TEG 6s data

Prof. P.I. Johansson

Dept. of Clinical Immunology

Rigshospitalet

Copenhagen

Coagulation cascade

MacFarlane RG. Nature 1961.

TEG is a whole blood assay that reflect the cell based model of coagulation

• Coagulation occurs in the surface of cells resulting in the

activation of platelets and formation of the fibrin strands.

• Plasma based tests can’t represent this

TEG 5000

TEG 5000

Concentric cylinders, 360uL sample

Outer cylinder moves, motion of the inner is resisted by a spring

Clotting increases shear modulus, opposing spring force and resulting in the

well-known tracing

Amplitude increases with clot strength

Downsides are large sample volume and sensitivity to vibration

… the new device - TEG 6s

Resonance-frequency viscoelasticity measurements and disposable multi-

channel microfluidic cartridges

The same physical properties measured with a different Measurement Technique

6

Test cell 20ul

Different sample geometry

• Single cylinder (ring); no pin

• Blood held in place by surface tension

Different measurement technique

Same physical property measured (shear modulus)

TEG 6s

TEG 6s Technology Innovation

Measurement Technique

• The TEG 6s measure

the same viscoelastic

properties as the TEG

5000.

• New measurement

technique

Automatic Sample Preparation

Resonant Measurement of Viscoelastic hemostasis.

Microfluidic Cartridge

• Microfluidics cartridge

with prepackage

reagents.

• Removes user

variability, and

simplifies operation.

• Up to 4 assays in one

cartridge.

Software

TEG Manager

• Analyzers networked

and accessed

anywhere within the

hospital/institute

network allowing for

remote access to test

results and

administration of

devices.

TEG 6s data

Method Comparison: TEG 5000 vs TEG 6s

Healthy volunteers

Inclusion/Exclusion Criteria

18 years of age

no antiplatelet medication within 14 days or females on contraception

chronic health problems or recent acute illness or know coagulopathies

Equal samples with respect to age, gender, race

Establish reference ranges of values

Patients

Open heart surgery or PCI

Inclusion/Exclusion Criteria:

>18 years of age

Known coagulopathies

Measure TEG 5000 vs. TEG-6S and correlate the results

METHODS

STUDY DESIGN 3 sites

Mayo Clinic, Rochester, MN Sinai Hospital, Baltimore, MD University of Pittsburgh Medical Center, Pittsburgh, PA

Healthy

Volunteers (n=165)

Patients Undergoing Open Heart

Surgery

(n=264)

Patients Undergoing PCI

(n=36)

Pre-OP

GH (n=98) and PLM (n=99)

During Procedure/ Post Heparin

GH (n=20)

Post-Procedure

GH (n=18) and PLM (n=18)

Pre-Procedure

GH (n=19) and PLM (n=18)

Post Procedure/ 30 min Post-Protamine

GH (n=80) and PLM (n=93)

ICU

GH (n=98) and PLM (n=101)

Inter and Intra-Assay Comparison

Citrate (n=165)

PLM (n=165)

Establish Normal Ranges

~5100 tests

TEG 6s Reference Ranges

The Reference Ranges were constructed following the guidelines established in

the Clinical Laboratory and Standards Institute (CLSI) Guideline C28-A3c for

Establishing Reference Intervals in the Clinical Laboratory

Global hemostasis Platelet mapping

Assay Parameter Min – Max Number of

samples Assay Parameter Min – Max

Number of

samples

CK

R K α angle MA LY30

4.6 – 9.1 0.8 – 2.1 63 – 78 52 – 69

0.0 – 2.6

157 157 155 151 132

HKH

R K α angle MA

4.2 – 9.8 1.0 – 2.9 57 – 75 53 – 68

153 152 151 149

CKH

R K α angle MA

4.3 – 8.3 0.8 – 1.9 64 – 77 52 – 69

155 157 154 154

ActF MA 2 – 19 152

CRT

CACT K α angle MA LY30

82 – 152 0.8 – 2.7 60 – 78 52 – 70

0.0 – 2.2

157 156 154 152 131

ADP MA 45 – 69 145

CFF MA 15 – 32 151 AA MA 51 – 71 144

TEG 5000 versus TEG 6s – Method comparison.

Correlation between TEG 5000 vs TEG 6s

R Parameter MA Parameter

LY30

Parameter

Agreement between TEG 5000 and TEG 6s.

Number

of samples

PA

(95% CI)

PPA

(95% CI)

NPA

(95% CI)

TEG 5000

Cut-off

TEG 6s

Cut-off

ADP Aggregation 261 72 (67, 78) 66 (60, 73) 90 (82, 97) <80 <83

ADP Inhibition 261 72 (67, 78) 66 (60, 73) 90 (82, 97) ≥20

≥17

AA Aggregation 267 90 (86, 94) 91 (87, 95) 91 (87, 95) <80

<89

AA Inhibition 267 90 (86, 94) 91 (87, 95) 91 (87, 95) ≥20

≥11

CI, confidence interval; NPA, negative percentage agreement; PA, overall percentage agreement; PPA, positive

percentage agreement.

ADP/AA ROC Curve improvement with TEG 6s vs. TEG 5000 PLM

This study proves that the TEG 6s ADP and AA assays are able to

identify platelet inhibition based on the cutoff established for ADP and

AA aggregation/inhibition.

More importantly, the ROC plots validate the reference ranges study

derived cutoffs.

TEG 6s study in Copenhagen

A comparison between the TEG 6s and Multiplate

A collaboration between the Blood Bank, Depts. of Thoracic Anesthesiology & Thoracic Surgery

A non-inferiority study

150 patients undergoing CABG in CPB

Samples are obtained pre-op, arrival in the ICU and 24 h postoperatively

Intraoperative bleeding and transfusions are registered

35 patients included to date

Easier-to-use TEG6s correlates to the TEG 5000 so it can be run as a true point of care:

Less time to run - Time to prepare sample is reduced

Greater ease of use - Less skilled operator required:

• No pipetting skills necessary

• Minimal reagent mixing necessary

• Intuitive

Better point of care test

• Operator independent

• Eliminates vibration issue

Summary