Study: Vitamins C and E Slow Arteriosclerosis in Heart Transplant Recipients

A new study reported in the March 30th issue of the Lancet has found that supplements of the antioxidant vitamins C and E can slow the progression of arteriosclerosis in the first year after heart transplantation, but it is not yet known whether such a benefit can be sustained over many years.

Within three years of receiving a new heart, about 70 percent of patients develop arteriosclerosis, which is believed to be associated with oxidant stress. That narrowing of the arteries is the reason that most heart transplant patients do not live longer than 10 years after the procedure.

In their study of 40 recent heart transplant patients, researchers at Brigham and Women's Hospital in Boston gave half of the participants a placebo and the other half doses of vitamin C and E two times a day for one year. They were looking to see how the vitamins affected the build-up of plaque using a measurement known as average intimal index that tells what percentage of the artery is occupied by plaque.

During the first year of treatment, the study found that this index increased in the placebo group by eight percent, but did not change significantly in those who received the vitamins. Researchers hailed this finding as suggesting that the vitamins were effective in halting the progression of plaque.

"We may have a second treatment that can prolong the life of patients after a heart transplant," Dr. Peter Ganz, one of the lead researchers and associate director of the cardiac catheterization laboratory at the hospital, told Medical Week. He said previous studies have shown that statins also are effective.

Ganz said the study was undertaken because the narrowing of the coronary arteries is particularly acute in heart transplant patients and limits the long-term chances of the transplant being successful.

"It's a very malignant, accelerated form of narrowing," Ganz explained. "By five years after the transplant, one-half of the patients have significant narrowing of their coronary arteries."

Because an immune response attacking the arteries and causing them to narrow is apparently turned on oxidization, Ganz said researchers were hoping that the antioxidant qualifies of the vitamins would act as a mitigating factor.

Dr. James C. Fang, a cardiologist at the hospital and a co-researcher, said further study is needed on whether the beneficial effects of vitamins C and E can be sustained over many years.

Fang also said that antioxidant therapy with these vitamins might also be useful in other solid-organ allografts such as kidney, lung and liver transplants, in which obliteration of vascular or tubular structures limits the long-term success.