HMG-CoA reductase inhibitors in the prevention of stroke.

Stroke is a heterogeneous disorder, with the definition including both haemorrhagic and ischaemic stroke. Although these subtypes of stroke have different underlying pathophysiological mechanisms, atherosclerosis plays a pivotal role in both. Most risk factors for cardiovascular disease are also risk factors for stroke. Patients with a history of cardiovascular events are at an increased risk of stroke. Although hypercholesterolaemia is the most characteristic risk factor for atherosclerotic diseases, recent data suggest that the correlation between cholesterol levels and either ischaemic or haemorrhagic stroke is weak. However, the interpretation of these results is hampered by the inconsistent use of classifications of the various subtypes of stroke in studies. Pooled data on the effect of HMG-CoA reductase inhibitors show a 30% risk reduction in strokes. These beneficial effects are obtained from studies in middle aged patients with ischaemic heart disease, the interpretation being that the effects of HMG-CoA reductase inhibitors on stroke are mediated via (i) cholesterol-lowering effects on the coronary vasculature or (ii) cholesterol-independent effects of these agents. The results cannot be extrapolated to the elderly, among whom stroke most frequently occurs.