 90.6% of these men on diet or oral hypoglycaemic therapy.

CONCLUSIONS

In older men, diabetes is associated with poorer self-perceived health, reduced healthy lifestyle behaviours and physical function, heart disease and injurious falls. The majority of these men with diabetes had good glycaemic control. Encouraging healthy lifestyle behaviours and improving physical function should be evaluated as interventions to improve quality-of-life and health outcomes.

Cerebral small vessel disease, medial temporal lobe atrophy and cognitive status in patients with ischaemic stroke and transient ischaemic attack

BACKGROUND AND PURPOSE

Small vessel disease (SVD) and Alzheimer's disease (AD) are two common causes of cognitive impairment and dementia, traditionally considered as distinct processes. The relationship between radiological features suggestive of AD and SVD was explored, and the association of each of these features with cognitive status at 1 year was investigated in patients with stroke or transient ischaemic attack.

METHODS

Anonymized data were accessed from the Virtual International Stroke Trials Archive (VISTA). Medial temporal lobe atrophy (MTA; a marker of AD) and markers of SVD were rated using validated ordinal visual scales. Cognitive status was evaluated with the Mini Mental State Examination (MMSE) 1 year after the index stroke. Logistic regression models were used to investigate independent associations between (i) baseline SVD features and MTA and (ii) all baseline neuroimaging features and cognitive status 1 year post-stroke.

RESULTS

In all, 234 patients were included, mean (±SD) age 65.7 ± 13.1 years, 145 (62%) male. Moderate to severe MTA was present in 104 (44%) patients. SVD features were independently associated with MTA (P < 0.001). After adjusting for age, sex, disability after stroke, hypertension and diabetes mellitus, MTA was the only radiological feature independently associated with cognitive impairment, defined using thresholds of MMSE ≤ 26 (odds ratio 1.94; 95% confidence interval 1.28-2.94) and MMSE ≤ 23 (odds ratio 2.31; 95% confidence interval 1.48-3.62).

CONCLUSION

In patients with ischaemic cerebrovascular disease, SVD features are associated with MTA, which is a common finding in stroke survivors. SVD and AD type neurodegeneration coexist, but the AD marker MTA, rather than SVD markers, is associated with post-stroke cognitive impairment.

Reported Amount of Salt Added to Food Is Associated with Increased All-Cause and Cancer-Related Mortality in Older Men in a Prospective Cohort Study

BACKGROUND

The effect of dietary salt intake on important population outcomes such as mortality is controversial. The aim of this study was to examine the association between the dietary habit of adding salt to food and mortality in older men. Design, participants, setting and measurements: A risk factor questionnaire which contained a question about the dietary habit of adding salt to food was completed by 11742 community recruited older men between 1996 and 1999. The men were followed by means of the Western Australia Data Linkage System until November 30th 2010. Deaths due to cardiovascular diseases and cancers were identified using ICD-10 codes in the ranges I00-I99 and C00-D48, respectively. The association between the frequencies of adding salt to food and mortality was assessed using Kaplan Meier estimates and Cox proportional hazard analysis.

RESULTS

Median follow-up for survivors was 12.5 years (inter-quartile range 8.3-13.2 years). A total of 5399 deaths occurred of which the primary cause registered was cancer and cardiovascular disease in 1962 (36.3%) and 1835 (34.0%) men, respectively. The reported frequency of adding salt to food was strongly positively associated with all-cause (p<0.001), cancer-related (p<0.001) but not cardiovascular-related (p=0.649) mortality. Men reporting adding salt to their food always had a 1.12-fold (95% CI 1.05-1.20, p<0.001) and a 1.20-fold (95% CI 1.07-1.34, p=0.001) increased risk of all-cause and cancer-related mortality, respectively, after adjusting for other risk factors. Men reporting adding salt to their food sometimes had a 1.16-fold (95% CI 1.04-1.29, p=0.007) increased risk of cancer-related mortality after adjusting for other risk factors.

CONCLUSION

A history of adding salt to food is associated with increased cancer-related mortality in older men.

Stroke prevention with rivaroxaban in higher-risk populations with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF), the most common cardiac arrhythmia, is a major risk factor for stroke. Rivaroxaban, an oral factor Xa inhibitor, is approved for the prevention of stroke in patients with non-valvular AF. In the pivotal phase III trial ROCKET AF, rivaroxaban demonstrated non-inferiority compared with warfarin for reducing the risk of stroke or systemic embolism (SE) in patients with AF (intention-to-treat analysis), without an increased risk of major bleeding. Superior efficacy vs. warfarin was achieved while patients were on study medication. Other direct oral factor Xa inhibitors have completed phase III clinical trials in this indication. Compared with warfarin, apixaban (in the ARISTOTLE trial) and edoxaban (in the ENGAGE-AF trial) were shown to be superior or non-inferior, respectively, for reduction in stroke or SE risk in patients with AF. Baseline stroke risk, as indicated by CHADS2 scores, was lower in patients in the ARISTOTLE and ENGAGE-AF trials than in ROCKET AF.

OBJECTIVES

This review discusses the main findings from ROCKET AF, specifically examining recent subgroup analyses investigating rivaroxaban use across various patient types at high risk for adverse outcomes, including those with prior stroke or transient ischaemic attack, reduced renal function, prior myocardial infarction, peripheral artery disease, heart failure or patients aged ≥ 75 years and those resident in East Asia.

CONCLUSIONS

These subgroup analyses demonstrate that the treatment effect for rivaroxaban vs. warfarin is broadly consistent across a wide range of patient groups, with respect to both efficacy and safety.

ICARUSS, the Integrated Care for the Reduction of Secondary Stroke trial: rationale and design of a randomized controlled trial of a multimodal intervention to prevent recurrent stroke in patients with a recent cerebrovascular event, ACTRN = 12611000264987

BACKGROUND

The majority of strokes, both ischaemic and haemorrhagic, are attributable to a relatively small number of risk factors which are readily manageable in primary care setting. Implementation of best-practice recommendations for risk factor management is calculated to reduce stroke recurrence by around 80%. However, risk factor management in stroke survivors has generally been poor at primary care level. A model of care that supports long-term effective risk factor management is needed.

AIM

To determine whether the model of Integrated Care for the Reduction of Recurrent Stroke (ICARUSS) will, through promotion of implementation of best-practice recommendations for risk factor management reduce the combined incidence of stroke, myocardial infarction and vascular death in patients with recent stroke or transient ischaemic attack (TIA) of the brain or eye.

DESIGN

A prospective, Australian, multicentre, randomized controlled trial.

SETTING

Academic stroke units in Melbourne, Perth and the John Hunter Hospital, New South Wales.

SUBJECTS

1000 stroke survivors recruited as from March 2007 with a recent (<3 months) stroke (ischaemic or haemorrhagic) or a TIA (brain or eye).

RANDOMIZATION

Randomization and data collection are performed by means of a central computer generated telephone system (IVRS).

INTERVENTION

Exposure to the ICARUSS model of integrated care or usual care.

PRIMARY OUTCOME

The composite of stroke, MI or death from any vascular cause, whichever occurs first.

SECONDARY OUTCOMES

Risk factor management in the community, depression, quality of life, disability and dementia.

STATISTICAL POWER

With 1000 patients followed up for a median of one-year, with a recurrence rate of 7-10% per year in patients exposed to usual care, the study will have at least 80% power to detect a significant reduction in primary end-points

CONCLUSION

The ICARUSS study aims to recruit and follow up patients between 2007 and 2013 and demonstrate the effectiveness of exposure to the ICARUSS model in stroke survivors to reduce recurrent stroke or vascular events and promote the implementation of best practice risk factor management at primary care level.

The triangular association of ADH1B genetic polymorphism, alcohol consumption and the risk of depression in older men

Alcohol use, particularly alcohol abuse and dependence, are associated with increased risk of depression. Current diagnostic criteria suggest that the relationship is causal, but the evidence has only been derived from observational studies that are subject to confounding and bias. Given the logistic and ethical constraints that would be associated with a trial of alcohol use to prevent depression, we aimed to complete a Mendelian randomization study to determine if a genetic polymorphism associated with alcohol abuse and dependence (ADH1B rs1229984 G-->A) contributed to modulate the risk of depression in a community-derived cohort of older men. This retrospective analysis of a cohort of 3873 community-dwelling men aged 65-83 years living in the metropolitan region of Perth, Western Australia, investigated the triangular association between the rs1229984 G-->A polymorphism and alcohol use and, after 3.2-8.2 years, the presence of current depression or history of depression. The mean number of standard drinks consumed per week (n; standard deviation; range) according to genotype was AA 1.8 (17; 2.7; 0-7), GA 5.9 (262; 7.5; 0-35), GG 8.5 (3594; 10.9; 0-140) (GG>AA, GG>GA; P<0.001). Consumption of 1 or 2 drinks per day decreased the odds of depression (n=610) by 30 and 40%, whereas consumption of more than six drinks daily more than doubled the odds of depression (odds ratio: 2.12, 95% confidence interval: 1.02, 4.40). The ADH1B rs1229984 G-->A polymorphism was not associated with current or past depression (P=0.857). In addition, the presence of the A allele did not interact with the alcohol use to modulate the risk of depression (P=0.725). These results suggest that alcohol consumption does not cause or prevent depression in older men.

Comparison of idrabiotaparinux with vitamin K antagonists for prevention of thromboembolism in patients with atrial fibrillation: the Borealis-Atrial Fibrillation Study

BACKGROUND

Idrabiotaparinux, a long-acting inhibitor of factor Xa, was shown to be effective in the treatment of patients with venous thromboembolism.

OBJECTIVE

To assess non-inferiority for the efficacy of idrabiotaparinux versus warfarin in patients with atrial fibrillation (AF) at risk of stroke and systemic embolism. Bleeding was also assessed.

METHODS

This randomized, double-blind trial enrolled patients with electrocardiogram-documented AF. Idrabiotaparinux was administered weekly via subcutaneous injection, and warfarin was administered daily with dose adjustment to maintain the international normalized ratio between 2.0 and 3.0. Each idrabiotaparinux injection was 3 mg for the first 7 weeks, followed by 2 mg thereafter, except in patients with a creatinine clearance of 30-50 mL min(-1) or aged ≥ 75 years. The patients received 1.5 mg after the first 7 weeks. The efficacy outcome was the composite of all fatal or non-fatal strokes and systemic embolism. The safety outcome was clinically relevant bleeding (major and clinically relevant non-major bleeding).

RESULTS

The study was terminated prematurely by the sponsor for strategic/commercial, not scientific, reasons, with 39% of the planned number of patients included and an average duration of treatment of 240 days. Of the 1886 idrabiotaparinux recipients, 20 developed stroke or systemic embolism (1.5% per year), whereas this occurred in 22 of the 1887 warfarin patients (1.6% per year, hazard ratio 0.98, 95% confidence interval 0.49-1.66). The annual incidence of bleeding was 6.1% in the idrabiotaparinux and 10.0% in the warfarin group (hazard ratio 0.61, 95% confidence interval 0.46-0.81).

CONCLUSION

If anything, despite its early termination, the idrabiotaparinux regimen studied suggested a comparable efficacy to dose-adjusted warfarin, with a lower bleeding risk.

Peripheral arterial disease increases the risk of subsequent hip fracture in older men: the Health in Men Study

The aim of the present study was to assess whether peripheral arterial disease is associated with an increased risk of hip fracture in a cohort of 12,094 older men. There was no association between claudication and hip fracture, but there was a significant association with an ankle brachial index (ABI) <0.9.

INTRODUCTION

It is uncertain whether peripheral arterial disease (PAD) is associated with an increased risk of subsequent hip fracture. The aim of the present study was to assess this in a large cohort of men aged 65 years and over.

METHODS

Claudication was assessed by means of the Edinburgh Claudication Questionnaire in 12,094 men, and the ABI was measured in 4,321 of these men. Hospitalisations with hip fracture were identified by record linkage. The association between both claudication and an ABI <0.9 and subsequent hip fractures was assessed using survival curves and Cox regression models.

RESULTS

Amongst the 12,094 men, the baseline prevalence of claudication according to the ECQ was 5.3 %. Amongst the 4,321 men with ABI results, the prevalence of an ABI <0.9 was 11.7 %. Of the 506 men with an ABI <0.9, 129 (25.5 %) also had claudication. Over a median (range) follow-up of 10.8 (0.3-12.7) years, 343 (2.8 %) of the 12,094 men were admitted to hospital with a hip fracture. There was no association between claudication and subsequent hip fractures (hazard ratio (HR) = 0.95; 95 % confidence interval (CI), 0.60, 1.52). Over a median (range) follow-up of 11.1 (0.06-12.3) years 135 (3.1 %) of the 4,321 men with ABI data were admitted to hospital with hip fractures. There was a significant association between an ABI <0.9 and subsequent hip fracture (HR = 1.69; 95 % CI, 1.08, 2.63).

CONCLUSION

Older men with PAD defined as ABI < 0.9 are at increased risk of hip fracture, whereas the symptom of claudication is not an independent predictor of hip fracture.

Is hypovitaminosis D associated with abdominal aortic aneurysm, and is there a dose-response relationship?

OBJECTIVE

This study aims to investigate the association between plasma 25-hydroxyvitamin D (25(OH)D) concentrations with the presence of abdominal aortic aneurysm (AAA) and aortic diameter.

DESIGN

An observational study of 4233 community-dwelling men aged 70-88 years, who participated in a randomised controlled trial of screening for AAA.

METHODS

Infrarenal aortic diameter measured by ultrasound and 25(OH)D by immunoassay.

RESULTS

A total of 311 men (7.4%) with AAA (defined as aortic diameter ≥ 30 mm) comprised the study. Multivariable models were adjusted for age, smoking, cardiovascular disease, hypertension, diabetes, dyslipidaemia, body mass index and serum creatinine concentration. Amongst men with the lowest 25(OH)D quartile of values compared with the highest quartile, the adjusted odds ratio of having an AAA increased in a graded fashion from 1.23 (95% confidence interval (CI) 0.87-1.73) for AAA ≥ 30 mm to 5.42 (95% CI 1.85-15.88) for AAA ≥ 40 mm. Similarly, there was a dose-response relationship between 25(OH)D concentrations and the size of the AAA: every 10-nmol l(-1) decrease in 25(OH)D levels was associated with 0.49 mm (95% CI 0.11-0.87) increase in mean aortic diameter.

CONCLUSIONS

Low vitamin D status is associated with the presence of larger AAA in older men, and there is a graded inverse relationship between 25(OH)D concentrations and AAA diameter. Further research is needed to clarify the mechanisms underlying these associations.

Assessing the risk of stroke from neck manipulation: a systematic review

BACKGROUND

Strokes, typically involving vertebral artery dissection, can follow cervical spinal manipulative therapy, and these types of stroke occur rarely. There is disagreement about whether a strong association between neck manipulation and stroke exists. An earlier systematic review found two relevant studies of association that used controls, which also discussed the limitations of the two papers. Our systematic review updates the earlier review, and aims to determine whether conclusive evidence of a strong association exists.

METHODS

PRISMA guidelines for systematic reviews were followed, and the literature was searched using a strategy that included the terms 'neck manipulation' and 'stroke' from the PubMed, Embase, CINAHL Plus and AMED databases. Citations were included if they met criteria such as being case-control studies, and dealt with neck manipulation and/or neck movement/positioning. Papers were scored for their quality, using similar criteria to the earlier review. For individual criteria, each study was assigned a full positive score if the criterion was satisfied completely.

RESULTS

Four case-control studies and one case-control study, which included a case- crossover design, met the selection criteria, but all of them had at least three items in the quality assessment that failed to be completely positive. Two studies were assessed to be the most robustly designed, one indicating a strong association between stroke and various intensities of neck movement, including manipulation, and the other suggesting a much reduced relative association when using primary care practitioners' visits as controls. However, potential biases and confounders render the results inconclusive.

CONCLUSION

Conclusive evidence is lacking for a strong association between neck manipulation and stroke, but is also absent for no association. Future studies of association will need to minimise potential biases and confounders, and ideally have sufficient numbers of cases to allow subgroup analysis for different types of neck manipulation and neck movement.

Aspirin decreases the risk of depression in older men with high plasma homocysteine

High total plasma homocysteine (tHcy) is associated with increased risk of cardiovascular events and depression. Consumption of B-vitamins (B6, B9 and B12) reduces tHcy by about 15%, but has equivocal effects on these health outcomes, suggesting that this relationship is either not causal or is confounded by other factors. The results of recent randomized trials suggest that antiplatelet therapy may confound these associations. This cross-sectional study assessed 3687 men aged 69-87 years for history of clinically significant depression (Geriatric Depression Scale 15 items 7) or a recorded diagnosis of depression in the Western Australian Data Linkage System, and collected information on the use of aspirin, B-vitamins and antidepressant medication, along with age, education, living arrangements, smoking history and medical comorbidity as assessed by the Charlson index. Participants donated a blood sample for the measurement of tHcy, and concentrations15 μmol l(-1) were considered high. Five hundred and thirteen (13.9%) men showed evidence of depression, and of those 31.4% had high tHcy, 41.5% were using aspirin, 6.8% were consuming B-vitamins. Multivariate logistic regression showed that high tHcy was associated with increased odds of depression (odds ratio (OR)=1.60, 95% confidence interval (CI)=1.20-2.14), as was the use of B-vitamins (OR=1.95, 95% CI=1.21-3.13). There was a significant interaction between high tHcy and aspirin use (OR=0.57, 95% CI=0.36-0.91), but not between high tHcy and B-vitamin use (OR=0.80, 95% CI=0.26-2.46). The analyses were adjusted for smoking status, Charlson index and use of antidepressants. The results of this study indicate that older men with high tHcy who use aspirin have lower risk of depression, and suggest that antiplatelet therapy may be an effective preventive or management strategy for these cases. Randomized trials are required to confirm the antidepressant effect of aspirin in people with high tHcy.

Homocysteine, methylenetetrahydrofolate reductase C677T polymorphism and cognitive impairment: the health in men study

High total plasma homocysteine (tHcy) has been associated with cognitive impairment in later life, but it is unclear if this association is causal or is due to confounding. The C677T polymorphism of the 5,10 methylenetetrahydrofolate reductase gene (MTHFR) increases basal tHcy, but its contribution to cognitive impairment has not been established. We designed this study to determine if tHcy is causally related to cognitive impairment in later life by investigating its association with high tHcy and the MTHFR-C677T polymorphism. We recruited 1778 older men from the Health in Men Study cohort and established caseness on the basis of the participants' scores on a Telephone Interview for Cognitive Status score 27 in 2008. Exposure to tHcy, gene status and other variables of interest were obtained from assessments 4-7 years earlier. Multivariate logistic regression showed that the odds of cognitive impairment increased with a doubling of tHcy (adjusted odds ratio, OR 1.36; 95% confidence interval, 95% CI 1.02-1.82). Compared with the wild CC genotype, participants with the MTHFR-TT genotype had 46% greater odds of cognitive impairment (OR 1.46, 95% CI 1.01-2.11, P=0.043). The results of this study are consistent with, but do not prove the hypothesis that high tHcy causes cognitive impairment in later life.

Associations of total osteocalcin with all-cause and cardiovascular mortality in older men. The Health In Men Study

SUMMARY

In older men, both lower and higher total osteocalcin levels predict increased all-cause mortality, with comparable associations for cardiovascular and non-cardiovascular deaths. Differences in osteocalcin levels might influence glucose metabolism and thereby cardiovascular risk, or reflect changes in bone turnover thus representing a marker for poorer health outcomes.

INTRODUCTION

Reduced levels of total osteocalcin (TOC) are associated with adiposity, insulin resistance and type 2 diabetes, implying this bone-derived peptide might modulate cardiovascular risk. However, there are few longitudinal data relating TOC levels to survival. We examined associations of TOC level with all-cause and cardiovascular mortality in older men.

METHODS

We conducted a prospective cohort study of community-dwelling men aged 70-89 years. Aliquots of plasma collected at baseline (2001-2004) were assayed for TOC. Incidence and causes of death to 31 December 2008 were ascertained using data linkage. Cox regression analyses were performed with adjustment for conventional cardiovascular risk factors.

RESULTS

From 3,542 men followed for median 5.2 years there were 572 deaths (16.1%). Mortality was lowest in men with TOC levels in the second quintile (12.6%). In multivariate analyses, men with TOC in the lowest and highest quintiles of values had increased all-cause mortality (Q1 vs Q2: hazard ratio [HR], 1.36; 95% confidence interval 1.02-1.80 and Q5 vs Q2: HR, 1.53, 95% CI 1.18-1.98). Men with low TOC levels had similar HR for cardiovascular and non-cardiovascular deaths (Q1 vs Q2: HR, 1.35 and 1.30 respectively). Higher TOC levels predicted cardiovascular disease (CVD)-related mortality (Q5 vs Q2, HR, 1.69, 95% CI 1.09-2.64).

CONCLUSIONS

TOC predicts all-cause and CVD-related mortality in community-dwelling older men. However, the relationship is U shaped with men at both ends of the distribution at increased risk. Further investigation is required to clarify whether the underlying mechanisms involve altered bone turnover or relate specifically to the biological activity of osteocalcin.

Bayesian methods for meta-analysis of causal relationships estimated using genetic instrumental variables

Genetic markers can be used as instrumental variables, in an analogous way to randomization in a clinical trial, to estimate the causal relationship between a phenotype and an outcome variable. Our purpose is to extend the existing methods for such Mendelian randomization studies to the context of multiple genetic markers measured in multiple studies, based on the analysis of individual participant data. First, for a single genetic marker in one study, we show that the usual ratio of coefficients approach can be reformulated as a regression with heterogeneous error in the explanatory variable. This can be implemented using a Bayesian approach, which is next extended to include multiple genetic markers. We then propose a hierarchical model for undertaking a meta-analysis of multiple studies, in which it is not necessary that the same genetic markers are measured in each study. This provides an overall estimate of the causal relationship between the phenotype and the outcome, and an assessment of its heterogeneity across studies. As an example, we estimate the causal relationship of blood concentrations of C-reactive protein on fibrinogen levels using data from 11 studies. These methods provide a flexible framework for efficient estimation of causal relationships derived from multiple studies. Issues discussed include weak instrument bias, analysis of binary outcome data such as disease risk, missing genetic data, and the use of haplotypes.

VITATOPS, the VITAmins TO prevent stroke trial: rationale and design of a randomised trial of B-vitamin therapy in patients with recent transient ischaemic attack or stroke (NCT00097669) (ISRCTN74743444)

BACKGROUND

Epidemiological studies suggest that raised plasma concentrations of total homocysteine (tHcy) may be a common, causal and treatable risk factor for atherothromboembolic ischaemic stroke, dementia and depression. Although tHcy can be lowered effectively with small doses of folic acid, vitamin B(12) and vitamin B(6), it is not known whether lowering tHcy, by means of B vitamin therapy, can prevent stroke and other major atherothromboembolic vascular events.

AIM

To determine whether the addition of B-vitamin supplements (folic acid 2 mg, B(6) 25 mg, B(12) 500 microg) to best medical and surgical management will reduce the combined incidence of stroke, myocardial infarction (MI) and vascular death in patients with recent stroke or transient ischaemic attack (TIA) of the brain or eye.

DESIGN

A prospective, international, multicentre, randomised, double blind, placebo-controlled clinical trial.

SETTING

One hundred and four medical centres in 20 countries on five continents.

SUBJECTS

Eight thousand (6600 recruited as of 5 January, 2006) patients with recent (<7 months) stroke (ischaemic or haemorrhagic) or TIA (brain or eye).

RANDOMISATION

Randomisation and data collection are performed by means of a central telephone service or secure internet site.

INTERVENTION

One tablet daily of either placebo or B vitamins (folic acid 2 mg, B(6) 25 mg, B(12) 500 mug).

PRIMARY OUTCOME

The composite of stroke, MI or death from any vascular cause, whichever occurs first. Outcome and serious adverse events are adjudicated blinded to treatment allocation.

SECONDARY OUTCOMES

TIA, unstable angina, revascularisation procedures, dementia, depression. STATISTICAL POWER: With 8000 patients followed up for a median of 2 years and an annual incidence of the primary outcome of 8% among patients assigned placebo, the study will have at least 80% power to detect a relative reduction of 15% in the incidence of the primary outcome among patients assigned B vitamins (to 6.8%/year), applying a two-tailed level of significance of 5%.

CONCLUSION

VITATOPS aims to recruit and follow-up 8000 patients between 1998 and 2008, and provide a reliable estimate of the safety and effectiveness of folic acid, vitamin B(12), and vitamin B(6) supplementation in reducing recurrent serious vascular events among a wide range of patients with TIA and stroke throughout the world.

When the patient fails to respond to treatment: TIAs that go on, and on

Most transient ischaemic attacks (TIAs) stop, with or without treatment, but some are followed by stroke within days or longer. But if the TIAs do not stop then the diagnosis must be reviewed (are they really TIAs or could they be migraine or epilepsy?), and if they are TIAs, what are they caused by (atherothromboembolism, embolism from the heart, etc)? With this information, both the medical and any surgical treatment can be optimised, even though one must accept that the randomised controlled trials mostly have not addressed the particular issue of continuing TIAs.

Rate, degree, and predictors of recovery from disability following ischemic stroke

OBJECTIVE

To determine the rate, degree, and predictors of recovery from disabling ischemic stroke.

METHODS

Patients with ischemic stroke enrolled in the Management of Atherothrombosis With Clopidogrel in High-Risk Patients (MATCH) study underwent long-term prospective assessment of their modified Rankin Scale (mRS) score. Disability (functionally dependent state) was defined as mRS > or = 3, and recovery (functionally independent state) was defined as mRS < 3. The timing and the independent predictors of recovery were determined using a Cox proportional hazards multiple regression analysis.

RESULTS

Of 7,599 patients enrolled with ischemic stroke or TIA, 1,662 (21.8%) were disabled (mRS > or = 3) at baseline (median of 14 [0 to 96] days after stroke onset). Disability was moderate (mRS 3) in 931 (56%) patients, severe (mRS 4) in 691 (42%), and very severe (mRS 5) in 40 (2%). By 18 months, 877 (52.8%, 95% CI 50% to 55%) patients had recovered, 589 (63%, 60% to 66%) with moderate disability, 281 (41%, 37% to 44%) with severe disability, and 7 (17%, 7 to 33%) with very severe disability. Median time to recovery was 3 months for patients with moderate disability and 18 months for severe disability; 82.5% of severely disabled patients remained so at 18 months. Predictors of recovery were moderate disability (mRS 3) at baseline compared with severe (mRS 4: hazard ratio [HR] 2.13, 1.86 to 2.44) or very severe disabling stroke (HR 5.88, 2.86 to 12.5); younger women (aged <65 years, compared with > or =75 years; HR 1.85, 1.47 to 2.33); decreasing time (days) between the qualifying event and the baseline assessment (HR 1.01, 1.01 to 1.02); and the absence of previous ischemic stroke (HR 1.61, 1.35 to 1.92), concurrent peripheral artery disease (HR 1.61, 1.23 to 2.13), or diabetes (HR 1.30, 1.10 to 1.54).

CONCLUSIONS

Half of patients with disabling ischemic stroke recovered within 18 months, and recovery was greatest within 6 months. Significant predictors of recovery included the severity of the index stroke and no history of ischemic stroke, peripheral artery disease, or diabetes.

Time frame and predictors of recovery from disability following recurrent ischemic stroke

OBJECTIVE

To assess the rate, degree, and predictors of recovery from a disabled to nondisabled state in patients disabled after recurrent ischemic stroke.

METHODS

Patients with ischemic stroke enrolled in the Management of Atherothrombosis with Clopidogrel in High Risk Patients (MATCH) Study underwent prospective assessment of their modified Rankin score (mRS) at 1, 3, 6, 12, and 18 months after enrollment and after recurrent stroke. Patients disabled (defined as mRS > or = 3) after recurrence were analyzed for recovery (defined as mRS < 3) during the 18 months, and predictors of recovery were sought using a Cox proportional-hazard multiple regression analysis.

RESULTS

Three hundred forty-five (54%) of 637 patients were disabled after recurrent ischemic stroke; 115 (33%) patients had been disabled and 230 (66%) nondisabled before stroke recurrence. At recurrence, the degree of disability was moderate (mRS 3) in 135 (39%) patients, severe (mRS 4) in 139 (40%), and very severe (mRS 5) in 71 (21%). After 12 months' median follow-up, 117 (34%, 95% CI: 29 to 39%) had recovered: 68 (50%, 42 to 59%) of 135 moderately disabled, 45 (32%, 25 to 41%) of 139 severely disabled, and 4 (6%, 2 to 14%) of 71 very severely disabled; 70 (20.3%) patients died. From recurrence, median time to recovery was 6 months (mRS 3) and 18 months (mRS 4); 94% with very severe disability had not recovered at 18 months. Independent predictors of recovery were moderate disability at recurrence (mRS 3) compared with severe (mRS 4: hazard ratio [HR] 1.5; 95% CI 1.04 to 2.3) or very severe disability (mRS 5: HR 7.6; 2.7 to 20) and a nondisabled vs disabled state before recurrence (HR 4.0; 2.3 to 6.8).

CONCLUSIONS

The rate of recovery from recurrent ischemic stroke was greatest in the first 6 months; one-third of patients recovered within 12 months. The significant predictors of recovery were a nondisabled state before recurrence and increasing severity of the recurrent stroke.

Association between phosphodiesterase 4D gene and ischaemic stroke

BACKGROUND

An association between the phosphodiesterase 4D (PDE4D) gene and risk of ischaemic stroke in an Icelandic population has been suggested by the deCODE group.

METHODS

A case-control study of 151 hospitalised patients with first-ever ischaemic stroke and 164 randomly selected age-matched and sex-matched community controls was conducted. PDE4D genotypes for the six single-nucleotide polymorphisms (SNPs) previously reported to be independently associated with stroke were determined, common haplotypes were inferred using the expectation-maximisation algorithm, and SNP and haplotype associations with stroke were examined. A meta-analysis of published studies examining the association between PDE4D and stroke was also carried out.

RESULTS

Our study of Australian patients with stroke showed an independent association between ischaemic stroke and PDE4D SNP 89 (CC: odds ratio (OR) 5.55, 95% confidence interval (CI) 1.02 to 30.19; CA: OR 1.68, 95% CI 0.96 to 2.96; AA: OR 1 (reference)), SNP 87 (CC: OR 2.13, 95% CI 1.08 to 4.20; TC: OR 1.64, 95% CI 0.89 to 3.00; TT: OR 1 (reference)) and SNP 83 (TT: OR 2.16, 95% CI 1.08 to 4.32; TC: OR 1.37, 95% CI 0.77 to 2.43; CC: OR 1 (reference)), and between ischaemic stroke and PDE4D haplotypes at SNP 89-87-83 (A-C-C: OR 2.13, 95% CI 1.15 to 3.96; C-C-T: OR 2.25, 95% CI 1.29 to 3.92), but no association between ischaemic stroke and PDE4D SNP 56, SNP 45 or SNP 41, or with PDE4D haplotypes at SNP 56-45-41. A meta-analysis of nine case-control studies (including our current results) of 3808 stroke cases and 4377 controls confirmed a significant association between stroke and PDE SNP 87 (pooled p = 0.002), SNP 83 (0.003) and SNP 41 (0.003). However, there was statistical heterogeneity (p < 0.1) among the studies in the direction of association for each of the individual SNPs tested.

CONCLUSIONS

Our results and the pooled analyses from all the studies indicate a strong association between PDE4D and ischaemic stroke. This strengthens the evidence that PDE4D plays a key part in the pathogenesis of ischaemic stroke. Heterogeneity among the studies in the direction of association between individual SNPs and stroke suggests that the SNPs tested are in linkage disequilibrium with the causal allele(s).

Enhanced antiplatelet effect of clopidogrel in patients whose platelets are least inhibited by aspirin: a randomized crossover trial

OBJECTIVE

We aimed to determine whether adding clopidogrel to aspirin in patients at high risk of future cardiovascular events would suppress laboratory measures of the antiplatelet effects of aspirin; and have greater platelet inhibitory effects in patients with the least inhibition of platelets by aspirin.

METHODS

We performed a randomized, double-blind, placebo-controlled, crossover trial, comparing clopidogrel 75 mg day(-1) versus placebo, in 36 aspirin-treated patients with symptomatic objectively confirmed peripheral arterial disease.

RESULTS

The addition of clopidogrel to aspirin did not suppress platelet aggregation induced by arachidonic acid, urinary 11 dehydro thromboxane B2 concentrations, or soluble markers of platelet activation markers (P-selectin, CD40-ligand) and inflammation (high sensitivity serum C-reactive protein, interleukin-6). Clopidogrel significantly inhibited platelet aggregation induced by ADP (reduction 26.2%; 95% CI: 21.3-31.1%, P < 0.0001) and collagen (reduction 6.2%; 95% CI: 3.2-9.3%, P = 0.0003). The greatest inhibition of collagen-induced platelet aggregation by clopidogrel was seen in patients with the least inhibition of arachidonic acid induced aggregation by aspirin [lower tertile of arachidonic acid-induced platelet aggregation: 2.8% (95% CI: -0.8 to 6.3%) reduction in mean collagen-induced aggregation by clopidogrel; middle tertile: 4.0% (95% CI: 0.4-7.6%); upper tertile 12.6% (95% CI: 4.5-20.8%); P-value for interaction 0.01].

CONCLUSIONS

The greatest platelet inhibitory effect of clopidogrel occurs in patients with the least inhibition of arachidonic acid-induced platelet aggregation by aspirin. This raises the possibility that the clinical benefits of adding clopidogrel to aspirin may be greatest in patients whose platelets are least inhibited by aspirin. Confirmation in clinical outcome studies may allow these patients to be targeted with antiplatelet drugs that inhibit the ADP receptor, thereby overcoming the problem of laboratory aspirin resistance.

Preventable stroke and stroke prevention

Stroke is a major cause of death and disability in the world. The main causes of stroke are atherothromboembolism and cardiogenic embolism. The main causal and treatable risk factors for atherothromboembolic ischemic stroke are increasing blood pressure (BP), increasing cholesterol, cigarette smoking and diabetes; and the main risk factors for cardiogenic ischemic stroke are atrial fibrillation (AF) and ischemic heart disease. Strategies to reduce the incidence of stroke include prevention of first-ever and recurrent stroke, and treatment of patients with acute stroke to reduce death and disability. The two main strategies of stroke prevention are the 'population' (or 'mass') approach and the 'high risk' approach. The 'population' approach aims to reduce stroke by lowering the prevalence and mean level of causal risk factors in the community, by means of public education and government legislation. The 'high risk' approach aims to reduce stroke by identifying individuals at high risk of stroke, and lowering their risk by means of optimal medical therapies. Level 1 evidence from randomized controlled trials indicates that effective treatments for high risk patients include control of causal risk factors (lowering BP, lowering blood cholesterol), antithrombotic therapy (antiplatelet therapy with aspirin, clopidogrel, or the combination of aspirin and dipyridamole for patients in sinus rhythm, and anticoagulation with warfarin or ximelagatran for patients in AF) and, where appropriate, carotid revascularization for patients with severe carotid stenosis.

Results of a Multicentre, Randomised Controlled Trial of Intra-Arterial Urokinase in the Treatment of Acute Posterior Circulation Ischaemic Stroke

BACKGROUND

Patients with ischaemic stroke due to occlusion of the basilar or vertebral arteries may develop a rapid deterioration in neurological status leading to coma and often to death. While intra-arterial thrombolysis may be used in this context, no randomised controlled data exist to support its safety or efficacy.

METHODS

Randomised controlled trial of intra-arterial urokinase within 24 h of symptom onset in patients with stroke and angiographic evidence of posterior circulation vascular occlusion.

RESULTS

Sixteen patients were randomised, and there was some imbalance between groups, with more severe strokes occurring in the treatment arm. A good outcome was observed in 4 of 8 patients who received intra-arterial urokinase compared with 1 of 8 patients in the control group.

CONCLUSIONS

These results support the need for a large-scale study to establish the efficacy of intra-arterial thrombolysis for acute basilar artery occlusion.

Protein Z Gene Polymorphisms, Protein Z Concentrations, and Ischemic Stroke

Background and Purpose— We aimed to determine whether A-13G or G79A polymorphisms of the protein Z gene that have been reported to be an important determinant of blood concentrations of protein Z are associated with risk of ischemic stroke in a broad range of stroke patients and controls.

Methods— We conducted a case control study of 151 hospital cases of first-ever ischemic stroke and 164 randomly selected community controls. Protein Z genotype was determined for the A-13G promoter polymorphism and the G79A intron F polymorphism, and plasma protein Z concentrations were measured during the first 7 days and at 3 to 6 months after the acute stroke event.

Results— Geometric mean concentrations of protein Z measured within 7 days of acute stroke were significantly higher in cases compared with controls (1.51 μg/mL versus 1.13 μg/mL; P <0·0001). Protein Z concentrations were highest among subjects with the A-13G AA genotype, intermediate among those with the AG genotype, and lowest among those with the GG genotype (1.39 μg/mL versus 1.05 μg/mL versus 0.76 μg/mL; P <0.0001); and highest among those with the G79A GG genotype, intermediate among those with the GA genotype, and lowest among those with the AA genotype (1.47 μg/mL versus 1.13 μg/mL versus 0.66 μg/mL; P <0.0001). The prevalence of A-13G and G79A genotypes was not significantly different between cases of ischemic stroke and controls. However, compared with the G79A GG genotype (reference), the odds of ischemic stroke was progressively lower for the heterozygote GA (odds ratio [OR], 0.83; 95% CI, 0.52 to 1.33) and the homozygote AA genotype (OR, 0.63; 95% CI, 0.20 to 1.98). A pooled analysis showed that compared with the G79A GG genotype (reference), the odds of ischemic stroke was progressively lower for the heterozygote GA (OR, 0.78; 95% CI, 0.57 to 1.07) and the homozygote AA genotype (OR, 0.31; 95% CI, 0.14 to 0.69).

Conclusion— The consistency of the association between protein Z genotypes, blood concentrations of protein Z, and ischemic stroke, determined using 2 different methods that have different sources of bias strengthens the evidence that increased blood concentrations of protein Z concentrations are associated causally with an increased risk of ischemic stroke.

Sustained Homocysteine-Lowering Effect over Time of Folic Acid-Based Multivitamin Therapy in Stroke Patients despite Increasing Folate Status in the Population

BACKGROUND AND AIMS

It is uncertain what impact increasing voluntary folate fortification may be having on the statistical power of randomized trials testing the homocysteine hypothesis of atherothrombosis. The objective of this study was to determine whether there has been a change in folate status between 1998 and 2002 in stroke patients randomized into the VITAmins TO Prevent Stroke (VITATOPS) Study at a single center in Perth, Australia, and what impact this may have had on the magnitude of the homocysteine-lowering effect achieved over time with folic acid-based multivitamin therapy.

METHODS

We conducted a randomized, double-blind, placebo-controlled study involving 285 patients with stroke or transient ischemic attack who were recruited between 1998 and 2002 and randomized to long-term folic acid 2.0 mg/day, pyridoxine 25 mg/day and cobalamin 0.5 mg/day (active VITATOPS medication) or placebo. Fasting plasma total homocysteine, red cell folate, serum cobalamin and serum pyridoxine levels were measured at baseline and 6 months, and the change in blood levels over 4 time quartiles and differences in levels between the two randomized treatments were examined.

RESULTS

Between 1998 and 2002, there was a significant rise in baseline mean red cell folate levels over 4 time quartiles among the entire stroke cohort (723.3, 780.1, 922.6 and 1,023.7 nmol/l in the first, second, third and fourth quartiles, respectively; p < 0.0001), but this was not associated with a spontaneous reduction in mean baseline total homocysteine levels during the same time period (12.7, 14.3, 12.1 and 12.8 micromol/l in the first, second, third and fourth quartiles, respectively; p = 0.55). The homocysteine-lowering effect of the active VITATOPS trial medication at 6 months after randomization also did not change significantly between 1998 and 2002 (difference between randomized groups: -4.1, -4.1, -3.1 and -3.6 micromol/l in the first, second, third and fourth quartiles, respectively; p = 0.56).

CONCLUSIONS

The homocysteine-lowering effect of the active VITATOPS trial medication has not attenuated significantly in the past 5 years despite increasing voluntary fortification of foods with folic acid as reflected by a progressive rise in baseline folate status. These data suggest that in the continuing absence of a program of mandatory folate fortification of food in populations served by centers participating in the VITATOPS trial, the study will remain adequately powered to test the homocysteine-lowering hypothesis for which it was designed.

Homocysteine-Lowering Treatment With Folic Acid, Cobalamin, and Pyridoxine Does Not Reduce Blood Markers of Inflammation, Endothelial Dysfunction, or Hypercoagulability in Patients With Previous Transient Ischemic Attack or Stroke

Background and Purpose— Epidemiological and laboratory studies suggest that increasing concentrations of plasma homocysteine (total homocysteine [tHcy]) accelerate cardiovascular disease by promoting vascular inflammation, endothelial dysfunction, and hypercoagulability.

Methods— We conducted a randomized controlled trial in 285 patients with recent transient ischemic attack or stroke to examine the effect of lowering tHcy with folic acid 2 mg, vitamin B 12 0.5 mg, and vitamin B 6 25 mg compared with placebo on laboratory markers of vascular inflammation, endothelial dysfunction, and hypercoagulability.

Results— At 6 months after randomization, there was no significant difference in blood concentrations of markers of vascular inflammation (high-sensitivity C-reactive protein [ P =0.32]; soluble CD40L [ P =0.33]; IL-6 [ P =0.77]), endothelial dysfunction (vascular cell adhesion molecule-1 [ P =0.27]; intercellular adhesion molecule-1 [ P =0.08]; von Willebrand factor [ P =0.92]), and hypercoagulability (P-selectin [ P =0.33]; prothrombin fragment 1 and 2 [ P =0.81]; D-dimer [ P =0.88]) among patients assigned vitamin therapy compared with placebo despite a 3.7-μmol/L (95% CI, 2.7 to 4.7) reduction in total homocysteine (tHcy).

Conclusions— Lowering tHcy by 3.7 μmol/L with folic acid-based multivitamin therapy does not significantly reduce blood concentrations of the biomarkers of inflammation, endothelial dysfunction, or hypercoagulability measured in our study. The possible explanations for our findings are: (1) these biomarkers are not sensitive to the effects of lowering tHcy (eg, multiple risk factor interventions may be required); (2) elevated tHcy causes cardiovascular disease by mechanisms other than the biomarkers measured; or (3) elevated tHcy is a noncausal marker of increased vascular risk.

Collagen platelet receptor polymorphisms integrin alpha2beta1 C807T and GPVI Q317L and risk of ischemic stroke

Several polymorphisms of integrin alpha2beta1 and glycoprotein (GP) VI that may modify platelet-collagen interactions or subsequent signaling have been described. We conducted a case-control study involving 180 stroke patients and 172 controls to determine whether the alpha2 C807T and GPVI Q317L polymorphisms were associated with an increased risk of ischemic stroke. We found no statistically significant differences in the distribution of alpha2 C807T and GPVI Q317L in patients and controls overall or after stratification by etiological subtype. The GPVI 317QQ genotype was found to be over-represented in a subgroup of patients >/=60 years compared to corresponding controls. However, this association did not remain significant after adjustment for other cardiovascular risk factors. Our results do not support a role for the integrin alpha2 C807T and GPVI Q317L polymorphisms in the development of first-ever ischemic stroke. However, larger studies are required to confirm this.

