Decreased patient charges following implementation of point-of-care cardiac troponin monitoring in acute coronary syndrome patients in a community hospital cardiology unit

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.

Intensity-Based Camera Setup for Refractometric and Biomolecular Sensing with a Photonic Crystal Microfluidic Chip

Label-free sensing is a promising approach for point-of-care testing devices. Among optical transducers, photonic crystal slabs (PCSs) have positioned themselves as an inexpensive yet versatile platform for label-free biosensing. A spectral resonance shift is observed upon biomolecular binding to the functionalized surface. Commonly, a PCS is read out by a spectrometer. Alternatively, the spectral shift may be translated into an intensity change by tailoring the system response. Intensity-based camera setups (IBCS) are of interest as they mitigate the need for postprocessing, enable spatial sampling, and have moderate hardware requirements. However, they exhibit modest performance compared with spectrometric approaches. Here, we show an increase of the sensitivity and limit of detection (LOD) of an IBCS by employing a sharp-edged cut-off filter to optimize the system response. We report an increase of the LOD from (7.1 ± 1.3) × 10^-4 RIU to (3.2 ± 0.7) × 10^-5 RIU. We discuss the influence of the region of interest (ROI) size on the achievable LOD. We fabricated a biochip by combining a microfluidic and a PCS and demonstrated autonomous transport. We analyzed the performance via refractive index steps and the biosensing ability via diluted glutathione S-transferase (GST) antibodies (1:250). In addition, we illustrate the speed of detection and demonstrate the advantage of the additional spatial information by detecting streptavidin (2.9 µg/mL). Finally, we present the detection of immunoglobulin G (IgG) from whole blood as a possible basis for point-of-care devices.

Label-free multiplex sensing from buffer and immunoglobulin G sensing from whole blood with photonic crystal slabs using angle-tuning of an optical interference filter

Direct detection of biomarkers from unpurified whole blood has been a challenge for label-free detection platforms, such as photonic crystal slabs (PCS). A wide range of measurement concepts for PCS exist, but exhibit technical limitations, which render them unsuitable for label-free biosensing with unfiltered whole blood. In this work, we single out the requirements for a label-free point-of-care setup based on PCS and present a wavelength selecting concept by angle tuning of an optical interference filter, which fulfills these requirements. We investigate the limit of detection (LOD) for bulk refractive index changes and obtain a value of 3.4 E-4 refractive index units (RIU). We demonstrate label-free multiplex detection for different types of immobilization entities, including aptamers, antigens, and simple proteins. For this multiplex setup we detect thrombin at a concentration of 6.3 µg/ml, antibodies of glutathione S-transferase (GST) diluted by a factor of 250, and streptavidin at a concentration of 33 µg/ml. In a first proof of principle experiment, we demonstrate the ability to detect immunoglobulins G (IgG) from unfiltered whole blood. These experiments are conducted directly in the hospital without temperature control of the photonic crystal transducer surface or the blood sample. We set the detected concentration levels into a medical frame of reference and point out possible applications.

Facilitators and barriers of the implementation of point-of-care devices for cardiometabolic diseases: a scoping review

BACKGROUND

Point-of-care testing (POCT) devices may facilitate the delivery of rapid and timely results, providing a clinically important advantage in patient management. The challenges and constraints in the implementation process, considering different levels of actors have not been much explored. This scoping review aimed to assess literature pertaining to implementation facilitators and barriers of POCT devices for the diagnosis or monitoring of cardiometabolic diseases.

METHODS

A scoping review of the literature was conducted. The inclusion criteria were studies on the inception, planning, or implementation of interventions with POCT devices for the diagnosis or monitoring of cardiometabolic diseases defined as dyslipidemia, cardiovascular diseases, type 2 diabetes, and chronic kidney disease. We searched MEDLINE, Embase, and Global Health databases using the OVID searching engine until May 2022. The Consolidated Framework of Implementation Research (CFIR) was used to classify implementation barriers and facilitators in five constructs. Also, patient, healthcare professional (HCP), and organization level was used.

RESULTS

Twenty studies met the eligibility criteria for data extraction. All studies except two were conducted in high-income countries. Some findings are: 1) Intervention: the most widely recognized facilitator was the quick turnaround time with which results are obtained. 2) Outer setting: at the organizational level, the lack of clear regulatory and accreditation mechanisms has hindered the adoption and sustainability of the use of POCT. 3) Inner setting: for HCP, performing POCT during the consultation was both a facilitator and a barrier in terms of time, personnel, and service delivery. 4) Individuals: the implementation of POCT may generate stress and discomfort in some HCP in terms of training and new responsibilities. 5) Process: for patients, it is highly appreciated that obtaining the sample was simple and more comfortable if venipuncture was not used.

