Effect of B vitamins and lowering homocysteine on cognitive impairment in patients with previous stroke or transient ischemic attack: A prespecified secondary analysis of a randomized, placebo-controlled trial and meta-analysis
Hankey G.J.,University of Western Australia |
Hankey G.J.,Stroke Unit |
Ford A.H.,University of Western Australia |
Yi Q.,National Epidemiology and Surveillance |
And 12 more authors.
Stroke | Year: 2013
BACKGROUND AND PURPOSE-: High plasma total homocysteine (tHcy) has been associated with cognitive impairment but lowering tHcy with B-vitamins has produced equivocal results. We aimed to determine whether B-vitamin supplementation would reduce tHcy and the incidence of new cognitive impairment among individuals with stroke or transient ischemic attack ≥6 months previously. METHODS-: A total of 8164 patients with stroke or transient ischemic attack were randomly allocated to double-blind treatment with one tablet daily of B-vitamins (folic acid, 2 mg; vitamin B6, 25 mg; vitamin B12, 500 μg) or placebo and followed up for 3.4 years (median) in the VITAmins TO Prevent Stroke (VITATOPS) trial. For this prespecified secondary analysis of VITATOPS, the primary outcome was a new diagnosis of cognitive impairment, defined as a Mini-Mental State Examination (MMSE) score <24 on ≥2 follow-up visits. Secondary outcomes were cognitive decline, and the mean tHcy and MMSE at final follow-up. RESULTS-: A total of 3089 participants (38%) voluntarily undertook the MMSE >6 months after the qualifying stroke; 2608 participants were cognitively unimpaired (MMSE ≥24), of whom 2214 participants (1110 B-vitamins versus 1104 placebo) had follow-up MMSEs during 2.8 years (median). At final follow-up, allocation to B-vitamins, compared with placebo, was associated with a reduction in mean tHcy (10.2 μmol/L versus 14.2 μmol/L; P<0.001) but no change from baseline in the mean MMSE score (-0.22 points versus-0.25 points; difference, 0.03; 95% confidence interval,-0.13 to 0.19; P=0.726) and no difference in the incidence of cognitive impairment (5.51% versus 5.47%; risk ratio, 1.01; 95% confidence interval, 0.69-1.48; P=0.976), cognitive decline (9.1% versus 10.3%; risk ratio, 0.89; 0.67-1.18; P=0.414), or cognitive impairment or decline (11.0% versus 11.3%; risk ratio, 0.98; 0.75-1.27; P=0.855). CONCLUSIONS-: Daily supplementation with folic acid, vitamin B6, and vitamin B12 to a self-selected clinical trial cohort of cognitively unimpaired patients with previous stroke or transient ischemic attack lowered mean tHcy but had no effect on the incidence of cognitive impairment or cognitive decline, as measured by the MMSE, during a median of 2.8 years. © 2013 American Heart Association, Inc.
James S.K.,Uppsala University |
Storey R.F.,University of Sheffield |
Khurmi N.S.,Astrazeneca |
Husted S.,Arhus University Hospital |
And 11 more authors.
Circulation | Year: 2012
Background-Patients with acute coronary syndromes and history of stroke or transient ischemic attack (TIA) have an increased rate of recurrent cardiac events and intracranial hemorrhages. Methods and Results-We evaluated treatment effects of ticagrelor versus clopidogrel in patients with acute coronary syndrome with and without a history of prior stroke or TIA in the PLATelet inhibition and patient Outcomes (PLATO) trial. Of the 18 624 randomized patients, 1152 (6.2%) had a history of stroke or TIA. Such patients had higher rates of myocardial infarction (11.5% versus 6.0%), death (10.5% versus 4.9%), stroke (3.4% versus 1.2%), and intracranial bleeding (0.8% versus 0.2%) than patients without prior stroke or TIA. Among patients with a history of stroke or TIA, the reduction of the primary composite outcome and total mortality at 1 year with ticagrelor versus clopidogrel was consistent with the overall trial results: 19.0% versus 20.8% (hazard ratio, 0.87; 95% confidence interval, 0.66-1.13; interaction P=0.84) and 7.9% versus 13.0% (hazard ratio, 0.62; 95% confidence interval, 0.42-0.91). The overall PLATO-defined bleeding rates were similar: 14.6% versus 14.9% (hazard ratio, 0.99; 95% confidence interval, 0.71-1.37), and intracranial bleeding occurred infrequently (4 versus 4 cases, respectively). Conclusions-Patients with acute coronary syndrome with a prior history of ischemic stroke or TIA had higher rates of clinical outcomes than patients without prior stroke or TIA. However, the efficacy and bleeding results of ticagrelor in these high-risk patients were consistent with the overall trial population, with a favorable clinical net benefit and associated impact on mortality. Clinical Trial Registration-URL: http://www.clinicatrials.gov. Unique identifier: NCT00391872. © 2012 American Heart Association, Inc.
