Antithrombotic therapy after insertion of a coronary artery stent

Patients who have had a coronary artery stent inserted are at risk of stent thrombosis—a rare but serious complication. Acute stent thrombosis often presents as ST elevation myocardial infarction (STEMI) or sudden cardiac death. The risk of acute stent thrombosis is very low but persists for many years after insertion of the stent. Contemporary (second generation) drug-eluting stents are associated with a lower rate of stent thrombosis and restenosis than bare-metal stentsBonaa, 2016Raber, 2019Sabate, 2016.

To minimise the risk of stent thrombosis, patients who have a coronary artery stent are routinely treated with a period of dual antiplatelet therapy (DAPT) (low-dose aspirin and a P2Y₁₂ inhibitor [clopidogrel, prasugrel or ticagrelor]). The duration of DAPT is determined by the indication for the stent (eg stable angina, acute coronary syndrome), the patient’s comorbidities, the type of stent used and the complexity of the coronary lesion that was treated.

Bare-metal stents are not commonly used; if used, DAPT is recommended for 6 weeksLawton, 2022.

For contemporary (second generation) drug-eluting stents:

• in patients with an acute coronary syndrome, DAPT is usually recommended for 12 months. DAPT for less than 12 months may be appropriate for selected patients (eg those at high risk of bleeding). DAPT for longer than 12 months may be appropriate for selected patients (eg those at high risk of recurrent ischaemic events)Neumann, 2019
• in the absence of an acute coronary syndrome, 1 to 3 months of DAPT is generally as effective and less likely to cause bleeding than longer durationsGiacoppo, 2021. For patients at high risk of bleeding, 1 month of DAPT followed by single antiplatelet therapy is noninferior to 3 months of DAPT followed by single antiplatelet therapy¹Valgimigli, 2021.

Additionally, there is evidence that aspirin may be replaced as the long-term single antiplatelet therapy by a P2Y₁₂ inhibitor. Single antiplatelet therapy should generally be continued indefinitely following insertion of any type of coronary artery stent (unless the patient has an indication for long-term anticoagulation).

Approximately 40% of cases of late stent thrombosis (more than 30 days after insertion of the stent) occur at the time of elective or urgent noncardiac surgery. The risk is especially high if the surgery occurs within 12 months of stent insertion and if antiplatelet drugs are withdrawn perioperativelyArtang, 2007 (see Periprocedural use of antiplatelet drugs). Do not stop or interrupt DAPT prematurely (including perioperative interruption for noncardiac surgery) without specialist advice.