[What is the current use of vitamin K antagonists in the elderly?]

Area of Science:

• Pharmacology
• Cardiology
• Geriatrics

Context:

• The advent of New Oral Anticoagulants (NOAC) challenges the established role of Vitamin K Antagonists (VKA).
• VKAs necessitate rigorous monitoring due to a narrow therapeutic index and potential for iatrogenic harm.
• Established efficacy and safety profiles of VKAs exist, particularly in elderly populations with atrial fibrillation.

Purpose:

• To redefine the future role of VKAs in light of NOAC availability.
• To compare the efficacy, safety, and monitoring requirements of VKAs and NOACs.
• To evaluate the suitability of VKAs and NOACs in specific patient subgroups, including the elderly and frail.

Summary:

• VKAs are effective for atrial fibrillation, with well-documented side effects and interactions, requiring International Normalized Ratio (INR) monitoring and having a readily available antidote.
• NOACs demonstrate comparable efficacy to VKAs with a potential reduction in side effects, notably cerebral hemorrhage, and do not require routine biological monitoring.
• Current evidence for NOACs primarily stems from phase III trials; real-world data in polypathologic and frail populations are still emerging, whereas VKAs have more extensive data in these groups.

Impact:

• A conservative approach may favor continuing VKAs in elderly patients with stable INR control.
• VKAs remain the sole anticoagulant option for patients with severe renal failure or valvular atrial fibrillation.
• Further research is ongoing to ascertain NOAC efficacy and safety in complex patient populations, informing future clinical practice guidelines.