Point-of-Care: Roadmap for Analytical Characterization and Validation of a High-Sensitivity Cardiac Troponin I Assay in Plasma and Whole Blood Matrices

Point-of-care high-sensitivity cardiac troponin in suspected acute myocardial infarction assessed at baseline and 2 h

BACKGROUND AND AIMS

Strategies to assess patients with suspected acute myocardial infarction (AMI) using a point-of-care (POC) high-sensitivity cardiac troponin I (hs-cTnI) assay may expedite emergency care. A 2-h POC hs-cTnI strategy for emergency patients with suspected AMI was derived and validated.

METHODS

In two international, multi-centre, prospective, observational studies of adult emergency patients (1486 derivation cohort and 1796 validation cohort) with suspected AMI, hs-cTnI (Siemens Atellica® VTLi) was measured at admission and 2 h later. Adjudicated final diagnoses utilized the hs-cTn assay in clinical use. A risk stratification algorithm was derived and validated. The primary diagnostic outcome was index AMI (Types 1 and 2). The primary safety outcome was 30-day major adverse cardiac events incorporating AMI and cardiac death.

RESULTS

Overall, 81 (5.5%) and 88 (4.9%) patients in the derivation and validation cohorts, respectively, had AMI. The 2-h algorithm defined 66.1% as low risk with a sensitivity of 98.8% [95% confidence interval (CI) 89.3%-99.9%] and a negative predictive value of 99.9 (95% CI 99.2%-100%) for index AMI in the derivation cohort. In the validation cohort, 53.3% were low risk with a sensitivity of 98.9% (95% CI 92.4%-99.8%) and a negative predictive value of 99.9% (95% CI 99.3%-100%) for index AMI. The high-risk metrics identified 5.4% of patients with a specificity of 98.5% (95% CI 96.6%-99.4%) and a positive predictive value of 74.5% (95% CI 62.7%-83.6%) for index AMI.

CONCLUSIONS

A 2-h algorithm using a POC hs-cTnI concentration enables safe and efficient risk assessment of patients with suspected AMI. The short turnaround time of POC testing may support significant efficiencies in the management of the large proportion of emergency patients with suspected AMI.

Diagnostic performance of a point of care high-sensitivity cardiac troponin I assay and single measurement evaluation to rule out and rule in acute coronary syndrome

OBJECTIVES

About 10 million individuals in USA presented annually in the emergency department (ED) with chest pain or with signs and symptoms of acute coronary syndrome (ACS). The advent of point of care (POC) devices, able to measure high sensitivity troponin, are a very interesting tool in the ED setting for its rapid turnaround time (<10 min).

METHODS

The present study evaluates the diagnostic performance of the Atellica VTLi (Siemens) in real life setting using the clinical data derived from integrated diagnoses of emergency room staff and cardiologist and in comparison with standard laboratory hs-cTnT assay (Cobas 8000, Elecsys, Roche). 966 patients admitted to the emergency department of "G. Mazzini Hospital" in Teramo, Italy, from July 27, 2022, through June 09, 2023, were enrolled.

RESULTS

The diagnostic performance of POC hs-cTnI was evaluated. An appropriate POC hs-cTnI threshold values <4 ng/L supplied a sensitivity and an NPV of 100 % (95 % CI: 99.5-100) in order to achieve rapid rule out for MI through a single measurement at patient presentation in the ED. Furthermore, a derivation POC hs-cTnI concentration >54 ng/L provided a specificity of 97.2 % (95 % CI: 95.9-98.1) and a PPV of 43.5 % (95 % CI: 40.3-46.7) for ruling in MI.

CONCLUSIONS

This platform showed comparable diagnostic performance for myocardial infarction to the central laboratory. Our data suggest the possible use of the Atellica VTLi hs-cTnI POC assay either in emergency department of urban medical centre, either in rural hospital for triage and patient management.

Optimizing the Clinical Use of High-Sensitivity Troponin Assays: A Review

Ischemic heart diseases (IHDs) remain a global health concern. Many IHD cases go undiagnosed due to challenges in the initial diagnostic process, particularly in cases of acute myocardial infarction (AMI). High-sensitivity cardiac troponin (hs-cTn) assays have revolutionized myocardial injury assessment, but variations in diagnostic cut-off values and population differences have raised challenges. This review addresses essential laboratory and clinical considerations for hs-cTn assays. Laboratory guidelines discuss the importance of establishing standardized 99th-percentile upper reference limits (URLs) considering factors such as age, sex, health status, and analytical precision. The reference population should exclude individuals with comorbidities like diabetes and renal disease, and rigorous selection is crucial. Some clinical guidelines emphasize the significance of sex-specific URL limits while others do not. They highlight the use of serial troponin assays for AMI diagnosis. In addition, timely reporting of accurate hs-cTn results is essential for effective clinical use. This review aims to provide a clearer understanding among laboratory professionals and clinicians on how to optimize the use of hs-cTn assays in clinical settings in order to ensure accurate AMI diagnosis and thus improve patient care and outcomes.

