Frequency of Troponin Testing in Inpatient Versus Outpatient Settings

Troponin elevation is required to diagnose acute myocardial infarction (AMI), yet elevated values are often encountered in noncardiac disease states. We evaluated inpatient (IP) and outpatient (OP) encounters at 14 hospitals in calendar year 2014 and found that troponin assays were performed during 12% of all OP visits and 29% of all IP visits: 82,853 encounters in all. We employed an expert panel to estimate the likelihood of AMI based on primary International Statistical Classification of Diseases and Related Health Problems, 9th edition diagnoses. We compared IP and OP testing, finding that AMI would not be expected in most IP encounters. Sepsis was the most common diagnosis associated with IP troponin testing. We found an association between troponin testing in patients with sepsis and utilization of electrocardiography, echocardiography, and cardiac catheterization. Our data indicate that troponin testing has expanded beyond patient populations in whom AMI might be expected.