Antioxidant Vitamins Slow Arteriosclerosis in Heart Transplant Recipient
In heart transplant recipients, supplementation with vitamins C and E appears to slow the progression of transplant-related arteriosclerosis, according to a report published in the March 30th issue of The Lancet.
Transplant-associated arteriosclerosis develops within 3 years in 70% of heart transplant recipients, the authors note. The exact mechanism involved is unclear, but oxidant stress appears to play a central role. Findings from animal studies suggest that antioxidants, like vitamins C and E, can improve survival, but this approach has not been tested in humans.
Dr. James C. Fang, from Brigham and Women’s Hospital in Boston, and colleagues randomized 40 patients who had undergone cardiac transplantation within the last 2 years to receive vitamins C and E or placebo for 1 year. Coronary intimal thickness was determined with intravascular ultrasonography, while coronary endothelial function was assessed with intracoronary acetylcholine infusions.
Patients in the treatment group received 500 mg of vitamin C and 400 IU of vitamin E twice daily. All patients received daily pravastatin therapy started immediately after transplantation.
At 1-year follow-up, the intimal index of the treatment group had not changed significantly from baseline, while that of the placebo group had increased by 8% (p = 0.008). In both groups, coronary endothelial function remained stable throughout the study period, Dr. Fang and colleagues report.
“Our results suggest that vitamins C and E provide a clinically useful approach to reducing arteriosclerosis after cardiac transplantation,” the investigators write. The mechanism seems to involve an inhibitory effect on plague growth rather than a vascular remodeling effect. Also, such therapy improves upon the benefits achieved with statins.
Further studies are needed to determine if the beneficial effects of vitamin therapy persist beyond 1 year, when most of the clinical complications of transplant-associated arteriosclerosis are likely to occur.
Lancet 2002;359:1108-1113.
