Fish oils cardiac death

At low doses, PUFAs provide protection against coronary heart disease and reduce the severity of cardiac arrhythmias at high doses, they lower blood cholesterol and triglycerides, reduce platelet aggregation, have antithrombotic activity, and reduce blood viscosity. Several clinical studies have reported beneficial effects of supplementation on mortality, sudden death, and arrhythmias. In the Diet and Reinfarction Trial (DART), the use of fatty fish or fish oil led to a 29% reduction in mortality, and the GlSSI-Preven-zione trial showed that consumption of 1 g n-3-PUFA daily resulted in a 20% decrease in mortality and 45%i reduction in sudden death. ° ... 

Leaf, A., Kang, J.X., Xiao, Y.-F., and Bilhnan, G.E. 2003. Qinical prevention of sudden cardiac death by n-3 polyunsaturated fatty acids and mechanism of prevention of arrhythmias by n-3 fish oils. Circulation 107, 2646-2652. 

The n-3 LC-PUFA have a beneficial effect on plasma triglycerides, high blood pressure, whole-blood viscosity, and platelet function they inhibit the expression of cell-adhesion molecules, shift the eicosanoid profile to one of lesser thrombotic and inflammatory potential, improve vessel-wall compliance, and have antiarrhythmic potential (1,2). A number of intervention trials have associated the consumption of fish with decreased mortality from CVD (3-5). High doses of fish oil eliminate both vascular thrombus as well as vascular lesion formation (6). In men who had had a recent myocardial infarction, low-dose dietary supplementation with n-3 LC-PUFA, in addition to the recommended secondary prevention treatments, reduced by 45% the risk of sudden cardiac death, but not the risk of nonfatal myocardial infarction (7). It has been shown to mitigate the course of coronary atherosclerosis in humans (8). 

Furthermore, dietary intake of fish oil has also shown to enhance the coronary vasomotor activity in patients with coronary artery disease [36] and reduce the number of deaths derived from chronic cardiac failure [29], Altogether, these data suggest that dietary intake of o-3 fatty acid supplements are beneficial to coimteract against cardiovascular-related diseases such as hyperlipidemia, hypertension, atherosclerosis, and myocardial infarction. 

Cardiovascular In a systematic review of deaths in 12 randomized controlled trials of fish oil as dietary supplements in 32 779 patients there was no beneficial effect in three studies ( = 1148) of implantable cardiac defibrillators (OR = 0.90 95% Cl = 0.55, 1.46) or in six studies (n = 31 111) of sudden cardiac death (OR = 0.81 0.52,1.25). In 11 studies (n = 32 439 and n = 32 519) there was a reduction in deaths from cardiac causes (OR = 0.80 0.69,0.92) but no effect on dysrhythmias or all-cause mortahty [21 ]. However, it was later pointed out that there is some evidence that fish oils may be dysrhyth-mogenic in some subgroups of patients with heart disease 22f. These include an increased risk of ventricular tachycardia in patients with implantable cardiovertor defibrillators whose primary dysrhythmia was ventricular tachycardia [23 ], and an increased risk of cardiac death in patients with angina [24 ]. 

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