title: Elevated serum creatinine at baseline predicts poor outcome in patients receiving cardiac resynchronization therapy.
abstract: BACKGROUND
  Renal insufficiency is recognized as a predictor of mortality and poor outcome in heart failure patients. We sought to study the impact of baseline serum creatinine on subsequent outcome in cardiac resynchronization therapy (CRT) recipients.
  
  
  METHODS
  We retrospectively reviewed hospital records of all CRT recipients at Pittsburgh Veterans Affairs (VA) Healthcare System (2003-2005) and University of Pittsburgh Medical Center (2004). We recorded clinical characteristics at the time of implantation including demographics, New York Heart Association (NYHA) functional class, ejection fraction, QRS duration, cardiomyopathy etiology, medical history, medication use, and serum creatinine. Mortality alone and mortality combined with heart failure hospitalization were the study endpoints.
  
  
  RESULTS
  Out of the 330 patients studied, a total of 66 (20.0%) patients died over a mean follow-up duration of 19.7 +/- 9.0 months (range 1-44). The cohort was studied by three creatinine tertiles (0.6-1.0, 1.1-1.3, 1.4-3.0 mg/dL). Both study endpoints were observed more frequently in patients in the highest creatinine tertile compared to others (28.7% vs 14.0%, P = 0.008 for death and 41.6% vs 21.5%, P = 0.001 for the combined endpoint). High creatinine remained an independent predictor of mortality (hazard ratio [HR] 1.89, 95% confidence interval [CI] 1.06-3.39, P = 0.032) and the combined endpoint (HR 1.94, 95% CI 1.20-3.13, P = 0.007) in multivariate adjusted models. Studied as a continuous variable, increase in creatinine level by 0.1 mg/dL was associated with an 11% increase in mortality risk and a 7% increase in the combined endpoint.
  
  
  CONCLUSIONS
  In an unselected cohort of CRT recipients, the baseline creatinine was found to predict worse survival and poor outcome over a modest follow-up duration.
authors.affiliation: Division of Cardiology, VA Pittsburgh Healthcare System, Pittsburgh, PA 15240, USA. alaa.shalaby@med.va.gov
authors.forename: Alaa
authors.initials: A
authors.lastname: Shalaby
authors.forename: Aiman
authors.initials: A
authors.lastname: El-Saed
authors.forename: Andrew
authors.initials: A
authors.lastname: Voigt
authors.forename: Constantine
authors.initials: C
authors.lastname: Albany
authors.forename: Samir
authors.initials: S
authors.lastname: Saba
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002304:Cardiac Pacing, Artificial / Q000401:mortality*; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood*; D006333:Heart Failure / Q000097:blood / Q000401:mortality / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D008297:Male; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data; D010414:Pennsylvania / Q000453:epidemiology; D011379:Prognosis; D051437:Renal Insufficiency / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D003404:Creatinine