Oral L‐arginine Supplementation in Acute Myocardial Infarction Therapy: A Meta‐analysis of Randomized Controlled Trials

Abstract

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.

An increased need for dietary cysteine in support of glutathione synthesis may underlie the increased risk for mortality associated with low protein intake in the elderly

“…On the other hand, another randomized controlled trial in post-MI patients, again using 9 g of arginine daily, but of only 1-month duration, found a non-significant trend toward protection with arginine (Bednarz et al 2005). A meta-analysis which incorporated these two trials found no impact of arginine on mortality risk (RR = 0.93; 95 % CI 0.74-1.17) (Sun et al 2009).…”

Emergence of Nonobstructive Coronary Artery Disease

“…Imipramine improves angina, possibly through visceral analgesic, anticholinergic, and alpha-antagonist effects (104). L-arginine improved angina and vascular function (105), but was adverse in an obstructive CAD trial (106). Postmenopausal hormone therapy improved emotional well-being, but had no effect on angina or exercise tolerance (107).…”

The regulation of vascular tetrahydrobiopterin bioavailability

“…Such investigations have primarily studied interventions that can enhance vascular NO levels for the treatment of endothelial dysfunction and include enhancing L-arginine substrate bioavailability 58,59 and introducing antioxidants to limit the destruction of NO by reactive oxidant species 60,61 . Unfortunately, studies investigating the chronic administration of these agents suggests that such interventions lack clear efficacy and in some cases worsen outcome, although it should be noted that there are inherent complexities with the design of these types of clinical trial [62][63][64][65][66] .…”