The low incidence of ischaemic heart disease amongst Greenlandic Eskimos has intrigued researchers for many years. The answer was found in their marine-based diet, very rich in omega-3 polyunsaturated fatty acids (n-3 PUFAs). These have shown anti-arrhythmic, endothelial protective, anti-atherogenic, antithrombotic and antiplatelet effects in many observational studies, which have paved the way for the potential role in secondary prevention post-myocardial infarction.
Many trials have emphasised the importance of oily fish in the secondary prevention of coronary heart disease. Oily fish consumption, however, is poor in the UK. It has the disadvantages of possible toxic chemical contaminants, a large calorific content and some people simply do not like it. The GISSI-Prevenzione trial studied the effect of a highly purified n-3 PUFA supplement and found it conferred a 20% relative risk reduction in mortality and a 45% reduction in the risk of sudden cardiac death. This early protection supports the anti-arrhythmic potential of n-3 PUFAs.
A supplement containing 90% concentrate of the n-3 PUFAs, eicosapentaenoic acid and docosahexanoic acid, known as Omacor™, is now licensed in the UK as adjuvant treatment in secondary prevention post-myocardial infarction, in addition to standard medical treatment including statins.
The prescription of n-3 PUFA supplements are best initiated in secondary care. The index admission is generally the best time to initiate secondary prevention when patients tend to be most receptive.
For UK healthcare professionals only