Effect of folic acid on endothelial function following acute myocardial infarction.
The aim of this study was to test the influence of high-dose folic acid (10 mg/d) on endothelial function in patients referred for coronary intervention after an acute myocardial infarction (AMI) and determine its relation to homocysteine levels. Flow-mediated dilation (FMD) of the brachial artery was performed in 40 patients after AMI (16 with normal homocysteine levels and 24 patients with elevated levels [>11 micromol/L]). Subjects were randomized to receive first folic acid (10 mg/day; group A) or placebo (group B) for 6 weeks in a double-blind crossover trial with a 2-week washout. Plasma folate, total homocysteine and its subtypes (oxidized, reduced, and protein-bound), FMD, and nitroglycerin-mediated dilation were assessed at baseline and at 6 and 14 weeks. In group A, folic acid improved FMD from 3.98 +/- 0.35% to 6.44 +/- 0.56% (p <0.001). This effect persisted after the crossover with placebo (5.42 +/- 0.59, p = 0.13). In group B, placebo did not increase FMD (4.01 +/- 0.34% vs 4.46 +/- 0.38, p = 0.38); however, a significant increase was observed in the second active treatment period (6.49 +/- 0.56%, p = 0.005). In both groups, improved FMD neither correlated with basal levels of homocysteine and its subtypes nor with changes induced during the folate treatment. Nitroglycerin-mediated dilation did not change significantly in either group. Folic acid increased FMD in both normo- and hyperhomocysteinanemic groups (p = 0.006 and p <0.001). In conclusion, 6-week treatment with high-dose folic acid improves endothelial function in post-AMI patients, independent from homocysteine status. Folic acid can be recommended to improve postinfarction endothelial dysfunction in patients with normo- and hyperhomocysteinemia.
Moens
An L
AL
Department of Cardiology, University Hospital of Antwerp, Antwerp, Belgium. Amoens1@jhmi.edu
Claeys
Marc J
MJ
Wuyts
Floris L
FL
Goovaerts
Inge
I
Van Hertbruggen
Els
E
Wendelen
Luc C
LC
Van Hoof
Viviane O
VO
Vrints
Christiaan J
CJ
D001916:Brachial Artery / Q000187:drug effects; D016009:Chi-Square Distribution; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D006710:Homocysteine / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D016896:Treatment Outcome; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000494:pharmacology*
D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid