Omega-3s Are Superior to Defibrillators in Saving Lives

Summarized by Robert W. Griffith, MD
November 6, 2006

Summary

Increasing omega-3 fatty acid intake - by eating fatty fish, or taking supplements - can reduce sudden cardiac death rate more effectively than the use of defibrillators, according to a simulation study.

Introduction

About a quarter of a million US citizens die suddenly each year with their death being the first indication that they have coronary heart disease. The immediate cause of such deaths is most likely to be ventricular fibrillation or ventricular tachycardia¹. Three approaches to prevention exist: implanted cardioversion defibrillators (ICFs), automated external defibrillators (AEDs), and the consumption of omega-3 fatty acids.

Minnesota researchers have compared these three methods using a virtual analysis of expected outcomes. They published their findings in the American Journal of Preventive Medicine, and we summarize the main points here.

What was done

The method used to make the comparison was 'virtual', in other words, an elaborate simulation of events, treatments, and outcomes in a hypothetical population resembling that of Olmsted County, Minnesota, using published probabilities of effectiveness.

The potential impacts tested were those following¹ raising blood omega-3 levels,² distributing AEDs, and³ implanting ICDs in appropriate candidate patients. Total mortality was used as the main measure of effectiveness.

Four different modules were used: a healthy individual, someone with congestive heart failure, an out-of-hospital cardiac arrest, and an acute heart attack (myocardial infarction or MI). And 5 scenarios were modeled: no intervention, one for each of the interventions, and one for all 3 interventions combined.

Probabilities for outcomes for each module/scenario were obtained from published studies - those with a meta-analysis whenever possible. These were used to derive the likely percentage change in deaths from those obtained for 'no intervention'.

What the simulation showed

The results obtained can be summarized in the following table:

Scenario	Percentage change in deaths from 'no intervention'
Omega-3 fatty acid supplementation	-6.4% (min. -1.6%, max. -10.3%)
AEDs	-0.8% (min. -0.2%, max. -1.3%)
ICDs	-3.3% (min. -0.6%, max. -8.7%)
All 3 interventions combined	-5.3% (min. -5.3%, max. -14.8%)

It can be seen that raising omega-3 fatty acid intake would have about 8 times the impact of distributing AEDs, and twice the impact of implanting ICDs. Further analyses showed that three-quarters of the reduction in deaths by raising omega-3 fatty acid levels would come in the healthy population.

What these analyses mean

The results of these simulations show quite clearly that raising omega-3 fatty acid blood levels could have a relevant impact on sudden cardiac death, especially in previously healthy people.

Although AEDs save lives, they are unlikely to have the same sort of benefit as omega-3 intake, due to the 'epidemiology of sudden death'. There's a series of events that must be followed if someone has a cardiac arrest outside a hospital setting: the event must be witnessed, the subjects rhythm must be ventricular tachycardia or ventricular fibrillation, and an AED has to be available, or there must be very rapid access to a hospital when no AED is to hand. Of these, AED availability is the weakest link; most homes don't have such an instrument.

A large published trial of AEDs resulted in a calculation that 2000 to 4000 lives a year could be saved if there was nation-wide public access to defibrillation.² However, this only represents less than 1% of sudden deaths in the USA.

The present study involves simulations that need to be confirmed or refuted in large-scale prospective clinical studies, if, indeed, such studies could ever be designed and completed. Until then, we suggest that people should make an effort to increase their intake of omega-3 fatty acids. These are found in fatty deep-sea fish (salmon, lake trout, tuna, herring). Either eat more fatty fish, or take a suitable supplement, or maybe do both.

Source

• Preventing sudden death with n-3 (omega-3) fatty acids and defibrillators. TE. Kottke , LA. Wu, LN. Brekke,  et al., Am J Prev Med, 2006, vol. 31, pp. 316--323

Footnotes
1. In ventricular fibrillation the lower heart chambers contract in rapid and unsynchronized rhythms and cannot pump blood into the body. In ventricular tachycardia there is an abnormally rapid resting heart rate (over 100 beats per minute), which can be life-threatening without emergency treatment.
2. Hallstroom AP, Ornato JP, Weisfeldt M,et al. Public-access defibrillation and survival after out-of-hospital cardiac arrest. N Engl J Med 2004;351:637-646

Related Links
Automated External Defibrillators
Implanted Cardioversion Defibrillators
Fish and Omega-3 Fatty Acids
About Omega-3 Supplements

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