Dr. Guido Schnyder and colleagues at the Swiss Cardiovascular Center in Bern, Switzerland, recruited 553 patients for the study that examined effects of vitamin therapy on treating heart disease after angioplasty. Half the group received a combination of folic acid, vitamin B12, and vitamin B6 daily for six months; the others were given an inactive compound.

One year later, data show that those on the vitamin regimen were nearly 40 percent less likely to have needed repeat angioplasties or heart bypass operations than those taking dummy pills.

An earlier study by the Swiss group, reported in the New England Journal of Medicine, showed a 48 percent reduction in the development of restenosis after six months of vitamin therapy.

"It was important to follow these patients for another six months because that's the time frame in which restenosis typically occurs," commented Dr. Schnyder, an assistant professor in the cardiology division at the University of California, San Diego. "We've now shown that the vitamin combination did not just delay the development of restenosis, it prevented it."

Researchers believe the treatment works by lowering excess levels of the amino acid homocysteine, implicated in heart disease. Patients in the studies were treated with daily doses of folic acid (one mg), vitamin B12 (400 micrograms), and vitamin B6 (10 mg).

"This inexpensive treatment, which has minimal side effects, should be considered as adjunctive therapy for patients underoing coronary angioplasty," Dr. Schnyder concluded. Larger studies will help confirm the findings.