Prognostic Value of High-sensitivity Troponin I in Patients with Septic Shock: A Prospective Observational Study

Septic shock is a leading cause of mortality in intensive care units (ICUs).Despite recent advances in the management of septic shock, mortality rates have remained remarkably high, ranging from 30 to 50%. 1 Myocardial dysfunction is one of the mechanisms involved in the pathophysiology of septic shock.Septic myocardial dysfunction is usually defined as global (systolic and diastolic) but reversible biventricular dysfunction.2 An incidence ranging from 20 to 60% has been reported in the first 3 days after the onset of septic shock.3 Ventricular function generally returns to normal within 7-10 days.4 The pathophysiology of this dysfunction is complex and not completely understood.It involves, in addition to circulatory abnormalities, alterations in coronary blood flow, circulating depressant factors, microvascular dysfunction, abnormalities of beta-adrenergic signal transduction 5 , apoptotic phenomena and calcium dysregulation.6 Cardiac troponins are specific biomarkers of myocardial cell injury and their role for risk stratification in acute coronary syndromes is well established.7 The role of troponin in risk stratification of sepsis is still debated.8,9 A new generation of highly sensitive troponin assays has recently been developed that allow the detection of concentrations 10 times lower than those measureable with conventional assays.10 The aim of this study was to determine the association between high-sensitivity cardiac troponin I (hs-cTnI) elevation and 28-day mortality in patients with septic shock. MaterIals a n d MethodsAfter approval of the Local Ethics Committee, a single center prospective observational cohort study was conducted in a 12-bed mixed surgical and medical ICU over a 12-month period, from 1st January 2017 to 31st December 2017.This study included consecutive septic shock adult patients (18 years old or more) admitted to the ICU.Septic shock was defined as sepsis with hypotension despite initial volume resuscitation of 30 mL/kg body weight in accordance abstract Background: Myocardial dysfunction is one of the mechanisms involved in the pathophysiology of septic shock.The role of troponin as a surrogate of myocardial injury in septic shock is still debated.The aim of this study was to assess the prognostic value of high-sensitivity cardiac troponin I (hs-cTnI) assay in predicting 28-day mortality in patients with septic shock.Materials and Methods: Prospective study including 75 patients with septic shock admitted to a medico-surgical ICU from January to December 2017.Patients under the age of 18 years, known pregnancy and patients in post-cardiac arrest were excluded.Clinical and demographic data including age, gender, comorbidities, SAPS II and SOFA scores were collected.Hs-cTnI was measured soon after admission and 12, 24, 48 and 72 after.Receiver operating characteristic (ROC) analysis was performed to identify the most useful troponin I cut-off level for the prediction of 28-day mortality.A p <0.05 was considered significant.Results: Seventy-five (M/F = 53/22) patients with septic shock were included in the study.The median SOFA and SAPS II scores were 10 and 42, respectively.The median duration of mechanical ventilation was 8 days and the median length of ICU stay was 11 days.The 28-day mortality was 54.6%.We found a high prevalence (47%) of elevated hs-cTnI in patients with septic shock.Median hs-cTnI on admission in the whole group was 36 ng/L.The 28-day mortality was found to be related to age (p <0.001), SAPS II score (p = 0.001), mean arterial pressure (p = 0.038), lactate (p <0.001) and glomerular filtration rate (p <0.001).Hs-cTnI levels were significantly higher in non-survival group than survival one at all time points: H12 (p = 0.006), H24 (p = 0.003), H48 (p = 0.005) and H72 (p=0.001).In multivariate analysis, hs-cTnI at H72 was independently associated with 28-day mortality.Conclusion: Hs-cTnI elevation at 72 hours was associated with 28-day mortality in septic shock patients.