Predicting Acute Myocardial Infarction with a Single Blood Draw

• Published in: Clinical chemistry (Baltimore, Md.) Md.), 2019-03, Vol.65 (3), p.437-450
• Main Authors: Boeddinghaus, Jasper, Nestelberger, Thomas, Badertscher, Patrick, Twerenbold, Raphael, Fitze, Brigitte, Wussler, Desiree, Strebel, Ivo, Rubini Giménez, Maria, Wildi, Karin, Puelacher, Christian, du Fay de Lavallaz, Jeanne, Oehen, Loris, Walter, Joan, Miró, Òscar, Martin-Sanchez, F Javier, Morawiec, Beata, Potlukova, Eliska, Keller, Dagmar I, Reichlin, Tobias, Mueller, Christian
• Format: Article
• Language: English
• Subjects: Acute coronary syndromes; Acute Disease; Aged; Aged, 80 and over; Angina pectoris; Angiography; Biomarkers; Biomarkers - blood; Blood Chemical Analysis - methods; Calcium-binding protein; Cardiology; Clinical decision making; Decision making; Diagnostic systems; Electrocardiography; Emergency medical services; Family medical history; Female; Heart; Heart attacks; Humans; Laboratories; Male; Medical imaging; Middle Aged; Myocardial infarction; Myocardial Infarction - diagnosis; Patients; Predictive Value of Tests; Prospective Studies; Signs and symptoms; Statistical analysis; Troponin; Troponin I - blood; Troponin T - blood
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1373/clinchem.2018.294124

We desired to determine cardiac troponin (cTn) concentrations necessary to achieve a positive predictive value (PPV) of ≥75% for acute myocardial infarction (AMI) to justify immediate admission of patients to a monitored unit and, in general, early coronary angiography. In a prospective multicenter diagnostic study enrolling patients presenting to the emergency department with symptoms suggestive of AMI, final diagnoses were adjudicated by 2 independent cardiologists based on clinical information including cardiac imaging. cTn concentrations were measured using 5 different sensitive and high-sensitivity cTn (hs-cTn) assays in a blinded fashion at presentation and serially thereafter. The diagnostic end point was PPV for rule-in of AMI of initial cTn concentrations alone and in combination with early changes. Among 3828 patients, 616 (16%) had an AMI. At presentation, 7% to 14% of patients had cTnT/I concentrations associated with a PPV of ≥75%. Adding absolute or relative changes did not significantly further increase the PPV. PPVs increased from 46.5% (95% CI, 43.6-49.4) for hs-cTnT at presentation >14 ng/L to 78.9% (95% CI, 74.7-82.5) for >52 ng/L ( < 0.001), whereas PPVs in higher hs-cTnT strata remained largely unchanged [e.g., 82.4% (95% CI, 77.5-86.7) for >80 ng/L vs 83.9% (95% CI, 76.0-90.1) for >200 ng/L ( = 0.72)]. The addition of early changes in hs-cTnT further increased the PPV up to 60 ng/L, but not for higher concentrations. Serial sampling does not seem necessary for predicting AMI and concurrent decision-making in about 10% of patients, as it only marginally increases the PPV for AMI and not in a statistically or clinically significant way. NCT00470587.