Effects Of N-3 Fatty Acids Following Acute Myocardial Infarction - Brief Article

Nutrition Research Newsletter, August, 2001 by D. Nilsen, G. Albrektsen, K. Landmark

Several studies have shown n-3 fatty acids to have cardiovascular benefits, including antiatherothrombogenic, antiarrhythmic, and antihypertensive effects and triacylglycerol-reducing ability. These potential effects may lead to significant benefits in individuals with coronary artery disease (CAD). However, the effect of n-3 fatty acids following an acute myocardial infarct is unknown.

A randomized, double-blind study set out to investigate the effect of high-dose polyunsaturated n-3 fatty acids introduced early after an acute MI on serum lipid concentrations and clinical prognosis compared to similar subjects receiving capsules containing corn oil, with no n-3 fatty acids. Three hundred patients with an acute MI were recruited from one facility in Norway. Patients were assigned to receive either two gelatin capsules of Omacor-R, containing 850-882 mg eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), or the same amount of corn oil. The intervention was administered for 12-24 months. At the initiation of the intervention, a detailed patient history was recorded and a clinical examination was performed. Clinical follow-up, including blood tests and electrocardiogram recordings, was repeated at six weeks, six months, one year, 18 months, and for some patients two years after the start of treatment. All cardiac events and ongoing medication were recorded. Cardiac events were defined as cardiac death, resuscitation, recurrent MI, and unstable angina. Potential differences in demographic and clinical characteristics between the

two treatment groups were examined by chi-square and two-sample t tests.

Researchers found no significant group differences in demographic or clinical characteristics at inclusion. The mean values of maximum creatine kinase muscle-brain and troponin T did not differ significantly between the two groups. There were also no significant differences between drug use in the two groups, including statin use. Twenty-eight percent of the patients in the n-3 and 24% of patients in the corn oil group experienced at least one cardiac event during the follow-up period. There were no significant differences noted between the groups in relation to revascularizations. A significant overall decrease in total cholesterol was observed in both groups. There was a significant increase in HDL-cholesterol in the n3 fatty acid group as well as significantly lower triacylglycerol concentrations when compared to the corn oil group.

Despite a favorable effect on serum triacylglycerol and HDL cholesterol, there were no observed beneficial effect on the hazard of different cardiac events following an acute MI following supplementation of a high-dose concentrate of n-3 fatty acids when compared to corn oil.

D. Nilsen, G. Albrektsen, K. Landmark, et al. Effects of a high-dose concentrate of n-3 fatty acids or corn oil introduced early after an acute myocardial infarction on serum triacylglycerol and HDL cholesterol. Am J Olin Nutr; 74:50-56 (July, 2001) [Correspondence: DWT Nilsen, Division of Cardiology, Central Hospital in Rogaland, 4011 Stavanger, Norway. E-mail: dnilsen1@chello.no].