Dietary supplementation with omega-3 polyunsaturated fatty acids in patients with stable coronary heart disease: Effects on indices of platelet and neutrophil function and exercise performance

Abstract

It has been suggested that omega-3 polyunsaturated fatty acids (PUFAs) may alter the course of coronary artery disease by influencing platelet and neutrophil function, arachidonic acid metabolism, and circulating lipid concentrations. To examine this hypothesis, placebo or omega-3 PUFAs as Max-EPA (equivalent to 3.2 g of eicosapentaenoic acid and 2.2 g of docosahexaenoic acid daily) was administered to eight patients with stable coronary artery disease and positive exercise stress test results in a randomized, double-blind, crossover fashion over a 12-week period. With Max-EPA administration, platelet aggregation threshold to epinephrine was increased in only two patients, but neutrophil aggregation and chemotaxic functions decreased consistently (both p <- 0.01 compared with preceding placebo phase) in all eight. Serum and platelet-rich plasma thromboxane B2 concentrations decreased 40 percent and 28 percent, respectively (both p ≤0.05). Neutrophil leukotriene B4 formation decreased 23 percent (p ≤0.01) and synthesis of leukotriene B5 became apparent in all subjects. Serum triglyceride concentrations fell 52 percent (p <-0.05) without significant change in total cholesterol, high-density lipoprotein-cholesterol, or low-density lipoprotein-cholesterol concentrations. Systolic blood pressure and the double product (heart rate × systolic blood pressure) were lower (p <-0.05) at the end of the Max-EPA phase than in the preceding placebo phase. Heart rate, systolic blood pressure, and the double product were also lower (p <-0.05) at three as well as at six minutes of an exercise stress test, indicating a significant reduction in myocardial oxygen demand. Despite these alterations in platelet and neutrophil function, arachidonic acid metabolism, serum triglyceride concentrations, and myocardial oxygen demand, there were no significant changes in subjective parameters of coronary artery disease during the Max-EPA phase (angina frequency 3.7 versus 2.8 episodes per week, nitroglycerin consumption 3.0 versus 1.9 tablets per week, both p = NS). Similarly, exercise times to ST-segment depression (6.5 versus 4.1 minutes) and to onset of angina (5.4 versus 5.0 minutes) were not altered by administration of Max-EPA. Thus, short-term dietary supplementation with omega-3 PUFAs to patients with stable coronary artery disease does not appear to alter subjective or objective parameters of myocardial ischemia.