Cystatin C for enhancement of risk stratification in non-ST elevation acute coronary syndrome patients with an increased troponin T.
BACKGROUND
We assessed the value of cystatin C for improvement of risk stratification in patients with non-ST elevation acute coronary syndrome (nSTE-ACS) and increased cardiac troponin T (cTnT), and we compared the long-term effects of an early invasive treatment strategy (EIS) with a selective invasive treatment strategy (SIS) with regard to renal function.


METHODS
Patients (n = 1128) randomized to an EIS or an SIS in the ICTUS trial were stratified according to the tertiles of the cystatin C concentration at baseline. The end points were death within 4 years and spontaneous myocardial infarction (MI) within 3 years.


RESULTS
Mortality was 3.4%, 6.2%, and 13.5% in the first, second, and third tertiles, respectively, of cystatin C concentration (log-rank P < 0.001), and the respective rates of spontaneous MI were 5.5%, 7.5%, and 9.8% (log-rank P = 0.03). In a multivariate Cox regression analysis, the cystatin C concentration in the third quartile remained independently predictive of mortality [hazard ratio (HR), 2.04; 95% CI, 1.02-4.10; P = 0.04] and spontaneous MI (HR, 1.95; 95% CI, 1.05-3.63; P = 0.04). The mortality rate in the second tertile was lower with the EIS than with the SIS (3.8% vs 8.7%). In the third tertile, the mortality rates with the EIS and the SIS were, respectively, 15.0% and 12.2% (P for interaction = 0.04). Rates of spontaneous MI were similar for the EIS and the SIS within cystatin C tertiles (P for interaction = 0.22).


CONCLUSIONS
In patients with nSTE-ACS and an increased cTnT concentration, mild to moderate renal dysfunction is associated with a higher risk of death and spontaneous MI. Use of cystatin C as a serum marker of renal function may improve risk stratification.
Windhausen
Fons
F
Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands.
Hirsch
Alexander
A
Fischer
Johan
J
van der Zee
P Marc
PM
Sanders
Gerard T
GT
van Straalen
Jan P
JP
Cornel
Jan Hein
JH
Tijssen
Jan G P
JG
Verheugt
Freek W A
FW
de Winter
Robbert J
RJ
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000628:therapy; D000368:Aged; D017023:Coronary Angiography; D055316:Cystatin C / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D020107:Troponin T / Q000097:blood*
D055316:Cystatin C; D020107:Troponin T