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Aims: Troponin is the gold-standard for diagnostic evaluation of patients with suspected myocardial infarction (MI). We aimed to evaluate the diagnostic and prognostic performance of a new ultra-sensitivity troponin I (us-TnI) assay in patients with suspected MI., Methods and Results: 1534 patients with suspected MI were included. Us-TnI measurements were performed directly on admission and after one hour. One-year rates of mortality and incident MI were assessed. For diagnostic evaluation the negative and positive predictive value (NPV/PPV) using admission us-TnI concentrations and 0/1h delta were calculated. For rule-out an NPV > 99.5% (100% for single-admission-value) and for rule-in a PPV > 80% was targeted. Internal derivation/validation was used. In the derivation dataset 155/767 (20.2%) patients were diagnosed with having non-ST-elevation MI (NSTEMI). For rule-out of NSTEMI an us-TnI < 1 ng/L directly on admission resulted in an NPV of 100.0% (CI 98.2-100.0). Using serial sampling an admission us-TnI < 2 ng/L and a 0/1h delta < 1 ng/L resulted in an NPV of 99.7% (CI 98.4-100.0) and ruled-out NSTEMI in 46.8% of all patients. The respective one-year rate of death or MI was 0.6%. For rule-in of NSTEMI an us-TnI ≥ 25 ng/L on admission or a 0/1h delta ≥ 6 ng/L resulted in a PPV of 81.3% (CI 73.7-87.5) and ruled-in NSTEMI in 18.5% of all patients. The one-year event rate was 12.7%. Results were similar in 767 patients from the validation cohort., Conclusion: Application of an us-TnI assay allows the accurate triage of a large proportion of patients with suspected MI using a 0/1h algorithm., Trial Registration: www.clinicaltrials.gov (NCT02355457)., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: The safety of the European Society of Cardiology (ESC) 0/1-h algorithm for rapid rule-out and rule-in of non-ST-segment elevation myocardial infarction (NSTEMI) using high-sensitivity cardiac troponin (hs-cTn) has been questioned., Objectives: This study aimed to validate the diagnostic performance of the 0/1-h algorithm in a large multicenter study., Methods: The authors prospectively enrolled unselected patients in 6 countries presenting to the emergency department with symptoms suggestive of NSTEMI. Final diagnosis was centrally adjudicated by 2 independent cardiologists. Hs-cTnT and hs-cTnI blood concentrations were measured at presentation and after 1 h. Safety of rule-out was quantified by the negative predictive value (NPV) for NSTEMI, accuracy of rule-in by the positive predictive value (PPV), and overall efficacy by the proportion of patients triaged towards rule-out or rule-in within 1 h., Results: Prevalence of NSTEMI was 17%. Among 4,368 patients with serial hs-cTnT measurements available, safety of rule-out (NPV 99.8%, 2,488 of 2,493), accuracy of rule-in (PPV 74.5%, 572 of 768), and overall efficacy were high by assigning three-fourths of patients either to rule-out (57%, 2,493 to 4,368) or rule-in (18%, 768 to 4,368). Similarly, among 3,500 patients with serial hs-cTnI measurements, safety of rule-out (NPV 99.7%, 1,528 of 1,533), accuracy of rule-in (PPV 62.3%, 498 of 800), and overall efficacy were high by assigning more than two-thirds of patients either to rule-out (44%, 1,533 of 3,500) or rule-in (23%, 800 of 3,500). Excellent safety was confirmed in multiple subgroup analyses including patients presenting early (≤3 h) after chest pain onset., Conclusions: The ESC 0/1-h algorithm using hs-cTnT and hs-cTnI is very safe and effective in triaging patients with suspected NSTEMI. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE]; NCT00470587; and Biomarkers in Acute Cardiac Care [BACC]; NCT02355457)., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Rule-out of non-ST-elevation myocardial infarction is based on consecutive measurements of cardiac troponins using the 99th percentile of the respective assay as cutoff. The new ESC guidelines alternatively offer rapid 1h algorithms with lower cutoffs than the 99th percentile for rule-out of non-ST-elevation myocardial infarction. We aimed to compare a recently introduced 1h algorithm based on a high-sensitivity cardiac troponin I (hs-TnI) cutoff of 6ng/L at 0h and 1h to the current standard of care using the 99th percentile (27ng/L) as cutoff with reference to follow-up events in a large chest pain cohort., Methods: Hs-TnI was measured at three time points (0h, 1h and 3h) in 1625 patients presenting with suspected