What is Coronary Artery Disease?
Coronary artery disease, or ischaemic heart disease, is the most
common type of heart disease. Of an estimated 56 million deaths worldwide
in 2001, more than 29% were due to cardiovascular disease, with over 12% attributed
to ischaemic heart disease.1 Coronary artery disease is the most common manifestation
of cardiovascular disease, accounting for more than half the cases of overt
heart failure in the general population under 75 years.2
When atherosclerosis narrows or blocks the coronary arteries, depleting
the oxygen-rich blood supply to the heart muscle, the muscle may malfunction
or stop working altogether.
Coronary artery disease is a progressive disease and because many people
do not develop symptoms, they may not be aware they have the disease until
a heart attack occurs.
Who is at risk of Coronary Artery Disease?
Although coronary artery disease occurs as a part of the natural ageing process,
certain people are more at risk than others. Modifiable risk factors include:
Smoking
Hypertension
Diabetes
Dyslipidaemia
Obesity
Sedentary lifestyle.
Risk factors which are beyond control include:
Gender
Being a postmenopausal female
Age
Ethnic background – some ethnic groups have a significantly higher
risk than others
Family history of cardiovascular disease.
What causes Coronary Artery Disease?
Coronary artery disease occurs, to some degree, as a natural result of ageing.
Progression may be more rapid in some people. It is thought that coronary artery
disease is initiated by damage to the endothelium, caused by the above-mentioned
risk factors.
Damaged artery walls are more susceptible to atherosclerosis. The plaque and
the surrounding material thicken the endothelium, shrinking the diameter
of the artery, decreasing the blood flow and thereby reducing oxygen supply
to the heart muscle. Blood clots (thrombi) may develop on the surface of
the plaque, further blocking the artery and stopping the blood flow.
Atherosclerosis has many inter-related causes, including elevated levels of
cholesterol and triglyceride in the blood, smoking, obesity, hypertension,
and a diet rich in dairy and animal fats.
What are the symptoms of Coronary Artery Disease?
Coronary artery disease varies both in symptoms and severity. When coronary arteries
become blocked, the ability to supply sufficient blood to the beating heart is
reduced. This results in insufficient oxygen supply to the heart muscle (ischaemia).
Ischaemia may result in:
No symptoms (silent
ischaemia)
Angina pectoris
Shortness of breath
Heart attack (myocardial
infarction)
Arrhythmia – these
include ectopic beats, tachycardia and ventricular fibrillation
Heart failure
Left ventricular systolic
dysfunction.
How to detect Coronary Artery Disease?
For many patients, the first symptom of coronary artery disease is a heart attack
or sudden death, with no prior warning. Patients thought to be at risk (or patients
who show symptoms of coronary artery disease, such as chest pain) should be tested
regularly. The following screening tests are used to detect blockages in the
coronary arteries:
Electrocardiogram (ECG) and exercise cardiac stress tests (ECST)
Radionuclide stress tests
Magnetic resonance imaging (MRI)
Coronary angiography
Coronary magnetic resonance angiography
Electron beam tomography (Ultrafast CT).
What is the current management in Coronary Artery Disease?
Current management of coronary artery disease should be directed towards improving
the efficiency of the heart by medications, coronary angioplasty, and surgery,
but in all cases the underlying cause should be addressed. Patients should stop
smoking, have their blood pressure and cholesterol levels regularly monitored,
modify their diet, reduce their weight, and exercise regularly (under guidance
from a physician).
The current medical management of ischemia includes:
Beta blockers
Nitroglycerin
Calcium channel blockers
Metabolic agents such as trimetazidine.
Secondary prevention of coronary artery disease may include one of the following
medications:
Cholesterol-lowering drugs, such as statins, niacin, fibrates
and bile acid sequestrants
Aspirin and other blood-thinners.
Surgery may include coronary angioplasty, with or without stents, or bypass
surgery.
Despite modifications in patients’ lifestyle, the use of newer medications
and improved surgical techniques, coronary artery disease remains one of
the leading causes of deaths worldwide. Furthermore, this disease burden
will continue to escalate and projections estimate that by 2020, at least
37% of all deaths will be due to cardiovascular disease,3 increasing the
need for effective preventive treatments.
References
1. The World Health Report 2002: Reducing risks, promoting healthy life. World
Health Organization. http://www.who.int
2. Fox KF, Cowie MR, Wood DA et al. Coronary artery disease as the cause of incident
heart failure in the population. Eur Heart J. 2001;22:228-236.
3. Murray C, Lopez A. Global patterns of cause and death and burden of disease
in 1990, with projections to 2020. In: Investing in Health Research and Development,
Report of the Ad Hoc Committee on Health Research Relating to Future Intervention
Options. Geneva, World Health Organization, 1996.
|
ESC 2003 Hotline - video
