The role of platelets in peripheral arterial disease: therapeutic implications

Peripheral arterial disease (PAD) is associated with platelet hyperaggregability as well as an increase in morbidity and mortality from myocardial infarction and stroke. Enhanced platelet activation in PAD may substantially contribute to these adverse outcomes. A relative resistance to aspirin therapy has been reported in patients with PAD. Therefore, clopidogrel may be superior to aspirin in treatment of PAD. Furthermore, the aspirin + clopidogrel combination could be more effective than monotherapy but its risk-benefit ratio has yet to be evaluated. Clopidogrel is preferable to ticlopidine because of its safer profile and the convenience of once-daily administration. The glycoprotein (Gp) IIb/IIIa inhibitors may also find a place as short-term therapy after peripheral angioplasty. There is a need to consider the use of clopidogrel in patients who cannot tolerate aspirin. Patients who have an event while taking aspirin also present a problem. One possibility here is to substitute aspirin with clopidogrel or to add clopidogrel to the aspirin. Although these options are currently not evidence based in patients with PAD, there is emerging evidence showing that they are realistic choices.