Risk Factors For Coronary Artery disease:

 


An essential part of the cardiac history involves

obtaining detailed information about a patient’s risk

factors—the patient’s cardiovascular risk factor profile

(see Questions box 4.4).

Previous ischaemic heart disease is the most

important risk factor for further ischaemia. The patient

may know of previous infarcts or have had a diagnosis

of angina in the past.

Hypercholesterolaemia is the next most important risk

factor for ischaemic heart disease. Many patients now

know their serum cholesterol levels because widespread

testing has become fashionable. The total serum

cholesterol is a useful screening test, and levels above

5.2 mmol / L are considered undesirable. Cholesterol

measurements (unlike triglyceride measurements) are

accurate even when a patient has not been fasting.

Patients with established coronary artery disease

benefit from lowering of total cholesterol to below

4 mmol / L with the low-density lipoprotein (LDL) of

1.8 mmol / L or less. An elevated total cholesterol level

is even more significant if the high-density lipoprotein

(HDL) level is low (less than 1.0 mmol / L). Significant

elevation of the triglyceride level is a coronary risk

factor in its own right and also adds further to the

risk if the total cholesterol is high. If a patient already

has coronary disease, hyperlipidaemia is even more

important. Control of risk factors for these patients is

called secondary prevention. Patients who have multiple

risk factors for ischaemic heart disease (e.g. diabetes and

hypertension) should have their cholesterol controlled

aggressively. If the patient’s cholesterol is known to beQUESTIONS TO ASK ABOUT POSSIBLE.



CARDIOVASCULAR RISK FACTORS:

1. Have you had angina or a heart attack

in the past?

2. Do you know what your cholesterol level

is? Before or after treatment?

3. Are you a diabetic? How well controlled

is your diabetes?

4. Have you had high blood pressure and

has it been treated?

5. Are you now or have you been a

smoker? How long since you stopped?

6. Have you had kidney problems?

7. Do you have rheumatoid arthritis?

8. Do you drink alcohol? How much?

9. For men: Have you had any problems

with sex? Obtaining erections?

10. Have people in your family had angina

or heart attacks? Who? How old were

they?

QUESTIONS BOX 4.4

h Hypertension is more important as a risk factor for stroke and cholesterol

for ischaemic heart disease.

Hypertensionh is another important risk factor for

coronary artery disease. Find out when hypertension

was first diagnosed and what treatment, if any, has

been instituted (see Questions box 4.4). Treatment

of hypertension reduces the risk of ischaemic heart

disease, hypertensive heart disease, cardiac failure

and cerebrovascular disease (stroke). Treatment of

hypertension has also been shown to reverse left

ventricular hypertrophy.

A family history of coronary artery disease increases

a patient’s risk, particularly if it has been present in

first-degree relatives (parents or siblings) and if it has

affected these people before the age of 60. Not all heart

disease, however, is ischaemic; a patient whose relatives

suffered from rheumatic heart disease is at no greater

risk of ischaemic heart disease than anybody else.

A history of diabetes mellitus increases the risk of

ischaemic heart disease very substantially. A diabetic

without a history of ischaemic heart disease has the

same risk of myocardial infarction as a non-diabetic

who has had an infarct. It is important to find out how

long a patient has been diabetic and whether insulin

treatment has been required. Good control of the blood

sugar level in diabetes mellitus may reduce this risk.

An attempt should therefore be made to find out how

well a patient’s diabetes has been controlled.

Chronic kidney disease is associated with a very high

risk of vascular disease. This is possibly related to high

calcium-×-phosphate product. The risk may be reduced

by dietary intervention, ‘phosphate binders’, efficient

dialysis or renal transplant. Ischaemic heart disease is

the most common cause of death in patients with kidney

disease on dialysis.

Chronic inflammatory diseases such as rheumatoid

arthritis, psoriasis, poor dentition and gingivitis, and

HIV infection significantly increase the risk of vascular

disease too.

Erectile dysfunction is a sensitive indicator of arterial

endothelial abnormality and is a risk factor for, or

indicator of, vascular disease.

The presence of multiple risk factors makes control

of each one more important. Aggressive control of risk

factors is often indicated in these patients.

It is interesting to note that in the diagnosis of angina

the patient’s description of typical symptoms is more

high, it is worth obtaining a dietary history. This can be

very trying. It is important to remember that not only

foods containing cholesterol but also those containing

saturated fats contribute to the serum cholesterol level.

High alcohol consumption and obesity are associated

with hypertriglyceridaemia.

Smoking is probably the next most important

risk factor for cardiovascular disease and peripheral

vascular disease. Some patients describe themselves

as non-smokers even though they stopped smoking

only a few hours ago. The number of years the patient

has smoked and the number of cigarettes smoked

per day are both very important (and are recorded

as packet-years; p 16). The significance of a history

of smoking for a patient who has not smoked for

many years is controversial. The risk of symptomatic

ischaemic heart disease falls gradually over the years

after smoking has been stopped. After about 2 years the

risk of myocardial infarction falls to the same level as for

those who have never smoked. After 10 years the risk

of developing angina falls close to that of non-smokers.

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