Prognostic value of troponin T in hemodialysis patients is independent of comorbidity.
BACKGROUND
Patients on long-term hemodialysis have a high mortality. Various clinical and biochemical markers are of prognostic value. Cardiac troponin T (cTnT) is a sensitive and specific marker for myocardial damage. Asymptomatic dialysis patients have a high prevalence of cTnT concentrations above the diagnostic threshold for myocardial damage. There is controversy over whether this represents a false positive cTnT or an underlying pathology with a poor outcome. It is not known whether cTnT reflects comorbidity in these patients.


METHODS
A cohort of 73 long-term hospital hemodialysis patients had cTnT estimated once prior to a mid-week dialysis. Samples were analyzed using the second-generation cTnT assay from Boehringer Mannheim on an Elecsys 1010 analyzer. The standard diagnostic threshold for myocardial damage of 0.1 ng/mL was used. A commonly employed measure of comorbidity (Khan) was applied at the time cTnT was measured. Patients were followed for 15 months. Mortality was used as the clinical end point. Kaplan-Meier survival analysis was employed and differences between groups were assessed using the Cox-Mantel log-rank test.


RESULTS
Of the 73 patients, 20 were positive for cTnT and 53 were negative, at the cut-off of 0.1 ng/mL. At fifteen months, 65% of the positive patients were dead, whereas only 15% of the negative patients were dead. Survival analysis confirmed that this difference was statistically significant (P < 0.00001), and that the effect of cTnT on survival was independent of comorbidity.


CONCLUSIONS
There is a high prevalence of positive cTnT in stable hemodialysis patients. A single estimation of cTnT in this group has significant prognostic value, independent of comorbidity.
Deegan
P B
PB
Department of Biochemical Medicine and Renal Unit, Ninewells Hospital and Medical School, Dundee, Scotland,United Kingdom. pbdeegan@doctors.org.uk
Lafferty
M E
ME
Blumsohn
A
A
Henderson
I S
IS
McGregor
E
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D011379:Prognosis; D012372:ROC Curve; D012044:Regression Analysis; D006435:Renal Dialysis / Q000401:mortality; D016019:Survival Analysis; D016896:Treatment Outcome; D020107:Troponin T / Q000097:blood* / Q000378:metabolism
D020107:Troponin T