3.5 Cessation of medications that affect haemostasis
Question 2 (Interventional) POQ2
In patients undergoing surgery or invasive procedures, what effect does the cessation and timing of cessation of medications that affect haemostasis have on morbidity, mortality and RBC transfusion?
3.5.1 Cardiac surgery
The systematic review process identified 13 studies that investigated the effect of cessation and the timing of cessation of antiplatelet medication on patient outcomes in cardiac surgery, specifically coronary artery bypass graft surgery (CABG).119–131 One study was Level II123 and 12 were Level III studies.119–122,124–131 They included studies of aspirin alone,122-125,131 clopidogrel alone,119–121 and dual antiplatelet therapy (aspirin and clopidogrel).126–130 The study populations included patients having either CABG with cardiopulmonary bypass (CPB) or off-pump coronary artery bypass surgery (OPCAB).
For the purpose of this research question, patients were classified as having received the intervention (i.e. cessation of antiplatelet therapy, including conversion to substitution therapy) where antiplatelet therapy was stopped before surgery for a longer period than an alternative perioperative antiplatelet management strategy. Patients were classified as having received the comparator (i.e. no cessation of antiplatelet therapy) where antiplatelet therapy was stopped before surgery for a shorter period than an alternative strategy, including continuation until surgery, or was not stopped before surgery.
Aspirin monotherapy
Overall, results from the studies that investigated the timing of aspirin cessation indicate that the effect on patient outcomes remains uncertain.122-124,131 Mortality, morbidity (myocardial infarction [MI] and pericardial effusion), hospital length of stay and ICU length of stay were similar, regardless of the timing of aspirin cessation; however, the studies were not powered to detect a difference. Blood loss (postoperative) and transfusion requirements (intraoperative and postoperative) were also similar, despite analyses that claimed statistical significance.
Clopidogrel monotherapy
Only three studies investigated the timing of cessation of clopidogrel monotherapy on patient outcomes in CABG surgery.119–121 Administration of clopidogrel within 5 days of surgery may be associated with an increase in transfusion, blood loss, risk of reoperation for bleeding and hospital length of stay.120,121 The effect on mortality is uncertain.119–121
Combination antiplatelet therapy
Five Level III studies reported on the perioperative management of patients who received combination antiplatelet medication.126–130 Patients underwent OPCAB127,129,130 and CABG with CPB.126,128 There was considerable variability and inconsistency of documentation regarding the timing of cessation of clopidogrel or aspirin (or both) in these studies.
In the highest quality study,127 the continuation of clopidogrel up to the time of surgery increased the need for RBC transfusion and the likelihood of reoperation.
Other anticoagulant therapy
No relevant evidence was identified on the perioperative management of cardiac surgery patients who had been receiving warfarin, nonsteroidal anti-inflammatory drugs (NSAIDs), statins, complementary medicines, vitamins or any other medications affecting haemostasis.