Measurement of circulating troponin Ic enhances the prognostic value of C-reactive protein in haemodialysis patients.
BACKGROUND
Cardiac Troponin I (cTnI) levels are considered an important diagnostic tool in acute coronary events. They could be of predictive value in haemodialysis (HD) patients. However, the relationship between cTnI and the HD-induced inflammatory state remains unclear. The aim of this study was to explore the prognostic relevance to all-cause and cardiovascular mortalities in HD patients of cTnI, in combination with highly sensitive C-reactive protein (hs-CRP) levels.


METHODS
We measured cTnI and hs-CRP at baseline (March 10 to November 16, 2001) in 191 HD patients without clinical signs of acute coronary artery disease [median age 66.7 years (range 22.3-93.5), 94 females, 97 males]. We used a cTnI concentration with a total imprecision of 10% (0.03 microg/l), determined in the laboratory, as the analytical threshold value. Patients were followed for mortality until 1 January, 2003 (median follow-up 418 days). The adjusted relative risks (RRs) of death and 95% confidence intervals (CIs) were estimated using Cox proportional hazard models.


RESULTS
A significant proportion (25.1%) of patients had elevated CTnl, > or =0.03 microg/l; 40.3% of patients had CRP concentrations > or =10 mg/l. During follow-up, 29 patients died, 44.8% due to cardiac causes. Elevated cTnI or CRP levels were associated with increased mortality [RR adjusted for age, sex and duration of dialysis 4.2 (1.9-9.0) for cTnI > or =0.03 microg/l and 3.6 (1.6-8.1) for CRP > or =10 mg/l], cTnI being particularly predictive of cardiovascular death. Moreover, the combination of elevated hs-CRP (> or =10 mg/l) and circulating cTnI (> or =0.03 microg/l) dramatically impaired the HD survival rate [adjusted RR for all-cause mortality 16.9 (4.5-63.8)].


CONCLUSIONS
Circulating cTnI was associated with poor prognosis, especially when combined with elevated CRP, strongly supporting the adoption of regular cTnI testing in HD patients.
Boulier
Alexandre
A
Biochemistry Laboratory, Hôpital Lapeyronie, 371 Av. Doyen Gaston Giraud, 34295 Montpellier cedex 5, France. jp-cristol@chu-montpellier.fr
Jaussent
Isabelle
I
Terrier
Nathalie
N
Maurice
François
F
Rivory
Jean-Pierre
JP
Chalabi
Lotfi
L
Boularan
Anne-Marie
AM
Delcourt
Cécile
C
Dupuy
Anne-Marie
AM
Canaud
Bernard
B
Cristol
Jean-Paul
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000401:mortality*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D006435:Renal Dialysis; D019210:Troponin I / Q000097:blood*
D019210:Troponin I; D002097:C-Reactive Protein