Question 1: How do you treat HIT in a patient with chronic kidney disease?

A 54-year-old male with history of hypertension, diabetes mellitus and chronic kidney disease stage 4, who recently had a right total knee replacement is diagnosed with Heparin Induced Thrombocytopenia (HIT) on post-op day 5. LMWH (Enoxaparin) is discontinued. The team considers starting the patient on argatroban although the patient has limited iv access. A hematology consult has been requested for guidance about the use of an oral anticoagulation agent. What is the ideal choice of anticoagulant?

A: HIT management is no longer limited to the use of parenteral or heparin anticoagulants such as argatroban, bivalirudin, fondaparinux, etc. Many studies have shown the efficacy of direct oral anticoagulants (DOACs) such as rivaroxaban, and apixaban.1–3 This patient should be started on apixaban in view of his chronic kidney disease for management of HIT.

Question 2: Should you stop clopidogrel pre-operatively in patients with vascular or coronary disease?

A 64-year-old male with history of COPD, peripheral vascular disease and ongoing tobacco use is noted to have a left hilar mass. He has been on clopidogrel and aspirin since he had his most recent vascular procedure which was about 3 months ago. Interventional radiology is recommending that patient stop clopidogrel for five days before proceeding with lung mass biopsy. The patient insists on having the procedure done as an inpatient. Should you hold the clopidogrel?

A: Clopidogrel detection assay can be used to ascertain whether this patient needs to wait for the recommended 5-7 days before having an invasive procedure. Evidence of absence of P2Y12 inhibition based on the laboratory results allows invasive procedures to be done earlier then recommended. The absence of this effect may be due to Clopidogrel resistance and/or non-compliance with medication regimen. P2Y12 monitoring can be potentially useful in three situations: (i) to assess risk of thrombosis or bleeding in patients treated with P2Y12 inhibitors, (ii) to guide antiplatelet therapy, and (iii) to determine the optimum timing of surgery following P2Y12 inhibitor discontinuation.4