Dual antiplatelet therapy in patients requiring urgent coronary artery bypass grafting surgery: a position statement of the Canadian Cardiovascular Society

Acute coronary syndrome (ACS) guidelines recommend that most patients receive dual antiplatelet therapy with clopidogrel and acetylsalicylic acid (ASA) at the time of presentation to prevent recurrent ischemic events. Approximately 10% of ACS patients require coronary artery bypass grafting surgery (CABG) during the index admission. Most studies show that patients who receive ASA and clopidogrel within five days of CABG have an increase in operative bleeding. Current consensus guidelines recommend discontinuation of clopidogrel therapy at least five days before planned CABG to reduce bleeding-related events. However, high-risk individuals may require urgent surgery without delay, to reduce the risk of potentially fatal ischemic events. The present multidisciplinary position statement provides evidence- based recommendations for the optimal use of dual antiplatelet therapy to balance ischemic and bleeding risks in patients with recent ACS who may require urgent CABG.

RECOMMENDATIONS

1. All ACS patients should be considered for dual antiplatelet therapy with ASA and clopidogrel at the earliest opportunity, despite the possibility of a need for urgent CABG. 2. For patients who have received clopidogrel and ASA, and require CABG: * Those at high risk of an early fatal event (eg, with refractory ischemia despite optimal medical treatment, and with high-risk coronary anatomy (eg, severe left main stenosis with severe right coronary artery disease), should be considered for early surgery without discontinuation of clopidogrel. * In patients with a high bleeding risk (eg, previous surgery, complex surgery) who are also at high risk for an ischemic event, consideration should be given to discontinuing clopidogrel for three to five days before surgery. * Patients at a lower risk for ischemic events (most patients) should have clopidogrel discontinued five days before surgery. 3. For patients who have CABG within five days of receiving clopidogrel and ASA, the risk of major bleeding and transfusion can be minimized by applying multiple strategies before and during surgery. 4. Patients who receive clopidogrel pre-CABG for a recent ACS indication should have clopidogrel restarted after surgery to decrease the risk of recurrent ACS. 5. For patients with a recent coronary stent, the decision to continue clopidogrel until the time of surgery or to discontinue will depend on the risk and potential impact of stent thrombosis. Restarting clopidogrel after CABG will depend on whether the stented vessel was revascularized, the type of stent and the time from stent implantation. Clopidogrel should be restarted when hemostasis is assured to prevent recurrent acute ischemic events.

Review Article: Examining Treatment of ST-Elevation Myocardial Infarction: The Importance of Early Intervention

Early reperfusion in ST-segment elevation myocardial infarction (STEMI) is imperative. Acute reperfusion may be achieved with fibrinolytic agents and/or percutaneous coronary intervention (PCI); however, PCI is associated with lower rates of death and myocardial infarction compared with fibrinolysis. As treatment delays are associated with worse outcomes, current guidelines recommend minimizing time from symptom onset to treatment initiation. Regardless of the reperfusion strategy, patients with STEMI are at increased risk of early recurrent ischemic events and death. These risks can be significantly reduced by promptly initiating a combination of pharmacotherapies that includes antiplatelet and anticoagulant agents, β-blockers, and inhibitors of the renin-angiotensin-aldosterone system. This manuscript reviews the evidence supporting the most recent guidelines for STEMI management published jointly by the American College of Cardiology and American Heart Association. More recent evidence and its potential impact on future evidence-based guidelines are also addressed.

Coronary bypass surgery in patients treated with clopidogrel. Is it safe?

PURPOSE OF REVIEW

Current guidelines for the management of acute coronary syndrome clearly recommend that clopidogrel should be started before diagnostic coronary angiography. If patients undergo coronary artery bypass grafting (CABG) early after clopidogrel loading or during continued exposure, it seems reasonable to expect an increase in bleeding complications.

RECENT FINDINGS

Earlier studies may have overestimated the risk of bleeding in patient undergoing CABG with prior clopidogrel exposure (5-10-fold increase). Some conflicting results are reported in literature. As reexploration because of excessive bleeding is concerned, a two to three-fold increase must be expected, which is demonstrated in actual trials properly matched to confounding factors. Discontinuation of clopidogrel for 5-7 days prior to urgent CABG as recommended by guidelines is not well adopted in clinical practice for several reasons.

SUMMARY

There is a moderately elevated risk of bleeding complications after CABG due to prior clopidogrel exposure alone. However, in clinical practice this risk is added often to patients who carry already elevated surgical risks (urgent procedures, worse coronary anatomy, history of previous myocardial infarction and prior percutaneous intervention), and after bleeding complications singular patients may suffer from consecutive adverse outcome. Cessation of clopidogrel in patients before CABG clearly prolongs hospitalization time and has an estimated 1% risk of coronary events during the waiting period. Risk and benefit have to be balanced in every individual case.

Management of bleeding and of invasive procedures in patients with platelet disorders and/or thrombocytopenia: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET)

The optimal management of bleeding or its prophylaxis in patients with disorders of platelet count or function is controversial. The bleeding diathesis of these patients is usually mild to moderate: therefore, transfusion of platelet concentrates may be inappropriate, as potential adverse effects might outweigh its benefit. The availability of several anti-hemorrhagic drugs further compounds this problem, mainly because the efficacy/suitability of the various treatment options in different clinical manifestations is not well defined. In these guidelines, promoted by the Italian Society for Studies on Haemostasis and Thrombosis (Società Italiana per lo Studio dell'Emostasi e della Trombosi [SISET]), we aim at offering the best available evidence to help the physicians involved in the management of patients with disorders of platelet count or function. Literature review and appraisal of available evidence are discussed for different clinical settings and for different available treatments, including platelet concentrates (PC), recombinant activated factor VII, desmopressin, antifibrinolytics, aprotinin and local hemostatic agents.

PCI, stents, clopidogrel and non-cardiac surgery

What follows in this discussion is partially abstracted from a wonderful ACCEL interview with Peter Berger by Freek W.A. Verheugt on the subject of stopping antiplatelet therapy prior to non-cardiac surgery. 1 I suspect what Dr. Berger believes is representative of the opinion of many interventional cardiologists.

Biological and pharmacological aspects of perioperative hemorrhagic complications associated with oral platelet-directed antithrombotic agents. Focus on isolated coronary artery bypass grafting and oral irreversible P2Y(12) receptor antagonists

Coronary arterial bypass grafting (CABG)-the most common heart surgery performed worldwide-is an effective procedure for treating patients with advanced, obstructive atherothrombotic coronary artery disease, prolonging survival in selected high-risk patients. However, CABG is also associated with hemorrhagic complications, which can impact outcome measures such as perioperative morbidity, mortality, length of hospital stay, and health care expenditures. Recent observations have expanded our understanding of the complex process of hemostasis, fostering a more informed view of CABG-associated bleeding complications. Additional research is warranted to determine whether new antithrombotic drug treatment options, such as reversible P2Y12 receptor antagonists among patients with acute coronary syndromes, will favorably impact these clinically relevant complications.