Are There Any Differences in Major Adverse Cardiac Events Between Undetectable vs. 99th Percentile High-Sensitivity Troponin? Jennifer Johnson, BA; Cristina Pelin, BA; Deshaun Allen. BS; Ryan Kenny, BS; Ajay Puri, MD; Mark Richman MD Department of Emergency Medicine, Northwell Health – Long Island Jewish Medical Center Donald and Barbara Zucker School of Medicine at Hofstra/Northwell
BACKGROUND • Acute Coronary Syndrome is a leading cause of death in the United States. Proper diagnosis is important for navigating appropriate treatment options. Troponin is the most-commonly used, “gold-standard” cardiac biomarker, and recent generations of have become more and more sensitive, yet have led to more false positives, and can be associated with increased patient financial burden, stress, and time spent in the ED. • LIJ Emergency Department's (ED's) ACS work-up algorithm says patients with undetectable high-sensitivity (HS) troponin (<6 ng/L) at least 3 hours after cardiac symptom onset do not need a repeat troponin, whereas patients with troponin 6-14 ng/L (detectable, but within the 99th percentile) require a repeat troponin 1 hour after the first troponin was drawn.
RESULTS Figure 1: CONSORT Diagram: Eligibility, Exclusion Criteria, and Randomization of Patients with Index Visit Initial Troponin Values
OBJECTIVE + HYPOTHESIS • Investigate whether patients with initial troponin results 6-14 ng/L (99th percentile) have significantly different rates or types of 30-day major adverse cardiac events (MACEs) than patients with initial troponin results <6 ng/L (undetectable). Finding no difference would support modifying LIJ ED's ACS work-up algorithm to expand the troponin values not requiring 1-hour repeat troponin from <6 ng/L to ≤14 ng/L.
METHODS • Setting: Single academic, urban, tertiary care adult Emergency Department (ED) with an annual volume of ~100,000 patients. • Participants: All adult ED patients with a troponin from July 1 – Dec. 31, 2017 and July 1 – Dec. 31, 2018 • Inclusion: High-sensitivity troponin ordered in ED. • Exclusion : <18 years old or confounding variables that elevate troponin, such as CHF, PE, sepsis, CKD, pericarditis, and myocarditis. • Statistics: Students T-test will be used to evaluate continuous parametric variables and Mann-Whitney for non-parametric values. Chi square analysis will be used to determine significance for proportions. ANOVA will be used for analysis of multiple comparisons. POSTER TEMPLATES BY:
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CONCLUSIONS • Pulmonary embolism (PE), sepsis, myocarditis, pericarditis, renal failure, and CHF cause troponin elevation. Patients with these conditions may have elevated values due to their condition, rather than to ACS. Excluding these patients enables a more accurate analysis of MACE differences between undetectable vs. 99th percentile HS troponin. • Both acute and chronic CHF cause elevated troponin. Patients with both a history of CHF, and whose index ED diagnosis was CHF, were excluded. • Patients with sepsis, myocarditis, pericarditis, and PE were excluded only if they were the index ED diagnosis, as these are rarely chronic. • Balancing the need for efficient and accurate diagnostic measures for myocardial injury and prevention of overcrowding in an ED via timely management of patients is challenging.
FUTURE DIRECTION
REFERENCES • Sethi A, Bajaj A, Malhotra G, Arora RR, Khosla S. Diagnostic accuracy of sensitive or high-sensitive troponin on presentation for myocardial infarction: a meta-analysis and systematic review. Vasc Health Risk Manag. 2014;10:435-450. Published 2014 Jul 21. doi:10.2147/VHRM.S63416 • Morrow DA, Cannon CP, Jesse RL, et al. National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines: clinical characteristics and utilization of biochemical markers in acute coronary syndromes. Clin Chem. 2007 Apr;53(4):55274. PMID: 17384001. • Roongsritong C, Warraich I, Bradley C. Common causes of troponin elevations in the absence of acute myocardial infarction: incidence and clinical significance. Chest. 2004 May;125(5):1877-84. PMID: 15136402. • Anda Bularga, Kuan Ken Lee, Stacey Stewart, Amy V. Ferry, Andrew R. Chapman, Lucy Marshall, Fiona E. Strachan, Anne Cruickshank, Donogh Maguire, Colin Berry, Iain Findlay, Anoop S.V. Shah, David E. Newby, Nicholas L. Mills, Atul Anand, On behalf of the High-STEACS Investigators. High-Sensitivity Troponin and the Application of Risk Stratification Thresholds in Patients With Suspected Acute Coronary Syndrome. Circulation. 2019;140:1557–1568. doi.org/10.1161/CIRCULATIONAHA.119.042866
• These initial steps have set the groundwork for the remainder of our project, including exclusion of patients with other explanations for elevated troponin, particularly decreased glomerular filtration rate (GFR). • We will characterize patients according to demographic characteristics such as age, gender, and race. • Additionally, this will enable us to perform descriptive statistics showing associations between demographic variables and troponin values, which will ultimately lead to our analysis: performing inferential statistics to demonstrate whether troponin values in different ranges were associated with different MACE outcomes.