I. Overview The pathological basis of unstable angina is the rupture of atherosclerotic plaques in coronary arteries and platelet aggregation and thrombosis on this basis. Therefore, the application of antiplatelet drugs is very important in the prevention and treatment of unstable angina in the elderly. There are three major classes of antiplatelet drugs currently used in clinical practice. (1) cyclooxygenase inhibitors: the representative drug is aspirin. Aspirin inhibits the synthesis of thromboxane by inhibiting platelet cyclooxygenase and exerts an anti-platelet aggregation effect, and is currently the most widely used anti-platelet drug. (2) Adenosine diphosphate (ADP) receptor antagonists: such as ticlopidine and clopidogrel. Clopidogrel, which is commonly used clinically, inhibits platelet aggregation with each other by competitively and selectively binding to the platelet surface ADP receptor so that the fibrinogen binding site of the platelet membrane glycoprotein receptor of platelets coupled to the ADP receptor cannot be exposed and fibrinogen cannot bind to it. (3) Platelet membrane glycoprotein receptor blockers: monoclonal antibody drugs and non-peptide inhibitors are under further study. Second, the diagnostic criteria of unstable angina in the elderly Unstable angina is similar to typical stable angina, but lasts longer, up to 30 minutes, and chest pass occurs mostly at rest. A sudden or persistent decrease in the threshold of activity that triggers angina; an increase in the frequency, severity, and duration of angina; the presence of resting or nocturnal angina; radiation of chest pain to nearby or new sites; and episodes with new associated symptoms, such as sweating, nausea, vomiting, palpitations, or difficulty with inspiration. Routine rest or nitroglycerin can only temporarily or not completely relieve the symptoms, especially in elderly patients with combined diabetes mellitus. Specific tests need to be done by ECG and continuous ECG monitoring, coronary angiography and other invasive tests, cardiac marker tests, etc. may help in the diagnosis. Third, the treatment of unstable angina pectoris in the elderly Aspirin 300mg orally once a day, (if gastrointestinal reactions can also be divided into doses), low molecular heparin calcium 6150IU, subcutaneous injection once every 12 hours, for 7 days. Clopidogrel 300mg orally once daily for the first time, followed by 75mg daily for 6 months. Simvastatin 10mg orally once daily for a long time. Other nitrates, ACE-I, and β-blockers are applied optionally, and non-cardiovascular complications are treated aggressively. IV. Precautions Patients should have electrocardiogram, blood routine, lipid, blood sugar, liver and kidney function, cardiac enzyme and blood coagulation function examination before treatment. The electrocardiogram, clinical symptoms and adverse reactions should be followed up weekly. The above regimen should not be used or reduced for those with significantly reduced platelets or significant bleeding tendency; those with recent history of active ulcers and surgery; those with severe hepatic and renal impairment; those with allergy to the above drugs; those with malignant tumors; those with history of myocardial infarction; and those who have undergone percutaneous coronary intervention. The pathophysiological basis of unstable angina is mainly the rupture of atherosclerotic plaques in coronary arteries, which exposes the highly thrombogenic substances in the plaques to blood flow, causing platelet adhesion and activation on the damaged surface, forming thrombus, and eventually impairing blood perfusion. Recent studies have shown that the main cause of acute cardiovascular events is the rupture of atherosclerotic plaques and thrombosis, which depends on the instability of the atherosclerosis. Thus, the treatment of vulnerable plaques has become a current hot topic in this field.