Evaluation of Thrombocytopenia in Patients Receiving Percutaneous Mechanical Circulatory Support With an Impella Device.

Evaluate the time course of thrombocytopenia in patients with Impella devices (Abiomed, Danvers, MA). DESIGN: This was a retrospective, multicenter review of electronic medical records at a large hospital system from April 2018 to August 2020. SETTING: Electronic medical records of patients at SSM Health hospitals were reviewed. PATIENTS: Patients 18-89 years old admitted to an SSM Health hospital from April 2018 to August 2020 who received greater than or equal to 24 hours of percutaneous mechanical circulatory support (pMCS) with an Impella device were included. Exclusion criteria were use of other pMCS devices, history of heparin-induced thrombocytopenia (HIT), and presence of device upon transfer from an outside hospital. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Ninety-three patients were included. The median duration of pMCS was 63.5 hours. Thrombocytopenia occurred in 86% of patients and was evident 24 hours after device placement. The platelet nadir occurred 84 hours after device placement. Platelet recovery occurred 86.5 hours after device removal. The duration of thrombocytopenia was 156 hours. Signs of hemolysis were present in 44.09% of patients, were evident 12-24 hours after device placement, and resolved after device removal. CONCLUSIONS: Thrombocytopenia occurred in the majority of patients and was evident 24 hours after device placement. The time course of thrombocytopenia mirrored that of hemolysis.

Drug Interactions Affecting Oral Anticoagulant Use.

Oral anticoagulants (OACs) are medications commonly used in patients with atrial fibrillation and other cardiovascular conditions. Both warfarin and direct oral anticoagulants are susceptible to drug-drug interactions (DDIs). DDIs are an important cause of adverse drug reactions and exact a large toll on the health care system. DDI for warfarin mainly involve moderate to strong inhibitors/inducers of cytochrome P450 (CYP) 2C9, which is responsible for the elimination of the more potent S-isomer of warfarin. However, inhibitor/inducers of CYP3A4 and CYP1A2 may also cause DDI with warfarin. Recognition of these precipitating agents along with increased frequency of monitoring when these agents are initiated or discontinued will minimize the impact of warfarin DDI. Direct oral anticoagulants are mainly affected by medications strongly affecting the permeability glycoprotein (P-gp), and to a lesser extent, strong CYP3A4 inhibitors/inducers. Dabigatran and edoxaban are affected by P-gp modulation. Strong inducers of CYP3A4 or P-gp should be avoided in all patients taking direct oral anticoagulant unless previously proven to be otherwise safe. Simultaneous strong CYP3A4 and P-gp inhibitors should be avoided in patients taking apixaban and rivaroxaban. Concomitant antiplatelet/anticoagulant use confers additive risk for bleeding, but their combination is unavoidable in many cases. Minimizing duration of concomitant anticoagulant/antiplatelet therapy as indicated by evidence-based clinical guidelines is the best way to reduce the risk of bleeding.