Diagnostic Performance of Initial High-Sensitivity Troponin I in Patients with Renal Dysfunction: A Systematic Review and Narrative Synthesis

Background and Objectives: Initial high-sensitivity cardiac troponin I (hs-cTnI) measurements can be difficult to interpret in patients with renal dysfunction because elevated concentrations may occur without acute myocardial infarction (AMI). This systematic review compared reported optimal hs-cTnI cutoffs and their diagnostic performance across assay platforms and patient subgroups. Materials and Methods: PubMed/MEDLINE, Embase, the Cochrane Library, and Web of Science were searched from inception to 21 August 2026. Studies evaluating initial hs-cTnI measurements in adults with renal dysfunction and reporting diagnostic cutoffs with corresponding sensitivity and specificity for AMI were eligible. Risk of bias was assessed using QUADAS-2. Findings were synthesized narratively because of clinical and methodological heterogeneity; no meta-analysis was performed. Results: Five studies were included. In studies analyzing patients with an estimated glomerular filtration rate below 60 mL/min/1.73 m2 as a single group, optimal cutoffs ranged from 25.9 to 54 ng/L, with sensitivities of 76–88.4% and specificities of 83–90%. One study reported substantially higher cutoffs of 500–2610 ng/L across selected subgroups defined by CKD stage, age, and sex, with sensitivities of 80.4–91.4% and specificities of 92.1–100%. In patients receiving dialysis, cutoffs were 75 ng/L for hemodialysis and 144 ng/L for peritoneal dialysis, yielding sensitivities of 93.3% and 100% and specificities of 60.8% and 83.1%, respectively. All five studies were rated as having a high risk of bias in the index test domain. Conclusions: Reported initial hs-cTnI cutoffs varied considerably across assays and patient populations. The available evidence does not establish a single cutoff applicable to all patients with renal dysfunction. These thresholds require external validation and should be interpreted alongside clinical findings and serial troponin measurements.