10 Which patients with coronary disease have
been proven to benefit from pharmacological
intervention? What lipid levels should I aim for?
John Betteridge
Three major statin trials (4S^1 , CARE^2 and LIPID^3 ) involving
approximately 18,000 patients have provided unequivocal
evidence of benefit of cholesterol-lowering in patients with
established coronary heart disease (CHD, angina, unstable angina,
post-myocardial infarction). The question might be better phrased,
which CHD patient should not receive statins, as the over-
whelming majority are likely to show substantial benefit. Debate
remains concerning the optimal treatment goal for LDL and the
level at which treatment should be initiated. The lesson from inter-
population epidemiology is that there is no threshold effect for
cholesterol and CHD and the relationship is maintained at low
levels. Furthermore, in LIPID the cholesterol inclusion criteria
went down to 4mmol/l. The recent joint British guidelines suggest
that treatment should be initiated at a total cholesterol >5mmol/l
(LDL >3mmol/l) and the goal should be cholesterol <5 and LDL
<3mmol/l. In the American Heart Association guidelines the goal
of therapy is an LDL cholesterol <2.6mmol/l. How low to lower
LDL remains an open question. Preliminary evidence from the Post
Coronary Artery Bypass Trial^4 suggests that lower is better but this
was an angiographic rather than an event study. Ongoing studies
such as TNT and SEARCH will provide more definitive
information on this question. In the meantime it is the clinical
practice of the author to lower LDL cholesterol if possible to
<2.5mmol/l.
RReeffeerreenncceess
1 Scandinavian Simvastatin Survival Study Group. Randomised trial of
cholesterol lowering in 4444 patients with coronary heart disease. The
Scandinavian simvastatin survival study. Lancet1994; 334444 : 1383–9.
2 Sacks FM, Pfeffer MA, Moye LA et al. The effect of pravastatin on
coronary events after myocardial infarction in patients with average
cholesterol levels. N Engl J Med1996; 333355 : 1001–9.
3 The Long-Term Intervention with Pravastatin in Ischaemic Disease
(LIPID) Study Group. Prevention of cardiovascular events and death
with pravastatin in patients with coronary heart disease and a broad
range of initial cholesterol levels. N Engl J Med1998; 333399 : 1349–57.