L-Arginine Does Not Help After Heart Attack, May Harm
Amino acid may increase risk of death in myocardial infarction patients
TUESDAY, Jan. 3 (HealthDay News) -- Administering the amino acid L-arginine after a myocardial infarction does not improve outcomes and may actually increase the risk of death, researchers report in the Jan. 4 issue of the Journal of the American Medical Association.
Steven P. Schulman, M.D., of Johns Hopkins Medical Institutions in Baltimore, Md., and colleagues randomly assigned 153 patients to receive either L-arginine (goal dose of three grams three times a day) or a placebo for six months following a first ST-segment elevation myocardial infarction. L-arginine is a substrate for nitric oxide synthase and has previously been shown to reduce vascular stiffness, according to the researchers.
There were no significant differences between the two groups as far as vascular stiffness, left ventricular ejection fraction, and clinical outcomes, even if the 77 patients aged 60 years or older were considered separately, according to the study. However, 8.6% of patients in the L-arginine group died compared with none in the placebo group, a significant difference. The researchers terminated the study early.
"L-arginine, when added to standard postinfarction therapies, does not improve vascular stiffness measurements or ejection fraction and may be associated with higher postinfarction mortality," Schulman and colleagues conclude. "L-arginine should not be recommended following acute myocardial infarction."