P5418Anticoagulation management of heartware left ventricular assist device thrombosis: comparison of heparin and bivalirudin
Authors: Bouzas Cruz N , Gonzalez-Fernandez O , Ferrera-Duran C , Woods A , Robinson-Smith N , Tovey S , Jungschleger J , Booth K , Shah A , Parry G , MacGowan G , Schueler S 
Published: October 2019

Abstract

Introduction and purpose
Pump thrombosis (PT) is a serious left ventricular assist device (LVAD) complication, though there are no guidelines regarding its treatment. We have adopted a strategy of intravenous anticoagulation as the initial treatment strategy in these patients.

Methods
All consecutive patients who received a HeartWare LVAD from July-2009 to January-2018 were retrospectively analyzed. Patients developing a PT were selected, and treatment, outcomes and complications were recorded.

Results
197 patients underwent HVAD, and 49 developed PT. All the patients were initially treated medically, though during the first PT 26.5% of the patients needed surgery [VAD exchange (n=6), transplant (n=6), or decommissioning (n=1)]. The overall survival at 1 year was 63.3%. Patients were treated predominantly with either intravenous heparin or bivalirudin. There were no significant differences neither in complications nor in survival between the 2 treatments (Figure 1); however, patients treated with bivalirudin during the first PT episode had less subsequent re-thrombosis episodes (18.2% vs 57.7%, p<0.05), and percentage time in therapeutic range was greater for bivalirudin compared with heparin (59.7±4.2 vs 36.3±7.1, p<0.01). Nevertheless, time to normalisation of LDH levels with bivalirudin was longer than with heparin (17.2±2.6 vs 10.2±4.5 days, p<0.01) (Table 1).
Table 1. Comparison of baseline characteristics and outcomes between Heparin and Bivalirudin Heparin (n=26) Bivalirudin (n=11) p-value Male, gender n (%) 20 (76.9) 9 (81.8) 1.00 Age when implant (years) 48±11.8 49.8±11.4 0.67 AF n (%) 9 (34.6) 6 (54.5) 0.50 Diagnosis:   Dilated cardiomyopathy n (%) 13 (50) 7 (63.6)   Ischemic heart disease n (%) 12 (46.2) 3 (27.3)   Congenital heart disease n (%) 1 (3.8) 1 (9) 0.50 Thrombolysis (+ alteplase) n (%) 19 (73.1) 4 (36.4) 0.08 Treatment duration (days) 11.5±7.2 15.3±6.5 0.15 % Time in range 36.3±7.1 59.7±4.2 0.009 Hospitalisation (days) 19.1±16.4 31.9±18.2 0.06 Complications:   Ischemic Stroke n (%) 2 (7.7) 4 (36.4) 0.09   Intracraneal bleeding n (%) 2 (7.7) 0 (0) 0.88   Gastrointestinal bleeding n (%) 1 (3.8) 0 (0) 1.00   Serious bleeding n (%) 5 (19.2) 0 (0) 0.29   Any bleeding n (%) 7 (26.9) 2 (18.2) 0.88 LDH   Baseline 271.7±79.3 221.6±41.3 0.10   Admision 727.8±448.2 517.5±171.3 0.21   Maximum 827.1±424.7 1217.6±1004 0.03   Discharge 334.9±135.9 308.6±111.8 0.70   Time to normalisation (days) 10.2±4.5 17.2±2.6 0.004 Outcomes:   Transplant (total) n (%) 7 (26.9) 2 (18.2) 0.88   VAD Exchange (total) n (%) 8 (30.8) 4 (36.4) 1.00   Mortality at 2 years n (%) 15 (57.7) 5 (45.4) 0.831 Rethrombosis:   Rethrombosis n (%) 15 (57.7) 2 (18.2) 0.03   Number of episodes of rethrombosis 0.15     +1 n=6 n=1     +2 n=4 n=1     +3 n=4 n=0     +4 n=1 n=0
Figure 1

Conclusion
VAD thrombosis is a serious life threatening complication, though an initial strategy with enhanced intravenous anticoagulation is an acceptable strategy with either intravenous heparin or bivalirudin.

Acknowledgement/Funding
N. Bouzas-Cruz would like to thank the Spanish Society of Cardiology (Sociedad Española de Cardiología), for her research grant and fellowship.