Cardiac troponin elevations across non-cardiac diseases: a comprehensive analysis

Abstract Background Cardiac troponins (cTn) serve as key biomarkers for myocardial injury and are extensively used in the diagnosis of acute coronary syndrome (ACS)(1). However, cTn elevations are frequently observed in non-cardiac conditions without clinical evidence of myocardial injury(2–3). Previous research suggests that troponin T (cTnT) is more frequently elevated in non-cardiac patients than troponin I (cTnI)(4), yet systematic comparisons across disease groups remain scarce. Understanding the prevalence and distribution of cTn elevations in various non-cardiac diseases could improve diagnostic accuracy and clinical decision-making, not least in cardiology. Purpose This study aims to assess the prevalence and distribution of cTnT and cTnI elevations in five non-cardiac disease groups: Sepsis, rhabdomyolysis, chronic kidney disease stage 5 (CKD5), Stroke and major non-cardiac surgery (MNCS). Methods We conducted a single-center, prospective observational study including 244 hospitalized patients across five disease groups over a 1-year period. Patients with a history of cardiac disease or symptoms suggestive of ACS were excluded. All patients were included within 48 hours of admission and underwent clinical assessments, blood sampling, electrocardiography, and echocardiography. cTnT was measured using the Cobas h232, cTnT point-of-care test, and cTnI was analyzed using the Siemens Atellica High-Sensitivity Troponin I assay. Results Among 244 patients (median age: 78 years, IQR 69-84; 52% male), a total of 85 patients (34.8%) had elevated cTnT above the 99th percentile. Thirty-five patients (14.3%) showed signs of cardiac disease other than ACS, confirmed by echocardiographic and/or electrocardiographic examinations and were therefore excluded. The prevalence of elevated cTnT in patients without signs of cardiac disease was observed in 32.4% with the highest prevalence in CKD5 (69.6%), followed by rhabdomyolysis (47.8%), sepsis (31.8%), MNCS (16.7%) and stroke (6.4%). Among patients with elevated cTnT, the median concentration across all groups was 91 ng/L (IQR 54–161 ng/L). For cTnI, elevated levels were observed in 18.8% of patients, with the highest prevalence in rhabdomyolysis (53.3%) (Table 1). McNemar’s test indicated a significant difference between cTnT and cTnI elevations (p = 0.003), with the largest difference observed in CKD5 (p 0.001), while no significant differences were found in the other disease groups. Conclusions Cardiac troponin elevations are common in various non-cardiac diseases, with the highest prevalence observed in patients with CKD5, rhabdomyolysis, and sepsis. The study highlights significant differences between cTnT and cTnI distributions across disease groups, suggesting distinct pathophysiological mechanisms influencing troponin release. These findings have implications for diagnostic work-up, not least for the differentiation between myocardial injury and non-cardiac troponin elevations.