How would you approach warfarin management in patients with mechanical aortic valve and atrial fibrillation, if they develop chemotherapy-related severe thrombocytopenia?   

In general, anticoagulants are held once the platelet count drops to < 50K due to excessive bleeding risk. In patients at very high thrombotic risk (i.e, mechanical mitral valve, tilting disk valve), unfractionated heparin can be considered with close PTT monitoring, though most case reports stil...