Complementary Prognostic Value of Cystatin C, N-Terminal Pro-B-Type Natriuretic Peptide and Cardiac Troponin T in Patients With Acute Heart Failure

The aims of this study were to compare the prognostic value of cystatin C over creatinine and the Modification of Diet in Renal Disease (MDRD) equation and to evaluate whether it provides complementary information to cardiac biomarkers in the risk stratification of an unselected cohort of patients with acute heart failure. Consecutive hospitalized patients with established diagnoses of acute heart failure were prospectively studied. Blood samples were collected on hospital arrival to determine cystatin C, cardiac troponin T, and N-terminal–pro-brain natriuretic peptide. Clinical follow-up was obtained, and the occurrence of mortality and/or heart failure readmission was registered. One hundred thirty-eight patients (median age 74 years, interquartile range 67 to 80; 54% men) were studied. During a median follow-up period of 261 days (interquartile range 161 to 449), 60 patients (43.5%) presented with adverse events. After multivariate adjustment, cystatin C, N-terminal–pro-brain natriuretic peptide, cardiac troponin T, New York Heart Association functional class III or IV, and diabetes mellitus were identified as independent predictors of mortality and/or heart failure readmission. In contrast to creatinine and the MDRD equation, the highest cystatin C tertile (>1.50 mg/L) was a significant independent risk factor for adverse events (hazard ratio 3.08, 95% confidence interval 1.54 to 6.14, p = 0.004). A multimarker approach combining cardiac troponin T, N-terminal–pro-brain natriuretic peptide, and cystatin C improved risk stratification further, showing that patients with 2 (hazard ratio 2.37, 95% confidence interval 1.10 to 5.71) or 3 (hazard ratio 3.64, 95% confidence interval 1.55 to 8.56) elevated biomarkers had a higher risk for adverse events than patients with no elevated biomarkers (p for trend = 0.015). In conclusion, in this unselected cohort, cystatin C was a stronger predictor of adverse events than conventional measures of kidney function. In addition, cystatin C offered complementary prognostic information to cardiac biomarkers and could help clinicians perform more accurate risk stratification of patients with acute heart failure.