Randomized trial of a medical food for the dietary management of chronic, stable angina.
OBJECTIVE
We determined the electrocardiographic, vascular and clinical effects of a medical food bar enriched with L-arginine and a combination of other nutrients known to enhance endothelium-derived nitric oxide (NO) in patients with stable angina.


BACKGROUND
Enhancement of vascular NO by supplementation with L-arginine and other nutrients has been shown to have clinical benefits in patients with angina secondary to atherosclerotic coronary artery disease (CAD). However, the amounts and combinations of these nutrients required to achieve a clinical effect make traditional delivery by capsules and pills less suitable than alternative delivery methods such as a specially formulated nutrition bar.


METHODS
Thirty-six stable outpatients with CAD and class II or III angina participated in a randomized, double-blind, placebo-controlled, crossover trial with two treatment periods each of two weeks' duration (two active bars or two placebo bars per day). Flow-mediated brachial artery dilation was measured by ultrasound. Electrocardiographic measures of ischemia, exercise capacity and angina onset time were measured by treadmill exercise testing and by Holter monitor during routine daily activities. Quality of life was assessed by SF-36 and Seattle Angina Questionnaires and by diary.


RESULTS
The medical food improved flow-mediated vasodilation (from 5.5 +/- 4.5 to 8.0 +/- 4.9, p = 0.004), treadmill exercise time (by 20% over placebo, p = 0.05) and quality-of-life scores (SF-36 summary score; 68 +/- 13 vs. 63 +/- 21 after placebo, p = 0.04, Seattle Angina Questionnaire summary score; 67 +/- 10 vs. 62 +/- 18, p = 0.04) without affecting electrocardiographic manifestations of ischemia or angina onset time.


CONCLUSIONS
These findings reveal that this arginine-rich medical food, when used as an adjunct to traditional therapy, improves vascular function, exercise capacity and aspects of quality of life in patients with stable angina.
Maxwell
Andrew J
AJ
Division of Research and Development, Cooke Pharma, Inc., Belmont, California, USA. amaxwell@ntgr8.com
Zapien
Michael P
MP
Pearce
Greg L
GL
MacCallum
Gail
G
Stone
Peter H
PH
D000328:Adult; D000787:Angina Pectoris / Q000178:diet therapy* / Q000503:physiopathology; D001120:Arginine; D002908:Chronic Disease; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D015716:Electrocardiography, Ambulatory; D004730:Endothelium, Vascular / Q000503:physiopathology; D017079:Exercise Tolerance; D005526:Food, Formulated; D006801:Humans; D011788:Quality of Life; D014664:Vasodilation
D001120:Arginine