In the natural history of patients with peripheral obliterative arterial disease (POAD) the prognosis of the complaint "
intermittent claudication" is relatively good and the
amputation rate is presently only about 3%. However, POAD patients carry a high risk of cardiovascular events and their cumultative mortality rate within 10 years is as high as 40-50%. Atherothrombotic events in the coronary and, less frequently, cerebral arteries are by far the first cause of death and disability in these patients. The rationale for antithrombotic drugs in the treatment of POAD lies in the pivotal role of platelet activation and
thrombin formation in the evolution of the atherothrombotic lesions, but also in the effect of some of these drugs on the regulation of microcirculatory responses. In acute thrombotic
arterial occlusion,
Heparin is the "first application"
drug, especially in support of interventional revascularisation procedures. Regional thrombolysis often coupled with angioplasty (PTA), or systemic thrombolysis, are effective in revascularisation of especially infrainguinal-supra popliteal occlusions. However, controlled clinical trials are needed. In chronic POAD,
intermittent claudication can be improved with a rational walking exercise programme, but, besides pentoxyphilline, especially
ticlopidine significantly adds to the benefits of exercise. Regarding districtual progression of
atherothrombosis and especially cardiovascular events, both
aspirin and
ticlopidine have been shown effective in single studies or meta-analyses. In a recent observational study of pooled data the cumulative endpoint including
myocardial infarction,
stroke and vascular death was reduced by 25 +/- 10% in the generality of patients treated with
antiplatelet drugs. Finally, in critical limbs
ischemia (CLI), some
prostanoid compounds as
Iloprost and
Prostaglandin E1 favourably influence rest
pain and
ulcer healing, but less evidence is available on their effects on hard events as
amputation and death. In conclusion, following the general indication to "be conservative" in the treatment of these patients, it seems clear that antithrombotic drugs have become by far a key medication in all different phases of POAD.