Thrombin inhibitors(Virginia Commonwealth University)

Platelet derived prothrombotic microparticles (MP) have been associated with hemocompatibility related adverse events in patients with continuous flow left ventricular assist devices; little is known with the contemporary Impella platform micro-axial flow pumps. Indeed, the extended duration of support provided by the Impella 5.5 calls for a specific evaluation. We report for the first time two patients in whom MP have been assessed during Impella 5.5 and concomitant dual antiplatelet and direct thrombin inhibitor therapy. Interestingly, the patients showed significantly different profile in overall MP release (peak: 78.1% vs 2.7%), which was not correlated to lactate dehydrogenase nor platelet count. The patient with the higher values suffered from minor stroke 4 days after pump removal, when systemic anticoagulation with Bivalirudin had been stopped. These preliminary data might envision a new predictor of hemocompatibility related adverse events in patients with Impella, and a rethinking on the post support antithrombotic strategy.

Type II heparin-induced thrombocytopenia and thrombosis (type II HITT) is a rare but serious complication in patients receiving heparin for anticoagulation. In type II HITT, an immune-mediated reaction against platelet factor four-heparin complexes results in thrombocytopenia and an elevated risk of thrombosis. This poses significant challenges for patients with advanced heart failure requiring urgent left-ventricular assist device (LVAD) implantation. The use of direct thrombin inhibitors, the typical alternative to heparin, is associated with increased bleeding risk and lacks a reversal agent, limiting their use in cardiac surgery. We present two cases of intraoperative epoprostenol to facilitate implantation of a durable LVAD in type II HITT, of which one case underwent preoperative plasmapheresis and intravenous immunoglobulin (IVIG) therapy. Epoprostenol, a prostacyclin analog, was used intraoperatively during LVAD implantation to inhibit platelet activation and allowed for the safe administration of heparin during cardiopulmonary bypass. Both patients underwent successful LVAD implantation without thrombotic or major bleeding complications. These cases highlight the potential of using intraoperative epoprostenol in conjunction with preoperative plasma exchange (PLEX) and IVIG to mitigate the risks associated with heparin use in patients with type II HITT, offering an alternative approach for this high-risk group requiring urgent cardiac surgery.