High-sensitivity cardiac troponin I has long been treated as one of the most ominous numbers on the chart of a patient admitted with acute heart failure. In a cohort of 431 patients hospitalized in an intensive care unit for acute heart failure between January 2020 and January 2025, the association between troponin levels and death was largely carried by three other processes measurable in the same blood draw: hemodynamic congestion, systemic inflammation, and declining kidney function.
Cardiac troponin I was quantified with a high-sensitivity assay with a 99th percentile upper reference limit of 24.2 ng/l and a coefficient of variation of at most 5 percent at that threshold. The patients averaged 79 years of age and 51 percent were men. Over the following months, the cohort recorded a cumulative mortality of 8 percent in hospital, 17 percent at 30 days, 29 percent at 90 days, and 36 percent at 180 days.
The first striking result is a set of correlations. Troponin levels rose in step with BNP (r = 0.28) and with hs-CRP (r = 0.31), and fell as kidney function improved (r = −0.23). Together, these three variables explained 18 percent of the overall variability in troponin concentrations, and multiple regression analysis confirmed that each was an independent predictor of the troponin value. Notably, troponin levels did not differ between patients with and without a previous history of ischemic heart disease, and they did not differ between women and men, although they did rise slightly with age.
When the investigators turned to survival, the picture became more revealing. In univariate Cox regression analysis, troponin, hs-CRP, BNP, and eGFR each predicted all-cause death at 180 days. Only ln hs-CRP (hazard ratio 1.21, 95 percent confidence interval 1.08 to 1.37), ln BNP (hazard ratio 1.37, 95 percent confidence interval 1.09 to 1.74), and eGFR (hazard ratio 0.99, 95 percent confidence interval 0.98 to 1.00) remained significant predictors.
The direct effect of ln troponin on 180-day mortality showed only a trend toward significance (hazard ratio 1.09, 95 percent confidence interval 0.99 to 1.40, p = 0.06). Inflammation, congestion, and renal function collectively explained 69 percent of the total effect of troponin on mortality. When the mediated pathway was partitioned on the log-hazard scale, hs-CRP accounted for 60 percent of it, BNP for 34 percent, and eGFR for just 5 percent.
What does this mean biologically? The authors argue that troponin release in acute heart failure is not solely a readout of ischemic myocyte death. Elevated filling pressures and wall stress can drive troponin into the bloodstream through subendocardial ischemia, cardiomyocyte apoptosis, breakdown of the contractile apparatus, and increased plasma membrane permeability. Inflammatory mediators can directly injure cardiomyocytes. Reduced renal clearance, uremic toxins, and plasma volume expansion can further raise circulating troponin.
The study’s framing is careful. The authors describe the mediation analysis as exploratory and hypothesis-generating, and they explicitly caution that definitive causal conclusions cannot be drawn from a retrospective design. They also note that troponin elevation might serve as a trigger for a comprehensive evaluation of the patient with acute heart failure rather than being interpreted as an isolated marker of irreversible myocardial injury. In their view, the prognostic information carried by troponin overlaps substantially with congestion, inflammation, and renal dysfunction, so an elevated value may be better understood as an integrated biomarker of multiple pathophysiological processes.
The findings sit within a longer literature. Peacock and colleagues reported in 2008 that abnormal troponin levels in acute heart failure were associated with higher in-hospital mortality, and subsequent work has repeatedly confirmed short- and long-term prognostic value, leading several risk scores to incorporate troponin. But the authors point out that most prior studies examined congestion, inflammation, or renal markers separately, and none had considered inflammatory markers as cofactors alongside natriuretic peptides and renal function in a single analytical framework. Sub-analyses of the RELAX-AHF trial did not assess inflammatory or renal status, and the CORONA study, which did adjust for those factors, enrolled patients with chronic rather than acute heart failure.
The study has clear boundaries. It was single-center and retrospective, the population was selected by exclusion criteria that rule out myocarditis, pulmonary embolism, acute coronary syndrome, recent or scheduled cardiac surgery, sepsis, active neoplasms, prior heart transplantation, invasive mechanical ventilation, and hemodialysis, and biomarkers were measured only once, at admission. Serial measurements during hospitalization could have added information. The authors call for validation in independent, prospective, multicenter cohorts before the integrated interpretation of troponin can shape routine risk stratification or therapeutic decision-making.
But this study suggests that the number itself may be reporting on the severity of congestion, the intensity of systemic inflammation, and the state of the kidneys as much as on the heart muscle.
Subject of Research: Mediation of the troponin–mortality association in acute heart failure by congestion, inflammation, and renal function
Article Title: Congestion, Inflammation, and Renal Impairment Mediate the Association Between Cardiac Troponin and Mortality in Acute Heart Failure
Article References: Scicchitano, P., Iacoviello, M., Ricci, G., De Feo, D., Di Rienzo, G., Bonfantino, V. M., & Massari, F. (2026). Congestion, Inflammation, and Renal Impairment Mediate the Association Between Cardiac Troponin and Mortality in Acute Heart Failure. Cardiology and Therapy. https://doi.org/10.1007/s40119-026-00487-z
Image Credits: AI Generated
DOI: 10.1007/s40119-026-00487-z
Keywords: acute heart failure, high-sensitivity troponin I, mediation analysis, brain natriuretic peptide, C-reactive protein, glomerular filtration rate, mortality risk, biomarkers, retrospective study, myocardial injury, renal dysfunction, systemic inflammation
News Source: Ophelia Keating. (November 4, 2026). Troponin’s Death Signal in Acute Heart Failure Is Largely a Mask for Congestion, Inflammation and Kidney Trouble. Scienmag.
