Lower Blood Plasma Levels of EPA Omega-3 as Predictor of Mortality following Myocardial Infarction
Lee, S. H. et al., Circulation Journal, 73: 2250-2257 , 2009.
Cardiology Division, Dept. Of Internal Medicine , Yonsei University College of Medicine , Seoul, Republic of Korea
The authors point out that previous research in healthy individuals has indicated that those with higher levels of (EPA plus DHA) in their blood samples were found to be at a considerably lower risk for sudden cardiac death. They indicate that a key rationale in their present study was to determine of any relationship could be found between blood levels of long-chain omega-3 fatty acids (EPA/DHA) and subsequent all-cause mortality in patients who had previously survived a myocardial infarction (heart attack). In their study, 508 patients (average age of 63 years , 28 % female and 72 % male) having experienced a confirmed myocardial infarction and receiving appropriate clinical treatment had blood samples taken for determining (by gas-liquid chromatographic analyses) the fatty acid (including EPA/DHA omega-3) contents of their blood plasma phospholipid. During the subsequent follow-up approaching 2.5 years , the authors reported that , by 16.1 months , 36 patients (7.1 % of total) had died with 81 % of the deaths being cardiovascular-related. For all patients combined , lower blood levels of EPA but not DHA were found to be an independent predictor of all-cause mortality. When stratified by gender, this relationship was highly significant in females but did not reach statistical significance in males.
It is of interest to note that the levels of EPA in the blood plasma phospholipid biomarker as used in the present study showed the EPA to average 1.5 % of total fatty acids in this population from Korea which is higher that typical levels in North America (approx. 1.0 % of fatty acids). Since much higher levels of EPA and also DHA are generally found in the blood plasma phospholipid of patients in Japan as compared to Korea or North America, it would be of considerable interest to have a similar study completed in the former population for comparison where much higher intakes of EPA/DHA from fish/seafood are prevalent.