1Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie Hamburg, Deutschland; 2Universitäres Herz- und Gefäßzentrum Hamburg Allgemeine und Interventionelle Kardiologie Hamburg, Deutschland; 3Universitäres Herz- und Gefäßzentrum Hamburg Klinik und Poliklinik für Kardiologie Hamburg, Deutschland
Measurement of cardiac troponin has become a crucial tool for ruling-in and ruling-out acute myocardial infarction (MI). Recently, the American College of Cardiology published an expert consensus clinical decision pathway (CDP) for patients with Acute Chest Pain in the Emergency Department. This CDP allows for classification of chest pain patients with non-ischemic ECG findings according to high-sensitivity cardiac troponin (hs-cTn) measurements in low, intermediate and high risk of MI.
Furthermore, to discriminate the intermediate risk patients, a re-evaluation including the incorporation of an additional troponin measurement after 3-6 hours is proposed. No or minimal increase in hs-cTn with either recent normal testing, chronic elevation or low modified HEART Score (≤3) or EDACS (<16) should be reclassified as lower risk, whereas a significant increase in hs-cTn, ongoing or recurrent chest pain or new ECG findings consistent with ischemia should lead to a reclassification as high risk. For those not meeting the criteria described above non-invasive testing should be considered before discharge. While there is extensive data supporting the concept of MI risk categories, there is no evidence supporting the proposed approach of re-evaluation in intermediate risk patients.
Therefore, our aim was to apply the proposed CDP for intermediate risk patients in a contemporary cohort of patients presenting with suspected MI to analyze the diagnostic and prognostic performance.We used data from the prospective cohort study Biomarkers in Acute Cardiac Care, which recruited patients presenting in the emergency department with possible acute coronary syndrome. After clinical assessment in accordance with current ESC guidelines, the final diagnosis was independently determined by two clinicians based on the fourth universal definition of MI. All participants were followed to assess incident MI and all-cause mortality. We then applied the 0/1h and the intermediate-risk CDP as recommended by the expert consensus using four different hs-cTn assays (Elecsys hs-cTnT, Architect hs-cTnI, Access hs-cTnI, Atellica hs-cTnI).
In total, 2,571 patients were included for analysis and 364 (14.2%) were diagnosed with MI. The 0/1h algorithm provided a high negative predictive value (NPV) ranging from 99.2 (95% CI 98.3-99.6) for the Access assay to 99.6 (95% CI 99.1-99.8) for the Elecsys assay, and a moderate positive predictive value (PPV) ranging from 50.4 (95% CI 45.2-55.7) for the Access assay to 67.4 (95% CI 62.2-72.2) for the Atellica assay.
Importantly, within the intermediate risk group, the prevalence of MI was similar in those individuals classified as lower risk and those recommended for more testing. The 1-year-mortality ranged from 6.66% to 8.31% in the higher risk subgroup, 2.84% to 10.59% in the lower risk subgroup and 5.15% to 8.0% for the subgroup indicated for more testing.
Our analyses provide the first clinical application of a recently recommended CDP for patients with suspected MI published by the American College of Cardiology. We show an excellent diagnostic performance using the 0/1h CDP. In those patients classified as intermediate risk, a novel CDP provided limited diagnostic value, as the NPV and PPV were low and MI prevalence was not well distributed across the groups. Furthermore, no decisive prognostic performance of the novel CDP regarding 1-year-mortality was observed.