Consequences of high-sensitivity troponin T testing applied in a primary care population with chest pain compared with a commercially available point-of-care troponin T analysis: an observational prospective study

Chest Pain in Primary Care: A Systematic Review of Risk Stratification Tools to Rule Out Acute Coronary Syndrome

PURPOSE

Chest pain frequently poses a diagnostic challenge for general practitioners (GPs). Utilizing risk stratification tools might help GPs to rule out acute coronary syndrome (ACS) and make appropriate referral decisions. We conducted a systematic review of studies evaluating risk stratification tools for chest pain in primary care settings, both with and without troponin assays. Our aims were to assess the performance of tools for ruling out ACS and to provide a comprehensive review of the current evidence.

METHODS

We searched PubMed and Embase for articles up to October 9, 2023 concerning adult patients with acute chest pain in primary care settings, for whom risk stratification tools (clinical decision rules [CDRs] and/or single biomarker tests) were used. To identify eligible studies, a combination of active learning and backward snowballing was applied. Screening, data extraction, and quality assessment (following the Quality Assessment of Diagnostic Accuracy Studies-2 tool) were performed independently by 2 researchers.

RESULTS

Of the 1,204 studies screened, 14 were included in the final review. Nine studies validated 7 different CDRs without troponin. Sensitivities ranged from 75.0% to 97.0%, and negative predictive values (NPV) ranged from 82.4% to 99.7%. None of the CDRs outperformed the unaided judgment of GP's. Five studies reported on strategies using troponin measurements. Studies using high-sensitivity troponin showed highest diagnostic accuracy with sensitivity 83.3% to 100% and NPV 98.8% to 100%.

CONCLUSION

Clinical decision rules without troponin and the use of conventional troponin showed insufficient sensitivity to rule out ACS in primary care and are not recommended as standalone tools. High-sensitivity troponin strategies are promising, but studies are limited. Further prospective validation in primary care is needed before implementation.

A prospective multi-centre study assessing the safety and effectiveness following the implementation of an accelerated chest pain pathway using point-of-care troponin for use in New Zealand rural hospital and primary care settings

Aims

Most rural hospitals and general practices in New Zealand (NZ) are reliant on point-of-care troponin. A rural accelerated chest pain pathway (RACPP), combining an electrocardiogram (ECG), a structured risk score (Emergency Department Assessment of Chest Pain Score), and serial point-of-care troponin, was designed for use in rural hospital and primary care settings across NZ. The aim of this study was to evaluate the safety and effectiveness of the RACPP.

Methods and results

A prospective multi-centre evaluation following implementation of the RACPP was undertaken from 1 July 2018 to 31 December 2020 in rural hospitals, rural and urban general practices, and urgent care clinics. The primary outcome measure was the presence of 30-day major adverse cardiac events (MACEs) in low-risk patients. The secondary outcome was the percentage of patients classified as low-risk that avoided transfer or were eligible for early discharge. There were 1205 patients enrolled in the study. 132 patients were excluded. Of the 1073 patients included in the primary analysis, 474 (44.0%) patients were identified as low-risk. There were no [95% confidence interval (CI): 0–0.3%] MACE within 30 days of the presentation among low-risk patients. Most of these patients (91.8%) were discharged without admission to hospital. Almost all patients who presented to general practice (99%) and urgent care clinics (97.6%) were discharged to home directly.

Conclusion

The RACPP is safe and effective at excluding MACEs in NZ rural hospital and primary care settings, where it can identify a group of low-risk patients who can be safely discharged home without transfer to hospital.

Implementation and evaluation of a rural general practice assessment pathway for possible cardiac chest pain using point-of-care troponin testing: a pilot study

OBJECTIVES

To assess the feasibility and acceptability, and additionally to preliminarily evaluate, the effectiveness and safety of an accelerated diagnostic chest pain pathway in rural general practice using point-of-care troponin to identify patients at low risk of acute myocardial infarction, avoiding unnecessary patient transfer to hospital and enabling early discharge home.

DESIGN

A prospective observational pilot evaluation.

SETTING

Twelve rural general (family) practices in the Midlands region of New Zealand.

PARTICIPANTS

Patients aged ≥18 years who presented acutely to rural general practice with suspected ischaemic chest pain for whom the doctor intended transfer to hospital for serial troponin measurement.

