Mechanical valve – warfarin — RACP Paediatrics MCQ

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HardCardiologyMechanical valve – warfarinRACP Paediatrics

A 14-year-old with a bileaflet mechanical prosthesis in the mitral position is ready for long-term outpatient antithrombotic therapy after postoperative heparin bridging. Which regimen is appropriate?

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Correct answer: D — Warfarin titrated to an INR target range of 2.5–3.5

Explanation lettering: D = shown as A · E = shown as B · A = shown as C · C = shown as D · B = shown as E

C is correct. C mechanical mitral valve requires lifelong vitamin K antagonist therapy; the cited Australian paediatric cardiac protocol uses warfarin with an INR target of 2.5–3.5 after heparin bridging. D is subtherapeutic for this high-thrombogenicity valve position. E uses a direct oral anticoagulant, which is not a substitute for warfarin in mechanical valves. A is neither therapeutic nor a suitable unmonitored lifelong strategy. B cannot prevent mechanical-valve thrombosis as monotherapy. Management also requires a specialist anticoagulation service, interaction and diet counselling, and a clear peri-procedural bridging plan.

Reference: Sydney Children’s Hospitals Network: Congenital Heart Disease—PICU peri-operative management: https://resources.schn.health.nsw.gov.au/policies/policies/pdf/2007-0051.pdf