myocardial infarction to the emergency department of the University-Medical Center Hamburg-Eppendorf. Seventy-five patients with ST-elevation myocardial infarction were excluded from the analysis. All-cause mortality, cardiac death, acute myocardial infarction, revascularization and cardiac rehospitalization after 12months were assessed., Results: Patients ruled out by the 1h algorithm showed significantly less cardiac rehospitalizations (12.84% vs. 17.66%; p<0.001), and overall mortality (1.30% vs 3.46%, p<0.001) compared to using the 99th percentile as cutoff. The majority of deaths were caused by non-cardiac reasons. Cardiac deaths were rare using the 1h algorithm (0.21%)., Conclusion: The commonly used 99th percentile as cutoff neglects patients with a high risk in the setting of acute chest pain., Trial Registration: www.clinicaltrials.gov (NCT02355457)., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Importance: Rapid and accurate diagnosis of acute myocardial infarction (AMI) currently constitutes an unmet need., Objective: To test a 1-hour diagnostic algorithm to diagnose AMI using a high-sensitivity troponin I assay with a new cutoff level of 6 ng/L., Design, Setting, and Participants: The Biomarkers in Acute Cardiac Care study is a prospective study that investigated the application of the troponin I assay for the diagnosis of AMI in 1040 patients presenting to the emergency department with acute chest pain from July 19, 2013, to December 31, 2014. Results were validated in 2 independent cohorts of 4009 patients. Final follow-up was completed on July 1, 2015, and data were assessed from July 2 to December 15, 2015., Exposure: Acute chest pain suggestive of AMI., Main Outcomes and Measures: Accurate diagnosis or exclusion of AMI and 12-month mortality in patients with acute chest pain., Results: Of the 1040 patients included from the study cohort, 673 (64.7%) were male and had a median age of 65 (interquartile range, 52-75) years. With application of a low troponin I cutoff value of 6 ng/L, the rule-out algorithm showed a high negative predictive value of 99.8% (95% CI, 98.6%-100.0%) after 1 hour for non-ST-segment elevation MI type 1. The 1-hour approach was comparable to a 3-hour approach. Similarly, a rule-in algorithm based on troponin I levels provided a high positive predictive value with 82.8% (95% CI, 73.2%-90.0%). Moreover, application of the cutoff of 6 ng/L resulted in lower follow-up mortality (1.0%) compared with the routinely used 99th percentile (3.7%) for this assay. Two independent cohorts further validated the performance of this algorithm with high negative and positive predictive values., Conclusions and Relevance: Patients with possible AMI can be triaged within 1 hour after admission with no loss of safety compared with a 3-hour approach, when a low and sensitive cutoff is applied. This concept enables safe discharge or rapid treatment initiation after 1 hour.

Objective: There is a clinical need for early and accurate diagnosis of acute myocardial infarction (AMI). Current European Society of Cardiology (ESC) guidelines recommend diagnosis of non-ST-elevation AMI based on serial troponin measurements. We aimed to challenge the ESC guidelines using 1) a high-sensitivity troponin I (hs-TnI) baseline cutoff, 2) an absolute hs-TnI change after 1 hour and 3) additional application of an ischemic ECG. Methods: 1,516 patients with suspected AMI presenting to the emergency department were included. Hs-TnI was measured directly at admission, after 1 and 3 hours. We investigated baseline concentrations, absolute changes of hs-TnI and additional application of an ischemic ECG to diagnose AMI. A positive predictive value (PPV) of more than 85% was targeted. Results: The median age of the study population was 65 years; 291 patients were diagnosed with AMI. The PPV of the 3-hours ESC algorithm was 85.5% (CI 79.7, 90.1) and 65.8% (CI 60.5,70.8) for the 1-hour algorithm. Using a high baseline hs-TnI concentration of 150 ng/L resulted in a PPV of 87.8% (CI 80.9,92.9). Alternatively, a hs-TnI change of 20 ng/L after 1 hour, resulted in a PPV of 86.5% (80.9,91.0), respectively for the diagnosis of AMI. Additional use of an ischemic ECG increased the PPV to 90.5% (CI 83.2,95.3), while reducing the efficacy. Conclusion: The diagnosis of AMI based on hs-TnI is challenging. The application of absolute hs-TnI changes after 1 hour may facilitate rapid rule-in of patients. Trial registration: (). [ABSTRACT FROM AUTHOR]