VITROS IMMUNODIAGNOSTIC PRODUCTS NT PRO-BNP REAGENT PACK,CALIBRATORS,RANGE VERIFIERS,680 2156,680 2157,680 2158
Device Facts
| Record ID | K060632 |
|---|---|
| Device Name | VITROS IMMUNODIAGNOSTIC PRODUCTS NT PRO-BNP REAGENT PACK,CALIBRATORS,RANGE VERIFIERS,680 2156,680 2157,680 2158 |
| Applicant | Ortho-Clinical Diagnostics, Inc. |
| Product Code | NBC · Clinical Chemistry |
| Decision Date | Jun 6, 2006 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 862.1117 |
| Device Class | Class 2 |
Intended Use
VITROS Immunodiagnostics NT-proBNP Reagent Pack: For the in vitro quantitative measurement of N-terminal pro Brain Natriuretic Peptide (NT-proBNP) in human serum and plasma (EDTA or heparin) to aid in the diagnosis of congestive heart failure and for the risk stratification of acute coronary syndrome and congestive heart failure. The test is further indicated as an aid in the assessment of increased risk of cardiovascular events and mortality in patients at risk for heart failure who have stable coronary artery disease. The test can also be used in the assessment of heart failure severity in patients diagnosed with congestive heart failure. VITROS Immunodiagnostic Products NT-proBNP Calibrator For in vitro use in the calibration of the VITROS Immunodiagnostic System for the quantitative measurement of N-terminal pro Brain Natriuretic Peptide (NT-proBNP) in human serum and plasma (EDTA or heparin). VITROS Immunodiagnostic Products NT-proBNP Range Verifiers For the in vitro use in verifying the calibration range of the VITROS Immunodiagnostic System when used for the quantitative measurement of N-terminal pro Brain Natriuretic Peptide (NT-proBNP).
Device Story
The VITROS NT-proBNP assay is an automated in vitro diagnostic test performed on the VITROS Immunodiagnostic System. It utilizes human serum or plasma (EDTA or heparin) as input. The system employs a chemiluminescence immunoassay principle using coated microwells as the solid phase separation system. The device transforms the presence of NT-proBNP into a light signal, which is measured to provide a quantitative result. The system is operated by laboratory personnel in a clinical setting. The output is provided to healthcare providers to aid in the diagnosis of congestive heart failure, risk stratification for acute coronary syndrome, and assessment of heart failure severity and cardiovascular risk. This information assists clinicians in making diagnostic and management decisions, potentially improving patient outcomes through timely identification and monitoring of heart failure.
Clinical Evidence
No clinical data provided; substantial equivalence is supported by bench testing comparing the VITROS NT-proBNP assay to the predicate device, including analytical sensitivity (<5.00 pg/mL), functional sensitivity (<10.0 pg/mL), measuring range (5.00-35,000 pg/mL), and hook effect evaluation.
Technological Characteristics
Immunometric assay; chemiluminescence detection. Reagents: streptavidin-coated wells, biotinylated sheep polyclonal anti-NT-proBNP, HRP-labeled sheep polyclonal anti-NT-proBNP. Energy source: VITROS Immunodiagnostic System. Reportable range: 5-35,000 pg/mL. No high-dose hook effect up to 500,000 pg/mL. Traceable to Roche Elecsys proBNP. Software: embedded in VITROS Immunodiagnostic System (k962919).
Indications for Use
Indicated for quantitative measurement of NT-proBNP in human serum/plasma to aid diagnosis of congestive heart failure (CHF), risk stratification of acute coronary syndrome and CHF, assessment of cardiovascular event/mortality risk in stable coronary artery disease patients, and assessment of heart failure severity in diagnosed CHF patients.
Regulatory Classification
Identification
The B-type natriuretic peptide (BNP) test system is an in vitro diagnostic device intended to measure BNP in whole blood and plasma. Measurements of BNP are used as an aid in the diagnosis of patients with congestive heart failure.
Special Controls
*Classification.* Class II (special controls). The special control is “Class II Special Control Guidance Document for B-Type Natriuretic Peptide Premarket Notifications; Final Guidance for Industry and FDA Reviewers.”
Predicate Devices
- Roche Elecsys proBNP Immunoassay (K051382)
- VITROS Immunodiagnostic Products CEA Range Verifiers (K990984)
Related Devices
- K201312 — VITROS Immunodiagnostic Products NT-proBNP II Reagent Pack · Ortho Clinical Diagnostics · Oct 4, 2021
- K051382 — ELECSYS PROBNP IMMUNOASSAY · Roche Diagnostics Corp. · Dec 5, 2005
Submission Summary (Full Text)
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE
A. 510(k) Number:
k060632
B. Purpose for Submission:
New device
C. Measurand:
N-terminal pro Brain Natriuretic Peptide (NT-proBNP)
D. Type of Test:
Quantitative
E. Applicant:
Ortho-Clinical Diagnostics, Inc.
F. Proprietary and Established Names:
VITROS Immunodiagnostic NT-proBNP Reagent Pack
VITROS Immunodiagnostic Products NT-proBNP Calibrator
VITROS Immunodiagnostic Products NT-proBNP Range Verifier
G. Regulatory Information:
| Product Code | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| NBC | Class II | 21 CFR 862.1117, B-type natriuretic peptide test system. | 75, Clinical Chemistry (CH) |
| JIT | Class II | 21 CFR 862.1150, Calibrator, Secondary | 75, Clinical Chemistry (CH) |
| JJX | Class I | 21 CFR 862.1660, Single (specified) analyte controls (assayed and unassayed) | 75, Clinical Chemistry (CH) |
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H. Intended Use:
1. Intended use(s):
VITROS Immunodiagnostic NT-proBNP Reagent Pack
For the in vitro quantitative measurement of N-terminal pro Brain Natriuretic Peptide (NT-proBNP) in human serum and plasma (EDTA or heparin) to aid in the diagnosis of congestive heart failure and for the risk stratification of acute coronary syndrome and congestive heart failure. The test is further indicated as an aid in the assessment of increased risk of cardiovascular events and mortality in patients at risk for heart failure who have stable coronary artery disease. The test can also be used in the assessment of heart failure severity in patients diagnosed with congestive heart failure.
VITROS Immunodiagnostic Products NT-proBNP Calibrator
For in vitro use in the calibration of the VITROS ImmunodiagnosticSystem for the quantitative measurement of N-terminal pro Brain Natriuretic Peptide (NT-proBNP) in human serum and plasma (EDTA or heparin).
VITROS Immunodiagnostic Products NT-proBNP Range Verifier
For the in vitro use in verifying the calibration range of the VITROS Immunodiagnostic System when used for the quantitative measurement of N-terminal pro Brain Natriuretic Peptide (NT-proBNP).
2. Indication(s) for use:
See Intended Use section above
3. Special conditions for use statement(s):
Prescription use only
4. Special instrument requirements:
The device is intended for use with the VITROS Immunodiagnostics System (k962919).
I. Device Description:
One VITROS NT-proBNP Reagent Pack contains:
- 100 coated wells (streptavidin source, bacterial; binds ≥ 3 ng biotin/well)
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- 8.2 mL conjugate reagent [HRP-sheep polyclonal anti-NT-proBNP, binds ≥ 37,000 pg NT-proBNP/mL (≥ 4,366 pmol NT-proBNP/L)] in buffer with bovine serum albumin and antimicrobial agent.
- 8.2 mL biotinylated antibody reagent [biotin-sheep polyclonal anti-NT-proBNP, binds ≥ 37,000 pg NT-proBNP/mL ≥ 4,366 pmol NT-proBNP/L)] in buffer with sheep serum, bovine serum albumin, bovine gamma globulin and antimicrobial agent.
NT-proBNP Calibrator contains 1 set of NT-proBNP Calibrators 1, 2, and 3 (2 mL, in buffer with bovine serum albumin and microbial agent).
NT-proBNP Range Verifier contains 2 sets of NT-proBNP range verifiers low and high (1 mL NT-proBNP in buffer with bovine serum albumin and antimicrobial agent).
Human source materials were tested by FDA approved methods and found to be negative /non-reactive for HCV, HIV-1/2, and HBsAg.
## J. Substantial Equivalence Information:
1. Predicate device name(s): Roche Diagnostics Elecsys proBNP Immunoassay
2. Predicate K number(s): k053182
Comparison with predicate
| Vitros NT-proBNP Reagent Pack Similarities | | |
| --- | --- | --- |
| Item | Vitros | Roche |
| Indications for Use | aid in the diagnosis of congestive heart failure and for the risk stratification of acute coronary syndrome and congestive heart failure. The test is further indicated as an aid in the assessment of increased risk of cardiovascular events and mortality in patients at risk for heart failure who have stable coronary artery disease. | aid in the diagnosis of individuals suspected of having congestive heart failure. The test is further indicated for the risk stratification of patients with acute coronary syndrome and congestive heart failure. The test may also serve as an aid in the assessment of increased risk of cardiovascular events and mortality in patients at risk for heart failure who have stable coronary artery disease. |
| Reportable Range | 5.00-35,000 pg/mL | 5.00-35,000 pg/mL |
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| Vitros NT-proBNP Reagent Pack Similarities | | |
| --- | --- | --- |
| Item | Vitros | Roche |
