Cystatin C: a novel predictor of outcome in suspected or confirmed non-ST-elevation acute coronary syndrome.
BACKGROUND
Patients with suspected or confirmed non-ST-elevation acute coronary syndrome (ACS) constitute a large and heterogeneous group. Measurements of renal function such as serum creatinine and estimation of creatinine clearance carry independent prognostic information in this population. Cystatin C is a new and better marker of renal function than creatinine. The aim was therefore to evaluate the prognostic value of cystatin C in this population.


RESULTS
Cystatin C was analyzed on admission in 726 patients admitted because of symptoms suggestive of an acute coronary syndrome and no ST-segment elevations. Patients were followed up with regard to death and myocardial infarction for a median of 40 and 6 months, respectively. The median cystatin C level was 1.00 mg/L (25th to 75th percentile, 0.83 to 1.24 mg/L). The risk of death during follow-up increased with increasing levels of cystatin C. In the group with non-ST-elevation ACS, patients in the second, third, and fourth quartiles had a relative risk of subsequent death of 1.8 (95% CI, 0.6 to 5.3), 3.2 (95% CI, 1.2 to 8.5), and 11.7 (95% CI, 4.7 to 29.3) compared with the lowest quartile. In Cox regression models including well-known predictors of outcome, cystatin C level was independently associated with mortality but not with the risk of subsequent myocardial infarction. In a comparison of the markers of renal function in receiver-operating curve analyses, cystatin C had the best ability to discriminate between survivors and nonsurvivors.


CONCLUSIONS
A single measurement of cystatin C will substantially improve the early risk stratification of patients with suspected or confirmed non-ST-elevation ACS.
Department of Medical Sciences, Cardiology, Uppsala Research Center, University Hospital, 751 85 Uppsala, Sweden. tomas.jernberg@medsci.uu.se
Tomas
T
Jernberg
Bertil
B
Lindahl
Stefan
S
James
Anders
A
Larsson
Lars-Olof
LO
Hansson
Lars
L
Wallentin
D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000209:etiology; D017202:Myocardial Ischemia / Q000097:blood* / Q000150:complications / Q000401:mortality / Q000628:therapy; D009204:Myocardial Revascularization; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D012306:Risk; D018570:Risk Assessment; D013548:Sweden / Q000453:epidemiology; D013577:Syndrome; D016896:Treatment Outcome
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins