Relationships Between Renal Function Variations And Relative Changes In Cardiac Troponin T Concentrations Based On Quantile Generalized Additive Models (Qgam)

Objectives: The relationship between high-sensitive cardiac troponin T concentration (hs-cTnT) and renal markers levels is known. However, the extent to which their variations are associated remains to be explored. Objective: model the relationship between relative changes in hs-cTnT (Delta hs-cTnT) and variations in creatinine (Delta cre) or estimated glomerular filtration rate (Delta eGFR), using a quantile generalized additive model (qgam).Methods: Concomitant plasma Delta hs-cTnT and Delta cre from patients aged 18-100 years, selected with a time variation (Delta time) of 3 h-7 days, were collected over a 5.8-year period. Relationships between Delta hs-cTnT and covariates Delta cre (A) or Delta eGFR (B), including age, Delta time, hour of blood sampling (HSB) and covariates interactions were fitted using qgam.Results: On the whole (n=106567), Delta hs-cTnT was mainly associated with Delta cre, in a positive and nonlinear way (-21, -6, +5, +20, +55% for -50, -20, +20, +50, +100%, respectively), but to a lesser extent with age (min -9%, max +2%), Delta time (min -4%, max +8%), and HSB (min -5%, max +7%). Delta hs-cTnT was negatively associated with Delta eGFR (+46, +7, -5, -11, -20% for -50, -20, +20, +50, + 100%, respectively). Classifying Delta hs-cTnT as consistent or not with myocardial injury based on recommendations, an interpretation of Delta hs-cTnT adjusted for model A or B led to statistically significant but small diagnostic discrepancies (<2%), as compared to an interpretation based on Delta hs-cTnT only.Conclusions: From a laboratory and statistical standpoint, considering renal function variations when interpreting relative changes in cardiac troponin T has a minor impact on the diagnosis rate of myocardial injury.