Antithrombotic Therapy in Peripheral Arterial Occlusive Disease: Chronic Extremity Arterial Insufficiency
Despite the rather benign prognosis for the limb, intermittent claudication may be viewed as an ominous sign of underlying disseminated atherosclerosis, and afflicted individuals have a twofold to threefold increase in cardiovascular mortality on long-term follow-up in comparison with age-matched control subjects.’ The prognosis for limb and life is worse for more severely affected individuals. The excessive mortality rate is related to stroke and myocardial infarction (MI) because carotid atherosclerosis and ischemic heart disease are common in patients with lower-extremity arterial disease. There is an inverse relationship between the ankle/brachial pressure index and clinically manifest cardiovascular disease and risk factors. The lower the index, the greater the occurrence of adverse cardiac events, strokes, and cardiovascular deaths. Even patients with modest, asymptomatic reductions in the ankle/brachial pressure index (0.8 to 1.0) are at increased risk of developing clinically manifest cardiovascular disease. These findings lead to the conclusion that leg arteiy disease should be regarded not only as a marker of generalized atherosclerosis but also as an indicator associated with an increased risk of premature death.
Aspirin therapy may modify the natural history of chronic lower extremity arterial insufficiency as well as lower the incidence of associated cardiovascular events. Data from level I studies suggests that aspirin, alone or combined with dipyridamole, will delay the progression of established arterial occlusive disease as assessed by serial angiography and decrease the need for arterial reconstruction when used for primary prevention of adverse cardiovascular events in men fully my canadian pharmacy online. The beneficial effect of aspirin is most likely due to prevention or retardation of platelet thrombogenesis on the surface of atherosclerotic plaques; experimental and clinical trials have suggested that aspirin has no effect on the enlargement of plaques. Aspirin appears superior to other currently available antithrombotic drugs. Although a few reports (levels II to IV) suggest beneficial effects of anticoagulants and antiplatelet agents in patients with peripheral vascular disease, no convincing data from properly designed large trials demonstrate that antithrombotic therapy will delay or prevent progression of atherosclerosis.