title: Outcomes of patients with chronic kidney disease and implantable cardiac defibrillator: primary versus secondary prevention.
abstract: BACKGROUND
  Chronic kidney disease (CKD) is associated with worse survival in patients with implantable cardiac defibrillators (ICDs). This study examined the association of outcomes with CKD in patients receiving an ICD for primary versus secondary prevention.
  
  
  METHODS
  The study included 696 patients who underwent ICD placement for clinical reasons (59% primary, 41% secondary prevention) at the University of Alabama at Birmingham between January 2002 and September 2007. CKD was defined as an estimated glomerular filtration rate<60 ml/min/1.73 m(2) but not on dialysis. Outcomes of interest included overall mortality and first appropriate ICD therapy (shocks or anti-tachycardia pacing).
  
  
  RESULTS
  After a follow-up of 50 ± 24 months, 213 patients died (31%) and 111 (16%) received appropriate ICD therapy. Patients with CKD had higher mortality than patients with no CKD in the primary (43% vs. 15%, p<0.001) and secondary prevention (37% vs. 23%, p = 0.003) groups. Patients with CKD were at higher risk of receiving an appropriate ICD therapy than patients without CKD in the primary (p<0.001) but not secondary prevention (p = 0.9) cohort. After adjusting for age, gender and multiple risk factors, CKD was independently associated with all-cause mortality and ICD therapy in the primary prevention group (HR 2.08 [1.34-3.23] and 3.53 [1.75-7.10], p = 0.001 and <0.0001, respectively) but not in the secondary prevention group (HR 1.27 [0.81-2.00], and 0.63 [0.35-1.13], p=0.3 and 0.2, respectively).
  
  
  CONCLUSIONS
  CKD is independently associated with increased mortality and appropriate ICD therapy in patients undergoing ICD implantation for primary but not secondary prevention.
authors.affiliation: Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States. fadihage@uab.edu
authors.forename: Fadi G
authors.initials: FG
authors.lastname: Hage
authors.forename: Wael
authors.initials: W
authors.lastname: Aljaroudi
authors.forename: Himanshu
authors.initials: H
authors.lastname: Aggarwal
authors.forename: Vikas
authors.initials: V
authors.lastname: Bhatia
authors.forename: John
authors.initials: J
authors.lastname: Miller
authors.forename: Harish
authors.initials: H
authors.lastname: Doppalapudi
authors.forename: Oussama
authors.initials: O
authors.lastname: Wazni
authors.forename: Ami E
authors.initials: AE
authors.lastname: Iskandrian
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D017147:Defibrillators, Implantable / Q000639:trends*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention / Q000639:trends*; D051436:Renal Insufficiency, Chronic / Q000401:mortality* / Q000628:therapy*; D055502:Secondary Prevention / Q000639:trends*; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome