Significance of acute versus chronic troponin T elevation in dialysis patients.
BACKGROUND
Cardiac troponin T (cTnT) is often elevated in hemodialysis (HD) patients without acute coronary syndrome (ACS). The aim was to assess the predictive value for mortality of pre-dialysis cTnT in asymptomatic patients. If patients became symptomatic during follow-up, cTnT was followed to assess its diagnostic value for ACS.


METHODS
Forty-nine asymptomatic HD patients were included: 30 patients with a history of cardiovascular disease (CV+) and 19 without (CV-). In 11 patients cTnT, myoglobin and creatine kinase (CK) were measured before and during HD. During ACS, cTnT was followed until recovery. A cTnT of > or =0.03 mug/l was considered elevated. Follow-up was 2 years.


RESULTS
cTnT was elevated in 82% (40/49). More CV+ patients had an elevated cTnT (28/30) than CV- patients (12/19; p = 0.02). There was no change in cTnT, myoglobin and CK during HD. During ACS, cTnT increased above baseline, and tended to return to baseline after recovery. Mortality was 33% (16/49). Patients with elevated cTnT had a higher mortality rate (16/40) than patients with negative cTnT (0/9; p = 0.02).


CONCLUSIONS
Elevated cTnT levels in asymptomatic HD patients are not caused by acute myocardial injury or by HD itself. They may be related to chronic myocardial damage and decreased clearance, and are of prognostic value. During ACS, however, a cTnT rise above the individual baseline is diagnostic of acute myocardial injury.
Ie
Eric H Y
EH
Department of Medicine, Erasmus MC, Rotterdam, The Netherlands. e.ie@erasmusmc.nl
Klootwijk
Peter J
PJ
Weimar
Willem
W
Zietse
Robert
R
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis; D003327:Coronary Disease / Q000097:blood / Q000175:diagnosis*; D003402:Creatine Kinase / Q000097:blood; D006801:Humans; D008875:Middle Aged; D009211:Myoglobin / Q000097:blood; D011379:Prognosis; D006435:Renal Dialysis; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D009211:Myoglobin; D020107:Troponin T; D003402:Creatine Kinase