Portal de Periódicos da CAPES

HeartMate II Implantation in Patients With Heparin-Induced Thrombocytopenia Type II

2009; Elsevier BV; Volume: 88; Issue: 2 Linguagem: Inglês

10.1016/j.athoracsur.2008.12.090

1552-6259

Anna L. Meyer, D. Malehsa, C. Kuehn, Christoph Bara, Clemens Gras, Carsten Hafer, Axel Haverich, Martin Strüber,

Mechanical Circulatory Support Devices

Diverse anticoagulation protocols are used in patients after implantation of ventricular assist devices. No consensus exists, especially in patients with heparin-induced thrombocytopenia type II. In a patient with heparin-induced thrombocytopenia type II, we implanted a left ventricular assist device (HeartMate XVE; Thoratec, Pleasanton, CA). Thirteen months later the device had to be replaced due to mechanical failure with a HeartMate II left ventricular assist device. We report on our successful protocol of perioperative anticoagulation management using heparin and iloprost during surgery and argatroban thereafter. Diverse anticoagulation protocols are used in patients after implantation of ventricular assist devices. No consensus exists, especially in patients with heparin-induced thrombocytopenia type II. In a patient with heparin-induced thrombocytopenia type II, we implanted a left ventricular assist device (HeartMate XVE; Thoratec, Pleasanton, CA). Thirteen months later the device had to be replaced due to mechanical failure with a HeartMate II left ventricular assist device. We report on our successful protocol of perioperative anticoagulation management using heparin and iloprost during surgery and argatroban thereafter. The incidence of a heparin-induced thrombocytopenia (HIT) type II is 0.5%, but it may lead to life-threatening thromboembolic complications. There is no consensus about the proper anti-coagulative management for patients with HIT type II who have to undergo cardiac operation with extracorporeal circulation. In the following case we describe the successful implantation of a left ventricular assist device with the use of perioperative heparin in combination with iloprost (Ilomedin; Bayer Vital GmbH, Leverkusen, Germany) and postoperative administration of the thrombin inhibitor argatroban (Argatra; Mitsubishi Pharma Deutschland GmbH, Düsseldorf, Germany). A 55-year-old man in heart failure with a dilated cardiomyopathy (ejection fraction, 10%) was transferred to our hospital. Other diagnoses were adiposis (body mass index, 31), renal failure, pulmonary hypertension, paroxysmal atrial fibrillation, deep vein thrombosis, and hyperuricemia. An implantable cardioverter defibrillator (ICD) was already implanted. In addition, an HIT II syndrome with circulating antibodies against complexes of heparin and platelet factor 4 was diagnosed. Due to cardiac decompensation, a left ventricular assist device HeartMate XVE (Thoratec, Pleasanton, CA) was implanted. Initiation of cardiopulmonary bypass was preceded by the administration of 500 μ/kg heparin (with an activated clotting time > 400 seconds), 1 million units of aprotinin (Trasylol; Bayer Vital GmbH, Leverkusen, Germany), and a continuous infusion of iloprost was started (with 0.04 μg/kg/min), which was reduced (down to 0.008 μg/kg/min after 30 min) when the extracorporeal circulation was initiated. After termination of the extracorporeal circulation heparin was fully antagonized with protamin-sulfate (Protamin Valeant; Valeant Pharmaceuticals Germany GmbH, Eschborn, Germany). Platelets were monitored every day (Fig 1), and for platelet inhibition we use iloprost (0.14 ng/kg/min) 16 postoperative days in combination with acetylsalicylic acid 100 mg/day. In addition, on the second postoperative day argatroban (2 μg/kg/min) was started with an activated partial thromboplastin time of 55 seconds. The patient was extubated on postoperative day 3. Two weeks postoperatively, argatroban was changed to Coumadin (warfarin; Bristol-Myers Squibb GmbH & Co, KGaA, Munich, Germany) with an international normalized ratio between 2.5 and 3.5. After 44 days the patient was discharged in very good condition under anticoagulation therapy with acetylsalicylic acid 100 mg/day and warfarin (international normalized ratio, 2.5 to 3.5). Thirteen months later the same patient was hospitalized in our hospital due to a mechanical failure of the HeartMate XVE left ventricular assist device. This time circulating antibodies were not detected. Now