Risk Factors for Thromboembolic Events in Pediatric Patients with Ventricular Assist Devices

Objective Pediatric patients on ventricular assist devices (VAD) are at-risk of thromboembolic (TE) complications. Our objective was to identify factors associated with TE events initial anticoagulation strategy and device type in the pediatric population. Methods This was a retrospective single center review (2005–2022) of children implanted with Paracorporeal Pulsatile (PP), Paracorporeal Continuous (PC) or a combination of devices. Patient and device-related factors were collected. Kaplan Meier (KM) survival analysis was performed to determine freedom from TE. Cox proportional hazard analysis was conducted to look for factors associated with TE events. Results Ninety-five patients included with a median age of 0.9 years (IQR 0.3, 5.4); median weight of 8.4 kg (IQR 4.5, 17.8) and 63.2% with non-congenital heart disease. Device breakdown included: 47.4% PC, 24.2% PP, and 23.2% combination of devices. Initial anticoagulation was either heparin (61.5%) or bivalirudin (38.5%). In KM analysis, unadjusted freedom from a TE event was significantly higher in those who received bivalirudin as their initial anticoagulation strategy (p=.02) and PP VADs (p=.02). In multivariate analysis, initial anticoagulation strategy with bivalirudin (HR 0.30, 95% CI 0.12–0.75, p=.01) was associated with a reduced hazard of TE events, while PC device strategy was found to be associated with an increased hazard (HR 2.78, 95% CI 1.12–6.88, p=.03). Conclusions This study suggests that PC device strategy and heparin as an initial anticoagulation strategy are associated with increased hazard of TE events. Further research is required to understand the interaction between device type and initial anticoagulation strategy.