From pathophysiology to targeted therapy for atherothrombosis: a role for the combination of statin and aspirin in secondary prevention

Abstract

Atherothrombosis results from direct interaction between the atherosclerotic plaque and arterial thrombosis, and underlies most forms of cardiovascular disease (CVD). The pathophysiology of atherosclerosis is now recognised to involve endothelial dysfunction and dyslipidemia with cholesterol accumulation, as well as critical immuno-inflammatory and apoptotic dimensions. Erosion or rupture of a vulnerable, lipid-rich, inflammatory atherosclerotic plaque triggers the formation of a platelet-rich thrombus that may partially or completely occlude the artery, with resultant clinical scenarios including stable and unstable angina, acute myocardial infarction (MI) and ischaemic stroke. Insight into the pathophysiology of atherothrombosis indicates that an integrated risk factor approach, focusing particularly on management of dyslipidaemia (with a statin) and thrombosis (with aspirin), may constitute an optimal therapeutic approach. Both agents have established roles in secondary prevention. Statin action on atherogenic lipoproteins mediates plaque stabilisation, modification of plaque morphology and attenuation of inflammation, and may lead to plaque regression, while aspirin reduces platelet activation and aggregation, decreases release of inflammatory cytokines at sites of vascular injury and attenuates vasoconstriction. Given these complementary modes of action, this combination would be a logical choice for reducing atherothrombotic risk in patients with CVD. Meta-analysis of 5 major clinical studies has demonstrated that the combination of pravastatin plus aspirin was significantly more effective than either agent alone in reducing the relative risk of key cardiovascular endpoints including MI and ischaemic stroke. This combination may therefore represent an important, cost-efficient therapeutic approach to reduction of cardiovascular risk and prevention of recurrent events in stable CVD.