Warfarin for stroke prevention following anterior ST-elevation myocardial infarction

Area of Science:

• Cardiology
• Neurology
• Pharmacology

Background:

• Anterior ST-elevation myocardial infarction (STEMI) survivors with reduced ejection fraction are at risk for ischemic stroke.
• The role of vitamin K antagonist (VKA) therapy in preventing stroke in this specific patient group remains unclear.
• Existing guidelines do not uniformly recommend anticoagulation for stroke prevention post-STEMI in patients with preserved or mildly reduced ejection fraction.

Purpose of the Study:

• To evaluate the efficacy of VKA therapy in preventing ischemic stroke in patients with anterior STEMI and reduced ejection fraction (≤40%).
• To assess the composite outcome of ischemic stroke, death, and clinically relevant bleeding in patients receiving VKA therapy versus those not receiving it.
• To investigate the impact of low-molecular-weight heparin bridging therapy in conjunction with VKA.

Main Methods:

• Prospective registry of anterior STEMI survivors with ejection fraction ≤40% over a 10-year period.
• Comparison of outcomes based on VKA use, including ischemic stroke, death, and bleeding.
• Secondary analysis of low-molecular-weight heparin bridging therapy effects.

Main Results:

• The primary composite outcome occurred in 24.7% of VKA users and 20.5% of non-VKA users (adjusted HR, 1.30; 95% CI, 0.71-2.31).
• Ischemic stroke rates were 2.5% in VKA patients and 0.9% in non-VKA patients (adjusted HR, 2.81; 95% CI, 0.31-25.1).
• Low-molecular-weight heparin bridging therapy was associated with increased bleeding events (adjusted HR, 2.55; 95% CI, 1.04-6.24).

Conclusions:

• Ischemic stroke was infrequent within 6 months post-anterior STEMI, regardless of VKA treatment.
• Routine anticoagulation with VKA therapy may not be beneficial for stroke prevention in this patient cohort.
• Further research is needed to define optimal antithrombotic strategies for anterior STEMI survivors with reduced ejection fraction.