Low-dose Acetylsalicylic Acid Before Non-cardiac Surgery

Acetylsalicylic acid (ASA) is widely used for primary and secondary prevention of cardiovascular diseases. A prothrombotic rebound phenomenon after aspirin cessation has been reported. ASA withdrawal is associated with an increased incidence of adverse cardiac events. In individuals with previous percutaneous coronary intervention (PCI), cessation of ASA may cause stent thrombosis or myocardial infarction. However, many patients undergo non-cardiac surgery within the first two years after PCI. Perioperatively, two counteracting risks have to be taken into account, first, the risk of thromboembolic complications, if ASA medication is discontinued and second, the risk of surgical bleeding, if ASA therapy is continued. However, factors contributing to preoperative decision-making for ASA-withdrawal are still unclear.

This study aims to assess independent factors associated with the clinical decision to discontinue ASA preoperatively in patients undergoing elective non-cardiac surgery. In particular this study aims to determine if the presence of coronary stents is independently associated with ASA discontinuation. Furthermore this study assesses, if benefit-risk-estimates (numerical rating scales) of the patients and the supervising physicians are associated with the decision to withdraw ASA.

Study design

Patients on long-term ASA undergoing non-cardiac surgery as well as their supervising anesthesiologist participate in a preoperative survey. Detailed information about ASA medication, perioperative ASA use, comorbidities, factors that might be associated with the decision to discontinue ASA preoperatively and benefit-risk-estimates (numerical rating scales) are sampled by questionnaires.