Telephone triage of chest pain in out-of-hours primary care: external validation of a symptom-based prediction rule to rule out acute coronary syndromes.

INTRODUCTION: Telephone triage is pivotal for evaluating the urgency of patient care, and in the Netherlands, the Netherlands Triage Standard (NTS) demonstrates moderate discrimination for chest pain. To address this, the Safety First Prediction Rule (SFPR) was developed to improve the safety of ruling out acute coronary syndrome (ACS) during telephone triage. METHODS: We conducted an external validation of the SFPR using data from the TRACE study, a retrospective cohort study in out-of-hours primary care. We evaluated the diagnostic accuracy assessment for ACS, major adverse cardiovascular events (MACE), and major events within 6 weeks. Moreover, we compared its performance with that of the NTS algorithm. RESULTS: Among 1404 included patients (57.3% female, 6.8% ACS, 8.6% MACE), the SFPR demonstrated good discrimination for ACS (C-statistic: 0.79; 95%-CI: 0.75-0.83) and MACE (C-statistic: 0.79; 95%-CI: 0.0.76-0.82). Calibration was satisfactory, with overestimation observed in high-risk patients for ACS. The SFPR (risk threshold 2.5%) trended toward higher sensitivity (95.8% vs. 86.3%) and negative predictive value (99.3% vs. 97.6%) with a lower negative likelihood ratio (0.10 vs. 0.34) than the NTS algorithm. CONCLUSION: The SFPR proved robust for risk stratification in patients with acute chest pain seeking out-of-hours primary care in the Netherlands. Further prospective validation and implementation are warranted to refine and establish the rule's clinical utility.

Troponin testing in routine primary care: observations from a dynamic cohort study in the Amsterdam metropolitan area.

OBJECTIVES: Troponin testing is indicated in the diagnostic work-up of acute coronary syndrome (ACS) and incorporated in risk stratification pathways. This study aims to gain insights on the use, outcomes, and diagnostic accuracy of troponin testing in routine primary care; a setting that is understudied. METHODS: Routine data were used from the academic primary care network in the Amsterdam metropolitan area (968,433 patient records). The study population included adult patients who underwent high-sensitivity troponin I or T (hs-TnI/T) testing between 2011 and 2021. The primary outcome was the reported diagnosis and the secondary outcome was the diagnostic accuracy measured by death or ACS at 30 days. RESULTS: 3,184 patients underwent hs-troponin testing, either with hsTNT (n=2,333) or hsTNI (n=851). Median patients' age was 55 (44-65) years, and 62.3 % were female. Predominant symptoms were chest pain and dyspnea (56.7 %). Additional diagnostic laboratory tests were commonly performed (CRP: 47.7 %, natriuretic peptides: 25.6 %, d-dimer: 21.5 %). Most common diagnoses were musculoskeletal symptoms (21.6 %) and coronary heart disease (7.1 %; 1.1 % ACS). Troponin testing showed sensitivity and specificity of 77.8 % (60.9-89.9) and 94.3 % (93.5-95.1), respectively. Negative and positive predictive values were 99.7 (99.5-99.9) and 13.5 (11.1-16.4), and positive and negative likelihood ratios were 13.7 (10.9-17.1) and 0.24 (0.13-0.43). CONCLUSIONS: GPs occasionally use troponin testing in very low-risk patients, often as part of a multi-marker rule-out strategy. The diagnostic characteristics of troponin tests, while promising, warrant prospective validation and implementation to facilitate appropriate use.

[Acute chest pain in out-of-hours primary care]. / Acute pijn op de borst op de huisartsenpost.

Out-of-hours primary care (OOH-PC) facilities act as a first point of contact in acute care in the Netherlands, including acute chest pain. The facilities perform initial triage to assess the patient's urgency using standardized triage protocols (Netherlands Triage Standard). The performance of the current protocol for chest pain assessment was recently evaluated and showed only moderate discriminatory properties. Although final triage decision-making is improved by the clinical experience of triage assistants and general practitioners, substantial over- and under-triage persists. Improving the care of patients with chest pain in OOH-PC should primarily be sought in improving the triage software, followed by the use of innovative diagnostic tools (such as troponine measurements).

Evaluation of telephone triage among chest pain patients in out-of-hours primary care in the Netherlands (TRACE).

BACKGROUND: Telephone triage is fully integrated in Dutch out-of-hours primary care (OOH-PC). Patients presenting with chest pain are initially assessed according to a standardized protocol ("Netherlands Triage Standard" [NTS]). Nevertheless, little is known about its (diagnostic) performance, nor on the impact of subsequent clinical judgements made by triage assistants and general practitioners (GPs). OBJECTIVE: To evaluate the performance of the current NTS chest pain protocol. METHODS: Observational, retrospective cohort study of adult patients with chest pain who contacted a regional OOH-PC facility in the Netherlands, in 2017. The clinical outcome measure involved the occurrence of a "major event," which is a composite of all-cause mortality and urgent cardiovascular and noncardiovascular conditions, occurring ≤6 weeks of initial contact. We assessed the performance using diagnostic and discriminatory properties. RESULTS: In total, 1,803 patients were included, median age was 54.0 and 57.5% were female. Major events occurred in 16.2% of patients with complete follow-up, including 99 (6.7%) cases of acute coronary syndrome and 22 (1.5%) fatal events. NTS urgency assessment showed moderate discriminatory abilities for predicting major events (c-statistic 0.66). Overall, NTS performance showed a sensitivity and specificity of 83.0% and 42.4% with a 17.0% underestimated major event rate. Triage assistants' revisions hardly improved urgency allocation. Further consideration of the clinical course following OOH-PC contact did generate a more pronounced improvement with a sensitivity of 89.4% and specificity of 61.9%. CONCLUSION: Performance of telephone triage of chest pain appears moderate at best, with acceptable safety yet limited efficiency, even after including further work-up by GPs.

Performance of risk scores for coronary artery disease: a retrospective cohort study of patients with chest pain in urgent primary care.

OBJECTIVE: To evaluate the diagnostic performance of the Marburg Heart Score (MHS), INTERCHEST, Gencer rule, Bruins Slot rule and compare these with unaided clinical judgement in patients with chest pain in urgent primary care. DESIGN: Retrospective, cohort study. SETTING: Regional primary care facility responsible for out-of-hours primary care for a quarter-million people in the Netherlands. PARTICIPANTS: Consecutive patients aged ≥18 years who were evaluated for chest pain. MAIN OUTCOME MEASURES: Discriminatory ability (C-statistic), sensitivity, specificity, positive and negative predictive values (PPV/NPV). The reference standard involved a composite endpoint of the occurrence of death, acute coronary syndrome or coronary revascularisation (=major adverse cardiac events; MACE) up to 6 weeks after initial contact. RESULTS: A total of 664 patients were included, of whom 4.8% (n=32) had a MACE event. C-statistics for MHS, INTERCHEST, Gencer and Bruins Slot rule were: 0.77 (95% CI 0.69 to 0.84), 0.85 (95% CI 0.78 to 0.92), 0.72 (95% CI 0.63 to 0.81) and 0.72 (95% CI 0.63 to 0.81), respectively. Optimal diagnostic accuracy was found for MHS ≥2 (sensitivity=81.3%, specificity=67.1%, PPV=11.1%, NPV=98.6%), INTERCHEST ≥2 (sensitivity=87.5%, specificity=78.8%, PPV=17.3%, NPV=99.1%), Gencer ≥2 (sensitivity=84.4%, specificity=37.8%, PPV=6.4%, NPV=98.0%) and Bruins Slot≥2 (sensitivity=90.6%, specificity=40.8%, PPV=7.2%, NPV=98.9%). Physicians referred 157 patients (23.6%) and missed 6 out of 32 MACEs (sensitivity=81.3%, specificity=79.3%, PPV=16.6%, NPV=98.8%). Using INTERCHEST with a referral threshold of ≥2 points, 4 MACEs would have been missed and 162 patients (24.4%) referred. The other risk scores resulted in far higher referral rates. CONCLUSION: While available risk scores have reasonable to good discriminatory properties, they do not outperform unaided clinical judgment for evaluating chest pain in urgent primary care. Only the INTERCHEST score may slightly improve risk stratification.

Rationale and design of a cohort study evaluating triage of acute chest pain in out-of-hours primary care in the Netherlands (TRACE).

The aims of this study are (1) to evaluate the performance of current triage for chest pain; (2) to describe the case mix of patients undergoing triage for chest pain; and (3) to identify opportunities to improve performance of current Dutch triage system for chest pain. Chest pain is a common symptom, and identifying patients with chest pain that require urgent care can be quite challenging. Making the correct assessment is even harder during telephone triage. Temporal trends show that the referral threshold has lowered over time, resulting in overcrowding of first responders and emergency services. While various stakeholders advocate for a more efficient triage system, careful evaluation of the performance of the current triage in primary care is lacking. TRiage of Acute Chest pain Evaluation in primary care (TRACE) is a large cohort study designed to describe the current Dutch triage system for chest pain and subsequently evaluate triage performance in regard to clinical outcomes. The study consists of consecutive patients who contacted the out-of-hours primary care facility with chest pain in the region of Alkmaar, the Netherlands, in 2017, with follow-up for clinical outcomes out to August 2019. The primary outcome of interest is 'major event', which is defined as the occurrence of death from any cause, acute coronary syndrome, urgent coronary revascularization, or other high-risk diagnoses in which delay is inadmissible and hospitalization is necessary. We will evaluate the performance of the triage system by assessing the ability of the triage system to correctly classify patients regarding urgency (accuracy), the proportion of safe actions following triage (safety) as well as rightfully deployed ambulances (efficacy). TRACE is designed to describe the current Dutch triage system for chest pain in primary care and to subsequently evaluate triage performance in regard to clinical outcomes.