Cardiac troponin-I and its prognostic significance in a dialysis population.
BACKGROUND
The objective was to study the prevalence and specificity of elevated levels of cardiac troponin-I (cT-I) in patients on maintenance hemodialysis in relation to creatine kinase (CK), the CK-MB fraction, and the ratio CK-MB of total CK and to assess its significance for the long-term prognosis in these patients, compared to other parameters known to influence the outcome.


METHODS
Predialysis blood samples were taken from 93 asymptomatic hemodialysis patients for cT-I, total CK, the CK-MB fraction, and the ratio of CK-MB to total CK. cT-I was measured by a microparticle enzyme immunoassay. The patients were followed for 1 year, after which baseline levels of cT-I and age, duration of dialysis, and the presence of diabetes mellitus and ischemic heart disease were correlated by linear regression analysis with the outcome parameter all-cause mortality.


RESULTS
None of the patients had a cT-I level higher than the manufacturer's indicated cutoff point of 2.0 ng/mL for myocardial infarction, indicating a specificity of 100%. Nine of the 93 patients (9.7%) had detectable cT-I levels (>0.0 ng/mL). Twelve patients died within 1 year, among which 4 had baseline cT-I levels above 0 ng/mL. From the study variables, an elevated baseline cT-I was found to be the only factor that significantly correlated with the outcome all-cause mortality (p = 0.029).


CONCLUSIONS
cT-I has a high specificity for the diagnosis of myocardial infarction in dialysis patients. Despite the relatively low number of positive test results, cT-I was found to be significantly correlated with the outcome all-cause mortality at 1 year.
Hussein
Magdi
M
Departments of Nephrology and Dialysis, Al Hada Armed Forces Hospital, Taif, Saudi Arabia. jaapmooy@arab.net.sa
Mooij
Jaap
J
Roujouleh
Haysam
H
Al Shenawi
Omer
O