24 Influence of Renal Dysfunction on High-Sensitivity Cardiac Troponin I for Diagnostic Accuracy of Myocardial Infarction and Outcomes Assessment. (11th January 2018)

• Record Type: Journal Article
• Authors: Gunsolus, Ian; Smith, Stephen; Herzog, Charles; Sexter, Anne; Apple, Fred
• Is Part Of: American journal of clinical pathology. Volume 149(2018)Supplement 1
• Page Start: S176
• Page End: S176
• Publication Date: 2018-01-11
• Subjects: Diagnosis, Laboratory -- Periodicals; Pathology -- Periodicals; 616.07
• DOI: 10.1093/ajcp/aqx149.393
• Languages: English
• ISSNs: 0002-9173

Abstract

Abstract: Renal dysfunction is known to increase the risk of cardiovascular events such as acute myocardial infarction (MI). The goals of the current study were to evaluate, according to varying renal function, the diagnostic accuracy of a high-sensitivity cardiac troponin I (hs-cTnI) assay both for MI and for outcomes in patients presenting to the emergency department with symptoms suggestive of ischemia. Enrolled were 1555 consecutive patients who presented to the emergency department with clinical indications suggestive of MI, with at least two hs-cTnI measurements (UTROPIA; NCT02060760). hs-cTnI was measured on the Abbott ARCHITECT using sex-specific 99th percentile upper reference limits (URL: female 16 ng/L; male 34 ng/L). MI was adjudicated along universal MI guidelines. One-hundred-eighty-day mortality outcomes were determined. Renal function was defined by eGFR (mL/min/1.73m 2 ; MDRD). Categorical variables were compared using Pearson χ-square test and continuous variables were compared using the F-test. Cox model assessed mortality with respect to both renal insufficiency and cTn together. Sensitivities (0h 68%, 3h 92%, 6h 94%) and negative predictive values (NPVs; 0h 97%, 3 and 6h >99%) were not significantly affected by renal function. However, specificities decreased with impaired renal function; ranging 90%-92% with normal renal function (eGFR ≥60; n = 1168); 68%-79% with impaired renal function (eGFR ≥30–59; n = 227); 56–60% with severely impaired renal function (eGFR <30; n = 83); 40%-42% in the dialysis group (n = 77). Positive predictive values (PPVs) also decreased with decreasing renal function; ranging 45%-57% with normal renal function, 35%-50% with impaired renal function; 29%-44% with severely impaired renal function; 15%-32% on dialysis. One-hundred-eighty-day all-cause mortality increased significantly with increasing hs-cTnI tertile (1.3%, 6.0%, 10.4%) and was significantly higher in patients with hs-cTnI greater than sex-specific URLs (11.7%) compared to patients with concentrations between their sex-specific URL and the LOD (6.2%) vs concentrations less than LOD (1.1%). In conclusion, our results suggest that renal dysfunction and dialysis treatment reduced the rule-in performance of hs-cTnI for AMI, and that mortality increased in patients with higher hs-cTnI concentrations and any level of renal dysfunction.