Abstract 3533: Long-Term Neurocognitive Outcome after Coronary Artery Bypass Surgery
Background-Although neurocognitive decline is well recognized early after coronary artery bypass grafting (CABG), follow-up studies reflecting cognitve performance beyond one year are rare. Furthermore, results as to the degree of neurocognitive changes and their relation to the operation are inconsistent.
Objectives-We prospectively assessed the course of neurocognitive function during three years after CABG and determined the relation between cognitive decline and structural brain injury detected by multi-sequence magnetic resonance imaging (MRI) including diffusion-weighted technique (DW).
Methods-In 39 patients scheduled for elective isolated CABG as the first-time cardiac operation, neuropsychological tests and MRI were performed preoperatively, at discharge, 3 months and 3 years after surgery. Neurocognitive performance was assessed with a series of 13 standardized tests, measuring six cognitive areas. Cognitive decline was defined as a drop of 1 standard deviation or more in the scores in 3 or more tests.
Results-Neurocognitive decline was present in 72% (28/39) of patients at discharge, 28% (11/39) at 3 months and 34% (11/32) at 3 years. Of the 28 patients with cognitive decline at discharge, 20 (71%) patients improved by 3 months compared to baseline. Of the 11 patients with cognitive decline by 3 years, only 3 showed deficits during the entire postoperative observation period, whereas 8 patients demonstrated early improvement followed by later decline. Postoperative DW-MRI disclosed 42 new ischemic small brain lesions in 51% of patients. All lesions were neurologically silent. Multiple linear regression analysis revealed cognitive decline to be related neither to new DWI brain lesions nor clinical and operative variables. A predictor of late postoperative cognitive decline was not identified.
Conclusions-Neurocognitive decline early after CABG frequently resolves within few months. Late deficits do not seem to be associated with previous CABG surgery.