Antithrombotic Therapy in Peripheral Arterial Occlusive Disease: Conclusion
Two randomized clinical trials have evaluated low-dose and high-dose aspirin for antiplatelet therapy administered in conjunction with peripheral PTA.’ Both studies showed equivalent 1- and 2-year patency rates with either a low dose (50 mg/d or 100 mg/d) or high dose (900 mg/d or 1,000 mg/d) of aspirin. GI side effects were greater in the high-dose groups. In another study, 100 patients with claudication treated with 100 mg aspirin daily were followed for 18 months after elective PTA, during which time platelet function was monitored by aggregometry. Only 40% of male patients demonstrated normal platelet inhibition on in vitro aggregation testing, and none of these 40% sustained occlusion of the angioplasty site. On the other hand, all eight occlusions that occurred by 18 months were in male patients who had inadequate platelet inhibition. These results suggest that some patients might require higher aspirin doses or alternative antiplatelet agents such as ticlopidine in order to achieve adequate platelet inhibition.
For all patients undergoing angioplasty, coronary or peripheral, lifelong therapy with aspirin should be considered in the absence of contraindications. As with patients with intermittent claudication, the need for angioplasty identifies a group of patients at high risk for future cardiovascular thromboembolic events that might benefit from lifelong aspirin therapy.
1. Patients who suffer acute arterial thrombi or emboli should be systemically heparinized to prevent proximal and distal thrombotic propagation. Heparin followed by oral anticoagulation should be used to prevent recurrent embolism in patients undergoing thrombo-embolectomy. These are grade Cl recommendations. birth control online
2. Intra-arterial thrombolytic therapy may be considered in patients with acute (less than 14 days) thrombotic or embolic occlusive disease provided that there is a low risk of myonecrosis developing during die time to achieve revascularization by this method. This is a grade B2 recommendation.
3. Aspirin alone or in combination with dipyridamole may modify the natural history of intermittent claudication from arteriosclerosis. In addition, because these patients are at high risk of future cardiovascular events (stroke and MI), diey should be treated with life-long aspirin therapy (81 to 325 mg^d) in the absence of contraindications. This is a grade A1 recommendation.
4. Clopidogrel may be superior to aspirin in reducing ischemic complications in patients with peripheral vascular disease and intermittent claudication and should be considered for treatment. This is a grade A2 recommendation.
5. Pentoxifylline should not be routinely used in patients with intermittent claudication. This is a grade A1 recommendation.