Early serum creatinine changes and outcomes in patients admitted for acute heart failure: the cardio-renal syndrome revisited

Background: The changes in renal function that occurred in patients with acute decompensated heart failure (ADHF) are prevalent, and have multifactorial etiology and dissimilar prognosis. To what extent the prognostic role of such changes may vary according to the presence of renal insufficiency at admission is not clear. Accordingly, we sought to determine whether early creatinine changes (Cr) (admission to 48-72 hours) had an effect on 1-year mortality relative to the presence of renal insufficiency at admission. Methods: We included 705 consecutive patients admitted with the diagnosis of ADHF. Admission renal insufficiency was defined as serum creatinine 1.4mg/dl (A-RIcr) or estimated glomerular filtration rate <60ml/min/1.73m(2) (A-RIGFR). Appropriate survival regression techniques were used. Results: The mean age was 72.911.4 years and 51.2% were males. Patients with admission renal insufficiency (24.7% and 42.8% for A-RIcr and A-RIGFR, respectively) had higher prevalence of extreme values in Cr in either direction (increasing/decreasing). At 1-year follow-up, 114 (16.2%) deaths were registered. The multivariable analysis showed a significant interaction between admission renal insufficiency and Cr (p=0.004 and p=0.019 for A-RIcr and A-RIGFR, respectively). In the presence of renal insufficiency, the continuum of Cr followed a positive and almost linear relationship with mortality risk. Conversely, in patients without renal insufficiency, those changes adopted a J-shape' trajectory with increased mortality at both ends of the curve distribution. Conclusions: In patients with ADHF the effect of Cr on 1-year mortality varied according to its magnitude and the presence of admission renal insufficiency. There was a graded-association with mortality when renal insufficiency was present on admission.