CONCLUSION

This scoping review has described the facilitators and barriers of implementing a POCT device for cardiometabolic conditions using the CFIR. The information can be used to design better strategies to implement these devices and benefit more populations that have low access to cardiometabolic tests.

Point-of-care testing with high-sensitivity cardiac troponin assays: the challenges and opportunities

Methods to improve the safety, accuracy and efficiency of assessment of patients with suspected acute coronary symptoms have occupied decades of study and have supported significant changes in clinical practice. Much of the progress is reliant on results of laboratory-based high-sensitivity cardiac troponin assays that can detect low concentrations with high precision. Until recently, point-of-care (POC) platforms were unable to perform with similar analytical precision as laboratory-based assays, and recommendations for their use in accelerated assessment strategies for patients with suspected acute coronary syndrome has been limited. As POC assays can provide troponin results within 20 min, and can be used proximate to patient care, improvements in the efficiency of assessment of patients with suspected acute coronary syndrome is possible, particularly with new high-sensitivity assays.

A review of biosensor technologies for blood biomarkers toward monitoring cardiovascular diseases at the point-of-care

Cardiovascular diseases (CVDs) cause significant mortality globally. Notably, CVDs disproportionately negatively impact underserved populations, such as those that are economically disadvantaged and often located in remote regions. Devices to measure cardiac biomarkers have traditionally been focused on large instruments in a central laboratory but the development of affordable, portable devices that measure multiple cardiac biomarkers at the point-of-care (POC) are needed to improve clinical outcomes for patients, especially in underserved populations. Considering the enormity of the global CVD problem, complexity of CVDs, and the large candidate pool of biomarkers, it is of great interest to evaluate and compare biomarker performance and identify potential multiplexed panels that can be used in combination with affordable and robust biosensors at the POC toward improved patient care. This review focuses on describing the known and emerging CVD biosensing technologies for analysis of cardiac biomarkers from blood. Initially, the global burden of CVDs and the standard of care for the primary CVD categories, namely heart failure (HF) and acute coronary syndrome (ACS) including myocardial infarction (MI) are discussed. The latest United States, Canadian and European society guidelines recommended standalone, emerging, and add-on cardiac biomarkers, as well as their combinations are then described for the prognosis, diagnosis, and risk stratification of CVDs. Finally, both commercial in vitro biosensing devices and recent state-of-art techniques for detection of cardiac biomarkers are reviewed that leverage single and multiplexed panels of cardiac biomarkers with a view toward affordable, compact devices with excellent performance for POC diagnosis and monitoring.

Review of Health Economics of Point-of-Care Testing Worldwide and Its Efficacy of Implementation in the Primary Health Care Setting in Remote Australia

There are important differences concerning health outcomes between the Australian population living in rural/remote regions and the urban population. Health care provision in remote areas, particularly in regions with a low number of inhabitants, is not without challenges. Aboriginal, rural and remote communities are therefore affected, as they face various obstacles in accessing health services, owing to geographical settings, difficulties in transportation to nearby hospitals, limited or inexistent local qualified personnel. The implementation of point-of-care testing could be a plausible solution to these challenges, as various point-of-care services that have been successfully put into action worldwide indicate towards positive clinical outcomes. Point-of-care units have a real potential in reducing morbidity and mortality in all population groups. This article aims to review the published literature on point-of-care testing around the world, with a focus on health economics and the feasibility of its implementation in Australian rural and remote regions.

