Impact of renal function on survival in patients with implantable cardioverter-defibrillators.
BACKGROUND
Although chronic renal insufficiency (CRI) is associated with increased cardiac and noncardiac mortality, there is limited data on the relationship between CRI and survival in patients with implantable cardioverter-defibrillators (ICDs), particularly across a wide range of renal function.


METHODS
We studied 507 consecutive patients receiving first-time ICDs from 1993-2003 at a single center. Preimplant serum creatinine measurements were used to determine glomerular filtration rate (GFR) and stage of chronic kidney disease (CKD). The primary outcome was time to death.


RESULTS
During a mean follow-up of 4 years, all-cause mortality through completion of follow-up increased stepwise by GFR stage (I: 16%, II: 20%, III: 35%; IV: 40%; V: 50%; P < 0.001 for trend). After multivariate adjustment, CRI was independently associated with death (HR = 1.7, P = 0.02), as were a serum creatinine >or=2.0 mg/dL (HR 2.5, P = 0.003) and the presence of end-stage renal disease (HR 6.8; P < 0.001). For every 10-unit decrease in GFR, the adjusted hazard of death increased 12% (P = 0.04).


CONCLUSIONS
The presence of CRI prior to implant is independently associated with increased mortality in patients receiving ICDs. The risk is proportional to the degree of renal dysfunction and is apparent even when GFR is only mildly reduced. Differences in mortality are observed within the first year of implant, and patients on dialysis are at highest risk. Because randomized trials of ICDs have not included large numbers of patients with moderate or severe renal disease, our findings may have important implications in prognosis and case selection of patients who otherwise meet current indications for ICD implantation.
Turakhia
Mintu P
MP
Cardiac Electrophysiology, Department of Medicine, University of California, San Francisco, California 94143-1354, USA.
Varosy
Paul D
PD
Lee
Keane
K
Tseng
Zian H
ZH
Lee
Randall
R
Badhwar
Nitish
N
Scheinman
Melvin
M
Lee
Byron K
BK
Olgin
Jeffrey E
JE
D000368:Aged; D015897:Comorbidity; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004554:Electric Countershock / Q000295:instrumentation / Q000401:mortality*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D016016:Proportional Hazards Models; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis* / Q000401:mortality*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate