CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 4, May 2012
186
AFRICA
Cardiovascular Topics
Association between troponin T and ICU mortality,
a changing trend
S HAJSADEGHI, S GHOLAMI, G GOHARDEHI, NS MOGHADAM, AS SABET, SRJ KERMAN, M MORADI,
R MOLLAHOSEINI
Abstract
Background:
Initially elevated levels of troponin predict
adverse outcomes in patients admitted to the intensive care
unit (ICU). No research team has investigated the changes in
concentration of cardiac troponin T (cTnT) during ICU stay
and their association with patient outcome.
Objective:
We investigated whether the change in cTnT levels
during ICU stay could predict outcomes (death or survival).
Methods:
In this cohort study, all patients admitted to the
medical ICU (10 beds) from January to July 2008 were
enrolled. Troponin levels were evaluated within the first 24
hours of ICU admission and on the fourth, seventh and 10th
days after admission.
Results:
The study population (135 patients) had a mean age
of 60.9
±
21.5 years. The outcome was significantly different
with regard to normal or elevated cTnT concentrations on
the first and seventh days of follow up (
p
=
0.03 and 0.023,
respectively). This difference was non-significant for cTnT
levels on the fourth and 10th days after admission (
p
=
0.69
and 0.78, respectively). The change in cTnT levels was not
significantly different between the deceased and discharged
patients (
p
=
0.4).
Conclusion:
Changes in cTnT levels during ICU stay did not
show a significant trend (power: 0.26). Patients whose cTnT
levels were increased on the first and seventh days of ICU
stay had a worse survival, which could be associated with
cardiac events on admission or at specific times during the
stay in ICU.
Keywords:
troponin T, ICU, mortality, serial measurement,
changing trend
Submitted 23/8/10, accepted 7/6/11
Cardiovasc J Afr
2012;
23
: 186–190
DOI: 10.5830/CVJA-2011-034
Dysfunction of, or injury to the myocardium was recently
found to be an important complication in non-cardiac critically
ill patients, including those with sepsis, pulmonary embolism,
renal insufficiency and acute stroke, resulting in increased
concentrationsofcardiactroponinT(cTnT).
1-5
Thepathophysiology
of myocardial injury in critically ill patients is believed to
be multifactorial, including the underlying disease process,
hypoxaemia and acidosis, as well as therapeutic activities.
6,7
Over the past decade, several studies have indicated that
cardiac dysfunction is a frequent and important factor in
determining the outcome of critically ill patients.
8,9
Damage to
the myocardial cells results in the release of contractile regulating
proteins such as cTnT, which is a highly sensitive and specific
marker of myocardial injury.
10,11
More importantly, elevated
levels of troponin predict a poor prognosis in patients with acute
coronary syndromes
12-16
and may also predict adverse outcomes
in other patients admitted to the intensive care unit (ICU).
In a medical ICU, patients with elevated levels of troponin
T or troponin I admitted without a diagnosis of acute coronary
syndrome exhibited a fourfold higher mortality rate.
17
In patients
in a surgical ICU, moderate elevations in troponin I were
associated with higher mortality rates, and a longer stay in
hospital and in the ICU.
16-18
Some studies
19,20
have shown that
increased cTnT levels are associated with increased mortality,
but others did not confirm this association.
21,22
The association
between elevated troponin level and adverse outcome was
uncertain, so the interpretation of elevated troponin levels during
critical illness remains unclear.
Cardiac events resulting in elevated biomarkers may occur
during ICU stay and have an important effect on patient outcome.
There is no research evaluating the relationship between changing
levels of any cardiac biomarkers during ICU stay and patients’
outcome. We therefore hypothesised that patients admitted to
the ICU with increased cTnT levels were at increased risk of
death, and determined whether elevated troponin levels were
related to outcome and length of stay and mortality in the
ICU. We also investigated whether the change in cTnT levels
during ICU stay could predict outcomes (death or survival).
Correlation of troponin levels with the most popular disease
Department of Cardiology, Rasoul-e-Akram Hospital, Tehran
University of Medical Sciences, Tehran, Iran
S HAJSADEGHI, MD
Firoozgar Clinical Research Development Centre, Firoozgar
Hospital, Tehran University of Medical Sciences, Tehran, Iran
S GHOLAMI,
Medical Student Research Committee, Tehran University of
Medical Sciences, Tehran, Iran
G GOHARDEHI
NS MOGHADAM
AS SABET
SRJ KERMAN
M MORADI
Department of Neurosurgery, Firoozgar Hospital, Tehran
University of Medical Sciences, Tehran, Iran
R MOLLAHOSEINI, MD