the same anticoagulation management was carried out to exchange the HeartMate XVE with the HeartMate II. After termination of the extracorporeal circulation, 100% of the heparin was antagonized by protamine. No anticoagulation was given. Five hours later a re-thoracotomy was necessary due to bleeding. On the second postoperative day, argatroban (2 μg/kg/min) was started with an acid activated partial thromboplastin time from 45 to 55 seconds when blood loss of the drains was lower than 50 mL/hr. Postoperative acute renal failure developed in the patient, which required dialysis for 12 days. Sixteen days after the operation we combined argatroban with acetylsalicylic acid 100 mg three times a week. Before discharge, a new electrode of the pacemaker was implanted and argatroban was switched to warfarin. The patient was discharged on postoperative day 49 in very good condition with anticoagulation therapy, with warfarin and acetylsalicylic acid that was reduced to 100 mg on 3 days per week because of a platelets function test-100 closure time of more than 300 seconds. Several options to avoid heparin in heart surgery with extracorporeal circulation are described, such as danaparoid-sodium (Orgaran [Organon GmbH, Oberschleiβheim, Germany]) and hirudin with moderate success concerning postoperative bleeding complications [1Christiansen S. Jahn U.R. Meyer J. et al.Anticoagulative management of patients requiring left ventricular assist device implantation and suffering from heparin-induced thrombocytopenia type II.Ann Thorac Surg. 2000; 69: 774-777Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar]. Argatroban was only used postoperatively after HIT developed [1Christiansen S. Jahn U.R. Meyer J. et al.Anticoagulative management of patients requiring left ventricular assist device implantation and suffering from heparin-induced thrombocytopenia type II.Ann Thorac Surg. 2000; 69: 774-777Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar]. In 2001, Aouifi published a series of 10 patients with HIT and showed that danaparoid was often associated with excessive bleeding and greater blood transfusion [2Aouifi A. Blanc P. Piriou V. et al.Cardiac surgery with cardiopulmonary bypass in patients with type II heparin-induced thrombocytopenia.Ann Thorac Surg. 2001; 71: 678-683Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar]. During cardiopulmonary bypass, inhibition of platelet aggregation by prostacyclin (in this study epoprostenol sodium) was considered a safer anticoagulation in patients with HIT II than danaparoid-sodium. Iloprost was used safely during cardiopulmonary bypass in patients with HIT by several other authors [3Addonizio Jr, V.P. Fisher C.A. Kappa J.R. Ellison N. Prevention of heparin-induced thrombocytopenia during open heart surgery with iloprost (ZK36374).Surgery. 1987; 102: 796-807PubMed Google Scholar, 4Kappa J.R. Fisher C.A. Todd B. et al.Intraoperative management of patients with heparin-induced thrombocytopenia.Ann Thorac Surg. 1990; 49: 714-723Abstract Full Text PDF PubMed Scopus (73) Google Scholar, 5Shorten G. Comunale M.E. Johnson R.G. Management of cardiopulmonary bypass in a patient with heparin-induced thrombocytopenia using prostaglandin E1 and aspirin.J Cardiothorac Vasc Anesth. 1994; 8: 556-558Abstract Full Text PDF PubMed Scopus (22) Google Scholar]. Therefore, we used iloprost and heparin to undergo cardiopulmonary bypass in a patient with a heparin-induced thrombocytopenia with circulation antibodies for implantation of a left ventricular assist device. Intraoperatively, no thrombosis occurred. Its short elimination half-life of 45 minutes and hepatic metabolism are important aspects for use of argatroban in patients with renal failure [6Di Nisio M. Middeldorp S. Buller H.R. Direct thrombin inhibitors.N Engl J Med. 2005; 353: 1028-1040Crossref PubMed Scopus (528) Google Scholar]. In a clinical study with end-stage renal disease, argatroban 2 μg/kg/min provided safe, adequate anticoagulation to enable successful hemodialysis. The implantation of left ventricular assist device is possible in patients with heparin-induced thrombocytopenia. This case demonstrates that the application of heparin for initiation of a cardiopulmonary bypass in combination with iloprost is a safe procedure. The complete antagonism with protamine at the end of the cardiopulmonary bypass minimizes the postoperative bleeding complications.