Implementation of point-of-care testing in a pediatric healthcare setting

Point-of-care testing (POCT) refers to testing performed outside the clinical laboratory near the patient or at the site of patient care. This could be in critical care settings like the intensive care unit (ICU) and emergency department (ED) or primary care settings like physician offices where testing is performed by nonlaboratory personnel. POCT circumvents several steps in central laboratory testing including specimen transportation and processing resulting in faster turnaround times. Provider access to rapid test results at the site of patient care allows for prompt medical decision making which can lead to improved patient outcomes, operational efficiencies, patient satisfaction, and even cost savings in some cases. In addition to providing results rapidly, POCT devices have small specimen volume requirements compared to central laboratory tests making POCT particularly attractive for pediatric healthcare settings. The availability of published reports on the impact of POCT implementation in pediatric care are helpful resources when evaluating the clinical necessity of POCT prior to implementation. Even though several studies have shown advantages to implementing POCT in different pediatric settings, it is important to note that limitations exist that might limit the utilization of certain POCTs in some pediatric populations. So, it is important that these limitations and the analytical performance of a test are considered while keeping the target patient population in mind. Since POCTs are performed by non-laboratory staff who are not trained laboratory personnel, one challenge with POCT is maintaining regulatory compliance and quality assurance. It is therefore important that regulatory and quality assurance programs be put in place prior to implementing POCT in the pediatric hospital. With advances in POCT technology, most POCT devices have the capability to interface to the laboratory information system (LIS) and electronic medical record (EMR). POCT device interfacing allows for improved compliance to regulatory and quality assurance standards. Maintaining a cost efficient POCT program is becoming increasingly important as hospitals and healthcare systems are undergoing consolidation and harmonization. This includes assessing the clinical and operational benefit of POCT before implementation and inventory management to ensure minimal reagent wastage. This review discusses these different considerations when implementing POCT with a focus on the pediatric healthcare setting.

Advances in Cardiac Biomarkers of Acute Coronary Syndrome

Acute coronary syndrome (ACS) encompasses a pathophysiological spectrum of cardiovascular diseases, all of which have significant morbidity and mortality. ACS was once considered an acute condition; however, new treatment strategies and improvements in biomarker assays have led to ACS being an acute and chronic disease. Cardiac troponin is the preferred biomarker for the diagnosis of myocardial infarction, and there is considerable interest and efforts toward development and implementation of high-sensitivity cardiac troponin (hs-cTn) assays worldwide. Analytical and clinical performance characteristics of hs-cTn assays as well as testing limitations are important for laboratorians and clinicians to understand in order to utilize testing appropriately. Furthermore, expanding the clinical utility of hs-cTn into other cohorts such as asymptomatic community dwelling populations, heart failure, and chronic kidney disease populations supports novel opportunities for improved short- and long-term prognosis.

Effectiveness of practices for improving the diagnostic accuracy of Non ST Elevation Myocardial Infarction in the Emergency Department: A Laboratory Medicine Best Practices™ systematic review

OBJECTIVES

This article is a systematic review of the effectiveness of four practices (assay selection, decision point cardiac troponin (cTn) threshold selection, serial testing, and point of care testing) for improving the diagnostic accuracy Non-ST-Segment Elevation Myocardial Infarction (NSTEMI) in the Emergency Department.

DESIGN AND METHODS

The CDC-funded Laboratory Medicine Best Practices (LMBP) Initiative systematic review method for quality improvement practices was used.

RESULTS

The current ACC/AHA guidelines recommend using cardiac troponin assays with a 99th percentile upper reference limit (URL) diagnostic threshold to diagnose NSTEMI. The evidence in this systematic review indicates that contemporary sensitive cTn assays meet the assay profile requirements (sensitivity, specificity, PPV, and NPV) to more accurately diagnose NSTEMI than alternate tests. Additional biomarkers did not increase diagnostic effectiveness of cTn assays. Sensitivity, specificity, and NPV were consistently high and low PPV improved with serial sampling. Evidence for use of point of care cTn testing was insufficient to make recommendation, though some evidence suggests that use may result in reduction to patient length of stay and costs.

CONCLUSIONS

Based on the review of and the LMBP(TM) A-6 Method criteria, we recommend the use of cardiac troponin assays without additional biomarkers using the 99th percentile URL as the clinical diagnostic threshold for the diagnosis of NSTEMI. We recommend serial sampling with one sample at presentation and at least one additional second sample taken at least 6h later to identify a rise or fall in the troponin level. No recommendation is made either for or against the use of point of care tests.

DISCLAIMER

The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention/the Agency for Toxic Substances and Disease Registry (CDC/ATSDR).

Point-of-care testing in the overcrowded emergency department--can it make a difference?