| Antibody | polyclonal anti-NT-proBNP (sheep) | polyclonal anti-NT-proBNP (sheep) |
| Sample Type | serum and plasma | serum and plasma |
| Expected Values | 125 pg/mL for patients younger than 75 years and 450 pg/mL for patients 75 years and older | 125 pg/mL for patients younger than 75 years and 450 pg/mL for patients 75 years and older |
| Analytical Sensitivity | less than 5 pg/mL | 5 pg/mL |
| Vitros NT-proBNP Reagent Pack Differences | | |
| --- | --- | --- |
| Item | Vitros | Roche |
| Indications for Use | The test can also be used in the assessment of heart failure severity in patients diagnosed with congestive heart failure | Does not include an indication for assessment of heart failure severity |
| Instrument | VITROS Immunodiagnostic System | Elecsys family of analyzers |
| Assay Principle | Chemiluminescence | Electrochemiluminescence |
| Hook Effect | No high dose hook up to 500,000 pg/mL | No high dose hook up to 300,000 pg/mL |
| Functional Sensitivity | less than 10 pg/mL | less than 50 pg/mL |
| VITROS NT-proBNP Calibrator Similarities | | |
| --- | --- | --- |
| Item | Vitros | Roche |
| Intended Use | used for calibrating the quantitative NT-proBNP assay | used for calibrating the quantitative NT-proBNP assay |
| VITROS Immunodiagnostic Products NT-proBNP Calibrator Differences | | |
| --- | --- | --- |
| Item | Vitros | Roche |
| Matrix | Liquid; NT-proBNP in buffer with bovine serum albumin and antimicrobial agent | Lyophilized equine serum matrix with added synthetic NT-proBNP |
| Levels | Cal 1 0 pg/mL; Cal 2 150 pg/mL; Cal 3 12,500 pg/mL | Cal 1 140 pg/mL; Cal 2 2700 pg/mL |
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| VITROS NT-proBNP Range Verifier Similarities | | |
| --- | --- | --- |
| Item | Vitros | Roche |
| Intended Use | in vitro use in verifying the calibration range of the VITROS Immunodiagnostic System | in vitro use in verifying the calibration range of the VITROS Immunodiagnostic System |
| Levels | Low and High | Low and High |
## K. Standard/Guidance Document Referenced (if applicable):
| STANDARDS |
| --- |
| Title and Reference Number |
| CLSI - Method Comparison and Bias Estimation Using Patient Samples; Approved Guideline (EP9-A 1995) |
| CLSI - Evaluation of Precision Performance of Clinical Chemistry Devices; Approved Guideline (EP5-A) |
| CLSI - Interference Testing in Clinical Chemistry; Approved Guideline (EP7-A) |
| CLSI – Evaluation of Linearity; Approved Guideline (EP6-A) |
| CLSI – Limits of Detection and Quantitation; Approved Guideline (EP17-A) |
| GUIDANCE | | | |
| --- | --- | --- | --- |
| Document Title | Office | Division | Web Page |
| Class II Special Control Guidance Document for B-Type Natriuretic Peptide Premarket Notifications; Final Guidance for Industry and FDA Reviewers | OIVD | DCTD | http://www.fda.gov/cdrh/ode/guidance/1072.html |
## L. Test Principle:
The VITROS NT-proBNP assay is performed using the VITROS Immunodiagnostic Products NT-proBNP Reagent Pack and VITROS Immunodiagnostic Products NT-proBNP Calibrators on the VITROS Immunodiagnostic System. An immunometric technique is used. NT-proBNP present in the specimen reacts simultaneously with a biotinylated antibody and a horseradish peroxidase (HRP)-labeled conjugate. The antigen-antibody complex is captured by streptavidin on the wells. Unbound materials are removed by washing. A reagent containing luminogenic substrates (a luminol derivative and peracid salt) and an electron transfer agent (a substituted acetanilide) is added to the wells. The HRP in the bound conjugate catalyzes the oxidation of the luminol derivative, producing light. The electron transfer agent increases the level and duration of the light produced. The light signals are read by the VITROS Immunodiagnostic System. The amount of HRP conjugate bound is directly proportional to the concentration of NT-proBNP present in the specimen.
## M. Performance Characteristics (if/when applicable):
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1. Analytical performance:
a. Precision/Reproducibility:
Precision was evaluated according to CLSI protocol EP5. Two replicates of each of 3 frozen control sera and 4 frozen human sample pools were assayed on 2 separate occasions per day on at least 20 different days. The experiment was performed using 3 reagent lots on three different VITROS Immunodiagnostic Systems.
