Coronary Artery Disease

One of the leading causes of premature death and disability

It is projected that by 2020, coronary artery disease (CAD) will be the leading cause of death and disability adjusted life years, accounted for by both the rapidly increasing prevalence in developing countries and Eastern Europe and the rising incidence of obesity and diabetes in the Western world.

CAD is a chronic degenerative condition which may present via a wide spectrum of clinical syndromes including stable angina, acute coronary syndrome, heart failure, arrhythmia and death. As with CAD mortality, there are marked regional, socio-economic and ethnic variations in the incidence and prevalence of myocardial infarction (MI) (58).

The INTERHEART study looked at various risk factors for myocardial infarction in over 15,000 patients in 52 countries, who were matched to controls with no history of heart disease. The mean age of first presentation with MI was 8 years younger in men than in women and 10 years younger in Africa, the Middle East and South Asia compared with the rest of the world. A number of easily recognised and potentially modifiable risk factors were identified including smoking, hypertension, diabetes mellitus, waist-to-hip ratio, low daily fruit and vegetable consumption, physical inactivity, alcohol excess, abnormal lipid profile and psycho-social factors. The influence of these risk factors was consistent across genders, ethnic groups and geographical variation (21).

Atherothrombosis, which may be defined as atherosclerosis with superimposed thrombus, is the key pathological process underlying the majority of clinical cardiovascular events. Atherosclerosis is a systemic process that may involve the aorta, carotid, coronary and peripheral arteries, with the epicardial coronary arteries being particularly susceptible. The molecular and cellular mechanisms underlying this process are not completely understood but it is well recognised that the disease develops in response to a chronic inflammatory process in the arterial intima (59). Exposure to risk factors combined with deposition of lipoprotein in the intima, lead to up-regulation of atherogenic and pro-thrombotic processes (60). Development of a necrotic lipid core within the plaque and degradation of the overlying fibrous cap render the plaque vulnerable to rupture (61-63). When this occurs, the core contents are exposed to the blood and this acts as a potent thrombogenic stimulus, activating the coagulation cascade resulting in arterial thrombosis (64). Not infrequently, coronary plaque rupture may occur as a ‘silent’ event but if the thrombosis impedes coronary blood flow causing ischaemia of the myocardium then the patient may present with an acute coronary syndrome, MI or even death (65-67).

The aim of treatment of CAD is to relieve symptoms and improve quality of life, reduce cardiovascular events and increase survival. There have been rapid improvement in the management over the last ten years with the development of new medications and pharmacological interventions alongside major advances in revascularisation techniques, both percutaneous (angioplasty and stenting) and surgical.