Peter A Kavsak1, Andrew Worster2, Colleen Shortt2, Jinhui Ma3, Natasha Clayton4, Jonathan Sherbino2, Stephen A Hill5, Matthew McQueen5, Lauren E Griffith3, Shamir R Mehta6, Andrew D McRae7, P J Devereaux6. 1. Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada. Electronic address: kavsakp@mcmaster.ca. 2. Division of Emergency Medicine, McMaster University, Hamilton, ON, Canada. 3. Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada. 4. Department of Medicine, McMaster University, Hamilton, ON, Canada. 5. Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada. 6. Division of Cardiology, and Population Health Research Institute, McMaster University, Hamilton, ON, Canada. 7. Department of Emergency Medicine, University of Calgary, Calgary, Alberta, Canada.
Abstract
BACKGROUND: Clinicians regularly observe increased high-sensitivity cardiac troponin (hs-cTn) concentrations in patients with low estimated glomerular filtration rate (eGFR). The challenge is to differentiate acute coronary syndrome (ACS) from increased hs-cTn results across a range of eGFR. The objective of this study was to determined the optimal hs-cTn concentrations for acute myocardial infarction (MI) and a composite cardiovascular outcome across different eGFR ranges and to assess the utility of a low hs-cTn cutoff to rule-out events. METHODS: We undertook an observational study in the emergency department of patients (n = 1212) with symptoms suggestive of ACS who had an eGFR and at least one Roche hs-cTnT and one Abbott hs-cTnI result. The 7-day outcomes were MI or a composite of MI, unstable angina, congestive heart failure, serious ventricular cardiac arrhythmia, or death. The maximum hs-cTn concentration was assessed across different eGFR ranges (<30,30-59,60-89,≥90 ml/min/1.73m2) by spearman correlation, ROC-curve analyses, and sensitivity and negative predictive value (NPV) for the proposed rule-out hs-cTn cutoffs (hs-cTnI<5 ng/l and hs-cTnT<6 ng/l) for the outcomes. RESULTS: Both hs-cTnI and hs-cTnT concentrations were negatively correlated with eGFR. The lower the eGFR, the lower the AUC and the higher the optimal hs-cTn cutoffs for both MI and the composite outcome. The highest combined sensitivity (100%), NPV (100%) and proportion of low-risk for MI (45% of group) was observed for patients with hs-cTnT<6 ng/l with an eGFR≥90. CONCLUSION: The test performance for hs-cTn for diagnosing or ruling-out an acute cardiac event varies per the eGFR. Accurate risk stratification requires knowledge of the eGFR.
BACKGROUND: Clinicians regularly observe increased high-sensitivity cardiac troponin (hs-cTn) concentrations in patients with low estimated glomerular filtration rate (eGFR). The challenge is to differentiate acute coronary syndrome (ACS) from increased hs-cTn results across a range of eGFR. The objective of this study was to determined the optimal hs-cTn concentrations for acute myocardial infarction (MI) and a composite cardiovascular outcome across different eGFR ranges and to assess the utility of a low hs-cTn cutoff to rule-out events. METHODS: We undertook an observational study in the emergency department of patients (n = 1212) with symptoms suggestive of ACS who had an eGFR and at least one Roche hs-cTnT and one Abbott hs-cTnI result. The 7-day outcomes were MI or a composite of MI, unstable angina, congestive heart failure, serious ventricular cardiac arrhythmia, or death. The maximum hs-cTn concentration was assessed across different eGFR ranges (<30,30-59,60-89,≥90 ml/min/1.73m2) by spearman correlation, ROC-curve analyses, and sensitivity and negative predictive value (NPV) for the proposed rule-out hs-cTn cutoffs (hs-cTnI<5 ng/l and hs-cTnT<6 ng/l) for the outcomes. RESULTS: Both hs-cTnI and hs-cTnT concentrations were negatively correlated with eGFR. The lower the eGFR, the lower the AUC and the higher the optimal hs-cTn cutoffs for both MI and the composite outcome. The highest combined sensitivity (100%), NPV (100%) and proportion of low-risk for MI (45% of group) was observed for patients with hs-cTnT<6 ng/l with an eGFR≥90. CONCLUSION: The test performance for hs-cTn for diagnosing or ruling-out an acute cardiac event varies per the eGFR. Accurate risk stratification requires knowledge of the eGFR.
Authors: Peter A Kavsak; Johannes T Neumann; Louise Cullen; Martin Than; Colleen Shortt; Jaimi H Greenslade; John W Pickering; Francisco Ojeda; Jinhui Ma; Natasha Clayton; Jonathan Sherbino; Stephen A Hill; Matthew McQueen; Dirk Westermann; Nils A Sörensen; William A Parsonage; Lauren Griffith; Shamir R Mehta; P J Devereaux; Mark Richards; Richard Troughton; Chris Pemberton; Sally Aldous; Stefan Blankenberg; Andrew Worster Journal: CMAJ Date: 2018-08-20 Impact factor: 8.262