Coagulation monitoring and management of anticoagulation during cardiac assist device support.

BACKGROUND: The incidence of clinically significant thromboembolic events due to the use of cardiac assist device systems remains high. Despite the considerable advances in cardiac assist device technology, the monitoring and management of the hypercoagulable coagulation status, resulting from foreign surfaces of the assist device system, altered rheologic conditions, and blood stasis in the recipient heart remain a challenge. Moreover septic complications and insufficient anticoagulation are responsible for thromboembolic events.

METHODS: In addition to standard coagulation analysis, functional coagulation tests were performed including the use of a thrombelastographic monitoring system (ROTEG) and a platelet function analyzer (PFA-100).

RESULTS: Severe biventricular ischemic heart failure developed in a 58-year-old man with acute myocardial infarction and he needed a biventricular assist device for a bridge to cardiac transplantation. Although the patient received acenocoumarol (Sintrom; Novartis Pharma, Vienna, Austria) and acetylsalicylic acid (Aspisol; Bayer AG, Leverkusen, Germany) as usual, ROTEG and the PFA-100 detected hypercoagulability while routine coagulation screening tests showed hypocoagulability. Moreover thrombus formation surrounding the canula of the left ventricular assist device was detected. Antithrombotic therapy with clopidogrel (Plavix) was initiated. Coagulation was closely monitored with modified thrombelastography and the PFA-100 to achieve sufficient but not overwhelming anticoagulation therapy. Three months after biventricular assist device implantation the patient underwent successful transplantation with no major blood loss.

CONCLUSIONS: Thrombelastography should be the standard form of monitoring in such patients to decrease the risk of thromboembolic events and prevent bleeding complications.