Overview of antithrombotic therapy after endovascular and cardiac interventions
Antithrombotic therapy is used after many endovascular and cardiac interventions to reduce the risk of thrombosis at the intervention site, which is a rare but life-threatening event. The risk of thrombosis must be balanced against the increased risk of bleeding associated with antithrombotic therapy.
Many types of endovascular and cardiac interventions are currently available (eg coronary artery stents, femoral and carotid artery stents, valve replacements, aneurysm repairs), and innovation in this field is fast moving. The large variety of interventions, devices and unique patient-related considerations mean that management after an endovascular or cardiac intervention requires specialist input and clinical judgement. There is also a lack of randomised clinical trials to provide exact guidance and management often varies among individual specialists.
Dual antiplatelet therapy (DAPT) (low-dose aspirin plus a P2Y12 inhibitor [clopidogrel, prasugrel or ticagrelor]) is used for thrombotic prophylaxis for a period of weeks to months following many interventions. The duration of DAPT depends on the type of intervention and the specific device used, as well as patient-related factors that affect the risk of bleeding or ischaemia. After a period of DAPT (often around 12 months), ongoing monotherapy with either low-dose aspirin or a P2Y12 inhibitor is often recommended. Evidence is lacking to guide the optimal combination and duration of DAPT and ongoing monotherapy; increasingly, P2Y12 inhibitors are replacing aspirin as the monotherapy of choice because they are associated with a lower risk of bleeding.
Oral anticoagulants are usually used following a mechanical or tissue heart valve replacement and some valve repairs, but are of little value for thrombotic prophylaxis following most other interventions.
Triple antithrombotic therapy (low-dose aspirin, a P2Y12 inhibitor and an oral anticoagulant) may be necessary when a patient who requires, or who has had, an endovascular or cardiac intervention also has an indication for long-term anticoagulation (eg atrial fibrillation). The interventionalist or cardiologist will determine whether to start and the duration of triple therapy, taking into account the risk of thrombosis associated with the intervention, as well as patient-related factors that affect the risk of bleeding or ischaemia. Clopidogrel is the preferred P2Y12 inhibitor in a triple-therapy regimen because prasugrel and ticagrelor may have a higher risk of bleedingJackson, 2015Kirchhof, 2016Sarafoff, 2013. Triple therapy is typically only used short term (eg 1 week to 6 months), after which one of the antiplatelet drugs is stopped; after around 12 months, the other antiplatelet drug is often stopped and anticoagulant monotherapy continued long termCollet, 2021Hindricks, 2021 Ibanez, 2018. If bleeding occurs in a patient taking triple therapy, consult the specialist to determine how to control the bleeding, including which drugs, if any, should be stopped.