Impact of myocardial function on cystatin C measurements in chronic systolic heart failure.
BACKGROUND
The influence of myocardial function on plasma levels of cystatin C (CysC), a sensitive marker of renal function, in chronic systolic heart failure (HF) has not been well established.


METHODS
We prospectively identified 139 subjects with stable, chronic HF (left ventricular ejection fraction < or = 35%) and measured plasma levels of CysC. We prospectively tracked patients' long-term adverse clinical outcomes (death, cardiac transplantation, and HF hospitalizations).


RESULTS
Plasma levels of CysC were elevated in 41% of patients with preserved renal function and directly correlated with N-terminal prohormone brain natriuretic peptide (r = 0.57, P < .0001). There was a significant association between CysC and mitral E/septal E' ratio (r = 0.34, P < .001), right ventricular systolic dysfunction severity (r = 0.30, P < .001), and mitral regurgitation severity (r = 0.31, P < .001), but not left ventricular ejection fraction. At the cutoff of 1.23 mg/dL, CysC remains a significant independent risk factor for adverse clinical outcomes (hazard ratio 1.88, 95% confidence interval 1.15-3.09, P = .012) after adjusting for estimated glomerular filtration rate, left ventricular ejection fraction, and E/septal E'.


CONCLUSIONS
CysC is associated with more advanced left ventricular diastolic dysfunction and right ventricular systolic dysfunction and remains an independent predictor of long-term prognosis in chronic systolic HF after adjusting for myocardial factors.
Kaufman Center for Heart Failure, Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland Ohio 44195, USA.
W H Wilson
WH
Tang
Frederick
F
Van Lente
Kevin
K
Shrestha
Richard W
RW
Troughton
Gary S
GS
Francis
Wilson
W
Tong
Maureen G
MG
Martin
Allen G
AG
Borowski
Sue
S
Jasper
Randall C
RC
Starling
Allan L
AL
Klein
D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D003971:Diastole; D005260:Female; D006305:Health Status Indicators; D006321:Heart / Q000503:physiopathology*; D054143:Heart Failure, Systolic / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013318:Stroke Volume; D013599:Systole; D014463:Ultrasonography
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins