Precision Antithrombotic Therapy

Inclusion criteria: * Age ≥ 8 years old; * Diagnosed with one of the following diseases and in need of long - term anticoagulant therapy: non - valvular atrial fibrillation (CHA₂DS₂ - VA score ≥ 1); venous thromboembolism (deep vein thrombosis or pulmonary embolism); having other indications for using NOACs to prevent and treat thrombotic diseases; * Currently receiving NOAC treatment (rivaroxaban, apixaban, dabigatran etexilate, edoxaban); * Willing and able to comply with the requirements of the research protocol and the follow - up plan; * Signed the informed consent form. * Age ≥ 18 years old; * Assessed as patients at high risk of bleeding within 72 hours after the onset of symptoms; * Receiving indobufen treatment for the first time after admission; * Willing and able to comply with the requirements of the research protocol and the follow - up plan; * Signed the informed consent form. Exclusion criteria: * Having contraindications to the use of NOACs or being allergic to NOACs; * Having been enrolled in other clinical trials. * Being allergic to or having contraindications to indobufen; * Needing to change antithrombotic drugs or combine with other antiplatelet/anticoagulant therapies (such as clopidogrel, ticagrelor, warfarin, heparin, etc.) during the study; * Cardiogenic stroke or stroke induced by angioplasty/vascular surgery; * Having a history of aneurysm (intracranial or peripheral); * Severe abnormal liver and kidney functions; * Pregnant, lactating women or women of childbearing age who are unwilling to take effective contraceptive measures; * Life expectancy \< 1 year; * Mental or emotional disorders preventing cooperation with follow - up; * Participating in other clinical trials within 30 days before enrollment; * Unable to complete blood concentration detection (such as difficulty in establishing venous access).