High-Dose Folic Acid Acutely Improves Coronary Vasodilator Function in Patients With Coronary Artery Disease

Objectives We investigated the acute effect of orally administered high-dose folic acid on coronary dilator function in humans. Background Folic acid and its active metabolite, 5-methyltetrahydrofolate, increase endothelium-dependent vasodilation in human peripheral circulation. However, the acute effect on coronary circulation is not known. Methods Fourteen patients with ischemic heart disease, age 62 ± 12 years (mean ± SD), were enrolled in a double-blind, placebo-controlled crossover trial. Basal and adenosine-stimulated myocardial blood flow (MBF) were determined by positron emission tomography, and myocardial flow reserve was calculated. Each patient was studied after ingestion of placebo and after ingestion of 30 mg folic acid. Myocardial zones were prospectively defined physiologically as “normal” versus “abnormal” on the basis of MBF response to adenosine 140 μg/kg/min (normal = MBF >1.65 ml/min/g). Abnormal and normal zones were analyzed separately in a patient-based analysis. Results Folate was associated with a reduction in mean arterial pressure (100 ± 12 mm Hg vs. 96 ± 11 mm Hg, placebo vs. folate, p Conclusions The data demonstrate that high-dose oral folate acutely lowers blood pressure and enhances coronary dilation in patients with coronary artery disease.