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.