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Folate Supplementation Linked to Increased Risk of Restenosis in Angioplasty/Stent Procedures: Presented at ACC

By Ed Susman

CHICAGO, IL -- April 1, 2003 -- Researchers admitted surprise at the results of a new study that indicate administering folate acid to patients who undergo angioplasty and stenting increases the risk of restenosis of the target vessel.

"Since this study was initiated to confirm earlier reports that folate acid supplementation reduced restenosis, these findings were surprising," said Helmut Lange, MD, of Kardiologische Praxis, Bremen, Germany, lead investigator of the Folate After Coronary Intervention Trial (FACIT).

Dr. Lange and colleagues recruited 626 patients, who were randomized to either folate or placebo for 6 months plus standard therapy after stenting. Follow-up angiography was completed in 76% of the patients.

In his late-breaker presentation at the 52^nd Annual Scientific Session of the American College of Cardiology, Dr. Lange reported that after 6 months of folate supplementation, the average minimal luminal diameter of the target vessels was 1.59 mm compared with 1.74 mm seen in patients who received placebo. The difference reached statistical significance at the P<0.01 level, he said.

Dr. Lange also reported that the restenosis rate in the folate arm was 35% compared with 27% in controls. Target lesion revascularization rate was 16% among patients taking folate supplements and 11% in the control arm. Late loss index -- a measure of tissue regrowth within the stented area -- was 61 in the patients receiving folate and 51 for those who received placebo. He said all these results achieved statistical significance at the P<0.05 level.

The researchers noted that their results contradict those from the Swiss Heart Study (N Engl J Med 2001;345:1593-1600), which reported that folate supplementation reduced restenosis by 50%.

"We found just the opposite results," Dr. Lange said. He suggested that patients in FACIT were given high levels of folate 1.2 mg, B₆ 48 mg, and B₁₂ 0.06mg, which might influence the results. "The amount of folate in a multivitamin is.4 mg, so we were 3 times that dose," he said. For example, he said that increasing the level of folate might promote "more robust cellular activity, which could lead to increased intimal growth."

Folate supplementation decreases circulating levels of homocysteine, and homocysteine is linked to cardiovascular disease. "So the hypothesis was that administration of a homocysteine-lowering vitamin combination would be protective," said Dr. Lange. "But this study suggests that it is too soon to make any recommendations on folate supplementation."

David O. Williams, MD, director of the Cardiac Catheterization Laboratories and Interventional Cardiology at Rhode Island Hospital, Providence, moderator of a press briefing at which the FACIT results were discussed, cautioned about over-interpreting the results.

"I wouldn't tell a patient to stop taking folate acid. What this is telling us is that the benefit reported in the earlier study is probably not 'real' but that doesn't mean this is a real risk. If they did another study, I doubt they would replicate these results."


[Study title: Folate After Coronary Intervention Trial (FACIT)]

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