Antithrombotic therapy for cerebrovascular disorders

Stroke remains one of the leading causes of death and disability throughout the world. It is the third commonest cause of death in developed countries, exceeded only by coronary artery disease and cancer.

The incidence of stroke is 1-2 cases in 1000 people a year in the Western world, and is probably slightly higher among African-Caribbeans than other ethnic groups. Cerebrovascular disorders are uncommon in people aged < 40 years, but there is a definite increase with age, with an incidence of 10 cases in 1000 people aged >75 in a year. Stroke is slightly more common in men, but women tend to have a poorer prognosis because of a higher mean age at onset. The incidence of stroke has been declining in recent decades in many Western countries because of better population control of hypertension, smoking, and other risk factors. However, the absolute number of strokes continues to increase because of the ageing population, which is predicted to peak in 2015. Thus, the present annual incidence of 700 000 strokes in the United States is expected to rise to 1 100 000 in 2015, without further advances in prevention.

About 80-85% of the strokes are ischaemic, with the rest primarily haemorrhagic. Even among patients with ischaemic stroke, there is much heterogeneity in aetiological and pathophysiological factors contributing to the disease.

Atherosclerosis of the major cerebral vessels probably accounts for most ischaemic strokes, either as thrombotic occlusion at the site of atherosclerotic plaques or atherogenic embolism. Embolism from a source in the heart (cardioembolic stroke) and lipohyalinosis of the penetrating small cerebral vessels (lacunar stroke) account for a substantial proportion of …