When "double antibody" meets surgical operation

This is the 4804th article of Da Yi Xiao Hu

A patient who had just undergone PCI (percutaneous coronary artery stent implantation) six months ago due to acute myocardial infarction needed surgery due to a leg fracture. However, the patient was taking antithrombotic drugs, and the surgeon recommended stopping the antithrombotic drugs aspirin and clopidogrel for one week before surgery. The family was quite worried about this. The patient had just undergone PCI surgery six months ago, and the cardiologist repeatedly warned him not to stop taking antithrombotic drugs casually after the surgery. Would stopping the drugs now cause a recurrence of heart disease? But if the drugs were not stopped, would it cause heavy bleeding during the surgery? The family was really in a dilemma.

PCI is currently an important means of treating coronary heart disease, and more than 1 million patients worldwide undergo this surgery every year. However, while coronary stents solve the problem of coronary artery blockage, they may also cause new problems. Some patients after PCI will develop intra-stent thrombosis, causing coronary artery re-occlusion, with an incidence rate of 0.5% to 3%. Since coronary artery re-obstruction is often sudden and there is no time to open collateral circulation, the incidence rate of myocardial infarction or sudden death in patients is 45% to 75%. Thrombosis in the stent after PCI is a serious problem that cannot be ignored in clinical practice. Why does intra-stent thrombosis form?

Interventional surgery itself can cause local coronary damage, rupture of atherosclerotic plaques, damage to the vascular intima and even the media, expose subendothelial tissue, activate platelets, and cause thrombosis. Stents as foreign bodies can also induce platelet adhesion and activation. The cations on the surface of metal stents promote platelet activation and blood coagulation through charge action, thus leading to thrombosis.

In order to reduce the formation of thrombosis in stents, people have thought of many ways. Coronary stents have evolved from bare metal stents to drug-coated stents, but drug-coated stents can delay the healing of endothelial damage and lead to incomplete endothelial cell coverage, which may still lead to the formation of thrombosis in the stent after a year or more. Taking dual antiplatelet drugs after PCI can significantly reduce the incidence of stent thrombosis. Early interruption of antiplatelet therapy is a common cause of recurrence of thrombosis after stent implantation.

It is very important to take antiplatelet drugs in a standardized manner after surgery. The most commonly used antiplatelet treatment regimen is dual antiplatelet therapy, which is aspirin combined with clopidogrel or ticagrelor. The treatment course for bare metal stents takes 1 month, and drug-coated stents takes 6 to 12 months. What should I do if the patient needs surgery during antithrombotic drug treatment?

In fact, this situation is often encountered in clinical practice. According to statistics, up to 20% of patients undergo non-cardiac surgery within 2 years after PCI, of which 3.5% to 7.5% are performed within 6 months after PCI. Perioperative interruption of antiplatelet therapy after PCI can cause thrombosis in coronary stents and lead to myocardial infarction, while continued antiplatelet therapy will increase the risk of surgical bleeding. Therefore, careful consideration is needed to assess which risk is higher and whether to suspend antithrombotic therapy or postpone surgery.

For patients undergoing antithrombotic therapy, if elective surgery is required, it is recommended to postpone the surgery as much as possible. If the patient is undergoing balloon angioplasty, the elective surgery can be postponed to 2 weeks after surgery; if bare metal stent PCI is performed, it can be postponed to 4 to 6 weeks after surgery; if drug-eluting stents are used, it should be postponed to 6 to 12 months as much as possible.

However, if the patient is facing an urgent limited-time surgery, such as tumor surgery, or emergency surgery such as intracranial hemorrhage, we need to adopt different strategies according to the patient's surgical bleeding risk and the risk of stent thrombosis. In general, even for surgical operations with high bleeding risks, aspirin should be retained as much as possible. If it is used in combination with clopidogrel, it should be discontinued 5 days before surgery, 7 days before surgery when it is used in combination with prasugrel, and only 48 to 72 hours before surgery when it is used in combination with ticagrelor. Dual antithrombotic therapy should be resumed as soon as possible after surgery. Aspirin can only be discontinued if the bleeding risk is too high and the severity even exceeds the occurrence of serious cardiac complications. Patients with high surgical bleeding risk and high risk of stent thrombosis after drug discontinuation can also consider bridging therapy, which is to discontinue the original long-acting antithrombotic drug and switch to a short-acting antithrombotic drug such as eptifibatide or tirofiban until a few hours before surgery. Antithrombotic therapy should be resumed as soon as possible after surgery to shorten the time without antithrombotic therapy as much as possible.

In summary, oral dual-antibody drugs are a very important part of the treatment of patients after PCI. When these patients need to undergo non-cardiac surgery, although intraoperative bleeding may increase, the mortality rate will not increase. The risk of thrombosis caused by premature discontinuation of antiplatelet drugs in the perioperative period may lead to fatal complications. Therefore, unless there is an extremely high risk of intraoperative bleeding, patients after PCI should continue to use aspirin for monotherapy of antiplatelet drugs during the perioperative period.

If you encounter similar problems, you must consult with specialists such as cardiologists and anesthesiologists, and work with surgeons to assess the patient's thrombosis and bleeding risks, develop the most optimized treatment plan, and avoid stopping medication at will. For example, in the case at the beginning of this article, lower limb fracture surgery is not a high-risk surgery for bleeding, but the risk of stent thrombosis is high within six months after PCI, so antithrombotic treatment cannot be stopped, at least aspirin cannot be stopped.

Author: Songjiang Hospital Affiliated to Shanghai Jiaotong University School of Medicine

Emergency and Critical Care Department Han Dan Wang Xuemin