Impact of renal insufficiency on short- and long-term outcomes after cardiac surgery.
BACKGROUND
Renal insufficiency is highly prevalent in North America and has been established as a nontraditional risk factor for cardiovascular disease. Cardiovascular disease remains the primary cause of mortality in the general population and is often treated with coronary artery bypass surgery (CABG). This population-based study aimed to determine the risk of nondialysis dependent renal insufficiency (RI) on the long-term outcomes of patients who undergo CABG.


METHODS
Prospectively collected data from 26,506 patients were abstracted from the Cardiac Care Network database from 9 revascularization hospitals in Ontario, Canada. Multivariate regression analysis examined associations between preoperative RI and inhospital, 30-day, and 1-year mortality according to 3 levels of serum creatinine: <120 micromol/L (normal), 120 to 180 micromol/L (mild RI), and >180 micromil/L (moderate-severe RI) and 5 levels of creatinine clearance (Cockcroft-Gault): >100 mL/min (normal), 80 to 99 mL/min (mild impairment), 60 to 79 mL/min (mild-moderate impairment), 40 to 59 mL/min (moderate impairment), and <40 mL/min (severe impairment).


RESULTS
The overall inhospital, 30-day, and 1-year mortality rates were 1.90%, 2.0%, and 4.5%, respectively. Patients with RI had greater overall comorbidity. After adjustment for confounding factors, RI was associated with the greater risk of both 30-day (odds ratio 3.7, 95% CI 2.3-5.8, P <.0001) and 1-year mortality (odds ratio 4.6, 95% CI 3.3-6.4, P <.0001).


CONCLUSIONS
Preoperative renal impairment should be recognized as a significant risk factor for mortality after CABG. A trend of increasing risk with severity of renal impairment was demonstrated for both 30-day and 1-year mortality in this large, population-based study.
Lok
Charmaine E
CE
Institute for Clinical Evaluative Sciences and the University of Toronto, Toronto, Ontario, Canada. charmaine.lok@uhn.on.ca
Austin
Peter C
PC
Wang
Hua
H
Tu
Jack V
JV
D000368:Aged; D000704:Analysis of Variance; D001026:Coronary Artery Bypass / Q000401:mortality*; D003327:Coronary Disease / Q000150:complications / Q000401:mortality / Q000601:surgery*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000150:complications*; D012307:Risk Factors; D016896:Treatment Outcome