MO175TROPONIN CUT-OFFS FOR ACUTE MYOCARDIAL INFARCTION IN PATIENTS WITH IMPAIRED RENAL FUNCTION - A SYSTEMATIC REVIEW AND META-ANALYSIS
Authors: Kampmann Jan , Granhøj Jeff , Brandt Kristensen Frans , Pedersen Andreas , Backer Mogensen Christian , Heaf James G , Mickley Hans 
Published: May 2021

Abstract

Background and Aims

Background
Identifying acute myocardial infarction in patients with renal disease is notoriously difficult due to atypical presentation and chronically elevated troponin.

Aim
To generate an optimized troponin cut-off value for patients with impaired renal function and acute myocardial infarction via meta-analysis.

Method
Two investigators screened 2,580 publications from Medline, Embase, Pubmed, Web of Science and Cochrane library. Only studies that investigated alternative cut-offs according to renal impairment were included.
15 articles fulfilled the inclusion criteria and results were included in a meta-analysis. Study characteristics and cut-off values were extracted. Study quality and risk of bias were assessed by using QUADAS-2 score. Six studies were included in the meta-analysis. To calculate the optimal cut off value in accordance to AUC for troponin T and troponin I in patients with renal impairment a bivariat mixed effect model on the sensitivity and specificity transformed by way of the inverse probit function similar to the model implemented in the R-package diagmeta was employed.

Results
Review: There was a considerable diversity in study design, study population and endpoint definition. The cut-off value for patients on peritoneal dialyses was twice as high (144 ng/L) when compared to patients on hemodialysis (75 ng/l). Asian studies suggested a substantially higher troponin cut-off when compared to European and American studies. The risk of bias was low in the analyzed studies, yet several studies were considered to have a low applicability.

Meta-analysis
Cut-off value for troponin T in patients not in dialysis with eGFR &lt;60 ml/min/1.73m2, a troponin T value of 47.89 ng (23.95; 71.83) was found. In patients on dialysis a troponin T value of 239.75 ng/l ( 69.27 ; 410.23) was demonstrated. The 99th percentile of the upper reference limit for troponin T was 14 ng/l. Cut-off value for troponin I: In patients not in dialysis with eGFR &lt; 60 ml/min/1.73m² a troponin I value of 42.45 ng/l ( 33.83 ; 51.08 ) was demonstrated. The 99th percentile of the upper reference limit for troponin I ranged from 9-42 ng/l depending on the assays used. Troponin I cut-off for patients in dialysis could not be calculated due to limited data.

Conclusion
The new cut-off values could help to identify patients whose troponin suggests acute myocardial infarction rather than renal function related troponin elevation. The meta-analysis is based on only six studies in total. Further subdivision according to eGFR would be desirable in order to optimize troponin cut-off values especially for dialysis patients. A differentiation on troponin cut-offs for HD and PD patients may yield further benefits. Asian studies suggested a substantially higher troponin cut-off when compared to European and American studies. The factors behind these findings may be worth investigating.