The perioperative management of patients who are receiving antiplatelet therapy is a common clinical problem given the large number of patients who are receiving these agents for treatment of coronary artery disease, cerebrovascular disease or peripheral arterial disease. Such patients may be receiving: acetylsalicylic acid (ASA) alone; clopidogrel alone; ASA and clopidogrel. Patients who are receiving antiplatelet drugs encompass a broad risk spectrum for cardiovascular events that depends on the clinical indication for antiplatelet therapy and whether patients are receiving treatment for the primary or secondary prevention of cardiovascular disease. There are no perioperative risk classification schemes that consider the benefits and risks of continuing or interrupting antiplatelet therapy.
The objectives of this chapter are: 1) to stratify patients according to their risk for acute coronary events if antiplatelet therapy is stopped and the risk for bleeding associated with surgery or procedure; and 2) to provide a practical approach to the perioperative interruption and resumption of antiplatelet therapy.
A 68-year-old man with a drug-eluting stent (DES) inserted 4 months ago (following myocardial infarction) requires surgery for removal of a parotid cancer. He is on aspirin and clopidogrel. The perioperative assessment of perioperative antiplatelet therapy should start from the assessment of his thromboembolic risk: given the recent DES implantation, the risk of stent-thrombosis if aspirin and/or clopidogrel are interrupted is very high (and associated also with high morbidity and mortality).
The second step is represented by the assessment of bleeding risk: this surgery involves a moderately vascular, nonclosed-space organ (parotid gland) with an expected small to moderate tissue injury and the potential for intraoperative cautery/suturing.
In this case, after balancing the high thrombotic risk (possibly associated with high morbidity and mortality) and the moderate bleeding risk, the suggested strategy is to continue aspirin and clopidogrel perioperatively.
Cautionary note: There are no randomized trials comparing continuation with interruption of antiplatelet drugs around the time of surgery and patient management should be based also as individual circumstances.
Perioperative Atherothrombotic Risk Assessment
Patients who are receiving antiplatelet drugs have a variable risk for atherothrombotic cardiovascular events, which depends to a large extent on the indication for the antiplatelet therapy. Although an overall risk classification scheme for atherothrombotic events does not exist, it is reasonable to consider patients who are receiving antiplatelet therapy as primary prevention against stroke or myocardial infarction as being at lowest risk for atherothrombotic events. On the other hand, patients considered at high risk for such events include those with a recent acute coronary syndrome, in particular within the past 3 months, and those with a recent placement of a coronary stent, in particular within the past 6 weeks to 6 months (Table 62-1).
Table 62-1 Risk for Thrombotic Cardiovascular Events in Patients Not Adhering or Discontinuing ASA in Secondary Prevention or Not Taking ASA ...