Impact of Perioperative Infarcts After Cardiac Surgery
Background and Purpose—Brain injury after cardiac surgery is a serious concern for patients and their families. The purpose of this study was to use 3-T fluid attenuated inversion recovery MRI to characterize new and pre-existing cerebral ischemic lesions in patients undergoing cardiac surgery and to test whether the accumulation of new ischemic lesions adversely affects cognition.
Methods—Digital comparison of before and after fluid attenuated inversion recovery MRI images was performed for 77 cardiac surgery. The burden of pre-existing versus new ischemic lesions was quantified and compared with the results of baseline and postoperative neuropsychological testing.
Results—After surgery, new lesions were identified in 31% of patients, averaging 0.5 lesions per patient (67 mm3 [0.004%] of brain tissue). Patients with pre-existing lesions were 10× more likely to receive new lesions after surgery than patients without pre-existing lesions. Pre-existing ischemic lesions were observed in 64% of patients, averaging 19.4 lesions (1542 mm3 [0.1%] of brain tissue). New lesions in the left hemisphere were significantly smaller and more numerous (29 lesions; median volume, 44 mm3; volume range, 5–404 mm3) than those on the right (10 lesions; median volume, 128 mm3; volume range, 13–1383 mm3), which is consistent with a cardioembolic source of particulate emboli. Overall, the incidence of postoperative cognitive decline was 46% and was independent of whether new lesions were present.
Conclusions—New lesions after cardiac surgery added a small (≈4%) contribution to the burden of pre-existing cerebrovascular disease and did not seem to affect cognitive function.
Clinical Trial Registration—U.K. Clinical Research Network. UKCRN ID: 11702.
- Received September 24, 2014.
- Revision received December 17, 2014.
- Accepted December 19, 2014.
- © 2015 American Heart Association, Inc.