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Real-Time Analysis of the Log Files of the HeartWare Continuous-Flow Left Ventricular Assist Device for the Early Diagnosis of Pump Thrombosis: a Step Forward Toward Clinical Translation


We evaluated the real-time diagnostic capability of a new tool enhancing early diagnosis of pump thrombosis (PT) of the HeartWare left ventricular assist device via time-frequency analysis (TFA) of the log files. We analyzed 173 log files, including 24 (14%) associated with a clinical diagnosis of PT and 149 (86%) controls. The 30-day log file records were discretized into consecutive windows of a 24-h duration, which were iteratively acquired and processed via TFA. This way, we simulated longitudinal acquisition of pump parameters and provided real-time analysis of consecutive data, thus resembling the clinical scenario. Sensitivity and specificity of the tool were 79% and 84%, respectively. Sensitivity against PT events with progressive “build-up” thrombus increased up to 95%, and early signs of a forthcoming PT were identified 10±8 days prior to its clinical manifestation. This study demonstrates high reliability and the potential for effective clinical translation of this prognostic tool.

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Interagency Registry of Mechanically Assisted Circulatory Support


Lactate dehydrogenase


Left ventricular assist device


Pump thrombosis


Time-frequency analysis


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Author information




All authors contributed to the study conception and design, material preparation, data collection, and analysis. The first draft of the manuscript was written by Filippo Consolo and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Filippo Consolo.

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Ethics Approval

This study was performed in line with the principles of the Declaration of Helsinki and was approved by the institutional review board of San Raffaele Scientific Institute (June 2017). All patients provided written informed consent. No animal studies were carried out by the authors for this article.

Conflict of Interest

FC and FP are co-inventors of the algorithm used in the study that is the object of an international patent application.

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Clinical registration number:

ClinicalTrials.govIdentifier: NCT03255928

Associate Editor Navin Kumar Kapur oversaw the review of this article

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Consolo, F., Pappalardo, F. Real-Time Analysis of the Log Files of the HeartWare Continuous-Flow Left Ventricular Assist Device for the Early Diagnosis of Pump Thrombosis: a Step Forward Toward Clinical Translation. J. of Cardiovasc. Trans. Res. (2021).

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  • Left ventricular assist device
  • Pump thrombosis
  • Log files
  • Circadian rhythm
  • Time-frequency analysis