Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Viewpoint
  • Published:

Etiology of cognitive change after CABG surgery: more than just the pump?

Nature Clinical Practice Cardiovascular Medicine volume 5, pages 314–315 (2008)Cite this article

Since the introduction of CABG surgery with cardiopulmonary bypass (CPB) in the early 1960s, there have been concerns that this procedure is associated with adverse neurological outcomes. With improvements in stroke rate and mortality after CABG surgery, interest has shifted to the problem of postoperative cognitive decline. A prospective study from 1987 reported that almost 60% of patients who had undergone CABG surgery experienced cognitive impairment,1 motivating several investigators to examine the nature and etiology of this complication. A 2001 study also reported a high incidence of cognitive decline 5 years after CABG surgery,2 which reinforced the urgent need to develop strategies for protecting the brain during cardiac surgery. On the widely held, but largely unproven, assumption that CPB was the primary cause of cognitive decline, efforts to develop new surgical techniques that did not rely on the use of CPB were initiated. Evidence is now emerging, however, that patient-related factors, particularly the degree of pre-existing vascular disease in the brain, might have a more important role in postoperative cognitive decline than previously thought.

Attempts to define the incidence of postoperative cognitive decline in patients undergoing CABG surgery have been hampered by several issues. First, there has been little consensus about the optimum time for follow-up testing. Second, most studies have not included appropriate comparison groups, such as nonsurgical patients or those undergoing different types of major surgery with anesthesia. Third, little attention has been paid to the severity and duration of postoperative cognitive changes, or to the use of arbitrary statistical criteria for classifying postoperative decline. A review of observational studies without control groups published between 1980 and 1999, concluded that, when tested 2 months after CABG surgery, approximately 20% of patients had cognitive decline.3 A more-recent prospective study, however, showed that, by approximately 3 months follow-up, there was no difference in cognitive performance between patients who had undergone surgery and medically and demographically similar patients who had not.4 This finding indicates that, for the majority of patients, postoperative cognitive changes are relatively mild and resolve by 3 months after surgery.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

References

  1. Shaw PJ et al. (1987) Long-term intellectual dysfunction following coronary artery bypass graft surgery: a six month follow-up study. Q J Med 62: 259–268

    CAS  PubMed  Google Scholar 

  2. Newman MF et al. for the Neurological Outcome Research Group and the Cardiothoracic Anesthesiology Research Endeavors Investigators (2001) Longitudinal assessment of neurocognitive function after coronary- artery bypass surgery. N Engl J Med 344: 395–402

    Article  CAS  Google Scholar 

  3. van Dijk D et al. (2000) Neurocognitive dysfunction after coronary artery bypass surgery: a systematic review. J Thorac Cardiovasc Surg 120: 632–639

    Article  CAS  Google Scholar 

  4. Selnes OA et al. (2003) Cognitive changes with coronary artery disease: a prospective study of coronary artery bypass graft patients and nonsurgical controls. Ann Thorac Surg 75: 1377–1384

    Article  Google Scholar 

  5. Ho PM et al. (2004) Predictors of cognitive decline following coronary artery bypass graft surgery. Ann Thorac Surg 77: 597–603

    Article  Google Scholar 

  6. Veliz-Reissmüller G et al. (2007) Pre-operative mild cognitive dysfunction predicts risk for post-operative delirium after elective cardiac surgery. Aging Clin Exp Res 19: 172–177

    Article  Google Scholar 

  7. Moller JT et al. for the ISPOCD investigators (1998) Long-term postoperative cognitive dysfunction in the elderly: ISPOCD1 study. Lancet 351: 857–861

    Article  CAS  Google Scholar 

  8. Sugiyama N et al. (2002) The incidence and severity of cognitive decline after major noncardiac surgery: a comparison with that after cardiac surgery with cardiopulmonary bypass. J Anesth 16: 261–264

    Article  Google Scholar 

  9. Selnes OA et al. (2005) Cognitive outcomes three years after coronary artery bypass surgery: a comparison of on-pump coronary artery bypass graft surgery and nonsurgical controls. Ann Thorac Surg 79: 1201–1209

    Article  Google Scholar 

  10. van Dijk D et al. for the Octopus Study Group (2007) Cognitive and cardiac outcomes 5 years after off-pump vs on-pump coronary artery bypass graft surgery. JAMA 297: 701–708

    Article  CAS  Google Scholar 

  11. Mullges W et al. (2002) Cognitive performance after coronary artery bypass grafting: a follow-up study. Neurology 59: 741–743

    Article  Google Scholar 

Download references

Acknowledgements

This study was supported by grant 35610 from the National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA, by the Charles A Dana Foundation, New York, NY, USA and by the Johns Hopkins Medical Institution GCRC grant RR 00052.

Author information

Author notes

  1. Division of Cognitive Neuroscience, Johns Hopkins University School of Medicine, 1620 McElderry Street, Reed Hall East–2, Baltimore, MD 21205–2189, USA oselnes@jhmi.edu

Authors and Affiliations

  1. and a Professor of Neurology in the Division of Cognitive Neuroscience at the Johns Hopkins University School of Medicine, OA Selnes is a Clinical Neuropsychologist in the Medical Psychology Clinic at the Johns Hopkins Hospital, Baltimore, MA, USA.,

    Ola A Selnes

Authors
  1. Ola A Selnes
    View author publications

    You can also search for this author in PubMed Google Scholar

Ethics declarations

Competing interests

The author declares no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Selnes, O. Etiology of cognitive change after CABG surgery: more than just the pump?. Nat Rev Cardiol 5, 314–315 (2008). https://doi.org/10.1038/ncpcardio1193

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ncpcardio1193

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing