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.