Bivalirudin Monitoring in Pediatric Ventricular Assist Device and Extracorporeal Membrane Oxygenation: Analysis of Single-Center Retrospective Cohort Data 2018-2022
Retrospective analysis published in Pediatric Critical Care Medicine (2024)
Abstract
OBJECTIVES: The activated partial thromboplastin time (aPTT) is the most frequently used monitoring assay for bivalirudin in children and young adults on mechanical circulatory support including ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO). However, intrinsic variability of the aPTT complicates management and risks bleeding or thrombotic complications. We evaluated the utility and reliability of a bivalirudin-calibrated dilute thrombin time (Bival dTT) assay for bivalirudin monitoring in this population. DESIGN: Retrospective analysis of clinical data (including aPTT, dilute thrombin time [dTT]) and results of residual plasma samples from VAD patients were assessed in two drug-calibrated experimental assays. One assay (Bival dTT) was validated for clinical use in VAD patients, and subsequently used by clinicians in ECMO patients. Pearson correlation and simple linear regression were used to determine R2 correlation coefficients between the different laboratory parameters using Statistical Package for Social Sciences (Armonk, NY). SETTING: ICUs at Cincinnati Children's Hospital Medical Center. SUBJECTS: Children on VAD or ECMO support anticoagulated with bivalirudin. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred fifteen plasma samples from 11 VAD patients were analyzed. Both drug-calibrated experimental assays (anti-IIa and Bival dTT) showed excellent correlation with each other ( R2 = 0.94) and with the dTT ( R2 = 0.87), but poor correlation with aPTT ( R2 = 0.1). Bival dTT was selected for validation in VAD patients. Subsequently, clinically ordered results (105) from 11 ECMO patients demonstrated excellent correlation between the Bival dTT and the standard dTT ( R2 = 0.86) but very poor correlation with aPTT ( R2 = 0.004). CONCLUSIONS: APTT is unreliable and correlates poorly with bivalirudin's anticoagulant effect in ECMO and VAD patients. A drug-calibrated Bival dTT offers superior reliability and opportunity to standardize results across institutions. Additional studies are needed to determine an appropriate therapeutic range and correlation with clinical outcomes.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
In pediatric VAD patients, a bivalirudin-calibrated dilute thrombin time assay correlated well with anti-IIa activity (R² = 0.94) but poorly with aPTT (R² = 0.1); a similarly poor aPTT correlation (R² = 0.004) was found in ECMO patients, supporting Bival dTT over aPTT for monitoring.
Why This Matters for Hirudotherapy
This retrospective study evaluated laboratory monitoring of bivalirudin therapy in pediatric ventricular assist device and extracorporeal membrane oxygenation patients, comparing the standard activated partial thromboplastin time (aPTT) against a bivalirudin-calibrated dilute thrombin time (Bival dTT) assay. Across 115 plasma samples from 11 ventricular assist device patients and 105 clinical results from 11 extracorporeal membrane oxygenation patients, the Bival dTT showed excellent correlation with standard dilute thrombin time (R-squared 0.87 and 0.86) but very poor correlation with aPTT (R-squared 0.1 and 0.004). The authors conclude that aPTT is unreliable for bivalirudin monitoring and that a drug-calibrated Bival dTT offers superior reliability. Bivalirudin (formerly Hirulog) is a synthetic peptide anticoagulant designed partly on the C-terminal sequence of hirudin, the anticoagulant of the medicinal leech (Maraganore et al., 1990); this paper studies the drug, not leech therapy.
Citation
Reference (Vancouver style)
Engel ER, Perry T, Block M, Palumbo JS, Lorts A, Luchtman-Jones L. Bivalirudin Monitoring in Pediatric Ventricular Assist Device and Extracorporeal Membrane Oxygenation: Analysis of Single-Center Retrospective Cohort Data 2018-2022. Pediatr Crit Care Med. 2024;25(7):e328-e337. doi:10.1097/PCC.0000000000003527. PMID: 38713010
Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.
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