SOFA score and cardiac troponin in Septic Shock: retrospective analysis of a case-series

Introduction: Sepsis and septic shock are severe medical conditions,often observed in Internal Medicine Departments (IMD). Even if not recognized by some authors as an additional risk factor, troponin I (TnI) could be an early marker of cardiac microvessels derangement and septic cardiomyopathy,but is not included in the common scores used to assess prognosis. Objective: To examine association between SOFA-score and TnI in a retrospective cohort of septic patients. Methods: We retrospectively collected data from patients’ files treated in our IMD for severe sepsis/septic shock. Age,sex,SOFA-score,TnI and in-hospital death were considered for the analysis. TnI was treated as binary(cutoff 0.08ng/ml),while SOFA-score was analyzed both as an ordinal variable and a binary variable(cutoff at 9 points). The relationship between SOFA-score and the risk of in-hospital death was analyzed with CHi-squared statistic. The association between SOFA-score and TnI was assessed with an ordinal regression model using a complementary log-log link function. Accounting of age and sex as covariates, we obtained a significant model(p<0.05). Results: 20 consecutive subjects affected by septic shock(males 42.1%)with a mean age of 75.84 years (SD±13,89)were enrolled. TnI was positive in 84,2% of the sample. Higher SOFA scores(>9 points)resulted significantly associated with an increased risk of in-hospital death(OR=3.00;95%CI 1.10-9.30;p<0.05). We calculated the OR of obtaining different SOFA-scores depending on the absence of TnI:negative TnI was highly predictive of lower SOFA-scores(SOFA=1:OR=5.89;95%CI 2.99-11.6;p<0.05),and negatively associated to the prediction of higher SOFA-scores(SOFA=13:OR 0.07;95%CI 0.03-0.14;p<0.05). Our analysis outlined an inverse-exponential relationship between the odds ratios (r2=0.992,p<0.05). Conclusions:In this small case series,SOFA-score predicted in-hospital mortality and was associated to TnI levels in severe sepsis/septic shock. TnI could be associated to both a systemic involvement and septic cardiomyopathy, and could be useful to stratify septic patients identifying the ones at higher risk. These data need validation in larger cohorts.