In this third up date of the Cochrane review , there were no differences in effects of homocysteine-lowering interventions in the form of supplements of vitamins B6 , B9 or B12 given alone or in combination comparing with placebo on myocardial infa rct ion , death from any cause or adverse events .
BACKGROUND Cardiovascular disease , which includes coronary artery disease , stroke and peripheral vascular disease , is a leading cause of death worldwide .
Homocysteine is an amino acid with biological functions in methionine metabolism .
A postulated risk factor for cardiovascular disease is an elevated circulating total homocysteine level .
The impact of homocysteine-lowering interventions , given to patients in the form of vitamins B6 , B9 or B12 supplements , on cardiovascular events has been investigated .
This is an up date of a review previously published in 2009 , 2013 , and 2015 .
OBJECTIVES To determine whether homocysteine-lowering interventions , provided to patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events , as well as reducing all-cause mortality , and to evaluate their safety .
Vitamin Intervention for Stroke Prevention Trial: An Efficacy Analysis
Background and Purpose — The Vitamin Intervention for Stroke Prevention trial ( VISP ) intention-to-treat analysis did not show efficacy of combined vitamin therapy for recurrent vascular events in patients with nondisabling stroke . Reasons for lack of efficacy may have included folate fortification of grain products , inclusion of the recommended daily intake for B12 in the low-dose arm , treatment with parenteral B12 in patients with low B12 levels in both study arms , a dose of B12 too low for patients with malabsorption , supplementation with non study vitamins , and failure of patients with significant renal impairment to respond to vitamin therapy . We conducted an efficacy analysis limited to patients most likely to benefit from the treatment , based on hypotheses arising from evidence developed since VISP was initiated . The criteria for this subgroup were defined before any data analysis . Methods — For this analysis , we excluded patients with low and very high B12 levels at baseline ( < 250 and > 637 pmol/L , representing the 25th and 95th percentiles ) , to exclude those likely to have B12 malabsorption or to be taking B12 supplements outside the study and patients with significant renal impairment ( glomerular filtration rate < 46.18 ; the 10th percentile ) . Results — This subgroup represents 2155 patients ( 37 % female ) , with a mean age of 66±10.7 years . For the combined end point of ischemic stroke , coronary disease , or death , there was a 21 % reduction in the risk of events in the high-dose group compared with the low-dose group ( unadjusted P=0.049 ; adjusted for age , sex , blood pressure , smoking , and B12 level P=0.056 ) . In Kaplan – Meier survival analysis comparing 4 groups , patients with a baseline B12 level at the median or higher r and omized to high-dose vitamin had the best overall outcome , and those with B12 less than the median assigned to low-dose vitamin had the worst ( P=0.02 for combined stroke , death , and coronary events ; P=0.03 for stroke and coronary events ) . Conclusions — In the era of folate fortification , B12 plays a key role in vitamin therapy for total homocysteine . Higher doses of B12 , and other treatments to lower total homocysteine may be needed for some patients
In this third up date of the Cochrane review , there were no differences in effects of homocysteine-lowering interventions in the form of supplements of vitamins B6 , B9 or B12 given alone or in combination comparing with placebo on myocardial infa rct ion , death from any cause or adverse events .
BACKGROUND Cardiovascular disease , which includes coronary artery disease , stroke and peripheral vascular disease , is a leading cause of death worldwide .
Homocysteine is an amino acid with biological functions in methionine metabolism .
A postulated risk factor for cardiovascular disease is an elevated circulating total homocysteine level .
The impact of homocysteine-lowering interventions , given to patients in the form of vitamins B6 , B9 or B12 supplements , on cardiovascular events has been investigated .
This is an up date of a review previously published in 2009 , 2013 , and 2015 .
OBJECTIVES To determine whether homocysteine-lowering interventions , provided to patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events , as well as reducing all-cause mortality , and to evaluate their safety .