Emergency departments (EDs) face several challenges in maintaining consistent quality care in the face of steadily increasing public demand. Improvements in the survival rate of critically ill patients in the ED are directly related to the advancement of early recognition and treatment. Frequent episodes of overcrowding and prolonged waiting times force EDs to operate beyond their capacity and threaten to impact upon patient care. The objectives of this review are as follows: (a) to establish overcrowding as a threat to patient outcomes, person-centered care, and public safety in the ED; (b) to describe scenarios in which point-of-care testing (POCT) has been found to ameliorate factors thought to contribute to overcrowding; and (c) to discuss how POCT can be used directly, and indirectly, to expedite patient care and improve outcomes. Various studies have shown that overcrowding in the ED has profound effects on operational efficiency and patient care. Several reports have quantified overcrowding in the ED and have described a relationship between heightened periods of overcrowding and delays in treatment, increased incidence of adverse events, and an even greater probability of mortality. In certain scenarios, POCT has been found to increase the number of patients discharged in a timely manner, expedite triage of urgent but non-emergency patients, and decrease delays to treatment initiation. This review concludes that POCT, when used effectively, may alleviate the negative impacts of overcrowding on the safety, effectiveness, and person-centeredness of care in the ED.

An Evaluation of Laboratory Efficiency in Shanghai Emergency by Turn Around Times Level

Objective

China launched a health care reform policy due to the aging population and rapid urbanization. However, emergency overcrowding is not improved. We assessed the laboratory efficiency of emergency department (ED) in Shanghai hospitals.

Methods

We recorded the turn around times for processing laboratory biomarkers to assess laboratory efficiency at 17 EDs in national/regional hospitals. We compared TAT between national and regional hospitals and between central and ED laboratories to analyze the relationship between the laboratory efficiency and the ED overcrowding.

Results

All the participating hospitals have an emergency laboratory. The median TAT for c‐TNT was 61 min (46–76 min) at regional EDs compared with 64 min (46–87 min) at national EDs; therefore, the TAT at regional EDs were more efficient (P < 0.05). The TAT were longer (65 min (53–85 min)) at ED labs than (60 min (42–83 min)) at central labs (P < 0.05), independent of the hospital tier and working period. We discovered that only 9% of investigated samples at Tier II EDs and 5% at Tier III EDs were assayed by point‐of‐care (POC) instruments.

Conclusion

Our TAT level is approaching the recommended international standard. However, the TAT evaluation from ED laboratories demonstrates that their existence does not decrease the waiting time for laboratory reports compared to central laboratory. Thus, they have not yet approached a level to share the burden of the ED overcrowding. Further arrangement should be assigned to separate the function of emergency laboratory and central laboratory. It is worth deploying the POC assay in the ED, which will save twice the TAT level. The idea of evaluating routine laboratory efficiency by TAT at ED is fast, convenient, although it does not represent the general level of laboratory efficiency.

Point-of-care testing: where is the evidence? A systematic survey

Point-of-care testing (POCT) has had rapid technological development and their use is widespread in clinical laboratories to assure reduction of turn-around-time and rapid patient management in some clinical settings where it is important to make quick decisions. Until now the papers published about the POCT have focused on the reliability of the technology used and their analytical accuracy. We aim to perform a systematic survey of the evidence of POCT efficacy focused on clinical outcomes, selecting POCT denoted special analytes characterized by possible high clinical impact. We searched in Medline and Embase. Two independent reviewers assessed the eligibility, extracted study details and assessed the methodological quality of studies. We analyzed 84 studies for five POCT instruments: neonatal bilirubin, procalcitonin, intra-operative parathyroid hormone, troponin and blood gas analysis. Studies were at high risk of bias. Most of the papers (50%) were studies of correlation between the results obtained by using POCT instruments and those obtained by using laboratory instruments. These data showed a satisfactory correlation between methods when similar analytical reactions were used. Only 13% of the studies evaluated the impact of POCT on clinical practice. POCT decreases the time elapsed for making decisions on patient management but the clinical outcomes have never been adequately evaluated. Our work shows that, although POCT has the potential to provide beneficial patient outcome, further studies may be required, especially for defining its real utility on clinical decision making.

Diagnostic performance of four point of care cardiac troponin I assays to rule in and rule out acute myocardial infarction

OBJECTIVE

This study evaluated the diagnostic performance of four point-of-care (POC) cardiac troponin I (cTnI) assays compared to a central laboratory cTnI assay for detecting myocardial injury and diagnosing acute myocardial infarction (AMI).

DESIGN AND METHODS

Plasma obtained at admission, 3 h, and 6 h post-admission in 169 patients presenting with symptoms suggestive of acute coronary syndrome (ACS) was studied. cTnI concentrations were measured on the Instrumentation Laboratory prototype GEM Immuno, Radiometer AQT90, Mitsubishi PATHFAST, Abbott i-STAT and the Ortho-Clinical Diagnostic Vitros assays. MI was determined based on 99th percentiles according to Universal MI guidelines.

