Preoperative Aspirin and Postoperative Antiplatelets in Coronary Artery Bypass Grafting: The PAPA CABG Study
Status:
Completed
Trial end date:
2008-12-01
Target enrollment:
Participant gender:
Summary
Main Research Question(s):
What is the effect of continuing aspirin until the time of coronary artery bypass graft
surgery and of adding clopidogrel to aspirin after coronary artery bypass graft surgery for
preventing blockage of coronary grafts, heart attack, stroke, and death? To reliably answer
this question requires a large randomised trial. Before applying for a major grant from the
Canadian Institute for Health Research to do the large study we would like to perform a small
pilot study of 150 patients to demonstrate that it is feasible to recruit patients and to use
a new test called "CT angiography" to determine whether the bypass grafts are still working
or have become blocked.
(ii) Why is this research important? Coronary artery bypass surgery has made a very important
contribution to improving the health and survival of patients with advanced coronary artery
disease but still has many problems. One in 10 patients experiences a heart attack at the
time of surgery, 1 in 20 experiences a heart attack, stroke, or death during hospitalization,
and 1 in 4 patients has at least 1 blocked graft within 1 year of surgery. Antiplatelet drugs
such as aspirin and clopidogrel are effective for preventing heart attacks, strokes and
deaths but aspirin is usually stopped before coronary artery bypass graft surgery because of
concerns about increasing the risk of bleeding. The effectiveness of the combination of
clopidogrel and aspirin after surgery has not been evaluated. Our pilot study will provide
key information about feasibility that will help us to design and perform a large definitive
study in the future.
(iii) What is being studied? We will be looking at blood flow in bypass grafts as well as the
occurrence of heart attack, stroke, and death. For safety we will be looking at bleeding,
transfusion, and need for further surgery because of bleeding. We will also perform
laboratory tests of platelet function to measure and compare the effect of the study
treatments to prevent blood clots from forming.