CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 1, January/February 2010
50
AFRICA
Your Life and Your Heart
Omega-3 intake in patients with coronary artery disease:
focus on recent studies
Despite the recommendations of the
American Heart Association (AHA)
and other expert groups on the value of
added intake of omega-3 polyunsaturated
fatty acids (
ω
-3 PUFA) in the secondary
prevention of CAD, either from the diet
(oily fish – herring, mackerel, sardines) or
from fish-oil supplements which contain
eicosapentaenoic acid (EPA) and docosa-
hexaenoic acid (DHA), these safe life-
style or medication therapies are still
under-prescribed.
A recent update of the omega-3 GISSI
– Prevenzione trial has continued to show
beneficial reductions in major clinical
events at 3.5-years’ follow up.
1
In this
1999 placebo-controlled trial, more than
11 000 post-MI patients were randomised
to receive 1 g/day of omega-3 PUFAs,
vitamin E, both, or neither, on top of
standard medical therapy and lifestyle-
modification ‘advice’, for three and a half
years. The omega-3s on their own were
associated with a significant 15% drop
in the primary endpoint of death, non-
fatal MI and stroke, a 20% decrease in
all-cause mortality, and a 30% decline in
cardiovascular mortality driven by a steep
reduction in sudden cardiac death.
Interestingly, a recent Danish study
2
of
57 053 middle-aged men and women who
were healthy and cancer free has shown a
lower risk of acute coronary syndromes
in the men with a high fatty fish intake
over a mean follow-up period of 7.6
years. A total of 1 122 cases of acute
coronary syndrome (ACS) were verified
during a mean follow-up period of 7.6
years. Among men, intake of fatty fish
was associated with a lower risk of ACS.
For men in the highest quintile of fish
intake compared with the lowest quin-
tile, the hazard ratio was 0.67 (95% CI:
0.53–0.85). The inverse association was
observed for intakes above 6 g of fatty
fish per day, with no obvious additional
benefit observed for higher intakes. Intake
of lean fish was not associated with ACS.
In the women, there were fewer cases of
ACS and results were not consistent.
The beneficial effect of
ω
-3 PUFA
on reducing sudden cardiac death and
acute coronary syndromes is likely to
originate from their anti-thrombotic and
anti-arrhymic effects. Also a stabilising
effect on human atherosclerotic plaque
has been reported.
3
Omega-3 intake in heart failure
patients
A recent report
4
from the Heart Failure
Society of America 2009 Scientific
Meeting points out that there are very
few beneficial therapies that you can add
to beta-blockers, ACE inhibitors, statins
and spironolactone and actually reduce
cardiovascular death by 10% in heart
failure. Omega-3s fit this bill and provide
this additional benefit safely.
The most solid randomised-trial
evidence for such a role comes from the
recent Gruppo Italiano per lo Studio della
Sopravvivenza nell’Infarto Miocardico
Heart Failure (GISSI-HF) trial,
5
in which
nearly 7 000 patients with chronic NYHA
class II to IV heart failure received either
omega-3 PUFAs from fish oil at 1 g/day
or placebo.
As reported by
Heartwire
4
when the
study results were announced last year,
the group getting omega-3s showed a
9% drop in all-cause mortality and an
8% decline in the composite of death
or cardiovascular hospitalisation over a
mean of about four years. Both co-prima-
ry endpoint outcomes were significant. In
a separate randomisation of the patients
to either 10-mg rosuvastatin (Crestor,
Astrazeneca) or placebo, the statin had no
significant effect on either endpoint.
6
An exceptionally large proportion of
GISSI-HF patients had been onACE inhib-
itors or angiotensin-receptor blockers,
beta-blocker, and spironolactone, and still
there was a significant omega-3 effect. ‘It’s
tough to get incremental benefit for hard
endpoints in maximally treated patients’,
observed Dr Dariush Mozaffarian,
Harvard University, Boston, USA.
He pointed out that for the pre-spec-
ified secondary endpoint of cardiovas-
cular death, the difference associated
with omega-3 therapy reached 10% (
p
=
0.045). That’s a very profound benefit’,
Mozaffarian said, adding that it’s similar
to the cardiovascular death reduction seen
with implantable defibrillator therapy.
Further insights on the value of
omega-3s may be in the offing from an
upcoming primary-prevention trial that
will randomise a planned 20 000 people
to receive vitamin D supplements, or
neither (double placebo).
7
The Vitamin D
and Omega-3 Trial (VITAL) will enroll
women older than 65 and men older than
60 years and follow them for five years,
starting in early 2010. Plans are for at
least 25% of the population to be African-
American, according to the study’s
co-chair Dr Jo-Ann E Manson, Brigham
and Womens Hospital, Boston, USA.
Sources of Omega-3 PUFA
The rapid depletion of fish stocks is
also driving the search for land-based
sources of EPA and DHA, such as oil-
seed crops that are genetically engineered
to produce ‘marine’-equivalent omega-3
PUFAs. Sustainable sources of omega-3
fatty acids will need to be identified if
long-term cardiovascular risk reduction is
to be achieved at the population level.
J Aalbers
Marchioli R,
1.
et al
.
Circulation
2002;
105
:1897–1903.
Bjerregaard LJ, Joensen AM, Dethlefsen C,
2.
Jensen MK, Johnsen SP,
et al
.
Euro Heart
J
2010;
31
: 29–34. doi:10.1093/eurheart/
ehp375.
Thies R, Garry JMC, Yaqoob P, Rerkasem K,
3.
Williams J, Searman CP,
et al
.
Lancet
2003;
361
: 477–485.
Heartwire
4.
, Oct 14, 2009.
Tavazzi L, Maggioni AP, Marchioli R,
5.
et al
.
Lancet
2008;
372
: 1223–1230.
Tavazzi L, Maggioni AP, Marchioli R,
6.
et al
.
Lancet
2008;
372
: 1231–1239.
Brigham and Womens Hospital. June 23,
7.
2009.
