atients
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.
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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.
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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.
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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.
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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 Heart, Lung, and Blood Institute of the NIH
Undated webpage.
http://www.nhlbi.nih.gov/chd/why4.htm
Also see
cholesterol, diabetes, and the statins
high blood cholesterol
keeping cholesterol under control
modifying fat intake to minimize cardiovascular risk
statins
Pharmacologic Lipid-Lowering Therapy in Type 2 Diabetes Mellitus: Background Paper for the American College of Physicians at the Annals of Internal Medicine
SUMMARIES FOR PATIENTS:
Control of Lipids in Patients with Type 2 Diabetes: Recommendations from the American College of Physicians
at the Annals of Internal Medicine