The role of cardiac troponin I as a prognosticator in critically ill medical patients: a prospective observational cohort study.
BACKGROUND
Myocardial injury is frequently unrecognized in intensive care unit (ICU) patients. Cardiac troponin I (cTnI), a surrogate of myocardial injury, has been shown to correlate with outcome in selected groups of patients. We wanted to determine if cTnI level measured upon admission is an independent predictor of mortality in a heterogeneous group of critically ill medical patients.


METHODS
We conducted a prospective observational cohort study; 128 consecutive patients admitted to a medical ICU at a tertiary university hospital were enrolled. cTnI levels were measured within 6 h of admission and were considered positive (>0.7 ng/ml) or negative. A variety of clinical and laboratory variables were recorded.


RESULTS
Both cTnI positive and negative groups were similar in terms of age, sex and pre-admission co-morbidity. In a univariate analysis, positive cTnI was associated with increased mortality (OR 7.0, 95% CI 2.44-20.5, p < 0.001), higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores and a higher rate of multi-organ failure and sepsis. This association between cTnI and mortality was more pronounced among elderly patients (>65 years of age). Multivariate analysis controlling for APACHE II score revealed that elevated cTnI levels are not independently associated with 28-day mortality.


CONCLUSIONS
In critically ill medical patients, elevated cTnI level measured upon admission is associated with increased mortality rate. cTnI does not independently contribute to the prediction of 28-day mortality beyond that provided by APACHE II.
King
Daniel A
DA
Medical Intensive Care Unit, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University, Beer Sheva, Israel. king@bgu.ac.il
Codish
Shlomi
S
Novack
Victor
V
Barski
Leonid
L
Almog
Yaniv
Y
D018806:APACHE; D017677:Age Distribution; D000368:Aged; D015415:Biomarkers / Q000097:blood; D009202:Cardiomyopathies / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D015331:Cohort Studies; D015897:Comorbidity; D003422:Critical Care / Q000379:methods / Q000706:statistics & numerical data; D016638:Critical Illness / Q000145:classification / Q000401:mortality*; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D019210:Troponin I / Q000097:blood*
D015415:Biomarkers; D019210:Troponin I