Evaluation of acute myocardial infarction using a change in high-sensitivity cardiac troponin i over 1 hour
Hana A, McCord J, Hudson MP, Cook B, Mueller C, Miller J, Moyer M, Akoegbe G, Jacobsen G, and Nowak RM. Evaluation of acute myocardial infarction using a change in high-sensitivity cardiac troponin i over 1 hour. Journal of the American College of Cardiology 2020; 75(11):19.
J Am Coll Cardiol
Background The use of a high sensitivity cardiac troponin (hs-cTn) 0/1-hour algorithm to evaluate for acute myocardial infarction (AMI) has been widely studied outside the United States (US). The algorithm divides patients into a rule-out, observation, or rule-in zone. This study evaluated the 0/1-hour algorithm using hs-cTnI in a US cohort. Methods Patients (N=552) at a single US urban emergency department (ED) were enrolled if they had symptoms suggestive of AMI which led the clinician to order cardiac markers. Patients with an ECG that led to immediate reperfusion therapy or required resuscitation were excluded. Baseline and 1-hour blood samples for hs-cTnI (Beckman Coulter) were obtained. AMI diagnosis was independently adjudicated by 2 physicians using the universal definition of AMI and measurement of hs-cTnT (Roche Diagnostics) at 0,1 and 3 hours. Results In total, 45(8.2%) had AMI during the index hospitalization while at 30 days events occurred in 14(2.5%) of patients (3 cardiac deaths, 2 non-cardiac deaths, 8 additional MIs, and 4 revascularizations). Hs-cTnI (0/1-hour) algorithm rule-out zone had high negative predictive value for AMI (99.6%), while the rule-in zone had moderate positive predictive value for AMI (56.6%). Conclusion We demonstrated that the rule-out zone of the 0/1-hour algorithm using a hs-cTnI assay has high negative predictive value for AMI and identifies patients with a good 30-day prognosis. These patients may be considered for early discharge from the ED.