OUTCOME MEASURES

The proportion of patients managed using the low-risk pathway without transfer to hospital and without 30-day major adverse cardiac event (MACE); pathway adherence; rate of 30-day MACE; patient satisfaction with care; and agreement between point-of-care and laboratory measured troponin concentrations.

RESULTS

A total of 180 patients were assessed by the pathway. The pathway classified 111 patients (61.7%) as low-risk and all were managed in rural general practice with no 30-day MACE (0%, 95% CI 0.0% to 3.3%). Adherence to the low-risk pathway was 95.5% (106 out of 111). Of the 56 patients classified as non-low-risk and referred to hospital, 9 (16.1%) had a 30-day MACE. A further 13 non-low-risk patients were not transferred to hospital, with no events. The sensitivity of the pathway for 30-day MACE was 100.0% (95% CI 70.1% to 100%). Of low-risk patients, 94% reported good to excellent satisfaction with care. Good concordance was observed between point-of-care and duplicate laboratory measured troponin concentrations.

CONCLUSIONS

The use of an accelerated diagnostic chest pain pathway incorporating point-of-care troponin in a rural general practice setting was feasible and acceptable, with preliminary results suggesting that it may safely and effectively reduce the urgent transfer of low-risk patients to hospital.

Prehospital risk assessment in patients suspected of non-ST-segment elevation acute coronary syndrome: a systematic review and meta-analysis

OBJECTIVE

To review, inventory and compare available diagnostic tools and investigate which tool has the best performance for prehospital risk assessment in patients suspected of non-ST-segment elevation acute coronary syndrome (NSTE-ACS).

METHODS

Systematic review and meta-analysis. Medline and Embase were searched up till 1 April 2021. Prospective studies with patients, suspected of NSTE-ACS, presenting in the primary care setting or by emergency medical services (EMS) were included. The most important exclusion criteria were studies including only patients with ST-elevation myocardial infarction and studies before 1995, the pretroponin era. The primary end point was the final hospital discharge diagnosis of NSTE-ACS or major adverse cardiac events (MACE) within 6 weeks. Risk of bias was evaluated by the Quality Assessment of Diagnostic Accuracy Studies Criteria.

MAIN OUTCOME AND MEASURES

Sensitivity, specificity and likelihood ratio of findings for risk stratification in patients suspected of NSTE-ACS.

RESULTS

In total, 15 prospective studies were included; these studies reflected in total 26 083 patients. No specific variables related to symptoms, physical examination or risk factors were useful in risk stratification for NSTE-ACS diagnosis. The most useful electrocardiographic finding was ST-segment depression (LR+3.85 (95% CI 2.58 to 5.76)). Point-of-care troponin was found to be a strong predictor for NSTE-ACS in primary care (LR+14.16 (95% CI 4.28 to 46.90) and EMS setting (LR+6.16 (95% CI 5.02 to 7.57)). Combined risk scores were the best for risk assessment in an NSTE-ACS. From the combined risk scores that can be used immediately in a prehospital setting, the PreHEART score, a validated combined risk score for prehospital use, derived from the HEART score (History, ECG, Age, Risk factors, Troponin), was most useful for risk stratification in patients with NSTE-ACS (LR+8.19 (95% CI 5.47 to 12.26)) and for identifying patients without ACS (LR-0.05 (95% CI 0.02 to 0.15)).

DISCUSSION

Important study limitations were verification bias and heterogeneity between studies. In the prehospital setting, several diagnostic tools have been reported which could improve risk stratification, triage and early treatment in patients suspected for NSTE-ACS. On-site assessment of troponin and combined risk scores derived from the HEART score are strong predictors. These results support further studies to investigate the impact of these new tools on logistics and clinical outcome.

FUNDING

This study is funded by ZonMw, the Dutch Organisation for Health Research and Development.

TRIAL REGISTRATION NUMBER

This meta-analysis was published for registration in PROSPERO prior to starting (CRD York, CRD42021254122).

