Five years after implantation of a cardiac stent, the LDL was 2.05 mmol/L, indicating that the LDL did not meet the desired standard. The reasons for this result may be, on the one hand, that lipid-lowering drugs were not taken after the operation as prescribed by the doctor; on the other hand, the limited efficacy of lipid-lowering drugs alone may not be able to control the blood lipid level within the required range. LDL is a key indicator for patients with a diagnosis of coronary artery disease, and is used to measure whether or not blood lipids are in compliance with the standard, in order to minimize the further development of atherosclerotic lesions. Statins should be taken after cardiac stenting to control lipid levels and reduce LDL to below 1.8 mmol/L. 1. If patients do not take lipid-lowering drugs after cardiac stent implantation, or take lipid-lowering drugs irregularly, the effect of lipid-lowering may be affected, resulting in failure to achieve the LDL standard. 2. Some patients do not take enough statin drugs, or statin drugs alone cannot control LDL within the required range, so the LDL level may not reach the standard. In this case, it is recommended that the patient actively seek medical advice from a specialist to adjust the dosage of the drug or add other drugs to lower the blood lipid level, to avoid unauthorized use of medication that may cause adverse consequences.