PowerPoint Slides for: Renal Function and Scaled Troponin in Patients Presenting to the Emergency Department with Symptoms of Myocardial Infarction
Background: Cardiac troponins are often found to be elevated in patients with renal dysfunction, even in the absence of acute myocardial injury. The objective of this report was to characterize the scaled troponin values and proportion of adjudicated acute myocardial infarction (AMI) among patients with and without renal dysfunction. Methods: The data was from a multicenter prospective study including patients presenting to the emergency department with symptoms of AMI. Troponin measurements were standardized across various assays by calculating the observed results as multiples of the assay-specific 99th percentile upper limit of normal. Patients with an estimated glomerular filtration rate (eGFR; calculated by the Chronic Kidney Disease Epidemiology Collaboration formula) <60 mL/min/1.73 m2 were considered to have renal dysfunction. Results: Of 430 included patients, 249 (58%) were male and 181 (42%) were female, with a mean age of 55.9 ± 12.3 and 57.3 ± 12.8 years, respectively. Eighty-seven (20.2%) had renal dysfunction. The proportions of patients with at least one scaled troponin value above the 99th percentile cut-off point among patients with and without renal dysfunction were 40 (45.9%) and 81 (23.6%) respectively (p < 0.001). The proportions of patients with an adjudicated diagnosis of AMI among those with and without renal dysfunction were 20.7 and 18.7%, respectively (p = 0.67). Using scaled troponins, by the second test there was >5X and by the third test >15X separation in the excursion of troponin among those with AMI compared to those without. Conclusions: One or more elevated troponin values are common in those with renal dysfunction. Scaled troponins for eGFR groups were similar, indicating that the use of this interpretative technique is applicable in discerning AMI for those with and without renal dysfunction.