Perioperative management of antiplatelet therapy

Abstract

Worldwide, cardiovascular events represent the major cause of morbidity and mortality. A key role in the pathogenesis of these events is played by platelets. Interventional procedures, with placement of coronary and vascular stents, often represent the preferred therapeutic strategy. Antiplatelet medications are considered first-line therapy in preventing cardiovascular thrombotic events. A wide array of antiplatelet agents is available, each with different pharmacological properties. When patients on antiplatelet agents present for surgery, the perioperative team must design an optimal strategy to manage antiplatelet medications. Each patient is stratified according to risk of developing a cardiovascular thrombotic event and inherent risk of surgical bleeding. After risk stratification analysis, various therapeutic pathways include continuing or discontinuing all antiplatelet agents or maintaining one antiplatelet agent and discontinuing the other. This review focuses on the pharmacological and pharmacokinetic properties of both older and novel antiplatelet drugs, and reviews current literature and guidelines addressing options for perioperative antiplatelet management.

Antiplatelet therapy – a summary for the general physicians

“…A general guide follows (also see Fig 2 ). 46,47 > An assessment of the thrombotic risk of the patient is considered fi rst. Clarifi cation about the necessity for the prescription of antiplatelet therapy and, the likely thrombotic risk from stopping the drug before the procedure.…”

“…If discontinuation is planned, current guidelines recommend stopping clopidogrel and ticagrelor 5 days before and prasugrel 7 days before the procedure. 46,47 > In the case of emergency procedures, a discussion is mandatory between the cardiologist and person undertaking the procedure. Current practice is based on platelet transfusions which may be given to 'overcome' the effect of the antiplatelet agents.…”

“…There are some data suggesting that this approach may be helpful in the case of aspirin but not clopidogrel (probably due to plasma half-life differences). 47,48 There is also the theoretical risk of stent thrombosis with platelet transfusions. > In relation to regional anaesthesia and spinal procedures, the American and European guidelines suggest neuraxial and peripheral blocks can be safely performed while on aspirin but not on the P2Y 12 blockers.…”

Functional assay of antiplatelet drugs based on margination of platelets in flowing blood

“…12 A large proportion of patients continue to receive these therapies indefinitely due to the increased risk of thrombosis and embolism associated with damaged vessel walls or with blood contacting implants. Examples of antiplatelet drugs currently prescribed include thromboxane inhibitors [acetylsalicylic acid (ASA)], GPIIb/ IIIa inhibitors (abciximab, eptifibatide, and tirofiban) and adenosine diphosphate (ADP) inhibitors (clopidogrel, prasugrel, and cangrelor).…”

Non-Steroidal Anti-Inflammatory Drugs; Comparative Analysis

“…11 Common mechanism of action of all NSAIDs is inhibition of synthesis of prostaglandins, thromboxanes and prostacycline by inhibiting cyclooxygenase pathway. 12 Aspirin is the irreversible blocker of cyclooxygenase enzyme 13 while diclofenac reversibly block the enzyme.…”