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Decreased Rate of Coronary Restenosis After Lowering of Plasma Homocysteine Levels - Decreased Rate of Coronary Restenosis After Lowering of Plasma Homocysteine Levels
Description:
Decreased Rate of Coronary Restenosis After Lowering of Plasma Homocysteine Levels.
Hypothesis:
There is an association between homocysteine levels and restenosis after PTCA. This study evaluated the effect of lowering homocysteine on the rate of restenosis following PTCA with or without stents.
Study Design
Study Design:
Patients Enrolled: 205
Female: 22
Drug/Procedures Used:
A double-blind, prospective, randomized trial of treatment with folic acid (1mg), vitamin B-12 (400ugm), and pyridoxine (10mg) vs. matching placebo in patients following successful angioplasty of at least one coronary stenosis of 50% or greater. Patients with acute coronary syndromes or creatinine >1.8mg/dl were excluded. The specifics of the PTCA, adjunctive treatment including antiplatelet drugs and use of stents was at the discretion of the operator. Quantitative coronary arteriography was performed at baseline, when clinically necessary, or routinely at 6 months following PCI. Study endpoints included restenosis of 50% or more and clinical cardiac events.
Principal Findings:
196 of 205 patients assigned to treatment of placebo were followed clinically and 177 had repeat angiography. There was no difference between groups in the following: average age 61 years, 22% were women, 40% were smokers, 28% diabetics, lipids, homocysteine (11μm/L), or treatment with statins (71%), beta blockers (65%), and ACIi (35%), use of stents (50%). Treatment lowered homocysteine levels from 11.1 +/- 4.3μm/L to 7.2 +/- 2.4 μm/L. The rate of restenosis was significantly lower on treatment (19.6% vs 37.6%, p = 0.01) as was the need for target vessel revascularization (10.8% vs. 22.3%, p = 0.047). The followup minimal luminal diameter and percent stenosis was also significantly better in the folate group. There was no difference in other coronary events. The benefit was predominately in those with PTCA without stenting.
Treatment with a combination of folic acid, vitamin B-12, and pyridoxine significantly reduces the rate of restenosis following PTCA and the need for target vessel revascularization after PCI.
Interpretation:
This vitamin arm was associated with a 48% relative reduction in restenosis, which is similar to that observed when the baseline homocysteine level is <9 μm/L. The optimal dose of folic acid is not clear, nor is the added benefit or detriment of vitamin B-12 and pyridoxine. Results from the HATS study by Brown et al showed that vitamin supplements can actually counteract the beneficial effects of lipid lowering in patients with a low HDL. Thus, to be prudent it would be advisable to examine the separate contributions of each component of these treatment arms.
References:
1. Schnyder G, Roffi M, Pin R, et al. N Engl J Med 2001;345:1593-600.
Clinical Topics: Acute Coronary Syndromes, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Stable Ischemic Heart Disease, Lipid Metabolism, Statins, Interventions and ACS, Interventions and Imaging, Angiography, Nuclear Imaging, Chronic Angina
Keywords: Acute Coronary Syndrome, Platelet Aggregation Inhibitors, Coronary Restenosis, Lipids, Constriction, Pathologic, Creatinine, Pyridoxine, Angioplasty, Vitamin B 12, Stents, Homocysteine, Coronary Angiography, Folic Acid, Diabetes Mellitus
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