Medicine - Xagena

Use of the amino acid supplement L-arginine following a myocardial infarction does not improve certain cardiac functions and measurements and may be associated with an increased risk of death.

L-arginine is a widely available dietary supplement and is publicized as having benefits for patients with hypertension, angina, heart failure and sexual dysfunction.

Prior studies suggest that L-arginine has the potential to reduce vascular stiffness.

Steven P. Schulman, of Johns Hopkins Medical Institutions, Baltimore, and colleagues conducted the Vascular Interaction with Age in Myocardial Infarction ( VINTAGE MI ) clinical trial to test whether administering L-arginine to patients following a first ST-segment elevation myocardial infarction ( STEMI ) over a 6-month period would decrease vascular stiffness and improve ejection fraction.

The randomized, double-blind, placebo-controlled trial included 153 STEMI patients; 77 were 60 years or older. Participants were enrolled from February 2002 to June 2004.
Patients were randomly assigned to receive L-arginine ( goal dose of 3 g three times a day ) or matching placebo for six months.

The researchers found: " The VINTAGE MI study demonstrated that 6 months of L-arginine added to standard postinfarct medications did not reduce noninvasive measures of vascular stiffness, improve ejection fraction, or improve clinical outcomes. To the contrary, we noted a possible increased risk of death in older patients after infarction while taking L-arginine compared with those taking a placebo, leading to the early termination of the study. These findings have broad public health implications given the increasing availability and use of L-arginine in patients with and without established cardiovascular diseases."

Death occurred in 6 patients ( 8.6 percent ) in the L-arginine group died during the 6-month study period versus none in the placebo group.

" In conclusion, L-arginine therapy should not be given to patients following a myocardial infarction. It neither alters noninvasive measures of vascular stiffness nor improves left ventricular function. L-arginine therapy in older patients with diffuse atherosclerosis may worsen clinical outcomes," the authors write.

Source: American Medical Association, 2006


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