Antithrombotic Therapy in Peripheral Arterial Occlusive Disease: Protective effects of aspirin
Based on these considerations, perioperative aspirin therapy, 80 to 650 mg twice daily, can be recommended in patients undergoing carotid endarterectomy. Therapy should be started at the time of clinical presentation and continued through the perioperative period. Bleeding complications, particularly wound hematomas, occur in 1.4 to 3.0% of patients undergoing carotid endarterectomy and are associated with incomplete reversal with protamine of intraoperative heparin, hypertension, and perioperative antiplatelet therapy. If intraoperative heparin is not fully reversed or continuous heparin anticoagulation is administered postoperatively, perioperative aspirin therapy would potentially increase the incidence of hematomas and other bleeding complications.
It is unknown whether aspirin therapy will prevent or delay the onset of TIAs and strokes in patients with asymptomatic cerebrovascular disease. Indirect evidence (level III) from the Veterans Administration asymptomatic carotid stenosis study suggests that aspirin may be beneficial in patients with advanced stenoses who do not undergo carotid endarterectomy. A surprising 16% of patients randomized to medical therapy were intolerant and had to discontinue aspirin. The incidence of neurologic events was significantly higher among these patients than in those who continued aspirin. asthma medications inhalers
The long-term protective effects of aspirin on stroke rate for asymptomatic patients with 50% or greater carotid stenosis is unclear. In a double-blind, placebo-controlled trial in which 372 asymptomatic patients with 50% or greater carotid stenosis were randomized to either aspirin (325 mg/d) or placebo, no difference in stroke rate or incidence of a composite end point of ischemic events was observed at a mean follow-up of 2.3 years. The clinical application of these findings, particularly concerning the use of aspirin in these patients as a means of preventing cardiac events, is tempered by the relatively short follow-up period and by the exclusion of patients with symptomatic cerebrovascular disease, recent MI, and unstable angina.
Significant stenoses recurring at the site of endarterec-tomy are found in as many as 10 to 19% of patients after carotid endarterectomy. Data from retrospective studies (level III) suggest that antiplatelet therapy does not reduce the incidence of recurrent carotid artery stenosis. A randomized trial (level I) confirmed that treatment with aspirin and dipyridamole does not prevent symptomatic or asymptomatic recurrent stenosis after carotid endarte recto my.