Antithrombotic therapies for patients with cerebrovascular, peripheral arterial, and coronary artery disease

Introduction Patients with extracoronary atherosclerotic vascular disease have the highest risk of death from coronary heart disease. 1,2 In patients with peripheral arterial disease (PAD), the risk of death is 15-30% at 5 years of follow-up, with 75% of these fatal events resulting from cardiovascular disease. 3 Similarly, patients with cerebrovascular disease (CVD) demonstrate elevated cardiovascular risk. In the Asymptomatic Carotid Surgery Trial (ACST), a 60-year-old patient with an asymptomatic, unilateral carotid artery stenosis had a 25% 10-year mortality rate. 4 In fact, patients with symptomatic PAD or CVD may have greater rates of cardiovascular death than patients initially presenting to medical attention for coronary heart disease. In one study, the annual mortality rate was higher among patients with PAD (8.2%) and stroke (11.3%) than after a myocardial infarction (6.3%) (Figure 27.1). 5 Adverse atherosclerotic sequelae result from the process of atherothrombosis. 6 Rupture of an unstable plaque incites a cascade of events initiated by the aggregation of platelets with attendant thrombosis and vascular occlusion. 6 In addition, patients with PAD have long been recognized as having elevated markers of thrombogenicity. 7 Thus, with increasing awareness of atherosclerosis as a systemic disease, more aggressive strategies for the prevention of atherothrombotic events have evolved to include antithrombotic therapy. 3 In this chapter, we will relate evidence for the rational application of antithrombotic therapy for primary or secondary prevention of atherothrombotic events in the ‘high-risk patient’, the patient with extracoronary atherosclerotic vascular disease. Our discussion will consider antiplatelet, antithrombin, and anticoagulant therapy. In addition, we will review the role of primary prevention of stroke.