Troponin I is a sensitive test used for the diagnosis of acute coronary syndromes. Sepsis is a leading cause of death in intensive care units (ICU), characterized by diffuse end organ damage including myocardial dysfunction. The clinical significance of elevated troponin I concentrations in sepsis is not clearly understood. We retrospectively examined the association of troponin I concentration with selected outcomes in patients who were diagnosed with sepsis.
The medical records of 24 patients admitted with documented troponin I concentrations within 10 days after onset of sepsis were reviewed. Patients with acute coronary syndrome, cardiac surgery, pulmonary embolus, or cerebrovascular accident were excluded. Continuous data were compared using Mann-Whitney U test. Correlation of selected outcomes was calculated using the Spearman rank correlation test. Mortality was compared using Kaplan-Meier analysis with log rank test.
Mean age was similar between groups of patients with normal troponin I (<1ng/ml, n=13, group 1) and elevated troponin I (>1ng/ml, n=11, group 2). Patients in group 2 were more ill (mean APACHE II score 20.6 vs. 13.5, p=0.01), required increased use of pressors (pressor-days 9.9 vs. 1, p=0.006), and experienced longer duration of mechanical ventilation (12 vs. 2 days, p=0.002). Mortality was significantly higher in group 2 (45.4% vs. 7.7%, log rank test = 4.218, p<0.04). The degree of elevation of troponin I concentrations correlated with APACHE II scores (r= 0.66; 95% CI, 0.34-0.84, p=0.0004). Patients in group 2 experienced a statistically nonsignificant trend toward longer ICU stay (16.3 vs. 5.3 days, p=0.082).
Elevated troponin I concentrations are associated with greater severity of illness, increased 28-day mortality, and longer duration of mechanical ventilation and vasopressor use in patients with sepsis.
The presence of elevated troponin I is a function of both the severity of sepsis and also the extent of myocardial injury, both of which contribute to poorer outcomes in such patients. Troponin I concentration may serve as a useful marker in identifying patients with sepsis at increased risk of mortality.
Table-Summary of Troponin I in Sepsis StudyAge (y)Troponin I (ng/ml)ICU Stay (Days)Ventilator daysPressor- dayscAPACHE II Score28-day MortalityGroup 1a n=13Mean± SD Median62.3±14.5 630.22±0.27 0.105.3±5.7 41.5±2.8 01±1.8 013.54±4.54 131/13(7.69%)Group 2b n=11Mean± SD Median63±19.4 6712.81±22.76 4.816.3±17.4 1012.4±11.4 108±9.8 620.64±6.84 205/11(45.45%)p value0.7943<0.00010.0820.00160.02350.0108p<0.04a
Group 1: Troponin I<1 ng/ml
P. Mannam, None.