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Objectives: 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.

Objectives: We sought to define the extent to which the therapeutic efficacy of three single-drug regimens on ambulatory ischemia paralleled efficacy on other clinical manifestations of ischemia, specifically exercise test performance and anginal symptoms., Background: Some studies have shown that the presence and severity of ambulatory ischemia are predictive of anginal symptoms and exercise test performance, whereas other studies have not. Less is known about effects of antianginal treatment and whether response to therapy for one clinical manifestation reflects therapeutic responses for other clinical manifestations., Methods: We studied 50 patients in the Angina and Silent Ischemia Study who had documented coronary disease, an exercise test positive for ischemia, the presence of ambulatory and asymptomatic ischemia on ambulatory electrocardiographic (ECG) Holter monitoring and stable anginal symptoms. Patients received maximally tolerated doses of sustained release propranolol (mean 293 mg/day), sustained release diltiazem (mean 350 mg/day), nifedipine (mean 79 mg/day) and placebo, each for 2-week periods in a double-blind, crossover fashion. Patients' responses to treatment were assessed by 48-h ambulatory ECG monitoring, exercise test (standard Bruce protocol) and diaries of angina. Levels of efficacy for each agent and for each clinical measure were compared using Spearman correlation analysis., Results: With placebo there was no correlation among the frequency of ischemic episodes by ambulatory ECG monitoring, exercise time to 1.0-mm ST segment depression or frequency of anginal episodes. Furthermore, for a given patient the efficacy of each active medication in reducing ambulatory ischemia was not correlated with response in anginal symptoms or exercise test performance (r = -0.21 to 0.24, p = NS). Within each of these clinical measures, efficacy of one drug was more strongly correlated with efficacy of another drug (r = 0.64 to 0.81 for ambulatory ischemia, 0.48 to 0.56 for exercise test performance and 0.16 to 0.54 for anginal symptoms)., Conclusions: Different measures of ischemia, specifically ambulatory ischemia assessed by ambulatory ECG monitoring, exercise performance on exercise test and anginal symptoms, are independent. Efficacy for each clinical end point must be assessed separately when considering response to drug treatment.