| | Conventional Units = pg/mL | | | | | | | No. Observ. | No. Days |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | Mean NT-proBNP Conc. | Within-run* | | Within-calibration** | | Within-lab*** | | | |
| | | SD | CV (%) | SD | CV (%) | SD | CV (%) | | |
| System 1 | 68.4 | 0.746 | 1.1 | 3.08 | 4.6 | 3.48 | 5.0 | 84 | 28 |
| | 112 | 0.825 | 0.7 | 6.66 | 6.0 | 6.26 | 5.5 | 84 | 28 |
| | 395 | 3.97 | 1.0 | 18.0 | 4.6 | 16.8 | 4.2 | 84 | 28 |
| | 26383 | 289 | 1.1 | 533 | 2.0 | 549 | 2.1 | 84 | 28 |
| | 212 | 2.03 | 1.0 | 5.24 | 2.5 | 5.67 | 2.6 | 84 | 28 |
| | 680 | 5.17 | 0.8 | 11.4 | 1.7 | 12.3 | 1.8 | 84 | 28 |
| | 7640 | 88.0 | 1.2 | 146 | 1.9 | 157 | 2.0 | 84 | 28 |
| System 2 | 67.6 | 1.18 | 1.7 | 3.19 | 4.7 | 3.03 | 4.5 | 84 | 28 |
| | 111 | 1.27 | 1.1 | 6.20 | 5.6 | 6.31 | 5.7 | 84 | 28 |
| | 394 | 4.83 | 1.2 | 16.5 | 4.2 | 16.9 | 4.3 | 84 | 28 |
| | 26723 | 357 | 1.3 | 889 | 3.3 | 1053 | 4.0 | 84 | 28 |
| | 212 | 1.74 | 0.8 | 4.51 | 2.1 | 4.37 | 2.1 | 84 | 28 |
| | 692 | 6.74 | 1.0 | 11.7 | 1.7 | 12.6 | 1.8 | 84 | 28 |
| | 7826 | 63.2 | 0.8 | 122 | 1.6 | 155 | 2.0 | 84 | 28 |
| System 3 | 71.2 | 0.817 | 1.2 | 3.11 | 4.4 | 3.04 | 4.2 | 84 | 28 |
| | 116 | 1.01 | 0.9 | 6.90 | 6.0 | 6.06 | 5.2 | 84 | 28 |
| | 406 | 3.48 | 0.9 | 20.1 | 5.0 | 16.8 | 4.1 | 84 | 28 |
| | 27449 | 342 | 1.3 | 831 | 3.1 | 705 | 2.5 | 84 | 28 |
| | 214 | 1.54 | 0.7 | 4.98 | 2.4 | 5.78 | 2.7 | 84 | 28 |
| | 685 | 4.48 | 0.7 | 13.4 | 2.0 | 14.2 | 2.0 | 84 | 28 |
| | 7702 | 79.3 | 1.0 | 170 | 2.3 | 179 | 2.3 | 84 | 28 |
* Within-run (Repeatability): Between-duplicate precision was determined using duplicate determinations.
** Within-calibration: Total within calibration precision was determined using a single lot of reagent over a single calibration interval.
***Within-lab: Total within-lab precision was estimated using a single reagent lot calibrated weekly
b. Linearity/assay reportable range:
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The claimed measuring range of the assay is 5 – 35,000 pg/mL.
A linearity study was conducted using 10 pooled samples with values ranging from 3.97 to 30,727 pg/mL. The mean measured concentrations of pools 2 to 10, when expressed as a percentage of the calculated concentrations, gave a mean result of 99.2%, with a range of 95.1% to 105%. Analysis by linear regression also indicated that the assay is linear across the range tested (3.97 to 30,727 pg/mL) with the following regression equation: y = 0.9687x - 15.011, R = 0.9999. An additional linearity study was conducted to assess the linearity of the assay up to 35,000 pg/mL, which is the upper limit of the reportable range of the assay. In this study, the samples ranged from 2.29 to 44,653 pg/mL. The mean measured concentrations of pools 2 to 10, when expressed as a percentage of the calculated concentrations, gave a mean result of 98.3%, with a range of 97.6% to 99.7%.
To assess the potential for high dose hook effect, a series of samples having NT-proBNP concentrations ranging from 8100 to 514,667 pg/mL were assayed in the VITROS NT-proBNP assay. Singleton determinations of each sample were made with each of 3 Master Lots. No high dose hook effect was observed in the VITROS NT-proBNP assay in samples containing up to 500,000 pg/mL NT-proBNP.
c. Traceability, Stability, Expected values (controls, calibrators, or methods): Both the Calibrators and Range Verifiers are value assigned by performing multiple determinations using several VITROS Immunodiagnostic Systems. The values for the calibrators are assigned by performing multiple determination of each calibrator. The calibrators are traceable to reference calibrators, which have been value assigned to correlate with the Roche Elecsys proBNP immunoassay. VITROS Immunodiagnostic Products NT-proBNP Range Verifiers and VITROS NT-proBNP Calibrators are supplied ready for use and are stored at 2-8 °C until the expiration date. Stability studies are ongoing.
To establish the open-vial stability of the VITROS NT-proBNP Range Verifiers, the verifiers were pooled and stored in sample cups at 2-8°C and -20°C. The pooled VITROS NT-proBNP Range Verifiers were tested at the initial time point (day 0) and days 4 (interim), 7 (expiry) and 10 (post expiry) of the trial using three Master Kit Lots and three lots of VITROS NT-proBNP Range Verifiers. All data for stored 2-8°C Range Verifiers and fresh Range Verifiers, returned results within acceptance limits up to and including the day 10 time-point, therefore, supporting the storage claim of 7 days at 2-8°C.
To establish the open-vial stability of the VITROS NT-proBNP Calibrators, the calibrators were opened, pooled and stored in sample cups at 2-8°C. The pooled calibrators were tested at the initial timepoint. The calibrators stored at 2-8°C were tested at weeks 0, 4, 8 and 10. The stored calibrators were
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compared against fresh calibrators using 3 Master Lots. The data obtained demonstrates no differences between the fresh and stored calibrators. The data supports the storage of the calibrators at $2 - 8^{\circ}\mathrm{C}$ after opening for up to 8 weeks.
