This study aims to assess independent factors associated with the clinical decision to discontinue ASA preoperatively in patients undergoing elective 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.

Inclusion Criteria:

• 18 Years and older
• Scheduled for elective non-cardiac surgery
• Regular long-term ASA use, defined as daily low-dose (≤100mg) ASA therapy, even if ASA-medication was interrupted within the last 30 days before study inclusion

Exclusion Criteria:

• < 18 Years
• No consent given

Patients scheduled for elective non-cardiac surgery, who present in the pre-assessment clinic of the University Medical Center Hamburg-Eppendorf during the study recruitment period, are screened for eligibility.