Abstract
Background
Left ventricular assist devices (LVADs) improve survival in patients with end-stage heart failure. Despite technological advancements, there is still a high risk of bleeding and thromboembolic events. To minimise device clotting, anticoagulation is usually started three days after implant. Unfractionated heparin (UFH) is the standard as a bridge to coumadin, however, current guidelines lack comparative evidence and do not delineate between anticoagulation agents (such as enoxaparin).
Purpose
To evaluate the safety of post-implant anticoagulation in LVAD patients using UFH and low molecular weight heparin enoxaparin (LMWH).
Methods
From October 2007 to October 2018, 83 patients underwent LVAD implantation (Heartmate II, III or HVAD) at Banner University Medical Center-Phoenix. Retrospective analysis was performed on 68 patients who received post-implant anticoagulation with a goal INR 1.8–2.5. Patients were bridged with either UFH (n=46) or LMWH (n=22).
Results
Demographics and patient characteristics were comparable between groups. We analysed adverse events, survival, and time to adverse events. The heparin group had a nonsignificant longer event-free period after implant compared with LMWH, median 9.4 and 1.8 months, respectively (p=0.428). The LMWH group had a significantly increased proportion of adverse events across all categories (p=0.021). Bleeding was the most common event for both groups, although substantially more for those receiving LMWH. Most notably 14 heparin patients (30.4%) had no adverse events compared to zero in the LMWH group.
Types of Adverse Events Post-Implant Bleeding Hemorrhagic Stroke Ischemic Stroke Pump Thrombus None Total Bridging Agent Heparin Count 18 3 8 3 14 46 % 39.1% 6.5% 17.4% 6.5% 30.4% 100% Enoxaparin Count 14 2 4 2 0 22 % 63.6% 9.1% 18.2% 9.1% 0% 100% Total Count 32 5 12 5 14 68 % 47.1% 7.4% 17.6% 7.4% 20.6% 100% p=0.021.
Post-Implant Event-Free Survival
Conclusions
Minimising bleeding and clotting are a persistent challenge in LVAD patients. Use of LMWH was associated with significantly more adverse events compared to UFH, with bleeding constituting the majority of events. Establishing institutional protocols and standards are necessary to improve patient outcomes; therefore, larger prospective studies are needed.
COMPARISON OF BRIDGING ANTICOAGULATION AGENTS IN LEFT VENTRICULAR ASSIST DEVICES