# d. Detection limit:
The limit of detection (LoD) for NT-proBNP is $4.29~\mathrm{pg / mL}$ , determined using methods consistent with the CLSI guideline EP17-A, with proportions of false positives $(\alpha)$ less than $1\%$ and false negatives $(\beta)$ less than $1\%$ . This determination was based on 1049 determinations, with 150 blank and 899 low-level samples. The Limit of Blank (LoB) was determined to be $1.71~\mathrm{pg / mL}$ . The limit of quantitation (LoQ) was set at $5.00~\mathrm{pg / mL}$ to ensure acceptable precision within the lower range of the assay.
Analytical Sensitivity $= < 5.00\mathrm{pg / mL}$
$\mathrm{LoB} = 1.71 \mathrm{pg/mL}$ , $\mathrm{LoD} = 4.29 \mathrm{pg/mL}$ and $\mathrm{LoQ} = 5.00 \mathrm{pg/mL}$
Functional sensitivity $= 10.0\mathrm{pg / mL}$ (The sponsor has defined function sensitivity as the concentration at which the assay achieves $20\%$ CV.)
# e. Analytical specificity:
Specificity of the VITROS NT-proBNP assay was evaluated by testing the following substances as recommended by the Clinical and Laboratory Standards Institute (CLSI) document EP7. They were found not to interfere (bias $< 10\%$ ) with the assay at a NT-proBNP concentration of approximately $125~\mathrm{pg / mL}$ .
| | 20 | 1.32 | | | 0.099 |
| --- | --- | --- | --- | --- | --- |
| Acetaminophen | mg/dL | mmol/L | Lisinopril | 4 mg/dL | mmol/L |
| | 271 | 16.6 | | | 0.198 |
| N-Acetyl-L-cysteine | mg/dL | mmol/L | Lovastatin (Mevinolin) | 8 mg/dL | mmol/L |
| | 100 | 5.55 | | 0.600 | 0.019 |
| Acetylsalicylic acid | mg/dL | mmol/L | Marcumar (Warfarin) | mg/dL | mmol/L |
| Adrenalin (Epinephrine HCl) | 0.037 | 1.68 | | | 0.084 |
| | mg/dL | μmol/L | Methyl Dopa | 2 mg/dL | mmol/L |
| Ampicillin | 100 | 2.69 | 6-alpha- | | 0.214 |
| | mg/dL | mmol/L | Methylprednisolone | 8 mg/dL | mmol/L |
| | 30 | 1.70 | | 1.5 | 0.022 |
| Ascorbic acid | mg/dL | mmol/L | Metoprolol +/- Tartrate | mg/dL | mmol/L |
| | 20 | 0.342 | | 20 | 1.17 |
| Bilirubin | mg/dL | mmol/L | Metronidazole | mg/dL | mmol/L |
| | 0.002 | 81.9 | | 2.4 | 0.099 |
| Biotin | mg/dL | nmol/L | Molsidomine | mg/dL | mmol/L |
| Bisoprolol | | 0.026 | | | 0.174 |
| Hemifumarate | 1 mg/dL | mmol/L | Nicardipine HCl | 9 mg/dL | mmol/L |
| | 15 | 0.690 | | | 0.173 |
| Captopril | mg/dL | mmol/L | Nifedipine | 6 mg/dL | mmol/L |
| | | 0.123 | | 40 | 1.30 |
| Carvedilol | 5 mg/dL | mmol/L | Phenylbutazone | mg/dL | mmol/L |
| | 250 | 5.56 | | | 0.090 |
| Cefoxitin Sodium | mg/dL | mmol/L | Pravastatin | 4 mg/dL | mmol/L |
| Cyclosporin A | 0.500 | 0.004 | Propafenone HCl | 90 | 2.38 |
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The cross-reactivity of the VITROS NT-proBNP assay was evaluated by adding the following substances to samples containing 0 and approximately $125~\mathrm{pg / mL}$ of analyte. Cross-reactivity was expressed as the mean result obtained for the cross-reactant pool divided by the cross-reactant concentration in percentage terms.
