Rule-out of non-ST-segment elevation acute coronary syndrome by a single, pre-hospital troponin measurement: a randomized trial.

AIMS: Patients with suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) are routinely transferred to the emergency department (ED). A clinical risk score with point-of-care (POC) troponin measurement might enable ambulance paramedics to identify low-risk patients in whom ED evaluation is unnecessary. The aim was to assess safety and healthcare costs of a pre-hospital rule-out strategy using a POC troponin measurement in low-risk suspected NSTE-ACS patients. METHODS AND RESULTS: This investigator-initiated, randomized clinical trial was conducted in five ambulance regions in the Netherlands. Suspected NSTE-ACS patients with HEAR (History, ECG, Age, Risk factors) score ≤3 were randomized to pre-hospital rule-out with POC troponin measurement or direct transfer to the ED. The sample size calculation was based on the primary outcome of 30-day healthcare costs. Secondary outcome was safety, defined as 30-day major adverse cardiac events (MACE), consisting of ACS, unplanned revascularization or all-cause death. : A total of 863 participants were randomized. Healthcare costs were significantly lower in the pre-hospital strategy (€1349 ± €2051 vs. €1960 ± €1808) with a mean difference of €611 [95% confidence interval (CI): 353-869; P < 0.001]. In the total population, MACE were comparable between groups [3.9% (17/434) in pre-hospital strategy vs. 3.7% (16/429) in ED strategy; P = 0.89]. In the ruled-out ACS population, MACE were very low [0.5% (2/419) vs. 1.0% (4/417)], with a risk difference of -0.5% (95% CI -1.6%-0.7%; P = 0.41) in favour of the pre-hospital strategy. CONCLUSION: Pre-hospital rule-out of ACS with a POC troponin measurement in low-risk patients significantly reduces healthcare costs while incidence of MACE was low in both strategies. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT05466591 and International Clinical Trials Registry Platform id NTR 7346.

Cardiac Troponin Composition Characterization after Non ST-Elevation Myocardial Infarction: Relation with Culprit Artery, Ischemic Time Window, and Severity of Injury.

BACKGROUND: Troponin composition characterization has been implicated as a next step to differentiate among non-ST elevation myocardial infarction (NSTEMI) patients and improve distinction from other conditions with troponin release. We therefore studied coronary and peripheral troponin compositions in relation to clinical variables of NSTEMI patients. METHODS: Samples were obtained from the great cardiac vein (GCV), coronary sinus (CS), and peripheral circulation of 45 patients with NSTEMI. We measured total cTnI concentrations, and assessed both complex cTnI (binary cTnIC + all ternary cTnTIC forms), and large-size cTnTIC (full-size and partially truncated cTnTIC). Troponin compositions were studied in relation to culprit vessel localization (left anterior descending artery [LAD] or non-LAD), ischemic time window, and peak CK-MB value. RESULTS: Sampling occurred at a median of 25 hours after symptom onset. Of total peripheral cTnI, a median of 87[78-100]% consisted of complex cTnI; and 9[6-15]% was large-size cTnTIC. All concentrations (total, complex cTnI, and large-size cTnTIC) were significantly higher in the CS than in peripheral samples (P < 0.001). For LAD culprit patients, GCV concentrations were all significantly higher; in non-LAD culprit patients, CS concentrations were higher. Proportionally, more large-size cTnTIC was present in the earliest sampled patients and in those with the highest CK-MB peaks. CONCLUSIONS: In coronary veins draining the infarct area, concentrations of both full-size and degraded troponin were higher than in the peripheral circulation. This finding, and the observed associations of troponin composition with the ischemic time window and the extent of sustained injury may contribute to future characterization of different disease states among NSTEMI patients.

Pre-hospital rule-out of non-ST-segment elevation acute coronary syndrome by a single troponin: final one-year outcomes of the ARTICA randomised trial.

BACKGROUND AND AIMS: The healthcare burden of acute chest pain is enormous. In the randomised ARTICA trial we showed that pre-hospital identification of low-risk patients and rule-out of non-ST-segment elevation acute coronary syndrome (NSTE-ACS) with point-of-care (POC) troponin measurement reduces 30-day healthcare costs with low major adverse cardiac events (MACE) incidence. Here we present the final one-year results of the ARTICA trial. METHODS: Low-risk patients with suspected NSTE-ACS were randomised to pre-hospital rule-out with POC troponin measurement or emergency department (ED) transfer. Primary one-year outcome was healthcare costs. Secondary outcomes were safety, quality of life (QoL) and cost-effectiveness. Safety was defined as one-year MACE, consisting of ACS, unplanned revascularisation or all-cause death. QoL was measured with EuroQol-5D-5 L questionnaires. Cost-effectiveness was defined as one-year healthcare costs difference per QoL difference. RESULTS: Follow-up was completed in all 863 patients. Healthcare costs were significantly lower in the pre-hospital strategy (€1932±€2784 vs €2649±€2750), mean difference €717 (95% confidence interval [CI] €347 to €1087; P < 0.001). In the total population, one-year MACE rate was comparable between groups (5.1% [22/434] in the pre-hospital strategy vs 4.2% [18/429] in the ED strategy; P = 0.54). In the ruled-out ACS population, one-year MACE remained low (1.7% [7/419] vs 1.4% [6/417]), risk difference 0.2% (95% CI -1.4% to 1.9%; P = 0.79). QoL showed no significant difference between strategies. CONCLUSIONS: Pre-hospital rule-out of NSTE-ACS with POC troponin testing in low-risk patients is cost-effective, expressed by a sustainable healthcare costs reduction and no significant effect on QoL. One-year MACE remained low for both strategies. Trial registration: Clinicaltrials.gov: NCT05466591, International Clinical Trials Registry Platform: NTR7346.

