Exploring the relationship between cardiac biomarkers and mortality risk in extensive burned patients ≥ 70 % TBSA: A retrospective study.

Background: Extensively burned patients face a significant risk of mortality, with their condition often being closely associated with severe cardiac insufficiency. However, the correlation between cardiac biomarkers and mortality in patients with burns involving ≥ 70 % total body surface area (TBSA) remains underexplored.

Materials And Methods: The study included 159 patients from the Kunshan factory explosion. A joint model was applied to assess the relationship between longitudinal data and survival outcomes. In addition, random forests were utilized to establish new clinical thresholds and to uncover the specific patterns presented by longitudinal measurements in deceased patients. We constructed the corresponding survival curves and calculated the predictive power. Finally, multivariate Cox regression analysis was used to determine whether these new thresholds independently predicted overall survival (OS), which was followed by external validation employing a 10-year cohort of 144 burn patients with TBSA ≥ 70 %.

Results: Of all the myocardial markers, BNP levels presented the most statistically significant association with mortality (HR:6.831, 95 %CI: 6.122-7.539). Similarly, proBNP, CK-MB, IL-6, Mb, D-dimer and cTnI displayed positive correlations. TBSA also showed a significant relation to outcomes. The specific rules defined by the new thresholds could effectively distinguish between high-risk and low-risk patients. Patients with two or more consecutive BNP measurements greater than or equal to 519.91 pg/ml within 56 days after burns had a higher risk of death (interval mean [SD], 1.06 [0.77] days). The predictive condition established on the basis of this new cut-off value of BNP was an independent risk factor for OS. External validation confirmed the model's satisfactory performance.

Conclusion: Cardiac biomarkers, particularly BNP, were significantly associated with death in extensively burned patients ≥ 70 % TBSA. This revealed a potential correlation between cardiac stress and mortality after burn injury.