| Test Substance | Concentration Tested | | | % Cross-Reactivity |
| --- | --- | --- | --- | --- |
| ANP28 | 3.1 μg/mL | 1.01 μmol/L | | < 0.1 |
| NT-proANP 1-30 (preproANP 26-55) | 3.5 μg/mL | 0.998 μmol/L | | < 0.1 |
| NT-proANP 31-67 (preproANP 56-92) | 1.0 ng/mL | 0.258 nmol/L | | < 0.1 |
| NT-proANP 79-98 (preproANP 104-123) | 1.0 ng/mL | 0.458 nmol/L | | < 0.1 |
| BNP52 (Natrecor) | 3.5 μg/mL | 1.01 μmol/L | | < 0.1 |
| CNP22 | 2.2 μg/mL | 1.00 μmol/L | | < 0.1 |
| Adrenomedullin | 1.0 ng/mL | 0.166 nmol/L | | < 0.1 |
| Aldosterone | 0.6 ng/mL | 1.66 nmol/L | | < 0.1 |
| Angiotensin I | 0.6 ng/mL | 0.463 nmol/L | | < 0.1 |
| Angiotensin II | 0.6 ng/mL | 0.574 nmol/L | | < 0.1 |
| Angiotensin III | 1.0 ng/mL | 1.29 nmol/L | | < 0.1 |
| Endothelin | 20 pg/mL | 8.45 pmol/L | | < 0.1 |
| Urodilatin | 3.5 μg/mL | 0.998 μmol/L | | < 0.1 |
| Arg-Vasopressin | 1.0 ng/mL | 0.922 nmol/L | | < 0.1 |
| Renin | 50 ng/mL | 21.9 nmol/L | | < 0.1 |
Hemoglobin may interfere with the VITROS NT-proBNP assay. At an NT-proBNP level of $88.4~\mathrm{pg / mL}$ (10.4 pmol/L), hemoglobin at 400
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and 500 mg/dL caused a positive bias of 11.4 and 15.8 pg/mL respectively.
| Interferent | Interferent Concentration | Units = pg/mL (pmol/L) | | |
| --- | --- | --- | --- | --- |
| | | | Analyte Conc* | Bias** |
| Hemoglobin | 0.248 mmol/L | 400 mg/dL | 88.4 (10.4) | 11.4 (1.34) |
| Hemoglobin | 0.310 mmol/L | 500 mg/dL | 88.4 (10.4) | 15.8 (1.86) |
## f. Assay cut-off:
The assay cutoffs are 125 pg/mL for patients younger than 75 years and 450 pg/mL for patients 75 years and older.
## 2. Comparison studies:
### a. Method comparison with predicate device:
Accuracy was evaluated based on CLSI Protocol EP9. The plots show the results of a method comparison study using patient samples analyzed on the VITROS System with those analyzed using the Roche Elecsys proBNP assay. The relationship between the two methods was determined by Deming's regression.
n = 596
Correlation Coefficient = 0.9966
VITROS NT-proBNP = 0.9839 x Roche Elecsys proBNP + 19.7 pg/mL
Range of Samples (VITROS NT-proBNP Values) = 8.23 to 34,600 pg/mL
### b. Matrix comparison:
Individual results from three determinations of each sample type (serum, EDTA plasma, and heparin plasma) and after storage at 2-8°C and after 1, 2 and 3 freeze/thaw cycles were tabulated. The mean value for each specimen type within each storage condition was calculated from the three determinations. The overall mean, SD and CV (%) for each sample type across storage conditions were also calculated. For each condition (sample type or storage), % differences were calculated from the baseline (serum for specimen type and fresh for storage condition). The mean and range of the % differences, across all samples, for each condition were calculated. The results indicated that all sample types are suitable (< 10% mean percent difference) for use in the VITROS NT-proBNP assay and that their suitability is not
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affected by storage.
# 3. Clinical studies:
# a. Clinical Sensitivity:
The clinical sensitivity and specificity of the VITROS NT-proBNP immunoassay using decision thresholds of $125~\mathrm{pg / mL}$ for patients younger than 75 years and $450~\mathrm{pg / mL}$ for patients 75 years and older are presented below.
| Males | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Age (yrs) | < 45 | 45-64 | 55-64 | 65-74 | <75 | >75 |
| % Sensitivity | 100.0 | 70.0 | 85.2 | 95.6 | 89.4 | 86.0 |
| 95% Confidence interval | 29.2-100.0 | 34.8-93.3 | 66.3-95.8 | 84.9-99.5 | 80.8-95.0 | 73.3-94.9 |
| N (total) | 3 | 10 | 27 | 45 | 85 | 50 |
| N (above decision threshold) | 3 | 7 | 23 | 43 | 76 | 43 |
| % Specificity | 87.5 | 100.0 | 88.6 | 63.2 | 84.1 | 100.0 |
| 95% Confidence interval | 61.7-98.4 | 73.5-100.0 | 73.3-96.8 | 38.4-83.7 | 74.4-91.3 | 75.3-100.0 |
| N (total) | 16 | 12 | 35 | 19 | 82 | 13 |
| N (below decision threshold) | 14 | 12 | 31 | 12 | 69 | 13 |
| Females | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Age (yrs) | < 45 | 45-64 | 55-64 | 65-74 | <75 | >75 |
| % Sensitivity | 66.7 | 100.0 | 94.7 | 96.4 | 94.9 | 79.2 |
| 95% Confidence interval | 9.43-99.2 | 66.4-100.0 | 74.0-99.9 | 81.7-99.9 | 85.9-98.9 | 65.0-91.4 |