Differences in risk and costs between prehospital identified low-risk men and women with chest pain.

OBJECTIVE: Prehospital rule-out of non-ST-segment elevation acute coronary syndrome (NSTE-ACS) in low-risk patient with a point-of-care troponin measurement reduces healthcare costs with similar safety to standard transfer to the hospital. Risk stratification is performed identical for men and women, despite important differences in clinical presentation, risk factors and age between men and women with NSTE-ACS. Our aim was to compare safety and healthcare costs between men and women in prehospital identified low-risk patients with suspected NSTE-ACS. METHODS: In the Acute Rule-out of non-ST-segment elevation acute coronary syndrome in the (pre)hospital setting by HEART (History, ECG, Age, Risk factors and Troponin) score assessment and a single poInt of CAre troponin randomised trial, the HEAR (History, ECG, Age and Risk factors) score was assessed by ambulance paramedics in suspected NSTE-ACS patients. Low-risk patients (HEAR score ≤3) were included. In this substudy, men and women were compared. Primary endpoint was 30-day major adverse cardiac events (MACE), secondary endpoints were 30-day healthcare costs and the scores for the HEAR score components. RESULTS: A total of 863 patients were included, of which 495 (57.4%) were women. Follow-up was completed in all patients. In the total population, MACE occurred in 6.8% of the men and 1.6% of the women (risk ratio (RR) 4.2 (95% CI 1.9 to 9.2, p<0.001)). In patients with ruled-out ACS (97% of the total population), MACE occurred in 1.4% of the men and in 0.2% of the women (RR 7.0 (95% CI 2.0 to 14.2, p<0.001). Mean healthcare costs were €504.55 (95% CI €242.22 to €766.87, p<0.001) higher in men, mainly related to MACE. CONCLUSIONS: In a prehospital population of low-risk suspected NSTE-ACS patients, 30-day incidence of MACE and MACE-related healthcare costs were significantly higher in men than in women. TRIAL REGISTRATION NUMBER: NCT05466591.

Implementation of the ESC 0 h/1h algorithm and the HEART score in the emergency department: A prospective cohort study.

Background: The European Society of Cardiology (ESC) 0 h/1h algorithm is the preferred diagnostic strategy for chest pain patients in the emergency department (ED). It is suggested that adding clinical information to the algorithm improves its diagnostic performance. This study evaluates implementation of the ESC 0 h/1h algorithm in the ED and investigates the potential advantages of combining it with a clinical decision rule, which might be especially relevant in the heterogenous observation category. Methods: In this prospective cohort study, chest pain patients in whom the ESC 0 h/1h algorithm was applied were enrolled. HEART score components were collected. Diagnostic characteristics were determined for the algorithm with and without addition of the HEART score. Primary endpoint was a composite endpoint at 30-day follow-up, consisting of myocardial infarction and death. Results: A total of 668 patients were enrolled. The rule-in and rule-out categories consisted of 8.2% and 54.9% of the patients, respectively. Positive predictive value and specificity of the rule-in category were 67.3% and 97.1%, respectively. Negative predictive value (NPV) and sensitivity of the rule-out category were both 100%. In the observation category, a HEART score ≤ 3 yielded a NPV and sensitivity of 97.1% and 93.8%, respectively. Conclusion: The ESC 0 h/1h algorithm yielded a NPV and sensitivity of 100% for myocardial infarction and death at 30-day follow-up. Addition of the HEART score did not provide clinically relevant advantages. Although the HEART score can be used to guide diagnostic testing in the observation category, a low HEART score did not yield an NPV of > 99%.

A multi-site coronary sampling study on CRP in non-STEMI: Novel insights into the inflammatory process in acute coronary syndromes.

BACKGROUND AND AIMS: Inflammation has become a key element in cardiovascular disease, and recently, new anti-inflammatory interventions have shown promising results. In this context, CRP levels have been thoroughly studied in vitro and in animals, but studies in humans are scarce and insights into its release, site(s) of production and uptake are not uniform. METHODS: We performed a biomarker study with multi-site sampling in the coronary circulation, in non-ST elevation MI (NSTEMI) patients with coronary angiography and right-sided catheterisation. Trans-lesional gradients were obtained by sampling distal to the culprit lesion, in patients with a suitable anatomy. To asses trans-cardiac gradients, blood was sampled from the systemic circulation, coronary sinus (CS) and great cardiac vein. Concentrations of CRP were measured with a high-sensitivity assay. RESULTS: In 42 patients, a median systemic venous CRP concentration of 4.97 mg/L was observed. There was no evidence of a trans-lesional gradient (4.59 mg/L versus 4.56 mg/L, p = 0.278; n = 14). A significant decrease in CRP concentration was observed between systemic arterial and CS samples (4.88 mg/L versus 4.44 mg/L; p < 0.001; n = 42). This trans-cardiac gradient was irrespective of time of presentation, infarct size and culprit lesion location. The gradient was not only driven by blood that ran through the injured myocardium, but also by lower CRP concentrations in the coronary veins that drain non-infarcted myocardium. CONCLUSIONS: In the context of NSTEMI, we observed a trans-cardiac decrease in CRP, which may indicate the first human in vivo proof of a net CRP uptake by the myocardium, with a role for CRP both in the injured and adjacent myocardium.