Cognitive Outcome After Off-Pump and On-Pump Coronary Artery Bypass Graft Surgery

Context:

Coronary artery bypass graft (CABG) surgery is associated with a decline
in cognitive function, which has largely been attributed to the use of cardiopulmonary
bypass (on-pump procedures). Cardiac stabilizers facilitate CABG surgery without
use of cardiopulmonary bypass (off-pump procedures) and should reduce the
cognitive decline associated with on-pump procedures.

Objective:

To compare the effect of CABG surgery with (on-pump) and without (off-pump)
cardiopulmonary bypass on cognitive outcome.

Design and Setting:

Randomized controlled trial conducted in the Netherlands of CABG surgery
patients enrolled from March 1998 through August 2000, with 3- and 12-month
follow-up.

Participants and Intervention:

Patients scheduled for their first CABG surgery (mean age, 61 years;
n = 281) were randomly assigned to off-pump surgery (n = 142) or on-pump surgery
(n = 139).

Main Outcome Measures:

Cognitive outcome at 3 and 12 months, which was determined by psychologists
(blinded for randomization) who administered 10 neuropsychological tests before
and after surgery. Quality of life, stroke rate, and all-cause mortality at
3 and 12 months were secondary outcome measures.

Results:

Cognitive outcome could be determined at 3 months in 248 patients. Cognitive
decline occurred in 21% in the off-pump group and 29% in the on-pump group
(relative risk [RR], 0.65; 95% confidence interval [CI], 0.36-1.16; P = .15). The overall standardized change score (ie, improvement
of cognitive performance) was 0.19 in the off-pump vs 0.13 in the on-pump
group (P = .03). At 12 months, cognitive decline
occurred in 30.8% in the off-pump group and 33.6% in the on-pump group (RR,
0.88; 95% CI, 0.52-1.49; P = .69). The overall standardized
change score was 0.19 in the off-pump vs 0.12 in the on-pump group (P = .09). No statistically significant differences were
observed between the on-pump and off-pump groups in quality of life, stroke
rate, or all-cause mortality at 3 and 12 months.

Conclusion:

Patients who received their first CABG surgery without cardiopulmonary
bypass had improved cognitive outcomes 3 months after the procedure, but the
effects were limited and became negligible at 12 months.

JAMA. 2002;287:1405-1412