Abstract 18677: A Quantitative Analysis of Pump Parameters in the HeartWare Left Ventricular Assist Device System for the Identification and Management of Pump Thrombus
Background: The HeartWare® left ventricular assist device (HVAD) is successfully being used as a bridge-to-transplant (BTT) in end-stage heart failure patients worldwide. A unique feature of the HVAD system is the controller log file which provides a detailed report of the pump power consumption. Use of the log files may allow for early diagnosis of suspected device thrombosis, identification of patients suited for thrombolysis, and a reduced need for pump exchange. The objective of this study is to characterize patterns in the pump parameters associated with thrombus formation and successful medical treatment.
Methods: An unexpected rise in the log file power signal can be due to the presence or ingestion of a thrombus. Patients from the ADVANCE BTT and Continued Access Protocol (CAP) trial with clinical records of pump thrombus events and medical therapy treatment were assessed with several power measurement criteria. The patients’ pump power histories were also fitted with an exponential model to characterize the growth rate of the events.
Results: There were 27 recorded pump thrombus events and medical therapy was successful in resolving 13 of those incidents. Medical therapy is generally successful when the growth rate is slow and the power is within the expected range (Figure 1, top), but is unlikely to resolve the event when the pump power is excessively high with a fast growth rate (Figure 1, bottom). Additional log file data from >30 global patients with device thrombosis is being used to validate these results.
Conclusions: This novel study quantitatively characterizes the pump power histories of patients in which medical therapy treatments for device thrombus were successful and unsuccessful. These findings could lead to the development of auxiliary diagnostic tools for determining treatment options and should have direct implications for assessing the likelihood of medical management to resolve a pump thrombus event.
Author Disclosures: U.P. Jorde: Consultant/Advisory Board; Modest; Thoratec, HeartWare, Jarvik. K.D. Aaronson: Research Grant; Modest; HeartWare Contract Research managed by University of Michigan. Consultant/Advisory Board; Modest; HeartWare (without remuneration). S.S. Najjar: Consultant/Advisory Board; Modest; HeartWare and XDX. C. Hayward: Other Research Support; Modest; HeartWare. D.T. Pham: Research Grant; Modest; HeartWare (without remuneration). Consultant/Advisory Board; Modest; HeartWare and Thoratec. D. Zimpfer: Research Grant; Modest; Research and Education Grant Heartware. T. Schloeglhofer: None. D.R. Hathaway: Employment; Significant; HeartWare. M. Chow: Employment; Significant; HeartWare. M.C. Brown: Employment; Significant; HeartWare. N. Uriel: Honoraria; Modest; Thoratec, heartware.
- © 2014 by American Heart Association, Inc.