Glomerular Filtration Rate-Specific Cutoffs Can Refine the Prognostic Value of Circulating Cardiac Biomarkers in Advanced Chronic Kidney Disease

Troponin Cut-Offs for Acute Myocardial Infarction in Patients with Impaired Renal Function—A Systematic Review and Meta-Analysis

Identifying acute myocardial infarction in patients with renal disease is notoriously difficult, due to atypical presentation and chronically elevated troponin. The aim of this study was to identify a specific troponin T/troponin I cut-off value for diagnosis of acute myocardial infarction in patients with renal impairment via meta-analysis. Two investigators screened 2590 publications from MEDLINE, Embase, PubMed, Web of Science, and the Cochrane library. Only studies that investigated alternative cut-offs according to renal impairment were included. Fifteen articles fulfilled the inclusion criteria. Six studies were combined for meta-analysis. The manufacturer’s upper reference level for troponin T is 14 ng/L. Based on the meta-analyses, cut-off values for troponin in patients with renal impairment with myocardial infarction was 42 ng/L for troponin I and 48 ng/L for troponin T. For patients on dialysis the troponin T cut-off is even higher at 239 ng/L. A troponin I cut-off value for dialysis patients could not be established due to lack of data. The 15 studies analyzed showed considerable diversity in study design, study population, and the definition of myocardial infarction. Further studies are needed to define a reliable troponin cut-off value for patients with kidney disease, especially in dialysis patients, and to allow necessary subanalysis.

High-Sensitivity Cardiac Troponin T in Patients with Severe Chronic Kidney Disease and Suspected Acute Coronary Syndrome

(1) Background: Patients with severe chronic kidney disease (CKD G4-G5) often have chronically elevated high-sensitivity cardiac troponin T (hs-cTnT) values above the 99th percentile of the upper reference limit. In these patients, optimal cutoff levels for diagnosing non-ST-elevation acute coronary syndrome (NSTE-ACS) requiring revascularization remain undefined. (2) Methods: Of 11,912 patients undergoing coronary angiography from 2012 to 2017 for suspected NSTE-ACS, 325 (3%) had severe CKD. Of these, 290 with available serial hs-cTnT measurements were included, and 300 matched patients with normal renal function were selected as a control cohort. (3) Results: In the CKD cohort, 222 patients (76%) had NSTE-ACS with indication for coronary revascularization. Diagnostic performance was high at presentation and similar to that of the control population (AUC, 95% CI: 0.81, 0.75-0.87 versus 0.85, 0.80-0.89, p = 0.68), and the ROC-derived cutoff value was 4 times higher compared to the conventional 99th percentile. Combining the ROC-derived cutoff levels for hs-cTnT at presentation and absolute 3 h changes, sensitivity increased to 98%, and PPV and NPV improved up to 93% and 86%, respectively. (4) Conclusions: In patients with severe CKD and suspected ACS, the diagnostic accuracy of hs-cTnT for the diagnosis of NSTE-ACS requiring revascularization is improved by using higher assay-specific cutoff levels combined with early absolute changes.

Variability of high-sensitivity cardiac troponin T and I in asymptomatic patients receiving hemodialysis

Variation of high-sensitivity cardiac troponin I and T (hs-cTn) during hemodialysis has been observed. Observational studies demonstrated the increased incidence of adverse cardiovascular events after long compared to short interdialytic intervals. Therefore, we aimed to compare variation of hs-cTnI and hs-cTnT before and after hemodialysis and between short and long interdialytic intervals. We enrolled 200 asymptomatic patients receiving regular hemodialysis. The hs-cTnI and hs-cTnT levels were measured before and after hemodialysis on the day after short and long interdialytic intervals. Mean age was 62.3 ± 14.8 years (Male 55.5%). Prevalence of increased hs-cTnI and hs-cTnT was 34.5% and 99.0%, respectively. The median ± interquartile range of hs-cTnT increased significantly after hemodialysis during short and long interdialytic intervals. However, hs-cTnI level did not increase after hemodialysis during short and long intervals. We found that levels of hs-cTnI and T did not differ between short interdialytic and long interdialytic intervals. We demonstrated higher prevalence of elevated hs-cTnT in patients with regular hemodialysis compared to hs-cTnI. The rise of hs-cTnT was observed immediately after hemodialysis but no significant change of hs-cTnI was noted. Accordingly, hs-cTnI may be preferable as a diagnostic marker in patients with suspected acute myocardial infarction than hs-cTnT.