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October 16, 2018
10/16/2018 3:15:00 PM - 10/16/2018 4:45:00 PM
Room North, Room 22
Comparison of the QuantraTmSystem to a Series OFLAB-based Clinical Composite Indexes: A Multi-center Investigation
Danja Groves, M.D.,Ph.D., Bhiken I. Naik, M.D., Ian J. Welsby, M.B.,B.S., Kenichi Tanaka, M.D., Jennifer Hauck, M.D., Charles Greenberg, M.D., Alan Finley, M.D., Deborah Winegar, Ph.D., Francesco Viola, Ph.D.
University of Virginia, Charlottesville, Virginia, United States
Disclosures: D. Groves: Funded Research; Self; HemoSonics LLC. B.I. Naik: Funded Research; Self; Merck, HemoSonics LLC. I.J. Welsby: Funded Research; Self; Investigator Initiated Trial Sponsored by CSL Behring. K. Tanaka: None. J. Hauck: None. C. Greenberg: Funded Research; Self; HemoSonics LLC. A. Finley: Funded Research; Self; HemoSonics LLC. D. Winegar: Salary; Self; HemoSonics LLC. F. Viola: Salary; Self; HemoSonics LLC.
Background: The management of perioperative bleeding and the optimization of the available therapies are subjects of significant clinical interest. Although viscoelastic testing devices have been shown to reduce the utilization of allogeneic blood products while reducing morbidity and mortality, these systems are not yet in widespread clinical use. Standardized routine coagulation tests (RCTs) are well known and often utilized in the perioperative setting to monitor coagulation function and guide transfusion therapies. Aim: To demonstrate concordance between the Quantra parameters and a series of indexes based on laboratory-based RCTs. Study Design: The Quantra Hemostasis Analyzer is a novel cartridge-based viscoelastic analyzer that measures changes in clot stiffness during coagulation using ultrasound detection of resonance. After IRB approval, three hundred and two (302) adult subjects were enrolled in a multi-site clinical study, consisting primarily of patients undergoing cardiac surgery with cardiopulmonary bypass or major spine surgery. For each enrolled patient, citrated whole blood samples were obtained at multiple time points before, during, and after surgery. Measurements were performed on an investigational use only version of the Quantra and included Clot Time (CT), Heparinase Clot Time (CTH), Clot Stiffness (CS), Fibrinogen Contribution (FCS) and Platelet Contribution (PCS) to clot stiffness. CTR and PCS are unique to Quantra and not clinically available in other viscoelastic devices. In addition, samples were also tested in a standard coagulation panel including PT/INR, aPTT, fibrinogen level, and platelet count. Methods: A series of clinical composite indexes (CCIs) were developed with support from the clinical literature and clinical guidelines. The CCI definitions are based primarily on the results of conventional RCTs. For each CCI, specific thresholds were established to allow the classification of a sample into three possible categories: (1) High - representative of increased coagulation function (hypercoagulable state), (2) Low - decrease in coagulation function (hypocoagulable state), or (3) Not Low and Not High - coagulation function within normal and subclinical ranges. The Quantra parameters were similarly classified in these three categories based on the respective reference range intervals. A concordance analysis was then performed to assess the agreement between the Quantra parameters and the CCIs in each of these three categories. Results: The results from the concordance analysis are summarized in the table below. Point estimates of the agreements in each category are presented along with their 95% confidence intervals.

Conclusions: Despite the fundamental differences between individual lab-based coagulation assays and whole blood viscoelastic testing, the data presented here demonstrated strong concordance between the Quantra and the CCIs in the clinically relevant spectrum of coagulation dysfunctions. The Quantra System provides an effective integration of the information generated from lab tests, enabling rapid and comprehensive information at the point-of-care.
Figure 1

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