RESULTS

For ruling in MI at presentation (0 h), the GEM Immuno (sensitivity 63%, specificity 85%) and PATHFAST (sensitivity 53%, specificity 86%) were comparable to the OCD (sensitivity 68%, specificity 81%), and significantly better (p<0.05) than the AQT90 (sensitivity 26%, specificity 93%) and i-STAT (sensitivity 32%, specificity 92%). cTnI concentrations and serial rising patterns after MI differed by each assay. Negative predictive values were >90% and ROC AUCs were >0.90 after 6h for all assays. Detection of myocardial injury in non-ischemic pathologies accounted for lower than 100% specificity for MI.

CONCLUSION

cTnI is a sensitive biomarker for detection of myocardial injury. The analytical variability that exists between POC cTnI assays demonstrates substantial diagnostic differences for ruling in and ruling out MI in patients presenting with symptoms suggestive of ACS.

Evidence-based point-of-care diagnostics: current status and emerging technologies

Point-of-care (POC) diagnostics brings tests nearer to the site of patient care. The turnaround time is short, and minimal manual interference enables quick clinical management decisions. Growth in POC diagnostics is being continuously fueled by the global burden of cardiovascular and infectious diseases. Early diagnosis and rapid initiation of treatment are crucial in the management of such patients. This review provides the rationale for the use of POC tests in acute coronary syndrome, heart failure, human immunodeficiency virus, and tuberculosis. We also consider emerging technologies that are based on advanced nanomaterials and microfluidics, improved assay sensitivity, miniaturization in device design, reduced costs, and high-throughput multiplex detection, all of which may shape the future development of POC diagnostics.

Cardiac troponin: a critical review of the case for point-of-care testing in the ED

The measurement of cardiac troponin concentrations in the blood is a key element in the evaluation of patients with suspected acute coronary syndromes, according to current guidelines, and contributes importantly to the ruling in or ruling out of acute myocardial infarction. The introduction of point-of-care testing for cardiac troponin has the potential to reduce turnaround time for assay results, compared with central laboratory testing, optimizing resource use. Although, in general, many point-of-care cardiac troponin tests are less sensitive than cardiac troponin tests developed for central laboratory-automated analyzers, point-of-care systems have been used successfully within accelerated protocols for the reliable ruling out of acute coronary syndromes, without increasing subsequent readmission rates for this condition. The impact of shortened assay turnaround times with point-of-care technology on length of stay in the emergency department has been limited to date, with most randomized evaluations of this technology having demonstrated little or no reduction in this outcome parameter. Accordingly, the point-of-care approach has not been shown to be cost-effective relative to central laboratory testing. Modeling studies suggest, however, that reengineering overall procedures within the emergency department setting, to take full advantage of reduced therapeutic turnaround time, has the potential to improve the flow of patients through the emergency department, to shorten discharge times, and to reduce cost. To properly evaluate the potential contribution of point-of-care technology in the emergency department, including its cost-effectiveness, future evaluations of point-of-care platforms will need to be embedded completely within a local decision-making structure designed for its use.

Interventions to improve the timeliness of emergency care

With a persistent trend of increasing emergency department (ED) volumes every year, services are intensifying. Thus, improving the timeliness of delivering emergency care should be a primary focus, both from an operational and from a research perspective. Much has been published on factors associated with delays in emergency care, and the next phase in this area of research will focus on exploring interventions to improve the timeliness of care. On June 1, 2011, Academic Emergency Medicine held a consensus conference titled "Interventions to Assure Quality in the Emergency Department." This article summarizes the findings of the breakout session that investigated interventions to improve the timeliness of emergency care. This article will explore the background on the concept of timeliness of emergency care, the current state of interventions that have been implemented to improve timeliness, and specific questions as a framework for a future research agenda.

Improving patient flow in acute coronary syndromes in the face of hospital crowding

BACKGROUND

The current paradigm for the evaluation of patients with suspected acute coronary syndromes (ACS) in the emergency department (ED) is focused on the identification of patients with active underlying coronary disease. The majority of patients evaluated in the ED setting do not have active underlying cardiac disease.

