Phenprocoumon in HeartWare venrticular assist device patients - a new regimen for early postoperative anticoagulation

Abstract

Objective: Implantation of a mechanical circulatory support system is one of the surgical options for end-stage heart failure. The new HeartWare ventricular assist device system (HVAD), a magnetically levitated centrifugal blood pump, shows a low complication rate. Advantages of this new system are less hemolysis, reduced neurological and thromboembolic events, simplified implantation procedure and less bleedings based on lower levels of anticoagulation compared to pulsatile assist devices. Due to these facts we evaluated a new regimen for early postoperative anticoagulation for HVAD implantation. Methods: Between 01/2010 and 07/2013 41 patients underwent HVAD implantation for left-, right-, or biventricular support. Indications were dilated cardiomyopathy in 16 (39.0%) patients, ischemic cardiomyopathy in 14 (34.1%) cases, cardiogenic shock or acute myocardial infarction in 7 (17.0%) patients, myocarditis in 3 (7.3%) patients as well as right heart failure in one (2.4%) long-term heart transplant recipient. No anticoagulation was given for the first twelve hours postoperatively. Then, oral phenprocoumon was started according to INR. Intravenous heparin bridging was performed in 6 (14.6%) patients only. The INR course was monitored from postoperative day one to five and early postoperative complications such as mortality, stroke, thrombosis and bleeding were recorded. Results: Mean patients age was 58.48 ± 12.10 years, 36 (87.8%) patients were male, five (12.1%) female. When patients were transferred to ICU, an anticoagulation profile was taken. The first INR on arrival was 1.39 ± 0.57 (1.0-3.1). Mean dosage of the first phenprocoumon administration was 6.0 ± 2.1 mg, given on postoperative day one. Mean INR level was 1.43 ± 0.77 (1.1-5.0) on postoperative days 1 and 2.18 ± 1.03 (0.9-5.0) on day 5. The average time needed to reach target INR levels of 2-3 was 3.8 ± 1.8 days. Two (4.8%) patients did not survived the early postoperative period and died of multi organ failure. No stroke, thrombosis or major bleeding complication occurred. One (2.4%) patient required re-thoracotomy for bleeding and minor gastrointestinal bleeding occurred in 1 (2.4%) patient. Conclusion: Early postoperative anticoagulation regimen without heparin bridging can be performed safely, thereby avoiding potential bleeding complications due to the additive effects of phenprocoumon and heparin. Despite lower anticoagulation levels, no stroke or thrombosis occurred in any of the patients.