| N (total) | 3 | 9 | 19 | 28 | 59 | 48 |
| N (above decision threshold) | 2 | 9 | 18 | 27 | 56 | 4338 |
| % Specificity | 92.0 | 80.6 | 66.0 | 68.0 | 75.0 | 84.2 |
| 95% Confidence interval | 74.0-99.0 | 62.5-92.5 | 50.7-79.1 | 46.5-85.1 | 66.2-82.2 | 60.4-97.1 |
| N (total) | 25 | 31 | 47 | 25 | 128 | 19 |
| N (below decision threshold) | 23 | 25 | 31 | 17 | 96 | 16 |
# b. Clinical specificity:
{11}
See Clinical Sensitivity section
c. Other clinical supportive data (when a. and b. are not applicable):
Three peer reviewed literature references were provided demonstrating clinical support of the additional indications for use as an aid in the assessment of increased risk of cardiovascular events and mortality in patients at risk for heart failure who have stable coronary artery disease. All three studies measured NT-proBNP using the Elecsys proBNP Immunoassay, to which the VITROS NT-proBNP assay is traceable. The VITROS NT-proBNP assay uses the same antibody as the Roche Elecsys assay. In the VITROS NT-proBNP assay, the calibrators are traceable to reference calibrators, which have been value assigned to correlate with the Roche Elecsys proBNP immunoassay. The Elecsys and VITROS assays have the same analytical range, 5-35,000 pg/mL. The method comparison between the Elecsys and VITROS assays shows that the two assays compare with the following regression equation: VITROS NT-proBNP (y) = 0.9839(x) Roche Elecsys proBNP + 19.7 pg/mL. The studies are:
Schnabel R, Rupprecht HJ, Lackner KJ, Lubos E, Bickel C, et al. Analysis of N-Terminal-pro-Brain Natriuretic Peptide and C-Reactive Protein for Risk Stratification in Stable and Unstable Coronary Artery Disease: Results from the AtheroGene Study. European Heart Journal, 2005. 26(3):241-249.
Kragelund C, Groenning B, Kober L, Hildebrandt P and Steffensen R. N-Terminal Pro-B-Type Natriuretic Peptide and Long-Term Mortality in Stable Coronary Heart Disease. The New England Journal of Medicine, 2005. 352(7):666-675.
Ndrepepa G, Braun S, Niemoller K, Mehilli J, von Beckerath N, et al. Prognostic Value of N-Terminal Pro-Brain Natriuretic Peptide in Patients with Chronic Stable Angina. Circulation, 2005. 112:2102-2107.
Three literature references were provided which provide support for the claim for the use of the VITROS NT-proBNP assay for the risk stratification of acute coronary syndrome and CHF:
James SK, et al. NT-proBNP and Other Risk Markers for the Separate Prediction of Mortality and Subsequent Myocardial Infarction in Patients with Unstable Coronary Artery Disease. (GUSTO)-IV Substudy. Circulation 2003; 108: 275-281.
Jernberg T, Stridsberg M, Venge P, Lindahl B. N-terminal Pro-Brain Natriuretic Peptide on Admission for Early Risk Stratification of Patients with Chest Pain and No ST-Segment Elevation. J Am Coll Cardiol 2002; 40:437-
{12}
445.
Fisher C, et al. NT-proBNP Predicts Prognosis in Patients with Chronic Heart Failure. Heart 2003; 89: 879-881.
# 4. Clinical cut-off:
Recommended clinical thresholds are $125\mathrm{pg / mL}$ for patients younger than 75 years and $450~\mathrm{pg / mL}$ for patients 75 years and older. The Receiver Operator Curve (ROC) compares clinical sensitivity and specificity at various decision thresholds. The optimum decision threshold maximizes the area under the curve (AUC) and represents the highest sensitivity and specificity for the assay. The ROC analysis for the VITROS NT-proBNP assay is presented below. The AUC for the VITROS NT-proBNP assay is 0.950 with a $95\%$ Confidence Interval of 0.931 to 0.968.
Reference Cohort $N = 242$
Disease Cohort $N = 242$
Area Under Curve $= 0.950$
A box and whisker plot for the clinical study population is presented below. Recommended clinical thresholds are $125\mathrm{pg / mL}$ (14.8 pmol/L) for patients younger than 75 years and $450~\mathrm{pg / mL}$ (53.1 pmol/L) for patients 75 years and older.
# 5. Expected values/Reference range:
{13}
The circulating NT-proBNP concentration was determined from 242 individuals without CHF (95 men and 147 women). This population included apparently healthy individuals and individuals with diabetes, hypertension, pulmonary disease, and mild renal insufficiency. The descriptive statistics for NT-proBNP concentrations in the reference cohort are shown in the following tables.
