Objectives: The History, ECG, Age, Risk Factors and Troponin (HEART) Score is a decision support tool applied by physicians in the emergency department developed to risk stratify low-risk patients presenting with chest pain. We assessed the potential value of this tool in prehospital setting, when applied by emergency medical services (EMS), and derived and validated a tool adapted to the prehospital setting in order to determine if it could assist with decisions regarding conveyance to a hospital.Methods: In 2017,EMS personnel prospectively determined the HEART Score, including point-of-care (POC) troponin measurements, in patients presenting with chest pain, in the north of the Netherlands. The primary endpoint was a major adverse cardiac event (MACE), consisting of acute myocardial infarction or death, within 3 days. The components of the HEART Score were evaluated for their discriminatory value, cut-offs were calibrated for the prehospital setting and sex was substituted for cardiac risk factors to develop a prehospital HEART (preHEART) Score. This score was validated in an independent prospective cohort of 435 patients in 2018.Results: Among 1208 patients prospectively recruited in the first cohort, 123 patients (10.2%) developed a MACE. The HEART Score had a negative predictive value (NPV) of 98.4% (96.4–99.3), a positive predictive value (PPV) of 35.5% (31.8–39.3) and an area under the receiver operating characteristic curve (AUC) of 0.81 (0.78–0.85). The preHEART Score had an NPV of 99.3% (98.1–99.8), a PPV of 49.4% (42.0–56.9) and an AUC of 0.85 (0.82–0.88), outperforming the HEART Score or POC troponin measurements on their own. Similar results were found in a validation cohort.Conclusions: The HEART Score can be used in the prehospital setting to assist with conveyance decisions and choice of hospitals; however, the preHEART Score outperforms both the HEART Score and single POC troponin measurements when applied by EMS personnel in the prehospital setting.

Objective Prehospital risk stratification and triage are currently not performed in patients suspected of non-ST-segment elevation acute coronary syndrome (NSTE-ACS). This may lead to prolonged time to revascularisation, increased duration of hospital admission and higher healthcare costs. The preHEART score (prehospital history, ECG, age, risk factors and point-of-care troponin score) can be used by emergency medical services (EMS) personnel for prehospital risk stratification and triage decisions in patients with NSTE-ACS. The aim of the current study was to evaluate the effect of prehospital risk stratification and direct transfer to a percutaneous coronary intervention (PCI) centre, based on the preHEART score, on time to final invasive diagnostics or culprit revascularisation. Methods Prospective, multicentre, two-cohort study in patients with suspected NSTE-ACS. The first cohort is observational (standard care), while the second (interventional) cohort includes patients who are stratified for direct transfer to either a PCI or a non-PCI centre based on their preHEART score. Risk stratification and triage are performed by EMS personnel. The primary endpoint of the study is time from first medical contact until final invasive diagnostics or revascularisation. Secondary endpoints are time from first medical contact until intracoronary angiography (ICA), duration of hospital admission, number of invasive diagnostics, number of inter-hospital transfers and major adverse cardiac events at 7 and 30 days. Results A total of 1069 patients were included. In the interventional cohort (n=577), time between final invasive diagnostics or revascularisation (42 (17–101) hours vs 20 (5–44) hours, p<0.001) and length of hospital admission (3 (2–5) days vs 2 (1–4) days, p=0.007) were shorter than in the observational cohort (n=492). In patients with NSTE-ACS in need for ICA or revascularisation, healthcare costs were reduced in the interventional cohort (€5599 (2978–9625) vs €4899 (2278–5947), p=0.02). Conclusion Prehospital risk stratification and direct transfer to a PCI centre, based on the preHEART score, reduces time from first medical contact to final invasive diagnostics and revascularisation, reduces duration of hospital admission and decreases healthcare costs in patients with NSTE-ACS in need for ICA or revascularisation. Trial registration NCT05243485.

Background Emergency Medical Services (EMS) studies have shown that prehospital risk stratification and triage decisions in patients with suspected non-ST-elevation acute coronary syndrome (NSTE-ACS) can be improved using clinical risk scores with point-of-care (POC) troponin. In current EMS studies, three different clinical risk scores are used in patients suspected of NSTE-ACS: the prehospital History, ECG, Age, Risk and Troponin (preHEART) score, History, ECG, Age, Risk and Troponin (HEART) score and Troponin-only Manchester Acute Coronary Syndromes (T-MACS). The preHEART score lacks external validation and there exists no prospective comparative analysis of the different risk scores within the prehospital setting. The aim of this analysis is to externally validate the preHEART score and compare the diagnostic performance of the these three clinical risk scores and POC-troponin. Methods Prespecified analysis from a prospective, multicentre, cohort study in patients with suspected NSTE-ACS who were transported to an ED between April 2021 and December 2022 in the Netherlands. Risk stratification is performed by EMS personnel using preHEART, HEART, T-MACS and POC-troponin. The primary end point was the hospital diagnosis of NSTE-ACS. The diagnostic performance was expressed as area under the receiver operating characteristic (AUROC), sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV). Results A total of 823 patients were included for external validation of the preHEART score, final hospital diagnosis of NSTE-ACS was made in 29% (n=235). The preHEART score classified 27% as low risk, with a sensitivity of 92.8% (95% CI 88.7 to 95.7) and NPV of 92.3% (95% CI 88.3 to 95.1). The preHEART classified 9% of the patients as high risk, with a specificity of 98.5% (95% CI 97.1 to 99.3) and PPV of 87.7% (95% CI 78.3 to 93.4). Data for comparing clinical risk scores and POC-troponin were available in 316 patients. No difference was found between the preHEART score and HEART score (AUROC 0.83 (95% CI 0.78 to 0.87) vs AUROC 0.80 (95% CI 0.74 to 0.85), p=0.19), and both were superior compared with T-MACS (AUROC 0.72 (95% CI 0.66 to 0.79), p≤0.001 and p=0.03, respectively) and POC-troponin measurement alone (AUROC 0.71 (95% CI 0.64 to 0.78), p<0.001 and p=0.01, respectively). Conclusion On external validation, the preHEART demonstrates good overall diagnostic performance as a prehospital risk stratification tool. Both the preHEART and HEART scores have better overall diagnostic performance compared with T-MACS and sole POC-troponin measurement. These data support the implementation of clinical risk scores in prehospital clinical pathways. Trial registration number NCT05243485.

Background: Emergency Medical Services (EMS) patients with chest pain are often suspected of having non-ST-elevation acute coronary syndrome (NSTE-ACS). Current risk stratification protocols for NSTE-ACS have limitations, leading to a lack of a well-organised prehospital diagnostic pathway. Recent studies have demonstrated that using clinical risk scores (CRS) including point-of-care (POC)-troponin in the EMS can improve prehospital diagnostic pathways for suspected NSTE-ACS. The primary aim of this systematic review and individual patient data meta-analysis was to assess safety of low-risk stratification for suspected NSTE-ACS patients in the prehospital setting. Methods: Prospective studies using CRS or POC-troponin for risk stratification in suspected NSTE-ACS patients within the EMS setting were included. Safety was assessed using sensitivity and negative predictive value (NPV) for patients identified as low risk, based on CRS or POC-troponin measurement, for three different endpoints within 30 days: (1) all-cause mortality, (2) composite of mortality and/or acute myocardial infarction (AMI), (3) major adverse cardiac events (MACE). Results: Of 1526 articles screened, 6 were included, comprising 5.239 patients, and all utilised CRS derived from the History, ECG, Age, Risk-factor and Troponin (HEART) score. The summary of low-risk CRS diagnostic performance predicted all-cause mortality with a sensitivity of 93.2% (83.5–98.1) and NPV of 99.8% (99.5–99.9); mortality and/or AMI with a sensitivity of 91.8% (83.0–96.2) and an NPV of 97.3% (89.9–99.3); and MACE with a sensitivity of 92.8% (88.7–95.5) and an NPV of 97.2% (92.1–99.0). Lowering the CRS cut-off value for identifying low-risk patients increased sensitivity and NPV but decreased the proportion of patients classified as low risk. Conclusion: In well-trained EMS systems, where prompt and accurate follow-up of low-risk patients is possible, HEART-derived CRS effectively identify patients with a very low risk of 30-day mortality and MACE. However, implementation in other healthcare systems requires additional validation, given the variations in healthcare structure, risk stratification processes and follow-up capabilities.

Background: Triage and support in conveyance decision making of patients with undifferentiated chest pain is the next chapter after validation of the PreHEART score. The PreHEART 3 study tests whether a PreHEART score-guided emergency medical services (EMSs) conveyance is non-inferior to usual care with respect to unexpected serious adverse events in adults attended by EMS for undifferentiated chest pain. Methods: Pragmatic, randomised, open-label, blinded-endpoint non-inferiority trial was conducted in the Netherlands by Emergency Medical Services. 5170 adults attended by EMS for undifferentiated chest pain, randomised 1:1 to a conveyance decision guided by the prehospital PreHEART score versus usual care. Main outcome measures hierarchical composite of unexpected serious adverse events at 3 days, analysed by win ratio (non-inferiority threshold: lower bound of the 95% CI >0.80). Results: PreHEART-guided care was non-inferior (win ratio 1.01; 95% CI 0.89 to 1.16; p<0.001), with no deaths within 3 days among 1526 non-conveyed patients. It increased non-conveyance (34.6% vs 24.5%), reduced 30-day emergency presentations (risk ratio (RR) 0.88) and lowered costs (−€345). In women, acute coronary syndrome (ACS) diagnosis (RR 1.48) and angiography (RR 1.66) increased; multiplicative interactions were nominally significant but not after Holm correction. Conclusions : PreHEART-guided EMS conveyance was non-inferior to usual care for serious adverse events, reduced emergency department presentations and costs, and was associated with increased ACS detection and coronary angiography in women. Trial registration number: NL-OMON27238.