Cognitive Outcomes Three Years After Coronary Artery Bypass Surgery: A Comparison of On-Pump Coronary Artery Bypass Graft Surgery and Nonsurgical Controls

doi:10.1016/j.athoracsur.2004.10.011

The Annals of Thoracic Surgery

Volume 79, Issue 4, April 2005, Pages 1201-1209

https://doi.org/10.1016/j.athoracsur.2004.10.011 Get rights and content

Background

Coronary artery bypass grafting has been associated with both early and late postoperative cognitive decline, but interpretation of previous studies has been limited by lack of appropriate control groups. We compared changes in cognitive performance from baseline to 3 years in patients undergoing coronary artery bypass grafting with those of a control group of patients with known risk factors for coronary artery disease but without surgery.

Methods

Patients undergoing coronary artery bypass grafting (n = 140) and a demographically similar nonsurgical control group with coronary artery disease (n = 92) completed baseline neuropsychological assessment and were followed up prospectively at 3, 12, and 36 months. Cognitive performance was assessed with a battery of neuropsychological tests, measuring the cognitive domains of attention, language, verbal and visual memory, visuospatial, executive function, and psychomotor and motor speed. The statistical analyses were performed in two ways: using data from all tested individuals, and using a model imputing missing observations for individuals lost to follow-up.

Results

Both the coronary artery bypass grafting and nonsurgical control groups improved from baseline to 1 year, with additional improvement between 1 and 3 years for some cognitive tests. The coronary artery bypass grafting group had statistically significantly greater improvement than the nonsurgical controls for some subtests, and had a comparable longitudinal course for the remainder of the subtests. Both study groups had a trend toward nonsignificant decline at 3 years on some measures, but the overall differences between groups over time were not statistically significant.

Conclusions

Prospective longitudinal neuropsychological performance of patients with coronary artery bypass grafting did not differ from that of a comparable nonsurgical control group of patients with coronary artery disease at 1 or 3 years after baseline examination. This finding suggests that previously reported late cognitive decline after coronary artery bypass grafting may not be specific to the use of cardiopulmonary bypass, but may also occur in patients with similar risk factors for cardiovascular and cerebrovascular disease.

Section snippets

Patients

The study was approved by the Johns Hopkins Institutional Review Board on July 14, 1997. Eligible candidates for CABG who were native English speaking, not intubated, able to sit upright, and able to give informed consent were approached. Enrollment was completed from September 1997 through March 1999. Of the 1,129 patients who underwent CABG during that period, 140 met study inclusion criteria and completed written informed consent and baseline testing. For the nonsurgical controls, three

Results

Demographic characteristics for the CABG patients and the nonsurgical controls have been previously described [5]. Of the 140 CABG patients recruited into the study, 70 completed the follow-up testing at 36 months, 47 refused further testing, 10 died, and 13 were lost to follow-up. Of the 92 nonsurgical controls, 57 completed 36-month testing, 15 refused further testing, 7 died, and 13 were lost to follow-up. The follow-up rate (excluding deaths) was thus somewhat higher among the nonsurgical

Comment

Coronary artery bypass grafting (CABG) can provide significant improvement in survival and quality of life for patients with CAD, but the possibility of delayed or late cognitive decline up to 5 years after CABG with CPB has been reported by several recent studies 1, 2, 10. None of the previous long-term outcome studies included a control group, and it is therefore not possible to determine if these late cognitive changes were due to delayed effects of the use of CPB, nonspecific effects of

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Citation Excerpt :
In the present study, the patients randomized to PCI with bare metal stenting had significantly more coronary revascularizations during follow-up than the patients randomized to off-pump CABG which may partially explain why cognitive performance was lower in this group. However, several recent studies have indicated that patient-related factors like advanced age, diabetes, a low level of education, and presence of cardiovascular disease are more important determinants of long-term cognitive outcome than the mode of coronary revascularization [6, 8, 16, 17]. The overall cognitive performance of the off-pump CABG group was superior to the PCI group.
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A multicenter trial in the Netherlands randomized 280 patients to percutaneous coronary intervention or off-pump coronary artery bypass grafting. Cognitive performance 7.5 years after randomization was assessed through a battery of 9 neuropsychologic tests and summarized into a combined Z-score.
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At 7.5 years follow-up, off-pump coronary artery bypass grafting patients had a similar or perhaps even better cognitive performance compared with percutaneous coronary intervention patients.

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Original articlesCardiovascularCognitive Outcomes Three Years After Coronary Artery Bypass Surgery: A Comparison of On-Pump Coronary Artery Bypass Graft Surgery and Nonsurgical Controls

Background

Methods

Results

Conclusions

Section snippets

Patients

Results

Comment

J Cardiothorac Vasc Anesth

Ann Thorac Surg

Longitudinal assessment of neurocognitive function after coronary-artery bypass surgery

N Engl J Med

Cognitive change 5 years after coronary artery bypass surgery

Health Psychol

Cognitive test performance and presence of subclinical cardiovascular disease in the cardiovascular health study

Neuroepidemiology

Cardiovascular risk factors and cognitive decline in middle-aged adults

Neurology

Cognitive changes with coronary artery disease: a prospective study of coronary artery bypass graft patients and nonsurgical controls

Ann Thorac Surg

Neuropsychological assessment

HIV Dementia Scale: a rapid screening test

J Acq Immune Defic Syndr Human Retrovirol

The CES-D scale: a self-report depression scale for research in the general population

Appl Psychol Measure

Original articles
Cardiovascular
Cognitive Outcomes Three Years After Coronary Artery Bypass Surgery: A Comparison of On-Pump Coronary Artery Bypass Graft Surgery and Nonsurgical Controls