Methods of the PivotaL triAl of the Atellica VTLi point of care emergencY dePartment high sensitivity troponin evalUationS

BACKGROUND

The Atellica® VTLi point-of-care (POC) High Sensitivity Cardiac Troponin-I (hs-cTnI) assay is intended for use as an aid in the diagnosis of myocardial infarction (MI). Our primary objective is to assess its diagnostic performance in patients presenting with suspected acute coronary syndrome (ACS).

METHODS

This prospective observational study will enrol ∼1500 patients at ∼20 U.S. Emergency Departments. After informed consent, adults (>21 years of age) with suspected ACS, and no prior enrollment in this study, will provide a fingerstick and venous blood sample within 2 h of ED presentation, >2 to ≤4 h, and >4 to ≤9 h (max. blood draw = 60 mL). HEART and EDACS scores will be prospectively documented. Patients without the first blood draw may be enrolled if the second draw was obtained. Capillary and venous whole blood will undergo Atellica VTLi assay testing, with remaining venous sample processed to plasma and run. All results will be blinded to the clinical care team. Site operators will undergo a 3-day familiarization period. Quality control testing will be performed daily. At 30 ± 3 days, patient mortality status, major adverse cardiac events, and rehospitalizations will be determined. A clinical endpoint adjudication committee, blinded to hs-cTnI VTLi result, will define the final diagnosis. Sensitivity, specificity, and predictive values will describe the assay performance.

RESULTS

We expect study completion within 114 weeks of enrollment of the first patient.

CONCLUSIONS

It is anticipated that the Atellica VTLi hs-cTnI assay validation study will define a performance equivalent to lab-based hs-cTnI, with results within ∼8 min at the point of care.

Consequences of different cut-off values for high-sensitivity cardiac troponin for risk stratification of patients suspected for NSTE-ACS with a modified HEART score

Aim: This study aims to enhance prehospital risk assessment for suspected non-ST-elevation acute coronary syndrome (NSTE-ACS) patients using the HEART-score. By incorporating novel point-of-care high-sensitivity cardiac troponin devices, a modified HEART-score was developed and compared with the conventional approach. Patients & methods: Troponin points within the modified HEART-score are based on values below the limit of quantitation (LoQ), between the LoQ and 99th percentile and above the 99th percentile of the used device. A total HEART-score of three or lower is considered low-risk for major adverse cardiac events. Results & conclusion: The number of low-risk patients decreased based on the modified HEART-score. The sensitivity and negative predictive value increased which suggests increasing safety in ruling out patients with suspected NSTE-ACS.

Ruling out acute coronary syndrome in primary care with a clinical decision rule and a capillary, high-sensitive troponin I point of care test: study protocol of a diagnostic RCT in the Netherlands (POB HELP)

INTRODUCTION

Chest pain is a common reason for consultation in primary care. To rule out acute coronary syndrome (ACS), general practitioners (GP) refer 40%-70% of patients with chest pain to the emergency department (ED). Only 10%-20% of those referred, are diagnosed with ACS. A clinical decision rule, including a high-sensitive cardiac troponin-I point-of-care test (hs-cTnI-POCT), may safely rule out ACS in primary care. Being able to safely rule out ACS at the GP level reduces referrals and thereby alleviates the burden on the ED. Moreover, prompt feedback to the patients may reduce anxiety and stress.

METHODS AND ANALYSIS

The POB HELP study is a clustered randomised controlled diagnostic trial investigating the (cost-)effectiveness and diagnostic accuracy of a primary care decision rule for acute chest pain, consisting of the Marburg Heart Score combined with a hs-cTnI-POCT (limit of detection 1.6 ng/L, 99th percentile 23 ng/L, cut-off value between negative and positive used in this study 3.8 ng/L). General practices are 2:1 randomised to the intervention group (clinical decision rule) or control group (regular care). In total 1500 patients with acute chest pain are planned to be included by GPs in three regions in The Netherlands. Primary endpoints are the number of hospital referrals and the diagnostic accuracy of the decision rule 24 hours, 6 weeks and 6 months after inclusion.

ETHICS AND DISSEMINATION

The medical ethics committee Leiden-Den Haag-Delft (the Netherlands) has approved this trial. Written informed consent will be obtained from all participating patients. The results of this trial will be disseminated in one main paper and additional papers on secondary endpoints and subgroup analyses.

TRIAL REGISTRATION NUMBERS

NL9525 and NCT05827237.

