Oral L-arginine supplementation in acute myocardial infarction therapy: a meta-analysis of randomized controlled trials.

Objective: The objective was to analyze completed trials assessing the effect of oral L-arginine supplementation on clinical outcomes of patients with acute myocardial infarction (AMI).

Background: Prior trials suggest that oral L-arginine administration improves endothelial function in patients with stable coronary artery disease (CAD). However, it is still unclear whether oral supplementation of L-arginine has any effect on clinical outcomes in patients with unstable CAD, such as AMI.

Methods: We systematically searched PubMed, Cochrane Library, Embase, reviews, and reference lists of relevant articles. The search strategy paired the term "arginine" with the following: "coronary heart disease," "myocardial infarction," "cardiovascular disease," "ischemia," and "trial." We conducted a meta-analysis of randomized, placebo-controlled L-arginine supplementation trials that evaluated clinical outcomes in AMI patients. Two reviewers independently assessed the trials. Differences were resolved by consensus.

Results: Only 2 trials (927 participants) were included. None of the 2 studies showed a significant difference in event rate between the L-arginine and placebo groups. In an overall pooled estimate, there was a 7% reduction in mortality in the L-arginine treatment group (105/459, 22.9%) compared with the control group (111/455, 24.4%), which did not reach statistical significance (risk ratio [RR]: 0.93, 95% confidence interval [CI]: 0.74-1.17; P = 0.54).

Conclusion: Oral L-arginine supplementation has no effect on the clinical outcomes of patients with AMI.