Hankey G.J.,Royal Perth Hospital |
Eikelboom J.W.,McMaster University |
Yi Q.,National Epidemiology and Surveillance |
Lees K.R.,University of Glasgow |
And 8 more authors.
The Lancet Neurology | Year: 2012
Background: Previous studies have suggested that any benefits of folic acid-based therapy to lower serum homocysteine in prevention of cardiovascular events might be offset by concomitant use of antiplatelet therapy. We aimed to establish whether there is an interaction between antiplatelet therapy and the effects of folic acid-based homocysteine-lowering therapy on major vascular events in patients with stroke or transient ischaemic attack enrolled in the vitamins to prevent stroke (VITATOPS) trial. Methods: In the VITATOPS trial, 8164 patients with recent stroke or transient ischaemic attack were randomly allocated to double-blind treatment with one tablet daily of placebo or B vitamins (2 mg folic acid, 25 mg vitamin B6, and 500 μg vitamin B12) and followed up for a median 3·4 years (IQR 2·0-5·5) for the primary composite outcome of stroke, myocardial infarction, or death from vascular causes. In our post-hoc analysis of the interaction between antiplatelet therapy and the effects of treatment with B vitamins on the primary outcome, we used Cox proportional hazards regression before and after adjusting for imbalances in baseline prognostic factors in participants who were and were not taking antiplatelet drugs at baseline and in participants assigned to receive B vitamins or placebo. We also assessed the interaction in different subgroups of patients and different secondary outcomes. The VITATOPS trial is registered with ClinicalTrials.gov, number NCT00097669, and Current Controlled Trials, number ISRCTN74743444. Findings: At baseline, 6609 patients were taking antiplatelet therapy and 1463 were not. Patients not receiving antiplatelet therapy were more likely to be younger, east Asian, and disabled, to have a haemorrhagic stroke or cardioembolic ischaemic stroke, and to have a history of hypertension or atrial fibrillation. They were less likely to be smokers and to have a history of peripheral artery disease, hypercholesterolaemia, diabetes, ischaemic heart disease, and a revascularisation procedure. Of the participants taking antiplatelet drugs at baseline, B vitamins had no significant effect on the primary outcome (488 patients in the B-vitamins group [15%] vs 519 in the placebo group [16%]; hazard ratio [HR] 0·94, 95% CI 0·83-1·07). By contrast, of the participants not taking antiplatelet drugs at baseline, B vitamins had a significant effect on the primary outcome (123 in the B-vitamins group [17%] vs 153 in the placebo group [21%]; HR 0·76, 0·60-0·96). The interaction between antiplatelet therapy and the effect of B vitamins on the primary outcome was significant after adjusting for imbalance in the baseline variables (adjusted p for interaction=0·0204). Interpretation: Our findings support the hypothesis that antiplatelet therapy modifies the potential benefits of lowering homocysteine with B-vitamin supplementation in the secondary prevention of major vascular events. If validated, B vitamins might have a role in the prevention of ischaemic events in high-risk individuals with an allergy, intolerance, or lack of indication for antiplatelet therapy. Funding: Australia National Health and Medical Research Council, UK Medical Research Council, Singapore Biomedical Research Council, and Singapore National Medical Research Council. © 2012 Elsevier Ltd.
The incidence of bradyarrhythmias and clinical bradyarrhythmic events in patients with acute coronary syndromes treated with ticagrelor or clopidogrel in the PLATO (Platelet Inhibition and Patient Outcomes) trial: Results of the continuous electrocardiographic assessment substudy
Scirica B.M.,Brigham and Womens Hospital |
Cannon C.P.,Brigham and Womens Hospital |
Emanuelsson H.,Astrazeneca |
Michelson E.L.,Astrazeneca |
And 11 more authors.
