Optimal Bridging Strategy Post-Ventricular Assist Device Implantation Remains Unclear.

Abstract

To the Editor: It was with enthusiasm that we read the article by Bates et al. describing bivalirudin utilization in a heterogeneous ventricular assist device (VAD) population.1 We were concerned, however, regarding their argument for the potential of bivalirudin as an initial bridging agent post-device implantation. No patients in their cohort received bivalirudin in this setting without being transitioned from either warfarin or heparin for either suspected or confirmed thrombosis or heparin-induced thrombocytopenia. Furthermore, the median time from VAD insertion to initiation of bivalirudin in their study was 116 days. Although we recognize the potential benefits of direct thrombin inhibitor therapy in the scenarios described within their cohort, the evidence for use of bivalirudin during the immediate postimplantation period as a bridge to oral anticoagulation is not well-elucidated. We have published the largest series to date of bivalirudin bridged patients (35) to oral anticoagulation after VAD placement.2 In our analysis, three different strategies were compared: bivalirudin, heparin, and no bridging immediately after VAD implantation. Our results suggested that bivalirudin was no different compared with heparin or no anticoagulation in terms of both thrombotic complications and bleeding events within 30 days of VAD implantation when controlling for international normalized ratio (INR) goals. In addition, the cost of heparin therapy was more than 40 times less than bivalirudin, although with the generic introduction of bivalirudin since the publication of our research, this number has certainly diminished. Overall, neither the Bates et al. data nor ours is sufficient to appropriately answer the question of which strategy is optimal to utilize post-VAD implantation.1,2 In addition, as the authors suggest, device type may also influence the benefits or weaknesses of various anticoagulant therapies. With the dramatic reduction in the rate of suspected of confirmed pump thrombosis observed in MOMENTUM-3, it is unclear if benefits observed in patients with older generation devices will translate to benefits in patients with the HeartMate 3.3 A large randomized trial, although welcome, is unlikely to be undertaken leaving a gap in the literature, which has yet to be filled for over a decade. Statements, however, on the utility of an approach without conclusive data, such as the use of bivalirudin in the post-implant period, and with some evidence showing that it has no discernable benefit should be made cautiously, if at all.