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The following is a summary of “Impact of impaired renal function on kinetics of high-sensitive cardiac troponin following cardiac surgery,” published in the January 2025 issue of Cardiology by Rudolph et al. 

Impaired renal function was known to elevate cardiac troponin levels, potentially hindering its diagnostic value, and the impact of renal function on high-sensitivity cardiac troponin I (hs-cTnI) kinetics after cardiac surgery remained poorly understood.  

Researchers conducted a retrospective study to analyze the influence of impaired renal function on hs-cTnI kinetics following cardiac surgery, differentiating between patients with and without postoperative myocardial infarction (PMI).  

They analyzed adult patients who underwent elective cardiac surgery between January 2013 and May 2019. Serial hs-cTnI measurements were collected from baseline to 48 hours post-surgery. Renal function was evaluated using the MDRD formula, with impaired renal function defined as a GFR < 60 ml/min. Acute kidney injury (AKI) was identified by postoperative creatinine levels, and PMI was defined using ARC-2 criteria. Cox regression was operated to analyze predictors of long-term all-cause mortality.  

The results showed that out of 14,355 patients (51.4% Coronary artery bypass grafting (CABG), 39.4% valvular procedures, 9.2% thoracic aortic procedures), 139 (1.0%) experienced PMI, Hs-cTnI levels were higher in patients with impaired renal function, except in those with PMI, where levels did not significantly correlate with renal function. Elevated hs-cTnI ≥ 213 times the upper limit of normal was a significant predictor of long-term mortality (hazard ratio: 1.28, 95% CI: 1.17–1.40, P < 0.001). However, early postoperative hs-cTnI levels had poor discriminatory value for predicting PMI (AUC: 0.55, 95% CI: 0.54–0.56).  

Investigators concluded the renal function and acute kidney injury influenced hs-cTnI kinetics post-surgery only in patients without PMI, while elevated hs-cTnI remained a strong predictor of long-term mortality, independent of renal function and early detection of PMI required additional metrics. 

Source: link.springer.com/article/10.1007/s00392-025-02595-7