Cardiac troponin measurement at the point of care: educational recommendations on analytical and clinical aspects by the IFCC Committee on Clinical Applications of Cardiac Bio-Markers (IFCC C-CB)

The International Federation of Clinical Chemistry and Laboarator Medicine (IFCC) Committee on Clinical Applications of Cardiac Bio-Markers (C-CB) has provided evidence-based educational resources to aid and improve the understanding of important analytical and clinical aspects of cardiac biomarkers. The present IFCC C-CB educational report focuses on recommendations for appropriate use, analytical performance, and gaps in clinical studies related to the use of cardiac troponin (cTn) by point of care (POC) measurement, often referred to as a point of care testing (POCT). The use of high-sensitivity (hs)-cTn POC devices in accelerated diagnostic protocols used in emergency departments or outpatient clinics investigating acute coronary syndrome has the potential for improved efficacy, reduction of length of stay and reduced costs in the health care system. POCT workflow integration includes location of the instrument, assignment of collection and testing responsibility to (non-lab) staff, instrument maintenance, in-service and recurrent training, quality control, proficiency assessments, discrepant result trapping, and troubleshooting and inventory management.

Single High-Sensitivity Point-of-Care Whole-Blood Cardiac Troponin I Measurement to Rule Out Acute Myocardial Infarction at Low Risk

BACKGROUND

High-sensitivity cardiac troponin (hs-cTn) laboratory assays are used to rule out myocardial infarction (MI) on presentation, but prolonged result turnaround times can delay patient management. Our primary aim was to identify patients at low risk of index MI using a rapid point-of-care (POC) whole-blood hs-cTnI assay at presentation with potential early patient discharge.

METHODS

Consecutive patients presenting to the emergency department from 2 prospective observational studies with suspected acute coronary syndrome were enrolled. A POC hs-cTnI assay (Atellica VTLi) threshold using whole blood at presentation, which resulted in a negative predictive value of ≥99.5% and sensitivity of >99% for index MI, was derived (SEIGE [Safe Emergency Department Discharge Rate]) and validated with plasma (SAMIE [Suspected Acute Myocardial Infarction in Emergency]). Event adjudications were established with hs-cTnI assay results from routine clinical care. The primary outcome was MI at 30 days.

RESULTS

A total of 1086 patients (8.1% with MI) were enrolled in a US derivation cohort (SEIGE) and 1486 (5.5% MI) in an Australian validation cohort (SAMIE). A derivation whole-blood POC hs-cTnI concentration of <4 ng/L provided a sensitivity of 98.9% (95% CI, 93.8%-100%) and negative predictive value of 99.5% (95% CI, 97.2%-100%) for ruling out MI. In the validation cohort, the sensitivity was 98.8% (95% CI, 93.3%-100%), and negative predictive value was 99.8% (95% CI, 99.1%-100%); 17.8% and 41.8%, respectively, were defined as low risk for discharge. The 30-day adverse cardiac events were 0.1% (n=1) for SEIGE and 0.8% (n=5) for SAMIE.

CONCLUSIONS

A POC whole-blood hs-cTnI assay permits accessible, rapid, and safe exclusion of MI and may expedite discharge from the emergency department.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04772157. URL: https://www.australianclinicaltrials.gov.au/anzctr_feed/form; Unique identifier: 12621000053820.

Point-of-care high-sensitivity troponin-I analysis in capillary blood for acute coronary syndrome diagnostics point-of-care troponin-I for ACS diagnostics

OBJECTIVES

Patients with acute coronary syndrome (ACS) should be referred promptly to the hospital to reduce mortality and morbidity. Differentiating between low-risk and high-risk patients remains a diagnostic challenge. Point-of-care testing can contribute to earlier disposition decisions for patients excluded from ACS. This study describes the validation of the Atellica^® VTLi. Patient-side Immunoassay Analyzer for high-sensitivity troponin point-of-care (POC) analysis. (The Atellica VTLi is not available for sale in the USA. The products/features (mentioned herein) are not commercially available in all countries. Their future availability cannot be guaranteed).

METHODS

A total of 152 patients with acute chest pain admitted at the cardiac emergency department (ED) were included in the study. Capillary blood was compared with a whole blood and plasma sample obtained by venipuncture. All samples were analyzed using the Atellica VTLi Patient-side Immunoassay Analyzer; in addition, plasma was analyzed by a central lab immunoassay analyzer.

RESULTS

No significant difference was observed between venous whole blood vs. plasma analyzed by the Atellica VTLi Patient-side Immunoassay Analyzer. The difference between capillary blood and venous blood showed a constant bias of 7.1%, for which a correction factor has been implemented. No clinically relevant differences were observed for the capillary POC results compared to plasma analyzed with a standard immunoassay analyzer.

CONCLUSIONS

The Atellica VTLi Patient-side Immunoassay Analyzer for high-sensitivity troponin analysis shows equivalent results for all sample types, including capillary blood. No clinically relevant discordances were observed between capillary POC and central laboratory results. With additional studies, this could pave the way towards rapid testing of high-sensitivity troponin in the ambulance or the general practitioner's office without the need for hospitalization of patients with acute chest pain.