1. Atrial Fibrilation
2. Vascular graft
3. VTE > 3 months ago
4. Biological heart valve
1. Arterial embolism of cardiac origin < 1 month (Delay surgery by 1 month).
2. VTE of < 3 months (delay surgery by 3 months).
3. Recurrent VTE.
4. Mechanical heart valve.
5. Thrombophilias (discuss with haematologist).
Stop warfarin 5 days before surgery.
check INR 1 day before or on the day of surgery. Give prophylactic LMWH (if required against VTE). Start usual dose of warfarin on post op day 1.
Stop warfarin 5 days before surgery.
Give 200u/kg (18,000U max) of Dalteparin 2 days before surgery. Give prophylactic dose of Dalteparin on eveining before surgery. Check INR 1 day before or on the day of surgery. Give prophylactic Dalteparin on postop day zero (in evening if no risk of bleeding). Start usual dose of warfarin on post op day 1. Give 200u/kg (18,000U max) of Dalteparin on post op day 1. Check INR on day 3 and 5 after starting warfarin. Stop Dalteparin once INR is in therapeutic range.