Background: Cognitive decline has been associated with coronary artery bypass grafting (CABG), but the extent to which these findings are related to the natural history of cognitive deficits in elderly patients with cardiac disease or have been influenced by the research methods used to determine abnormalities warrants further study.
Methods: After excluding individuals with conditions known to cause brain dysfunction, individuals referred for percutaneous coronary intervention (n = 42) or CABG (n = 35) were compared with an age-matched and education-matched control group without clinical evidence of coronary artery disease (n = 44). These subjects underwent a battery of 14 neurocognitive tests at baseline (preoperatively) and at 3 weeks and 4 months postoperatively.
Results: The majority of test scores for all three cohorts were within nonimpaired ranges at baseline and 3 weeks later. Change in impairment status from baseline to 3-week assessment was not associated statistically with type of treatment as referenced to clinical norms, and was associated with type of treatment on only one measure as referenced to control group performances. A further overall improvement in impairment status from 3 weeks' to 4 months' follow-up was seen in both CABG and percutaneous coronary intervention patients. Mean test scores were significantly worse in CABG patients versus percutaneous coronary intervention patients in 4 of 13 measures at 3 weeks' follow-up, but significant de novo impairment at 3 weeks' follow-up in the CABG group compared with the percutaneous coronary intervention and control groups was present in only one test. As assessed by reliable change methodology, impairment was statistically associated with type of treatment for only 1 of 13 measures.
Conclusions: As compared with changes seen in repeat testing of healthy control subjects and individuals who underwent percutaneous coronary intervention, clinically meaningful cognitive deterioration was not observed after CABG.