Postoperative renal dysfunction and preoperative left ventricular dysfunction predispose patients to increased long-term mortality after coronary artery bypass graft surgery.
BACKGROUND
Both preoperative left ventricular dysfunction and postoperative renal function deterioration are associated with increased long-term mortality after cardiac surgery. The influence of preoperative left ventricular dysfunction on postoperative renal dysfunction and long-term mortality is not defined.


METHODS
We collected data from 641 consecutive patients undergoing coronary bypass surgery with cardiopulmonary bypass in 1991 at our institution. Prospective follow-up was through to July 2004.


RESULTS
In-hospital mortality was 2.7% (17 of 641). During follow-up, 248 (40%) patients discharged alive died (5 and 10 yr survival 90% and 70%, respectively). On univariate analysis, preoperative left ventricular dysfunction (ejection fraction <50%) and an increase in serum creatinine > or =25% in the first postoperative week were associated with long-term mortality. The associated mortality risk was additive in predominantly non-overlapping patients groups: the hazard ratio (HR) for renal function deterioration only was 1.41 [95% confidence interval (CI) 0.95-2.32, P=0.083; n=64] and for left ventricular dysfunction only 1.71 (95% CI 1.26-2.95, P=0.0026; n=73). In patients in whom both were present, HR was 3.23 (95% CI 2.52-20.28, P<0.0001; n=20). Although postoperative renal dysfunction was associated with left ventricular dysfunction (P=0.008), both left ventricular dysfunction and postoperative renal function deterioration were independently associated with long-term mortality on multivariate analysis, as were age and the use of venous conduits.


CONCLUSIONS
Both postoperative renal function deterioration and preoperative left ventricular dysfunction independently identify largely non-overlapping groups of patients with increased long-term mortality after coronary bypass surgery. In the group of patients with both factors present, the mortality risks appear additive.
Loef
B G
BG
Department of Cardiothoracic Surgery, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, Groningen 9713 GZ, The Netherlands. b.loef@hccnet.nl
Epema
A H
AH
Navis
G
G
Ebels
T
T
Stegeman
C A
CA
D058186:Acute Kidney Injury / Q000209:etiology* / Q000628:therapy; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000401:mortality; D003404:Creatinine / Q000097:blood; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011379:Prognosis; D017582:Renal Replacement Therapy; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000401:mortality
D015415:Biomarkers; D003404:Creatinine