The use of omega-3 polyunsaturated fatty acid (PUFA) supplements in patients with coronary heart disease (CHD) does not reduce major cardiovascular events, a large meta-analysis has found.

Fourteen randomised controlled trials were analysed. Overall, 16,338 CHD patients received omega-3 PUFAs and 16,318 patients acted as controls.

• Patients in the omega-3 PUFA group had no significant reduction in cardiovascular events, OR 0.93 (95% CI:0.86-1.01; P = 0.08)

However, a slight reduction in mortality rates was seen in the omega-3 PUFA group compared with controls:

• Death from cardiac causes, OR 0.88 (95% CI:0.80-0.96; P = 0.003)

• Sudden cardiac death, OR 0.86 (95% CI:0.76-0.98; P = 0.03)

• Death from all causes, OR 0.92 (95% CI:0.85-0.99; P = 0.02)

The authors conclude that supplementation with omega-3 PUFAs in patients with CHD is not associated with a protective effect on major cardiovascular events but does have a beneficial effect in reducing death from cardiac causes, sudden cardiac death and death from all causes. However, it should be noted that the margin of such beneficial effects was small.

Omega-3 PUFAs have fallen in and out of favour over recent years as a component of secondary prevention in CHD. This is a further study that appears to support the notion that the use of such supplements is probably not justified in this situation.

Indeed NICE has now revised its view on this subject. The updated post-myocardial infarction secondary prevention guideline (CG172), published in November 2013, recommends that oily fish, omega-3 fatty acid capsules and omega-3 supplemented foods should not be routinely recommended for the sole purpose of preventing another myocardial infarction.¹

The guideline does acknowledge, however, that there is no evidence of harm should patients choose to take such supplements.

From a practical perspective the message is that a Mediterranean-style diet which may include fish is fine but there is no need for patients to seek out specific supplementation with omega-3 PUFAs in order to try to prevent a further coronary event.

Dr Peter Savill

• Wen YT, Dai JH, Gao Q. Effects of omega-3 fatty acid on major cardiovascular events and mortality in patients with coronary heart disease: A meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis 2013 Dec 25. pii: S0939-4753(13) 00308-6. doi: 10.1016/j.numecd.2013. 12.004