Impact of a modi fi ed anti-thrombotic guideline on stroke in children supported with a pediatric ventricular assist device

t matter r 2017 I 16/j.healun.2017. vidnr@stanford.ed David Rosenthal, 50 Welch Road, 7913. Fax: +650s (D.N.R. and C. BACKGROUND: Stroke is the most feared complication associated with the Berlin Heart EXCOR pediatric ventricular assist device (VAD), the most commonly used VAD in children, and affects 1 in 3 children. We sought to determine whether a modified anti-thrombotic guideline, involving more intense platelet inhibition and less reliance on platelet function testing, is associated with a lower incidence of stroke. METHODS: All children supported with the EXCOR at Stanford from 2009 to 2014 were divided into 2 cohorts based on the primary anti-thrombotic guideline used to prevent pump thrombosis: (1) the Edmonton Anti-thrombotic Guideline (EG) cohort, which included children implanted before September 2012 when dual anti-platelet therapy was used with doses titrated to Thromboelastrography/ PlateletMapping (TEG/PM); and (2) the Stanford Modified Anti-thrombotic Guideline (SG) cohort, which included children implanted on or after September 2012 when triple anti-platelet therapy was used routinely and where doses were uptitrated to high, weight-based dosing targets, with low-dose steroids administered as needed for inflammation. RESULTS: At baseline, the EG (N 1⁄4 16) and SG (N 1⁄4 11) cohorts were similar. The incidence rate of stroke in the SG cohort was 84% lower than in the EG cohort (0.8 vs 4.9 events per 1,000 days of support, p 1⁄4 0.031), and 86% lower than in the previous Investigational Device Exemption trial (p 1⁄4 0.006). The bleeding rate was also lower in the SG cohort (p 1⁄4 0.015). Target doses of aspirin, clopidogrel and dipyridamole were higher (all p o 0.003), with less dosing variability in the SG cohort than in the EG cohort. There was no difference in adenosine diphosphate inhibition by TEG/PM, but arachidonic acid inhibition was higher in the SG cohort (median 75% vs 39%, p 1⁄4 0.008). CONCLUSIONS: Stroke was significantly less common in pediatric patients supported with the Berlin Heart EXCOR VAD using a triple anti-platelet regimen uptitrated to high, weight-based dosing targets