The purpose of this pragmatic interventional study is to evaluate whether a protocol-based management of antithrombotic drugs can reduce a composite of perioperative outcomes in patients with chronic antithrombotic therapy before surgery.

Aging population and chronic medical disease make the management of surgical patients more complex. About one tenth of patients scheduled for surgery are taking antithrombotic medications. Coagulation disturbance induced by these medications may increase the risk of bleeding, whereas withholding these medications may increase the risk of thrombotic events. It is a dilemma when managing these patients.

The guidelines and expert consensus published by multiple disciplinary teams constitute the perioperative antithrombotic management protocols. However, the effects of perioperative antithrombotic management guided by these guidelines or expert consensus are seldom reported. The investigators hypothesize that a protocol-based perioperative antithrombotic management can benefit patients with chronic antithrombotic therapy before surgery.

Inclusion Criteria:

• 1. Patients with continuing antithrombotic therapy (including antiplatelet and/or anticoagulant therapies) for cardiovascular and cerebrovascular diseases for more than 2 weeks.
• 2. Patients who have one or more of the following situations: (1) non-valvular atrial fibrillation with a CHA2DS2-VASc score >4; (2) post-artificial valve replacement (including mitral valve, ball-cage valve or tilting disc aortic valve); (3) venous thromboembolism occurred within 1 year, or venous thromboembolism with other high-risk factors which require long-term anticoagulation treatment; (4) coronary heart disease with coronary stent implantation, thrombolytic therapy or other coronary procedures within 2 years, or who had undergone coronary artery bypass grafting within 1 year, or who experienced myocardial infarction or acute coronary syndrome within 1 year; (5) a history of stroke/transient ischemic accident within 1 year, or a history of cervical or intracranial revascularization treatment within 1 year; (6) peripheral arterial disease.
• 3. Patients who are scheduled to undergo intra-abdominal surgery (including general and urologic surgery).
• 4. Patients who sign written informed consents.

Exclusion Criteria:

• 1. Refuse to participate.
• 2. Emergency surgery.
• 3. Unable to complete the preoperative assessment and follow-up plan.
• 4. Other reasons that are considered unsuitable for study participation by the investigators or the attending doctors.

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