Pump thrombosis (PT) is a serious adverse event in patients receiving left ventricular assist devices (LVAD). The study aims to determine whether pump parameters and clinical data may enable early detection of PT. This retrospective study included 88 patients who received an LVAD between 2012 and 2015 among which those with intra-PT were identified. In a propensity score–matched control group observation, time periods were matched with time before thrombosis. International normalized ratio (INR) time in therapeutic range (TTR) and lactate dehydrogenase (LDH) were analyzed for 60 days preceding PT. Furthermore, pump data (power, flow, and speed) in HeartWare ventricular assist devices (HVAD) patients were analyzed 7 days before PT using a mixed-design analysis of variance to investigate temporal changes in pump data. Pump thrombosis occurred in 15 patients (13 males, age 58 ± 10 years, 7 HeartMate II and 8 HVAD). International normalized ratio therapeutic range (2.0–3.0) and acetylsalicylic acid daily doses (100–200 mg) were similar for both groups, but patients with PT had lower TTR (36% vs. 65%; p = 0.025). No significant difference in LVAD power between groups was seen at baseline (p = 0.31), and power did not change in the control group over time (p > 0.99). Lactate dehydrogenase increased already 1 week prior PT and power from 4.4 ± 0.8 W at baseline to 4.9 ± 0.8 W (p = 0.007) 2 days before readmission and to 6.5 ± 1.8 W (p=0.015) at readmission. Pump thrombosis is associated with a lower percentage of INR TTR and elevated LDH before the event. A better monitoring of pump parameters would enable PT detection already up to 2 days in advance.
From the *Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
†Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
‡Ludwig-Boltzmann-Cluster for Cardiovascular Research, Vienna, Austria.
Submitted for consideration October 2018; accepted for publication in revised form April 2019.
Disclosure: Joanna Grabska, Christoph Gross, and Francesco Moscato received a research grant by the Austrian Science Fund (Grant: FWF-KLI 357). None of the authors has any financial relationship related to this article to disclose.
The first two authors contributed equally to this work.
Correspondence: Thomas Schlöglhofer, Department of Cardiac Surgery, Medical University of Vienna, Währinger Gürtel 18, A-1090 Vienna, Austria. E-mail: email@example.com.