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Patients with heart disease are at high risk for a heart attack. This high
risk is expressed as "more than 20% in the next 10 years," which means that more
than 20 out of 100 people with heart disease will have a heart attack within 10
years. Several studies have been carried out to see whether cholesterol lowering
in such high risk people would be beneficial.
A 1994 study called the Scandinavian Simvastatin Survival Study (also called
4S) found that lowering cholesterol can prevent heart attacks and reduce death
in men and women who already have heart disease and high cholesterol. For over 5
years, more than 4,400 patients with heart disease and total cholesterol levels
of 213 mg/dL to 310 mg/dL were given either a cholesterol-lowering drug or a
placebo (a dummy pill that looks exactly like the medication). The drug they
were given is known as a statin, and it reduced total cholesterol levels by 25
percent and LDL-cholesterol levels by 35 percent. The study found that in those
receiving statin, deaths from heart disease were reduced by 42 percent, the
chance of having a nonfatal heart attack was reduced by 37 percent, and the need
for bypass surgery or angioplasty was reduced by 37 percent. A very important
finding is that deaths from causes other than cardiovascular disease were not
increased, and so the 42 percent reduction in heart disease deaths resulted in a
30 percent drop in overall deaths from all causes.
The 4S researchers say
that the following benefits could be expected if doctors were to treat their
heart disease patients for the same 5-year period and lower cholesterol to the
same extent. For every 1,000 patients:
40 people would be saved out of the 90 who would otherwise die from heart
disease.
70 of the expected 210 nonfatal heart attacks would be avoided.
Heart procedures such as bypass surgery would be avoided in 60 of the 210
patients who would be expected to need these procedures.
In 1996
the results of the Cholesterol and Recurrent Events (CARE) Study also showed the
benefits of cholesterol lowering in heart disease patients. This study reported
that even in patients with seemingly normal cholesterol levels (average of 209
mg/dL), cholesterol lowering with a statin drug lowered the risk of having
another heart attack or dying by 24 percent. These patients were also less
likely to need bypass surgery (26 percent reduction) or angioplasty (22 percent
reduction) during the study. Women benefited even more than men, reducing their
risk of having another heart attack by 45 percent. The CARE researchers estimate
that treatment of 1,000 patients similar to those in CARE would result in 153
fewer heart attacks and deaths from heart disease. If the patients were over 60,
there would be 214 fewer, and if they were all women, there would be 248
fewer.
A study published in 1998, the Long-Term Intervention with Pravastatin in
Ischaemic Disease (LIPID) study, examined the effects of cholesterol lowering in
people with CHD (those who had already experienced a heart attack or had been
hospitalized for angina) and who had relatively average cholesterol levels. The
LIPID study used a statin drug to lower cholesterol levels in the treatment
group. All study participants were counseled about following a
cholesterol-lowering diet. The LIPID results showed that a drop of 18 percent in
total cholesterol and 25 percent in LDL-cholesterol produced a 24 percent
decrease in deaths from CHD among the treatment group compared with the control
group. Similarly, cholesterol-lowering in the treatment group reduced the
overall death rate by 22 percent, heart attacks by 29 percent, the need for
bypass surgery or angioplasty by 20 percent, and stroke by 19 percent.
Cholesterol lowering in the LIPID study resulted in significant reductions in
CHD-related deaths and events without increasing non-CHD deaths.
In the 4S, CARE, and LIPID trials, diabetic patients benefited from
cholesterol lowering as much as nondiabetics. These studies along with many
others support the need to lower cholesterol levels in heart disease patients.
People with diabetes who do not have heart disease have a high risk for
developing it - more than 20% over the next 10 years. People with a combination
of several risk factors may also have more than a 20% risk of developing heart
disease in the next 10 years. If your risk for developing heart disease is high
(you have diabetes but do not have heart disease, or if you have a combination
of risk factors and more than 20% risk in the next 20 years), you can expect
benefits from cholesterol-lowering similar to those in people with heart
disease. If you lower your cholesterol, you too can see benefits like those in
4S, CARE, and LIPID.
From the National Institutes of Health |
