The prognostic importance of different definitions of worsening renal function in congestive heart failure.
BACKGROUND
Worsening renal function in patients hospitalized for heart failure portends a poor prognosis. However, criteria used to define worsening renal function are arbitrary, and the implications of different definitions remain unclear. We therefore compared the prognostic importance of various definitions of worsening renal function in 1,002 patients hospitalized for congestive heart failure (CHF).


RESULTS
The patient population was 49% female, aged 67 +/- 15 years. Twenty-three percent had a prior history of renal failure, 73% had known depressed ejection fraction, and 63% had known CHF. On admission to the hospital, 47% were receiving ACE inhibitors, 22% beta-blockers, 70% diuretics and 6% NAID's. 72% developed increased serum creatinine during the hospitalization, with 20% developing an increase of > or = 0.5 mg/dL. Worsening renal function predicted both in-hospital mortality and length of stay > 10 days. Even an increased creatinine of 0.1 mg/dL was associated with worse outcome. Sensitivity for death decreased from 92% to 65% as the threshold for increased creatinine was raised from 0.1 to 0.5 mg/dL, with specificity increasing from 28% to 81%. At a threshold of a 0.3 mg/dL increase, sensitivity was 81% and specificity was 62% for death and 64% and 65% for length of stay >10 days. Adding a requirement of final creatinine of > or = 1.5 mg/dL improved specificity.


CONCLUSIONS
This analysis demonstrates that any detectable decrease in renal function is associated with increased mortality and prolonged hospital stay. This suggests that therapeutic interventions which improve renal function might be beneficial.
Division of Cardiology, University of Maryland School of Medicine and the D.V.A. Medical Center, Baltimore, Maryland 21201, USA.
Stephen S
SS
Gottlieb
William
W
Abraham
Javed
J
Butler
Daniel E
DE
Forman
Evan
E
Loh
Barry M
BM
Massie
Christopher M
CM
O'connor
Michael W
MW
Rich
Lynne Warner
LW
Stevenson
James
J
Young
Harlan M
HM
Krumholz
D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000097:blood*; D005260:Female; D006333:Heart Failure / Q000150:complications*; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012372:ROC Curve; D051437:Renal Insufficiency / Q000097:blood* / Q000209:etiology; D012680:Sensitivity and Specificity; D013997:Time Factors
D003404:Creatinine