Homocysteine levels in patients with stroke: clinical relevance and therapeutic implications

High plasma levels of the amino acid homocysteine have been implicated in the development of vascular diseases, including stroke. Elevated plasma levels of total homocysteine (tHcy) above 15 micromol/L are present in less than 5% of the general population, but in as many as 50% of patients with stroke (and other atherothromboembolic vascular diseases). However, it remains uncertain whether a high tHcy level is a causal risk factor for stroke and should be lowered, or is a marker of another factor associated with stroke (e.g. acute tissue damage or tissue repair after an acute vascular event) and therefore should not be lowered. Plasma levels of tHcy can be lowered effectively by folic acid, vitamin B(6) and vitamin B(12) supplementation, and controlled trials have shown some beneficial effects on surrogate markers of vascular function. However, these markers are not established vascular risk factors or valid predictors of 'hard' clinical vascular outcome events. Until it has been shown in large randomised trials [such as the ongoing Vitamins to Prevent Stroke Study (VITATOPS) and the Vitamins in Stroke Prevention (VISP) study] that multivitamin therapy reduces the rate of recurrent stroke and other serious vascular events in patients with prior stroke or transient ischaemic attack, widespread screening for, and treatment of, high tHcy levels remains experimental and cannot be recommended.

Initial clinical and demographic predictors of swallowing impairment following acute stroke

Swallowing impairment (dysphagia) is a frequent sequela of acute stroke; however, the ability to accurately detect dysphagia at the bedside and predict which patients may be at risk of dysphagic complications, such as aspiration, remains limited. Despite this, clinical assessment batteries continue to be the first point of assessment for acute dysphagia. We examined the predictive value of clinical factors suggestive of swallowing dysfunction in an attempt to identify the important independent clinical signs at initial presentation that are associated with dysphagia, aspiration, and the combined variable aspiration and/or penetration (ASPEN) in acute stroke patients. For the purposes of this study, dysphagia was defined as a disorder of bolus flow. Aspiration was defined as entry of swallowed material below the level of the true vocal cords which was not expectorated. The clinical items identified as independent predictors of dysphagia (measured radiographically) at initial presentation were age > 70 years, male gender, disabling stroke (Barthel score < 60), palatal weakness or asymmetry, incomplete oral clearance, and impaired pharyngeal response (cough/gurgle). The clinical predictors of aspiration (determined radiographically) at initial presentation were delayed oral transit and incomplete oral clearance. Incorporating clinical signs, such as those identified by this study, into clinical assessments of swallowing impairment may increase their predictive utility.

Inherited thrombophilia in ischemic stroke and its pathogenic subtypes

BACKGROUND AND PURPOSE

One or more of the inherited thrombophilias may be causal risk factor for a proportion of ischemic strokes, but few studies have addressed this association or the association between thrombophilia and pathogenic subtypes of stroke.

METHODS

We conducted a case-control study of 219 hospital cases with a first-ever ischemic stroke and 205 randomly selected community control subjects stratified by age, sex, and postal code. With the use of established criteria, cases of stroke were classified by pathogenic subtype in a blinded fashion. The prevalence of conventional vascular risk factors; fasting plasma levels of protein C, protein S, antithrombin III; and genetic tests for the factor V Leiden and the prothrombin 20210A mutation were determined in cases and control subjects.

RESULTS

The prevalence of any thrombophilia was 14.7% (95% CI, 9.9% to 19.5%) among cases and 11.7% (95% CI, 7.4% to 17.0%) among control subjects (OR, 1.3; 95% CI, 0.7% to 2.3%). The prevalence of individual thrombophilias among cases ranged from 0.9% (95% CI, 0.1% to 3.4%) for protein S deficiency to 5.2% (95% CI, 0.3% to 9.1%) for antithrombin III deficiency; among control subjects, the prevalence ranged from 1.0% (95% CI, 0.1% to 3.6%) for protein S deficiency to 4.1% (95% CI, 0.2% to 7.8%) for antithrombin III deficiency. There were no significant differences in the prevalence of thrombophilia between cases and control subjects or between pathogenic subtypes of ischemic stroke.

CONCLUSIONS

One in 7 patients with first-ever acute ischemic stroke will test positive for one of the inherited thrombophilias, but the relation is likely to be coincidental rather than causal in almost all cases, irrespective of the pathogenic subtype of the ischemic stroke. These results suggest that routine testing for thrombophilia in most patients with acute ischemic stroke may be unnecessary. Whether the thrombophilias may still be important in younger patients with ischemic stroke or in predicting complications (eg, venous thrombosis) and stroke outcome remains uncertain.

Current oral antiplatelet agents to prevent atherothrombosis

Aspirin inhibits platelet activation by irreversibly inhibiting platelet cyclooxygenase and thromboxane production, and reduces the odds of serious vascular events (stroke, myocardial infarction or vascular death) by about one quarter in a range of patients with symptomatic atherosclerosis at high risk of a subsequent event. The adenosine diphosphate (ADP) receptor antagonists clopidogrel and ticlopidine are significantly more effective than aspirin in high-risk vascular patients, further reducing the odds of serious vascular events by about 10% (95% CI 2-19%) over the benefit provided by aspirin. The ADP receptor antagonists are also associated with a significant 30% reduction in the odds of gastrointestinal haemorrhage (odds ratio 0.71, 95% CI 0.59-0.86). Ticlopidine increases the odds of skin rash and of diarrhoea by more than twofold compared with aspirin, whereas clopidogrel is associated with a one-third increase in the odds of rash and of diarrhoea. Only ticlopidine increases the odds of neutropenia compared with aspirin. There is no clear evidence as yet for the benefit of dipyridamole or an oral GP IIb/IIIa receptor antagonist as single antiplatelet agents in atherothrombotic patients. Amongst high vascular risk patients, the combination of low-dose aspirin and high-dose dipyridamole is associated with about a 10% (95% CI 0-20%) reduction in the odds of a serious vascular event. Most of this reduction is due to a 23% reduction in non-fatal stroke. The size of this estimate continues to be investigated in an ongoing study of patients with transient ischaemic attack and stroke. The combined use of aspirin and ticlopidine is markedly superior to heparin, warfarin and aspirin for reducing thrombotic complications after coronary artery stenting. Clopidogrel plus aspirin has been shown to be safer than aspirin and ticlopidine in coronary stenting, and is now under long-term evaluation in unstable angina, and other conditions in which patients are at high risk of atherothrombotic events.