[Anticoagulant therapy in secondary prevention of coronary events]

Area of Science:

• Cardiology
• Pharmacology
• Clinical Trials

Background:

• Secondary prevention of atherothrombotic events relies on antiplatelet therapy, using single-drug or dual-drug strategies (aspirin plus ADP receptor blockers).
• The combination of dual antiplatelet therapy with direct oral anticoagulants (DOACs) like xabans or dabigatran has been investigated in clinical trials.

Purpose of the Study:

• To evaluate the efficacy and safety of combining dual antiplatelet therapy with DOACs for secondary prevention of atherothrombotic events.
• To review clinical trial data on the net clinical benefit and bleeding risks associated with these combination therapies.

Main Methods:

• Review of 6 clinical trials investigating dual antiplatelet therapy combined with xabans or dabigatran.
• Analysis of data from the ATLAS ACS 2-TIMI 51 trial regarding rivaroxaban addition to aspirin and clopidogrel.
• Discussion of findings from a trial comparing dabigatran with warfarin, focusing on myocardial infarction incidence.

Main Results:

• Adding low-dose rivaroxaban (2 × 2.5 mg) to dual aspirin and clopidogrel therapy showed a small net clinical benefit (approx. 0.5% per year) but increased major bleeding risk.
• Dual therapy with aspirin and prasugrel or ticagrelor demonstrated clear benefits.
• A trial comparing dabigatran and warfarin noted a higher incidence of myocardial infarction in the warfarin group, though this relationship remains unresolved.

Conclusions:

• Dual antiplatelet therapy with aspirin plus prasugrel or ticagrelor is recommended for secondary prevention.
• In patients with high coronary event risk requiring anticoagulation, direct oral anticoagulants (DOACs) such as apixaban and rivaroxaban are preferred over dabigatran.
• Combination therapy of dual antiplatelet agents with low-dose rivaroxaban offers limited net clinical benefit and increases bleeding risk.