Arginine After a Heart Attack: The VINTAGE MI Warning
The arginine trial most supplement pages never mention was stopped early. Here is what happened and who should take note.
The trial
VINTAGE MI (Vascular Interaction With Age in Myocardial Infarction) randomized 153 patients who had recently had a heart attack to arginine, 3 grams three times a day, or placebo for six months. The researchers hoped arginine would improve arterial stiffness and heart function, especially in older patients, whose blood vessels make less nitric oxide[1].
The results
Arginine did not improve vascular stiffness or ejection fraction compared with placebo. Six patients in the arginine group died during the study, compared with none in the placebo group. The data and safety monitoring board stopped the trial early. The authors concluded that arginine should not be recommended after a heart attack[1].
Why might arginine be harmful here?
Nobody knows for certain, and with small numbers the deaths may partly reflect chance. Proposed explanations include effects on the nitric oxide system in damaged heart tissue and changes in how arginine is handled in disease states[2][3]. What matters for patients is simpler: a randomized trial in this group found no benefit and a signal of harm.
What it means for supplements
Over-the-counter nitric oxide products, including low-dose ones such as Melonex, are marketed for heart and circulation support, which naturally attracts people with heart disease. Their doses are far lower than VINTAGE MI's 9 grams a day, and no trial has tested them. But if you have had a heart attack, have coronary disease or heart failure, or take nitrates, the prudent step is to ask your cardiologist before taking any arginine product. Nitrates and PDE5 inhibitors are a dangerous combination on their own[4].
Bottom line
Arginine is not a benign "heart nutrient" for everyone. For heart attack survivors, the best evidence available argues against it unless a cardiologist decides otherwise.
Sources for this page
Every entry links to the original record. The trials used single amino acids, usually at several grams a day; none of them tested the Melonex capsule.
- 1Schulman SP, Becker LC, Kass DA, et al. L-arginine therapy in acute myocardial infarction: the Vascular Interaction With Age in Myocardial Infarction (VINTAGE MI) randomized clinical trial. JAMA. 2006;295(1):58-64. pubmed.ncbi.nlm.nih.gov/16391217/
- 2Boger RH. The pharmacodynamics of L-arginine. J Nutr. 2007;137(6 Suppl 2):1650S-1655S. pubmed.ncbi.nlm.nih.gov/17513442/
- 3Gambardella J, Khondkar W, Morelli MB, et al. Arginine and endothelial function. Biomedicines. 2020;8(8):277. pubmed.ncbi.nlm.nih.gov/32781796/
- 4MedlinePlus (U.S. National Library of Medicine). Sildenafil: Drug Information. medlineplus.gov/druginfo/meds/a699015.html
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