STS: Off-Pump CABG No Easier on Brain

SAN DIEGO, Jan. 29 -- Off-pump coronary artery bypass graft (CABG) offers no advantage for cognitive function over conventional on-pump surgery, researchers said here.

Overall neurocognitive function was no different between the two revascularization methods early in the recovery period or six months later, said Felix Hernandez, Jr., M.D., of the Eastern Main Medical Center in Bangor, and colleagues, at the Society of Thoracic Surgeons meeting.

In the study, the researchers prospectively randomized 201 non-emergent patients to on-pump or off-pump procedures. Participants also underwent a battery of neuropsychological tests before the operation, at hospital discharge, and six months later.

The CABG patients were ages 40 to 80 and had procedures from 2001 to 2004. Patient s needing concomitant valve or carotid artery procedures, emergency operations, reoperations, or several other risk factors were excluded.

The researchers found no significant difference in the primary endpoints of neurocognitive decline, defined as at least a 20% reduction from baseline in at least 20% of the tests. The on-pump versus off-pump findings were:

• 61.8% versus 51.5% for in-hospital neurocognitive decline (relative risk 0.83, 95% confidence interval 0.65 to 1.07), and
• 47.1% versus 44.4% for six-month neurocognitive decline (RR 0.94, 95% CI 0.70 to 1.28).

All but three individual psychocognitive tests likewise showed no difference between groups at discharge or six-month follow-up. The exceptions were:

• A significant decline in psychomotor scores on the Trail-Making A test at discharge for the off-pump group compared with the on-pump group (change in Z score from baseline -0.4 versus -0.2, P=0.03),
• Improved mood at discharge for the on-pump group compared with baseline versus a significant decline in State Anxiety Test score for the off-pump group (change in Z score from baseline 0.2 versus -0.6, P=0.03), and
• Declines for the off-pump group in reasoning ability scores on the Brixton Spatial Anticipation Test at six months compared with improvements for the on-pump group (change in Z score from baseline -0.2 versus 0.4, P=0.01).

Dr. Hernandez and colleagues concluded that off-pump CABG may offer some advantages over on-pump procedures but neurocognitive function is not included among them.

Commenting on the study, William A. Walker, M.D., of the Johnson City Medical Center Hospital, in Johnson City, Tenn., it was hoped that the off-pump procedure would eliminate declines in cognitive function, but the off-pump procedures failed to deliver for the majority of patients.

"It's not a panacea to solve all the problems we had with on-pump CABG," he said.