Abstract 19160: Prevention of Strokes in Patients With Mechanical Aortic Prostheses: Use of Clopidrogel or Prasugrel and Aspirin as Sole Anticoagulants
Objective: Embolization from mechanical aortic- prostheses is due to platelet activation and aggregation secondary to shear forces and the release of ADP from RBC. Anti-thrombotic therapy should be directed to the prevention of platelet activation instead of the suppression of coagulation factors. We summarize the long terms results of patients with mechanical aortic prostheses treated exclusively with antiplatelet agents.
Methods: Starting in 2001 two hundred three (203) patients average age 63.8 ± 11.8 years received mechanical aortic prostheses alone or with other cardiac or thoracic procedures received a loading dose of clopidogel (300mg) or prasugrel (60mg) and aspirin (325mg) one hour after extubation. The maintenance dose was 75mg clopidrogel or 10mg prasugrel and 81mg ASA daily. Beginning 2006 we measured platelet reactivity with Accumetrics® and Thromboelectrography (TEG).
Platelet inhibition was measured 6 hours after loading. Patients not responsive to clopidogrel were changed to prasugrel. Follow up was at 1 and every 6 months by echocardiography and platelet reactivity.
Results: Total months at risk were 9016.7(751.5 pt-yr) average follow up is 44.4 ± 37.8 months.
34 (16.7%) patients died. Seven patients had strokes (0.93% patient-years). Five strokes occurred in patients who discontinued the antiplatelet medication, one in a patient non responsive to clopidrogel and one in a compliant patient prior to 2006. We have not observed strokes since 2007 (5½ years).
9 patients bled (4%)(1.2% pt-yr), 8 from the GI tract and 1 from a cerebral aneurysm.
One non-compliant patient formed a clot in the prosthesis.
Conclusions: Embolism from aortic prostheses is platelet mediated and should be treated with antiplatelet agents. We employed an antiplatelet regimen of clopidrogrel or prasugrel and aspirin as sole anticoagulants in patients with aortic mechanical prostheses. It is mandatory that the patient respond to the antiplatelet agent employed. In patients non responsive to clopidrogel, prasugrel is utilized.
With this protocol the incidence of bleeding is 1.2% pt-yr, and the incidence of stroke 0.93%/ pt-yr.
Our date is suggestive that dual antiplatelet therapy medications can prevent strokes in patients with aortic mechanical prostheses.
- © 2013 by American Heart Association, Inc.