Role of thromboelastography in predicting and defining pump thrombosis in left ventricular assist device patients

Optimal anticoagulation for left ventricular assist device recipients aims to balance thrombosis and bleeding complications. Routine plasma-based coagulation tests may not accurately reflect overall hemostasis, and surrogate markers are used to help guide clinicians in the diagnosis of pump thrombosis. Thromboelastography derived coagulation index (CI) has been shown to be a parameter that can reflect "normocoagulability" in mechanical circulatory support device patients, but there is minimal data with regard to outcomes available. Our aim was to determine the role of CI in predicting and defining suspected pump thrombosis in HeartMate II™ recipients.

We performed a single center, retrospective longitudinal cohort study with a nested case-control analysis to compare serial CI values over time in adult HeartMate II™ recipients who had confirmed or suspected pump thrombosis to those who did not.

A multivariate linear mixed model analysis of the suspected pump thrombosis versus no pump thrombosis groups found a significantly lower mean change in CI over time when recipients were followed for 24 months post-implant [0.71 (95% CI 0.1-1.32, p = .02)]; CI was first significant at six months. Within each arm, CI significantly decreased in the no pump thrombosis group, but did not significantly differ within the suspected pump thrombosis group. No significant differences were found between the two groups regarding the outcomes of death, transplant, or neurological events.