OBJECTIVE

To measure the effect of bedside point-of-care (POC) cardiac biomarker testing on telemetry unit admissions from the ED. Furthermore, to evaluate the effect telemetry admissions have on ED length of stay (LOS) and overall hospital LOS.

METHODS

Primary data were collected over two 6-month periods in an urban teaching hospital ED. This was an observational cohort study conducted pre- and post-availability of a POC testing platform for cardiac biomarkers. Major measures included number of overall telemetry admissions, ED LOS, hospital LOS, and disposition. Patients were followed at 30 days for significant cardiac events, repeat ED visit or admission, and death.

RESULTS

In the post-implementation period there was a 30% (95% confidence interval [CI] 36-44%) reduction in admissions to telemetry with a 33% (95% CI 26-39%) reduction in ED LOS and a 20% (95% CI 7-34%) reduction in hospital LOS. There was a 62% reduction in overall mortality between the pre-implementation period and the post-implementation period (p=0.001).

CONCLUSION

The focused use of a rapid cardiac disposition protocol can dramatically impact resource utilization, expedite patient flow, and improve short-term outcomes for patients with suspected ACS.

The future of point-of-care testing in emergency departments

Emergency physicians and administrators continue to face operational challenges as they attempt to increase emergency department (ED) efficiency and throughput to meet the growing demand for emergency health services. Point-of-care (POC) testing technology can provide clinicians with accurate and reliable results with at least a 50% reduction in turnaround time. Despite the near perfect alignment of POC technology goals with ED operational strategy, there has been a relatively slow adoption of comprehensive POC systems. The authors discuss current market trends for the POC products in the ED and review trends in outcomes data (including operational, clinical and financial). The authors also discuss observed managerial obstacles to implementation. The goal of this paper is to provide readers with a business psychology perspective on the current challenges that organizations face in adopting a new technology and provide an evaluation of the key drivers that influence institutional-level decisions to implement an ED-based POC system. The reader will gain an understanding of the dynamic forces that are slowing the adoption of POC technology. Also, the reader is provided with the authors' future perspectives for POC testing in emergency medicine. The current healthcare system is putting a lot of pressure on EDs to be able to provide efficient care using advanced diagnostic tests. Clinicians and administrators alike must understand the gaps between the clinician's perceived benefit of POC testing and the inconsistent literature on the operational and clinical outcomes before adopting POC systems in ED.

A point-of-care chemistry test for reduction of turnaround and clinical decision time

PURPOSE

Our study compared clinical decision time between patients managed with a point-of-care chemistry test (POCT) and patients managed with the traditional central laboratory test (CLT).

BASIC PROCEDURE

This was a randomized controlled multicenter trial in the emergency departments (EDs) of 5 academic teaching hospitals. We randomly assigned patients to POCT or CLT stratified by the Emergency Severity Index. A POCT chemistry analyzer (Piccolo; Abaxis, Inc, Union City, Calif), which is able to test liver panel, renal panel, pancreas enzymes, lipid panel, electrolytes, and blood gases, was set up in each ED. Primary and secondary end point was turnaround time and door-to-clinical-decision time.

MAIN FINDINGS

The total 2323 patients were randomly assigned to the POCT group (n = 1167) or to the CLT group (n = 1156). All of the basic characteristics were similar in the 2 groups. The turnaround time (median, interquartile range [IQR]) of the POCT group was shorter than that of the CLT group (14, 12-19 versus 55, 45-69 minutes; P < .0001). The median (IQR) door-to-clinical-decision time was also shorter in the POCT compared with the CLT group (46, 33-61 versus 86, 68-107 minutes; P < .0001). The proportion of patients who had new decisions within 60 minutes was 72.8% for the POCT group and 12.5% for the CLT group (P < .0001).

CONCLUSIONS

A POCT chemistry analyzer in the ED shortens the test turnaround and ED clinical decision times compared with CLT.

Estimating the clinical impact of bringing a multimarker cardiac panel to the bedside in the ED

OBJECTIVES

We examined the use of point-of-care (POC) testing of cardiac biomarkers against standard core laboratory testing to determine the time-savings and estimate a cost-benefit ratio at our institution.

METHODS

We prospectively enrolled 151 patients presenting to the emergency department undergoing evaluation for acute coronary syndrome and conducted both central laboratory troponin T (TnT) testing at baseline and 6 hours as well as POC assays of creatine kinase MB, troponin I (TnI), and myoglobin at baseline and 2 hours. Sensitivity/specificity was calculated to measure the ability of the POC-accelerated pathway to identify enzyme elevations at rates parallel to our core laboratory. The time-savings were calculated as the difference between the median of the current protocol and the accelerated POC pathway.

RESULTS

Troponin T tests were elevated in 12 patients, which were all detected by the accelerated pathway yielding a relative sensitivity of 100%. Time-saving between the accelerated pathway and core laboratory showed a saving of 390 minutes (6.5 hours). The accelerated POC pathway would have benefited 60% (95% confidence interval [CI], 52%-68%) of our patients with an estimated cost of $7.40 (95% CI, $6.40-$8.70) per direct patient care hour saved.

CONCLUSION

Our data suggest that the use of an accelerated cardiac POC pathway could have dramatically impacted the care provided to a large percentage of our patients at a minimal cost per direct patient care hour saved.

Perspectives on cost and outcomes for point-of-care testing

Point-of-care testing (POCT) is usually more expensive on a unit-cost basis than testing performed in a central laboratory. It is difficult to manage POCT and to maintain regulatory compliance, especially in large institutions. However, some POCT technologies have improved patient outcomes (patient self-glucose monitoring in the home, tight glycemic control in intensive care settings) or hospital or emergency department operations (whole-blood cardiac-marker testing and D-dimer testing in emergency departments). In some cases, these outcomes result simply from making a new test available, rather than performing the test at the point of care. In most cases, the rapid turnaround time provided by POCT is the main factor that is ultimately responsible for the improvement in outcomes.

Point-of-care testing for cardiac markers in acute coronary syndromes and heart failure

Advances in technologies for immunoassay testing have enabled the development of 15-minute whole-blood assays for cardiac markers in the evaluation of patients with acute coronary syndromes (ACS) and congestive heart failure. In many cases, the analytical performance of these assays is equivalent to that of testing in the central laboratory. Rapid whole-blood point-of-care assays for troponin, creatine kinase isoenzyme CK-MB, myoglobin, and B-type natriuretic peptides have facilitated efforts to restructure conventional approaches to ACS and heart failure in the emergency room. Improvements in outcomes, including decreased emergency room and hospital length-of-stay, decreased overall cost, and earlier discharge of low-risk patients, have been documented following implementation of these technologies.

The usage patterns of cardiac bedside markers employing point-of-care testing for troponin in non-ST-segment elevation acute coronary syndrome: results from CRUSADE

BACKGROUND

Point-of-care (POC) testing may expedite the care of emergency department (ED) patients suspected of having acute coronary syndromes (ACS). We evaluated the use patterns of cardiac bedside markers or POC testing for troponin in patients with non-ST-segment elevation (NSTE) ACS.

METHODS

NSTE ACS data were collected from the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the American College of Cardiology/American Heart Association (ACC/AHA) Guidelines (CRUSADE) registry. We compared hospital and patient characteristics, in-hospital events, and process-of-care variables between hospitals to those that did not use POC testing in > or = 50% of enrolled patients. We examined characteristics, in-hospital events, and process-of-care differences between patients with negative vs positive troponin POC testing results.

RESULTS

Of 568 hospitals, 74 (16,276 patients) had high POC usage compared with 197 hospitals (50,782 patients) with no troponin POC usage. From the high POC usage hospitals, 12,604 patients had recorded troponin POC test results. Hospitals with high POC usage had a shorter ED length of stay and were less likely to administer aspirin, beta-blockers, and heparin during the first 24 hours of care. Patients with positive troponin POC results were more often older, minority, female, Medicare-insured, diabetic, and renally impaired. They had fewer electrocardiograms within 10 minutes but were more likely to get aspirin, beta-blockers, glycoprotein IIb/IIIa inhibitors, and heparin within 24 hours of arrival. They also had longer ED lengths of stay, received fewer in-hospital and interventional procedures, and had more adverse clinical events.

CONCLUSION

Differences existed in how hospitals used POC testing and the care given based on those results. Positive POC results are associated with expedited and higher use of anti-ischemic therapies.

Stroke biomarkers: progress and challenges for diagnosis, prognosis, differentiation, and treatment

BACKGROUND

Stroke is a devastating condition encompassing a wide range of pathophysiological entities that include thrombosis, hemorrhage, and embolism. Current diagnosis of stroke relies on physician clinical examination and is further supplemented with various neuroimaging techniques. A single set or multiple sets of blood biomarkers that could be used in an acute setting to diagnosis stroke, differentiate between stroke types, or even predict an initial/reoccurring stroke would be extremely valuable.

CONTENT

We discuss the current classification, diagnosis, and treatment of stroke, focusing on use of novel biomarkers (either solitary markers or multiple markers within a panel) that have been studied in a variety of clinical settings.

SUMMARY

The current diagnosis of stroke remains hampered and delayed due to lack of a suitable mechanism for rapid (ideally point-of-care), accurate, and analytically sensitive biomarker-based testing. There is a clear need for further development and translational research in this area. Potential biomarkers identified need to be transitioned quickly into clinical validation testing for further evaluation in an acute stroke setting; to do so would impact and improve patient outcomes and quality of life.

Decreasing lab turnaround time improves emergency department throughput and decreases emergency medical services diversion: a simulation model

BACKGROUND

The effect of decreasing lab turnaround times on emergency department (ED) efficiency can be estimated through system-level simulation models and help identify important outcome measures to study prospectively. Furthermore, such models may suggest the advantage of bedside or point-of-care testing and how they might affect efficiency measures.

OBJECTIVES

The authors used a sophisticated simulation model in place at an adult urban ED with an annual census of 55,000 patient visits. The effect of decreasing turnaround times on emergency medical services (EMS) diversion, ED patient throughput, and total ED length of stay (LOS) was determined.

METHODS

Data were generated by using system dynamics analytic modeling and simulation approach on 90 separate days from December 2, 2007, through February 29, 2008. The model was a continuous simulation of ED flow, driven by real-time actual patient data, and had intrinsic error checking to assume reasonable goodness-of-fit. A return of complete laboratory results incrementally at 120, 100, 80, 60, 40, 20, and 10 minutes was compared. Diversion calculation assumed EMS closure when more than 10 patients were in the waiting room and 100% ED bed occupancy had been reached for longer than 30 minutes, as per local practice. LOS was generated from data insertion into the patient flow stream and calculation of time to specific predefined gates. The average accuracy of four separate measurement channels (waiting room volume, ED census, inpatient admit stream, and ED discharge stream), all across 24 hours, was measured by comparing the area under the simulated curve against the area under the measured curve. Each channel's accuracy was summed and averaged for an overall accuracy rating.

RESULTS

As lab turnaround time decreased from 120 to 10 minutes, the total number of diversion days (maximum 57 at 120 minutes, minimum 29 at 10 minutes), average diversion hours per day (10.8 hours vs. 6.0 hours), percentage of days with diversion (63% vs. 32%), and average ED LOS (2.77 hours vs. 2.17 hours) incrementally decreased, while average daily throughput (104 patients vs. 120 patients) increased. All runs were at least 85% accurate.

CONCLUSIONS

This simulation model suggests compelling improvement in ED efficiency with decreasing lab turnaround time. Outcomes such as time on EMS diversion, ED LOS, and ED throughput represent important but understudied areas that should be evaluated prospectively. EDs should consider processes that will improve turnaround time, such as point-of-care testing, to obtain these goals.

Impact of point-of-care testing in the emergency department evaluation and treatment of patients with suspected acute coronary syndromes

OBJECTIVES

To assess the impact of point-of-care testing (POCT) for troponin I (cTnI) measurement on the time to anti-ischemic therapy (TAIT) for patients with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) presenting to the emergency department (ED).

METHODS

This was an open-label, randomized, single-center trial conducted in a university-affiliated hospital. cTnI measurement of patients with suspicion of NSTE-ACS coming to the ED was randomly allocated to POCT or central hospital laboratory testing (CHLT). The authors compared patients' baseline characteristics, time to anti-ischemic therapy, and medical outcomes between the randomized groups, in all study participants and in high-risk NSTE-ACS (cTnI level >or= 0.10 microg/mL), and in those with low suspicion ACS (no chest pain and no ST deviation).

RESULTS

Of the 860 patients enrolled, 113 were high-risk NSTE-ACS patients, including 53 (46.9%) allocated to POCT and 60 (53.1%) to CHLT. POCT was associated with decreased time to anti-ischemic therapy of about three-quarters of an hour, which was due to a shorter time to physician notification of cTnI level, in both all and subgroup participants. In contrast, neither ED length of stay nor medical outcomes differed between study groups.

CONCLUSIONS

Point-of-care testing for cTnI measurement might be clinically relevant for ED patients with a suspicion of NSTE-ACS, particularly for high-risk patients with a low suspicion of ACS.