Renal Compromise after treatment of decompensated heart failure with diuretics is not
uncommon. The purpose of our study is to investigate the relationship between cystatin C and
worsening renal function in this setting. Cystatin C is a biomarker produced at a constant
rate by all cells that is a sensitive biomarker of renal function.Cystatin C and Plasma
amino terminal proB-type natriuretic peptide (NT-proBNP) levels will be obtained at baseline
and daily. Our goal is to enroll 100 subjects with an estimated 5 samples per each subject.
The time course of changes in cystatin C in relation to serum creatinine levels over time
will be plotted.
Our hypothesis is that sequential changes in cystatin C levels following initial treatment
with diuretic therapy in the setting of acute decompensated heart failure may provide early
insight into cardio-renal compromise. Understanding the natural history and time course of
the changes in sequential cystatin C levels may facilitate further studies to guide the
judicious use of diuretic therapy in acute decompensated heart failure, and to predict the
risk of subsequent development of worsening renal function. If serial testing of cystatin C
can provide accurate assessment and prediction of worsening renal function, clinical
applications of these observations can be evaluated in future prospective studies.
This is a single-center, prospective, cohort study. The design of this pilot study focuses
on the feasibility to complete the project in a short period of time by the applicant.
Subjects will be identified in the morning after their hospital admission and informed
consent will be obtained for the study. At the time of enrollment blood samples and urine
samples will be collected as baseline, together with a brief history and physical
examination to document degree of congestion and basic vital signs. In addition their unused
(to be discarded) blood samples from previous clinical labs from this admission may be
retrieved from the clinical laboratory.
Patients will be followed daily, and each day a blood draw and urine sample will be obtained
for research purposes until the day of discharge. Changes in vital signs, available
laboratory data for serum creatinine and BUN, and congestion score will be documented.
Physicians treating the patient will be blinded from the laboratory results. Because of the
small sample size and the low anticipated rate of adverse events, this study uses a combined
outcome of either death in hospital, death within 90 days after discharge or readmission to
the hospital facility for heart failure within 90 days. Patients will be called after 90
days for follow up if readmission or death information is not available in the Electronic
Specific aims include:
Specific Aim 1 - To examine the natural history of changes in sequential cystatin C levels
during diuretic therapy in Acute Decompensated Heart Failure.
Specific Aim 2 - To determine the predictive value of changes in sequential cystatin C
levels to subsequent development of worsening renal function (WRF) and WRF in association
with aminoterminal pro B-type natriuretic peptide (NT-proBNP) levels.
- Hospital admission within 48 hours for ADHF, with an expected stay over 24 hours.
- Evidence of fluid overload, including jugular venous distention, pulmonary rales,
peripheral edema, and/or ascites receiving diuretic therapy
- Heart failure due to congenital heart disease or critical aortic stenosis
(potentially different cardio-renal pathophysiology)
- Acute myocardial infarction or unstable acute coronary syndromes
- End-stage renal insufficiency on renal replacement therapy (already has underlying
advanced renal failure).
- Patients with active cancer (cystatin C has been shown to be produced by some tumors)
- Known exposure to nephrotoxic agents (such as contrast dye) or planned surgery during
hospitalization at the time of enrollment
- Hemoglobin < 9 mg/dL or clinically significant active bleeding.
- Unable to comply with protocol or unable to have informed consent