Benefits of off-pump bypass on neurologic and clinical morbidity: a prospective randomized trial

Background Neurologic and clinical morbidity after coronary artery bypass grafting (CABG) can be significant. By avoiding cardiopulmonary bypass, off-pump CABG (OPCAB) may reduce morbidity. Methods Sixty patients (30 CABG and 30 OPCAB) were prospectively randomized. Neurocognitive testing was performed before the operation and 2 weeks and 1 year after the operation. Neurologic testing to detect stroke and 99mTc-HMPAO whole-brain single photon emission computed tomography scanning to assess cerebral perfusion were performed before the operation and 3 days afterward. Bilateral middle cerebral artery transcranial Doppler scanning was performed intraoperatively to detect cerebral microemboli. All examiners were blinded to treatment group. Clinical morbidity and costs were compared. Results Coronary artery bypass grafting was associated with more cerebral microemboli (575 ± 278.5 CABG versus 16.0 ± 19.5 OPCAB (median ± semiinterquartile range) and significantly reduced cerebral perfusion after the operation to the bilateral occipital, cerebellar, precunei, thalami, and left temporal lobes (p ≤ 0.01). Cerebral perfusion with OPCAB was unchanged. Compared with base line, OPCAB patients performed better on the Rey Auditory Verbal Learning Test (total and recognition scores) at both 2 weeks and at 1 year (p ≤ 0.05), whereas CABG performance was statistically unchanged for all cognitive measures. Patients who underwent CABG had more chest tube drainage (1389 ± 1256 mL CABG versus 789 ± 586 mL OPCAB, p = 0.02) and required more blood (3.9 ± 5.8 U CABG versus 1.2 ± 2.2 U OPCAB, p = 0.02), fresh frozen plasma (3.0 ± 6.0 U CABG versus 0.5 ± 2.2 U OPCAB, p = 0.03), and hours of postoperative use of dopamine (16.3 ± 21.2 hours CABG versus 7.3 ± 9.7 hours OPCAB, p = 0.04). These differences culminated in higher costs for CABG ($23,053 ± $5,320 CABG versus $17,780 ± $4,390 OPCAB, p< 0.0001). One stroke occurred with CABG, compared with none with OPCAB (p = NS). One OPCAB patient died because of a pulmonary embolus (p = NS). Conclusions Compared with CABG, OPCAB may reduce neurologic and clinical morbidity as well as cost.