رجل عمره ٤٥ سنة رُكب له صمام ميكانيكي تاجي قبل شهر، ويأخذ وارفارين والـINR الأخير ٣٫٠. سمع من صديقه أن هناك مميعات جديدة لا تحتاج تحاليل، ويريد التحويل لأبيكسابان. أي معلومة في التعليم صحيحة؟

A 45-year-old man had a mechanical mitral valve placed a month ago and takes warfarin; the latest INR is 3.0. A friend told him about newer anticoagulants without blood tests, and he wants to switch to apixaban. Which teaching point is correct?

1. He can switch to apixaban because it is easier and needs no blood tests
2. An INR target of 1.0–1.5 is enough to prevent valve clots
3. He needs warfarin for the first three months only, then aspirin alone
4. He needs lifelong warfarin; newer oral agents such as apixaban are not substitutes

Answer: D) He needs lifelong warfarin; newer oral agents such as apixaban are not substitutes. Mechanical valves need lifelong warfarin; direct oral anticoagulants are contraindicated because they protect less. The INR target is above normal, set by valve type and position (often 2.5–3.5 for mitral).