Homocysteine-lowering trials for prevention of heart disease and stroke

Dietary supplementation with B-vitamins that lower plasma total homocysteine concentrations are expected to lower the risk of cardiovascular disease. Folic acid and vitamin B (12) lower blood homocysteine concentrations by about 25-30% in populations without folic acid fortification, but by only 10-15% in populations with fortification. In observational studies, 25% lower homocysteine is associated with about 10% less coronary heart disease (CHD) and about 20% less stroke. This review examines the current status of 12 large-scale randomized trials of B-vitamin supplementation and risk of cardiovascular disease. Seven of these trials are being performed in populations without fortification (five involving participants with prior CHD, two with prior stroke) and five in populations with fortification (two with prior CHD, two with renal disease, and one with prior stroke). Many of these trials may not have included a sufficient number of people or lasted long enough to have adequate power to exclude false-negative results. Taken together, however, these trials involve 32,000 patients with prior vascular disease in unfortified populations and 20,000 (14,000 with vascular disease and 6000 with renal disease) patients in fortified populations. A metaanalysis of these trials should have adequate power to determine whether homocysteine-lowering vitamin supplements can reduce the risk of cardiovascular disease.     

Rheumatic heart disease in the developing world: prevalence,prevention, and control

Rheumatic heart disease (RHD) continues to be a common healthproblem in the developing world, causing morbidity and mortalityamong both children and adults. Although little longitudinaldata are available, evidence suggests that there has been littleif any decline in the occurrence of RHD over the past few decades.Recent reports from the developing world have documented rheumaticfever (RE) incidence rates as high as 206/100 000 and RHD prevalencerates as high as 18.6/1000. The high frequency of RHD in thedeveloping world necessitates aggressive prevention and controlmeasures. The major interventions for prevention and controlinclude: (1) reduction of exposure to group A streptococci,(2) primary prophylaxis to prevent initial episodes of RF, and(3) secondary prophylaxis to prevent recurrent episodes of RE.Because recurrent episodes of RE cause increasingly severe cardiaccomplications, secondary prophylaxis is the most crucial featureof an effective RHD programme. For some impoverished countries,secondary prophylaxis may be the only intervention that canrealistically be implemented. In addition to this intervention,however, financial and human resources must be committed, andall of these elements must be integrated into existing primaryhealth care systems. Because RHD continues to be a common healthproblem in the developing world, greater emphasis needs to beplaced on the simple and cost-effective prevention and controlmeasures that are currently available to combat this disablingdisease.     

Heart to Heart: a computerized decision aid for assessment of coronary heart disease risk and the impact of risk-reduction interventions for primary prevention

Heart to Heart is a computer-based decision aid for patients and providers that provides personalized, evidence-based information about coronary heart disease (CHD) risk and potential risk-reducing interventions. To develop Heart to Heart, the authors used Framingham risk equations and systematic reviews of risk-reducing interventions. The Web version was programmed using PHP: Hypertext Processor, a Web-based programming language, and has separate interfaces for providers and patients. The authors subsequently developed a modified version for personal digital assistants. Heart to Heart uses information about a patient's CHD risk factors (age, gender, total and high-density lipoprotein cholesterol levels, diabetes, smoking, systolic blood pressure, and left ventricular hypertrophy) to calculate risk of total CHD events over 5 or 10 years. Patients and providers can then examine the effect of introducing one or more risk-reducing interventions (aspirin, lipid-lowering drug therapy, antihypertensive medication, or smoking cessation) on the patient's CHD risk. Future research will be directed to determining whether Heart to Heart can improve utilization of effective CHD risk-reducing interventions.