Angioplasty-related restenosis can be significantly reduced by lowering homocysteine levels with vitamin therapy. Angioplasty (percutaneous coronary intervention or PCI) is used to open up (dilate) coronary arteries so as to produce a more abundant blood supply to the heart. The beneficial effect of angioplasty is, unfortunately, often short-lived with 40% or more of the opened artery segments closing up again (restenosis) within 6 months of the operation. A team of American researchers now reports that the incidence of restenosis in smaller coronary arteries can be markedly reduced by decreasing homocysteine levels through supplementation with folic acid and vitamins B6 and B12. Their double-blind, randomized clinical trial involved 205 patients who underwent angioplasty to open up small (diameter less than 3 mm) coronary arteries that were at least 50% blocked (stenosis). Half the participants received 1 mg folic acid, 400 micrograms vitamin B12, and 10 mg vitamin B6 on a daily basis while the other half received a placebo. After 28 weeks (plus or minus 6 weeks) 42% of the control group had experienced restenosis as compared to only 15% of the vitamin-treated patients; this is a relative reduction in restenosis rate of 66%. The benefit of homocysteine lowering therapy was highest among patients treated with balloon angioplasty only (82% relative risk reduction) and significantly less in patients who had stents implanted. The benefits were also higher among patients with high levels of low- density lipoprotein cholesterol. The researchers conclude that homocysteine lowering therapy with vitamins significantly reduces the risk of restenosis in patients treated with PCI for stenosis of small coronary arteries.
Schnyder, Guido, et al. Effect of homocysteine-lowering therapy on restenosis after percutaneous coronary intervention for narrowing in small coronary arteries. American Journal of Cardiology, Vol. 91, May 15, 2003, pp. 1265-69