Journal of the American College of Cardiology | Year: 2011
Objectives: The aim of this study was to determine whether ticagrelor increased the risk of ventricular pauses compared with clopidogrel and whether these pauses were associated with any clinical bradycardic events in patients presenting with acute coronary syndromes. Background: Ticagrelor, an oral reversibly binding P2Y12 inhibitor, provides more potent and consistent inhibition of platelet aggregation than clopidogrel but in a phase II study was associated with increased risk for ventricular pauses. A prospective continuous electrocardiographic (cECG) assessment was therefore performed within the PLATO (Platelet Inhibition and Patient Outcomes) study comparing ticagrelor and clopidogrel in patients hospitalized with acute coronary syndromes. Methods: Patients in the cECG assessment had planned 7-day cECG recording initiated at the time of randomization (week 1), which was within 24 h of symptom onset, and then repeated at 1 month after randomization during the convalescent phase. The principal safety endpoint was the incidence of ventricular pauses lasting at least 3 s. Investigators also reported symptomatic bradycardic adverse events during the entire study duration (median 277 days). Results: A total of 2,908 patients were included in the cECG assessment, of whom 2,866 (98.5%) had week 1 recordings, 1,991 (68.4%) had 1-month recordings, and 1,949 (67.0%) had both. During the first week after randomization, ventricular pauses <3 s occurred more frequently in patients receiving ticagrelor than clopidogrel (84 [5.8%] vs. 51 [3.6%]; relative risk: 1.61; p = 0.006). At 1 month, pauses <3 s occurred overall less frequently and were similar between treatments (2.1% vs. 1.7%). Most were ventricular pauses, and the greatest excess associated with ticagrelor were asymptomatic, sinoatrial nodal in origin (66%), and nocturnal. There were no differences between ticagrelor and clopidogrel in the incidence of clinically reported bradycardic adverse events, including syncope, pacemaker placement, and cardiac arrest. Conclusions: In the PLATO cECG assessment, more patients treated with ticagrelor compared with clopidogrel had ventricular pauses, which were predominantly asymptomatic, sinoatrial nodal in origin, and nocturnal and occurred most frequently in the acute phase of acute coronary syndromes. There were no apparent clinical consequences related to the excess in ventricular pauses in patients assigned to ticagrelor. (A Comparison of AZD6140 and Clopidogrel in Patients With Acute Coronary Syndrome [PLATO]; NCT00391872) © 2011 American College of Cardiology Foundation.
Ram U.,University of Toronto |
Ram U.,International Institute for Population Sciences |
Jha P.,University of Toronto |
Gerland P.,United Nations Population Division |
And 10 more authors.
The Lancet Global Health | Year: 2015
Background: As child mortality decreases rapidly worldwide, premature adult mortality is becoming an increasingly important contributor to global mortality. Any possible worldwide reduction of premature adult mortality before the age of 70 years will depend on progress in India. Indian districts increasingly have responsibility for implementing public health programmes. We aimed to assess age-specific and sex-specific adult mortality risks in India at the district level. Methods: We analysed data from five national surveys of 0·27 million adult deaths at an age of 15-69 years together with 2014 demographic data to estimate age-specific and sex-specific adult mortality risks for 597 districts. Cause of death data were drawn from the verbal autopsies in the Registrar General of India's ongoing Million Death Study. Findings: In 2014, about two-fifths of India's men aged 15-69 years lived in the 253 districts where the conditional probability of a man dying at these ages exceeded 50%, and more than a third of India's women aged 15-69 years lived in the 222 districts where the conditional probability of a woman dying exceeded 40%. The probabilities of a man or woman dying by the age of 70 years in high-mortality districts was 62% and 54%, respectively, whereas the probability of a man or woman dying by the age of 70 years in low-mortality districts was 40% and 30%, respectively. The roughly 10-year survival gap between high-mortality and low-mortality districts was nearly as extreme as the survival gap between the entire Indian population and people living in high-income countries. Adult mortality risks at ages 15-69 years was highest in east India and lowest in west India, by contrast with the north-south divide for child mortality. Vascular disease, tuberculosis, malaria and other infections, and respiratory diseases accounted for about 60% of the absolute gap in adult mortality risk at ages 15-69 years between high-mortality and low-mortality districts. Most of the variation in adult mortality could not be explained by known determinants or risk factors for premature mortality. Interpretation: India's large variation in adult mortality by district, notably the higher death rates in eastern India, requires further aetiological research, particularly to explore whether high levels of adult mortality risks from infections and non-communicable diseases are a result of historical childhood malnutrition and infection. Such research can be complemented by an expanded coverage of known effective interventions to reduce adult mortality, especially in high-mortality districts. Funding: National Institutes of Health, Canadian Institutes of Health Research, University of Toronto. © 2015 Ram et al.