| All | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Age (yrs) | <45 | 45-54 | 55-64 | 65-74 | <75 | >=75 |
| Mean (pg/mL) | 64.0 | 61.5 | 102 | 120 | 90.2 | 249 |
| SD | 74.4 | 53.1 | 132 | 95.0 | 104 | 170 |
| Median (pg/mL) | 43.8 | 40.2 | 63.6 | 98.3 | 60.6 | 206 |
| 95th Percentile | 251 | 158 | 288 | 288 | 271 | 598 |
| % <125 pg/mL | 90.2 | 86.0 | 75.6 | 65.9 | 78.6 | - |
| % <450 pg/mL | - | - | - | - | - | 90.6 |
| N | 41 | 43 | 82 | 44 | 210 | 32 |
| Males | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Age (yrs) | <45 | 45-54 | 55-64 | 65-74 | <75 | >=75 |
| Mean (pg/mL) | 61.4 | 36.5 | 96.3 | 146 | 92.3 | 187 |
| SD | 89.0 | 34.0 | 173 | 127 | 138 | 128 |
| Median (pg/mL) | 32.6 | 22.4 | 48.0 | 107 | 52.2 | 145 |
| 95th Percentile | 266 | 87.7 | 351 | 346 | 310 | 391 |
| % <125 pg/mL | 87.5 | 100.0 | 88.6 | 63.2 | 84.1 | - |
| % <450 pg/mL | - | - | - | - | - | 100.0 |
| N | 16 | 12 | 35 | 19 | 82 | 13 |
| Females | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Age (yrs) | <45 | 45-54 | 55-64 | 65-74 | <75 | >=75 |
| Mean (pg/mL) | 65.6 | 71.2 | 106 | 101 | 88.9 | 292 |
| SD | 65.3 | 56.4 | 91.6 | 55.5 | 74.2 | 185 |
| Median (pg/mL) | 55.7 | 47.0 | 73.4 | 87.3 | 66.7 | 254 |
| 95th Percentile | 168 | 162 | 288 | 213 | 228 | 615 |
| % <125 pg/mL | 92.0 | 80.6 | 66.0 | 68.0 | 75.0 | - |
| % <450 pg/mL | - | - | - | - | - | 84.2 |
| N | 25 | 31 | 47 | 25 | 128 | 19 |
Blood samples were obtained from 242 patients diagnosed with CHF (135 men and 107 women). The descriptive statistics for NT-proBNP concentrations in patients with CHF and NYHA Classifications I – IV are presented in the tables below.
{14}
| CHF Population - All | | | | | |
| --- | --- | --- | --- | --- | --- |
| NYHA Functional Class | | | | | |
| | ALL | NYHA I | NYHA II | NYHA III | NYHA IV |
| Mean (pg/mL) | 2124 | 1299 | 1467 | 3390 | 2956 |
| SD | 4165 | 1730 | 1638 | 7089 | 3179 |
| Median (pg/mL) | 1210 | 741 | 917 | 1870 | 1665 |
| 5th Percentile | 109 | 137 | 86.3 | 191 | 260 |
| 95th Percentile | 7193 | 2923 | 4514 | 10584 | 8993 |
| % > cutoff | 88.0 | 86.0 | 83.8 | 91.0 | 100.0 |
| N | 242 | 50 | 99 | 67 | 26 |
| Minimum | 15.3 | 78.1 | 15.3 | 48.0 | 139 |
| Maximum | 55600 | 9220 | 7900 | 55600 | 10800 |
| CHF Population- Males | | | | | |
| --- | --- | --- | --- | --- | --- |
| NYHA Functional Class | | | | | |
| | ALL | NYHA I | NYHA II | NYHA III | NYHA IV |
| Mean (pg/mL) | 2124 | 1338 | 1674 | 2905 | 3598 |
| SD | 2471 | 1761 | 1791 | 3232 | 3066 |
| Median (pg/mL) | 1490 | 802 | 960 | 2305 | 2115 |
| 5th Percentile | 98.0 | 125 | 83.1 | 385 | 318 |
| 95th Percentile | 7305 | 2941 | 5664 | 8044 | 8758 |
| % > cutoff | 88.1 | 85.7 | 83.1 | 93.8 | 100.0 |
| N | 135 | 28 | 59 | 32 | 16 |
| Minimum | 48.0 | 78.1 | 50.6 | 48.0 | 253 |
| Maximum | 16000 | 9220 | 7900 | 16000 | 9110 |
| CHF Population - Females | | | | | |
| --- | --- | --- | --- | --- | --- |
| NYHA Functional Class | | | | | |
| | ALL | NYHA I | NYHA II | NYHA III | NYHA IV |
| Mean (pg/mL) | 2125 | 1249 | 1161 | 3832 | 1929 |
| SD | 5632 | 1730 | 1344 | 9360 | 3241 |
| Median (pg/mL) | 862 | 658 | 735 | 1550 | 701 |
| 5th Percentile | 138 | 301 | 103 | 259 | 202 |
| 95th Percentile | 6957 | 2397 | 3100 | 9896 | 7348 |
| % > cutoff | 87.9 | 86.4 | 85.0 | 88.6 | 100.0 |
| N | 107 | 22 | 40 | 35 | 10 |
| Minimum | 15.3 | 133 | 15.3 | 56.3 | 139 |
| Maximum | 55600 | 8380 | 7200 | 55600 | 10800 |
# N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.
# O. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
