Unfractionated Heparin Protocol During Percutaneous Left Ventricular Mechanical Circulatory (Impella) Support

Aortic thrombosis with visceral malperfusion during circulatory support with a combination of Impella and extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock

Although veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used to aid myocardial recovery in patients with postcardiotomy cardiogenic shock (PCCS), it has been associated with adverse effects. The combined use of VA-ECMO and Impella (ECPELLA) for PCCS, however, has been reported to be efficacious with few reports of thromboembolic events. We present a case of aortic thrombosis with visceral malperfusion during ECPELLA management for PCCS. We performed the Bentall procedure, mitral valve repair, tricuspid annuloplasty, and coronary artery bypass graft on a 73-year-old man admitted with congestive heart failure caused by annuloaortic ectasia, along with severe aortic and mitral regurgitation. VA-ECMO and Impella were required, since the cardiopulmonary bypass weaning was difficult. Impella was removed on postoperative day 4. On postoperative days 5 and 6, laboratory data showed worsening renal dysfunction, lactate levels, and acidosis. Contrast-enhanced computed tomography showed thrombosis in the celiac and superior mesenteric arteries. Aortic thrombectomy was performed. Hyperkalemia, caused by a reperfusion injury, resulted in ventricular fibrillation. Continuous hemodiafiltration improved the hyperkalemia. However, irreversible acidosis progressed, and the VA-ECMO flow rate could not be sustained. On postoperative day 7, the patient died. Perioperative use of Impella for PCCS may be effective in improving postoperative cardiac function. When sudden organ failure is observed after surgery, it is necessary to not only keep the exacerbation of cardiogenic shock in mind, but also the possibility of thrombosis.

Management of Anticoagulation with Impella® Percutaneous Ventricular Assist Devices and Review of New Literature

Cardiogenic shock is a life-threatening condition that may occur secondary to a variety of cardiac conditions, and may require temporary support with percutaneous ventricular devices like the Impella®. Anticoagulation in patients with Impella® devices can often be complicated due to unpredictable purge flow rates, pre-existing coagulopathy, or heparin allergies. The purpose of this article is to discuss the various options for anticoagulation in the setting of Impella®. The article will also describe recent updates (2014-current) in literature surrounding anticoagulation therapy for Impella® devices. At total of 228 articles were initially obtained through the PubMed search, with inclusion of 6 articles. A total of 51 patients had data in the six studies that were included in the review. Heparin for anticoagulation in the purge solution, at two different dextrose concentrations (5% and 20%), was associated with similar therapeutic activated partial thromboplastin time rates, thrombotic and bleeding events. One case series described the use of argatroban in the purge solution for anticoagulation in two patients with suspected heparin-induced thrombocytopenia, without bleeding or thrombotic complications. Pump thrombosis was not reported in any of the six studies. Anticoagulation in the setting of mechanical circulatory support devices is a challenging aspect of critical care. Institutions should have set protocols that clearly define the options for anticoagulation. Future studies that look at longer durations of support and possible operation of the Impella® device with a heparin-free purge solution are needed.