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Setting New Standards with the First FDA Cleared High Sensitivity Troponin I |
| The second-generation Siemens Healthcare Diagnostics Acute Care™ troponin I (cTnI) method is the first FDA cleared high sensitivity cTnI assay with the low-end precision necessary to meet the ESC/ACC guidelines (CV <10% at the 99th percentile of normal). |
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The use of cardiac markers, specifically cardiac troponin I, has become the standard for the detection of myocardial cell damage1-3 and for risk stratification of chest pain patients.2,4 The excellent cardiac sensitivity and “nearly absolute” cardiac specificity of the second-generation cTnI assay helps detect microscopic myocardial necrosis that is associated with a high risk.1-3,5,6 |
| "The extreme sensitivity of the cardiac troponin I assay integral to this system [the Stratus® CS] was responsible for the high diagnostic accuracy (100% sensitivity; virtually 100% specificity, compared with the final assigned diagnosis).” |
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Timothy E. Caragher, et al. The Journal of Emergency Medicine. 2002.7
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As an example of the intense focus Siemens has on customer needs, we were the first manufacturer to introduce an automated cardiac troponin I (cTnI) assay. In our continued commitment to meeting clinical needs, as well as enhancing the skills of medical professionals, our second-generation Acute Care™ troponin I (cTnI) method is the first FDA cleared high sensitivity cTnI assay with the low-end precision necessary to meet the ESC/ACC recommendations (CV < 10% at the 99th percentile of normal).
“…reliable measurement of cardiac troponin concentrations is of increasing importance for diagnosis, identification of high-risk patients and guiding therapy or intervention…the Stratus® CS troponin I method is a high sensitivity troponin method in compliance with the ESC/ACC recommendations…is in harmony with the central laboratory Dimension® RxL cTnI method, and is appropriate for the sensitive cTnI measurements in acute care setting.”
Robert H. Christenson, et al. University of Maryland Medical Center Clinical Biochemistry. 2004.8
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The Need to Correlate Cardiac Marker Results
Paul O. Collinson, MD, PhD
Consultant, Chemical Pathologist
Mayday University Hospital
Croydon, England
Director, Clinical Biochemistry
Director, Preventative Cardiology Program
St. George’s University Teaching Hospital
London, England |
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Complying with the Latest Practice Guidelines
| Guidelines |
Recommendations |
Stratus® CS Acute Care™ cTnI |
NACB2
ACC/AHA9
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Assay TAT of < 30 minutes |
1 test ~ 14 minutes10
2 tests ~ 18 minutes10
3 tests ~ 22 minutes10
4 tests ~ 26 minutes10
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| NACB2 |
Plasma or anticoagulated whole blood are the specimens of choice |
Whole blood and plasma samples are accepted11 |
| ESC/ACC1 |
An increased value for troponin should be defined as a measurement exceeding the 99th percentile of a reference control group |
0.06 ng/mL (97.5% Upper
Reference Interval)11
0.07 ng/mL (99% Upper
Reference Interval)10
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ESC/ACC1
NACB2
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Acceptable precision (CV) at the 99th percentile for each assay should be defined as ≤ 10% |
4.5% @ 0.1 ng/mL12
10% @ 0.06 ng/mL10,13
20% @ 0.03 ng/mL13
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The risk assessment and diagnosis of acute coronary syndromes (ACS) is critical for reducing morbidity and mortality. Given the impressive levels of myocardial specificity and sensitivity, the Joint ESC/ACC Committee has recognized troponin as the preferred biochemical marker for myocardial damage, and redefined myocardial infarction, in part, as a rise and gradual fall of troponin levels.1
A joint committee from the ACC/AHA subsequently defined the short-term risk of death or non-fatal MI in association with a troponin level at high risk with elevated (> 0.1 mg/mL) levels, intermediate risk with slightly elevated levels (< 0.1 mg/mL) and low risk for normal levels.7
The Acute Care™ cTnI method on the Stratus® CS Acute Care™ Diagnostic System features impressive performance characteristics:*
- Meets the ESC/ACC joint committee recommendations of "< 10%" CV at the 99th percentile of a reference population for a high sensitivity assay
- Analytical sensitivity of < 0.03 ng/mL
- Risk stratification cut off of 0.1 ng/mL
Stratus® CS Acute Care™ cTnl Imprecision Study
Reproducibility 11†
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Mean
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Within-run
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Total
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Material
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ng/mL [µg/L]
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SD (%CV)
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SD (%CV)
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Human Plasma Pools
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Plasma Pool 1
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0.344
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0.009 (2.7)
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0.014 (4.0)
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Plasma Pool 2
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0.122
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0.007 (5.8)
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0.007 (5.9)
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Plasma Pool 3
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0.067
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0.005 (8.2)
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0.005 (8.2)
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Liquichek™ Cardiac Markers Control
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Level 1
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0.64
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0.03 (4.3)
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0.03 (5.1)
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Level 2
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3.29
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0.09 (2.7)
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0.12 (3.5)
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Level 3
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6.48
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0.22 (3.4)
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0.22 (3.4)
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Acute Care™ cTnI is Available in Acute Care Settings
The Stratus® CS Acute Care™ Diagnostic System provides rapid, quantitative results from whole blood in the ED.
