Predictors of early neurocognitive deficits in low-risk patients undergoing on-pump coronary artery bypass surgery.
BACKGROUND
Postoperative cognitive deficits (POCDs) are a source of morbidity and occur frequently even in low-risk patients undergoing cardiac surgery. Predictors of neurocognitive deficits can identify potentially modifiable risk factors as well as high-risk patients in whom alternate revascularization strategies may be considered.


RESULTS
448 patients undergoing coronary surgery (coronary artery bypass graft [CABG]) underwent standardized preoperative and postoperative neurocognitive testing as part of 2 randomized trials evaluating the effects of mild hypothermia during coronary surgery. Prospectively collected data were used to identify univariate predictors of POCDs and multivariable logistic regression models were constructed. Models were bootstrapped 1000 times. POCDs occurred in 59% of patients. Significant univariate predictors included intraoperative normothermia, impaired left ventricular (LV) function, higher educational level, elevated serum creatinine and reduced creatinine clearance, prolonged intubation time, intensive care unit (ICU) stay, and hospital stay. Advanced age, presence of carotid disease, and cardiopulmonary bypass time were not associated with increased POCDs in this cohort. Multivariable modeling identified intraoperative normothermia (odds ratio [95% confidence interval] -1.15 [1.01, 1.31]), poor LV function (1.53 [1.02, 2.30]), and elevated preoperative creatinine (1.01 [1.00 to 1.03] for every 1 mmol/L increase), prolonged (>24 hours) ICU stay (1.88 [1.27 to 2.79]), and higher educational level (1.52 [1.01 to 2.28]) as independent predictors of POCD occurrence.


CONCLUSIONS
Mild hypothermia, in the intraoperative and perioperative period, may be a protective strategy for the prevention of POCDs. Patients with elevated pre-operative creatinine and poor LV function carry a higher risk of POCDs and may benefit from revascularization strategies other than conventional on-pump CABG.
Boodhwani
Munir
M
Divisions of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, Canada.
Rubens
Fraser D
FD
Wozny
Denise
D
Rodriguez
Rosendo
R
Alsefaou
Abdualla
A
Hendry
Paul J
PJ
Nathan
Howard J
HJ
D000368:Aged; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology*; D015331:Cohort Studies; D015897:Comorbidity; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D003404:Creatinine / Q000097:blood; D003422:Critical Care / Q000706:statistics & numerical data; D004522:Educational Status; D005260:Female; D005544:Forecasting; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods; D007430:Intraoperative Care; D007674:Kidney Diseases / Q000453:epidemiology; D007859:Learning Disabilities / Q000453:epidemiology / Q000209:etiology; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008569:Memory Disorders / Q000453:epidemiology / Q000209:etiology; D008875:Middle Aged; D008955:Models, Cardiovascular; D009483:Neuropsychological Tests; D011182:Postoperative Care; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology
D003404:Creatinine