Study protocol for an observational study to evaluate an accelerated chest pain pathway using point-of-care troponin in New Zealand rural and primary care populations

INTRODUCTION Accelerated diagnostic chest pain pathways are used widely in urban New Zealand hospitals. These pathways use laboratory-based troponin assays with good analytical precision. Widespread implementation has not occurred in many of New Zealand's rural hospitals and general practices as they are reliant on point-of-care troponin assays, which are less sensitive and precise. An accelerated chest pain pathway using point-of-care troponin has been adapted for use in rural settings. A pilot study in a low-risk rural population showed no major adverse cardiac events at 30 days. A larger study is required to be confident that the pathway is safe. AIMS To assess the safety and effectiveness of an accelerated chest pain pathway adapted for rural settings and general practice using point-of-care troponin to identify low-risk patients and allow early discharge. METHODS This is a prospective observational study of an accelerated chest pain pathway using point-of-care troponin in rural hospitals and general practices in New Zealand. A total of 1000 patients, of whom we estimate 400 will be low risk, will be enrolled in the study. OUTCOME MEASURES The primary outcome is the proportion of patients identified by the pathway as low risk for a 30-day major adverse cardiac event. Secondary outcomes include the proportion of low-risk patients who were discharged directly from general practice or rural hospitals, the proportion of patients reclassified as having acute myocardial infarction by the pathway and the proportion of patients with low and intermediate risk safely managed in the rural hospital.

Evaluating possible acute coronary syndrome in primary care: the value of signs, symptoms, and plasma heart-type fatty acid-binding protein (H-FABP). A diagnostic study

Background

Additional diagnostic means could be of added value when evaluating possible acute coronary syndrome (ACS) in primary care.

Aim

To determine whether heart-type fatty acid-binding protein (H-FABP)-based point-of-care (POC) biomarker testing, embedded in a clinical decision rule (CDR), is helpful to the GP when evaluating possible ACS.

Design & setting

A prospective, non-randomised, double-blinded, diagnostic derivation study was undertaken, with a delayed-type cross-sectional diagnostic model among GPs in the Netherlands and Belgium.

Method

Signs and symptoms predicting acute myocardial infarction (AMI) or ACS were identified using both logistic regression analysis, and classification and regression trees (CART). Diagnostic values of the POC H-FABP test (cut-off value 4 ng/ml) alone and as part of a CDR were determined.

Results

A total of 303 participants (48.8% male) with chest pain or discomfort who had consulted a GP were enrolled. ACS was found in 32 (10.6%) of these 303 patients. For ACS, sensitivity and negative predictive value (NPV) of the POC H-FABP test was 25.8% (95% confidence interval [CI] = 12.5 to 44.9) and 91.6% (95% CI = 87.6% to 94.5%), respectively. The area under the receiver operating curve of the optimal CDR was 0.78 for ACS.

Conclusion

Sensitivity of the current H-FABP POC test (cut-off value 4 ng/ml) as a stand-alone test is poor, either owing to limitations of the marker or of the test device. Usability of a CDR derived from these results is doubtful: the number of ACS cases missed by the GP is reduced but, as a consequence, disproportionally more ACS-negative patients are referred.

Characteristics of patients with acute myocardial infarction contacting primary healthcare before hospitalisation: a cross-sectional study

Background

The characteristics of patients with on-going myocardial infarction (MI) contacting the primary healthcare (PHC) centre before hospitalisation are not well known. Prompt diagnosis is crucial in patients with MI, but many patients delay seeking medical care. The aims of this study was to 1) describe background characteristics, symptoms, actions and delay times in patients contacting the PHC before hospitalisation when falling ill with an acute MI, 2) compare those patients with acute MI patients not contacting the PHC, and 3) explore factors associated with a PHC contact in acute MI patients.

Methods

This was a cross-sectional multicentre study, enrolling consecutive patients with MI within 24 hours of admission to hospital from Nov 2012 until Feb 2014.

Results

A total of 688 patients with MI, 519 men and 169 women, were included; the mean age was 66±11 years. One in five people contacted PHC instead of the recommended emergency medical services (EMS), and 94% of these patients experienced cardinal symptoms of an acute MI; i.e., chest pain, and/or radiating pain in the arms, and/or cold sweat. Median delay time from symptom-onset-to-decision-to-seek-care was 2:15 hours in PHC patients and 0:40 hours in non-PHC patients (p<0.01). The probability of utilising the PHC before hospitalisation was associated with fluctuating symptoms (OR 1.74), pain intensity (OR 0.90) symptoms during off-hours (OR 0.42), study hospital (OR 3.49 and 2.52, respectively, for two of the county hospitals) and a final STEMI diagnosis (OR 0.58).

Conclusions

Ambulance services are still underutilized in acute MI patients. A substantial part of the patients contacts their primary healthcare centre before they are diagnosed with MI, although experiencing cardinal symptoms such as chest pain. There is need for better knowledge in the population about symptoms of MI and adequate pathways to qualified care. Knowledge and awareness amongst primary healthcare professionals on the occurrence of MI patients is imperative.

Troponin and CRP as Indicators of Possible Ventricular Arrhythmias in Myocardial Infarction of the Anterior and Inferior Walls of the Heart

Introduction

Heart rhythm disorders are quite common in the clinical course of acute myocardial infarction and have a significant influence on the prognosis of the disease.

Aim

To investigate the type and frequency of ventricular arrhythmias in patients with acute myocardial infarction (AMI) by sex and age, according to localization of myocardial infarction, and correlated with troponin and C reactive protein (CRP).

Material and Methods

A prospective, analytical, comparative clinical study was performed. A total of 100 patients was included who were hospitalized at the Clinic for Heart Disease and Rheumatism at the Clinical Center University of Sarajevo for a period of 6 months, of both sexes, aged from 20 to 90 years. The occurrence of ventricular arrhythmias, CRP and troponin, were observed in relation to the localization (anterior and inferior myocardial wall).

Results

It was found that men are more represented in comparison to women and that the largest number of males were in the age group of 51-60 years of life and women in the age group of 71-80 years. It has been established that there is no significant difference between ventricular arrhythmia according to localization of AMI. By determining the mean CRP and troponin levels, a positive correlation was found between CRP and troponin values and recorded ventricular arrhythmias.

Conclusion

There is a positive correlation between the troponin and CRP values and ventricular arrhythmias, not related to the localization of AMI, which is important in prevention and planning the treatment of complications of potentially malignant ventricular arrhythmias and fatal outcome at AMI.

Early health technology assessment of future clinical decision rule aided triage of patients presenting with acute chest pain in primary care

The objective of the paper is to estimate the number of patients presenting with chest pain suspected of acute coronary syndrome (ACS) in primary care and to calculate possible cost effects of a future clinical decision rule (CDR) incorporating a point-of-care test (PoCT) as compared with current practice. The annual incidence of chest pain, referrals and ACS in primary care was estimated based on a literature review and on a Dutch and Belgian registration study. A health economic model was developed to calculate the potential impact of a future CDR on costs and effects (ie, correct referral decisions), in several scenarios with varying correct referral decisions. One-way, two-way, and probabilistic sensitivity analyses were performed to test robustness of the model outcome to changes in input parameters. Annually, over one million patient contacts in primary care in the Netherlands concern chest pain. Currently, referral of eventual ACS negative patients (false positives, FPs) is estimated to cost €1,448 per FP patient, with total annual cost exceeding 165 million Euros in the Netherlands. Based on 'international data', at least a 29% reduction in FPs is required for the addition of a PoCT as part of a CDR to become cost-saving, and an additional €16 per chest pain patient (ie, 16.4 million Euros annually in the Netherlands) is saved for every further 10% relative decrease in FPs. Sensitivity analyses revealed that the model outcome was robust to changes in model inputs, with costs outcomes mainly driven by costs of FPs and costs of PoCT. If PoCT-aided triage of patients with chest pain in primary care could improve exclusion of ACS, this CDR could lead to a considerable reduction in annual healthcare costs as compared with current practice.

A systematic evaluation of immunoassay point-of-care testing to define impact on patients' outcomes

Background Point-of-care testing has been developed to provide rapid test results. Most published studies focus on analytical performance, neglecting its impact on patient outcomes. Objective To review the analytical performance and accuracy of point-of-care testing specifically planned for immunoassay and to evaluate the impact of faster results on patient management. Methods A search of electronic databases for studies reporting immunoassay results obtained in both point-of-care testing and central laboratory scenarios was performed. Data were extracted concerning the study details, and the methodological quality was assessed. The analytical characteristics and diagnostic accuracy of six points-of-care testing: troponin, procalcitonin, parathyroid hormone, brain natriuretic peptide, C-reactive protein and neutrophil gelatinase-associated lipocalin were evaluated. Results A total of 116 scientific papers were analysed. Studies measuring procalcitonin, parathyroid hormone and neutrophil gelatinase-associated lipocalin reported a limited impact on diagnostic decisions. Seven studies measuring C-reactive protein claimed a significant reduction of antibiotic prescription. Several authors evaluated brain natriuretic peptide or troponin reporting faster decision-making without any improvement in clinical outcome. Forty-four per cent of studies reported analytical data, showing satisfactory correlations between results obtained through point-of-care testing and central laboratory setting. Half of studies defined the diagnostic accuracy of point-of-care testing as acceptable for troponin (median sensitivity and specificity: 74% and 94%, respectively), brain natriuretic peptide (median sensitivity and specificity: 82% and 88%, respectively) and C-reactive protein (median sensitivity and specificity 85%). Conclusions Point-of-care testing immunoassay results seem to be reliable and accurate for troponin, brain natriuretic peptide and C-reactive protein. The satisfactory analytical performance, together with an excellent practicability, suggests that it could be a consistent tool in clinical practice, but data are lacking regarding the patient outcomes.

Improving early exclusion of acute coronary syndrome in primary care: the added value of point-of-care troponin as stated by general practitioners

Aim To investigate general practitioners' (GPs') desire and perceived added value of point-of-care (POC) troponin, its effect on referral decisions, and test requirements.

BACKGROUND

Excluding acute coronary syndrome (ACS) in primary care remains a diagnostic challenges for GPs. Consequently, referral rates of chest pain patients are high, while the incidence of a cardiovascular problem is only 8-15%. Previous studies have shown that GPs are interested in a POC troponin test. This test could enhance rapid exclusion of ACS, thereby preventing unnecessary patient distress, without compromising safety and while reducing costs. However, using this test is not recommended in current guidelines due to uncertainty in the test's potential added value, and the lower sensitivity early after symptom onset as compared with troponin tests in a regular laboratory.

METHODS

An online survey containing 34 questions was distributed among 837 Dutch GPs in June 2015. Findings A total of 126 GPs (15.1%) completed at least 75% of the questions. 67.1% of GPs believe that POC troponin tests have moderate to very high added value. Although the availability of a POC test is expected to increase the frequency at which troponin tests are used, it likely decreases (immediate) referral rates. Of the responding GPs, 78.3% only accept 10 min as the maximum test duration, 78.1% think reimbursement of the POC device is required for implementation, and 68.9% consider it necessary that it can be performed with a finger prick blood sample. In conclusion, according to GPs, the POC troponin test can be of added value to exclude ACS early on. Actual test implementation will depend on test characteristics, including test duration, type of blood sample required, and reimbursement of the analyzer.

Asia-Pacific consensus statement on the optimal use of high-sensitivity troponin assays in acute coronary syndromes diagnosis: focus on hs-TnI

OBJECTIVE

High-sensitivity troponin (hs-Tn) assays need to be applied appropriately to improve diagnosis and patient outcomes in acute coronary syndromes (ACS).

METHODS

Experts from Asia Pacific convened in 2015 to provide data-driven consensus-based, region-specific recommendations and develop an algorithm for the appropriate incorporation of this assay into the ACS assessment and treatment pathway.

RESULTS

Nine recommendations were developed by the expert panel: (1) troponin is the preferred cardiac biomarker for diagnostic assessment of ACS and is indicated for patients with symptoms of possible ACS; (2) hs-Tn assays are recommended; (3) serial testing is required for all patients; (4) testing should be performed at presentation and 3 hours later; (5) gender-specific cut-off values should be used for hs-Tn I assays; (6) hs-Tn I level >10 times the upper limit of normal should be considered to 'rule in' a diagnosis of ACS; (7) dynamic change >50% in hs-Tn I level from presentation to 3-hour retest identifies patients at high risk for ACS; (8) where only point-of-care testing is available, patients with elevated readings should be considered at high risk, while patients with low/undetectable readings should be retested after 6 hours or sent for laboratory testing and (9) regular education on the appropriate use of troponin tests is essential.

CONCLUSIONS

We propose an algorithm that will potentially reduce delays in discharge by the accurate 'rule out' of non-ACS patients within 3 hours. Appropriate research should be undertaken to ensure the efficacy and safety of the algorithm in clinical practice, with the long-term goal of improvement of care of patients with ACS in Asia Pacific.