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The Acute Care™ cTnI results on the Stratus® CS System also correlate with those on Dimension® Systems.
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Correlation11
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Comparative Method
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Slope
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Intercept
ng/mL [µg/L]
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Correlation
Coefficient
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n
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Dimension® Clinical
Chemistry System
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.93
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0.00
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0.99
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163
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Documenting the Benefits of POC Testing
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“…the substantial reductions in overall costs per patient, coinciding with risk stratification, has solidified the Stratus® CS' place as part of decentralized POC cTnI testing for patient care in our CSSU.”
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M.M. Murakami, et al. AACC Poster Presentation. 2004 14
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Recently, a study was conducted to evaluate the impact of point of care (POC) cardiac troponin I (cTnI) testing versus routine cTnI testing on patient outcomes and resource utilization in coronary care (CCU) and cardiac short stay (CSSU) units at Hennepin County Medical Center in Minneapolis, MN. A total of 545 patients with symptoms suggestive of acute coronary syndromes were enrolled in the study.14
- Routine Testing: cTnI determinations were performed on 274 patients in the central laboratory by medical technologists using the Dimension® Clinical Chemistry System
- POC Testing: cTnI determinations were performed 271 patients at the bedside by nurses using the Stratus® CS Acute Care™ Diagnostic System
Improvements from POC Testing14
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Criteria
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Routine Testing
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POC Testing
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% Improvement
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Turnaround Time
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76 minutes
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< 20 minutes
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> 300%
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Mean Length of Stay
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2.36 days
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2.19 days
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8%
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Impact on Costs per Patient Admission14
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Category
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Routine Testing Charges
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POC Testing Charges
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% Change
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Boarding
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$5,454
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$4,329
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-21%
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Pharmacy
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$1,542
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$1,112
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-28%
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Labs
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$2,076
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$1,637
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-22%
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Cardiac Procedures
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$3,159
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$2,722
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-14%
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Emergency Dept
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$730
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$748
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+2%
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Total
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$17,163
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$12,882
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-25%
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To listen to a presentation on the benefits of POC testing by Dr. Fred Apple, Click Here.
To find out how point of care testing can benefit you, click here.
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Technical Bulletins and Package Inserts for this product are available to Siemens customers who are registered users of the Siemens Corporate Internet Site. To visit the site, click here.
Stratus® CS System
Acute Care™ Cardiac troponin I
Acute Care™ Myoglobin
Acute Care™ CK-MB (mass)
Acute Care™ ßhCG
Acute Care™ D-Dimer
Acute Care™ NT-proBNP
Correlation
Connectivity
* All specific performance characteristics were run after normal recommended equipment quality control checks were performed (refer to the Stratus® CS Operator’s Guide).
† Specimens at each level were analyzed in duplicate for 20 runs. The within-run and total standard deviations were calculated by the analysis of variance method.
Liquichek™ is a trademark of Bio-Rad Laboratories ECS Division, Hercules, CA 94547
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