Long-Term Cognitive Decline After Coronary Artery Bypass Grafting: is Off-Pump Surgery Beneficial?

Coronary artery bypass surgery is associated with postoperative cognitive decline, which has largely been attributed to the use of the heart lung machine. We hypothesized that long-term cognitive outcome may improve by avoiding the heart lung machine. The objective of the present study is to compare the effect of coronary bypass surgery with and without heart lung machine on cognitive and clinical outcome, five years after surgery.

Background: Coronary artery bypass surgery is associated with postoperative cognitive decline, which has largely been attributed to the use of cardiopulmonary bypass (CPB). A large recent study by Newman et al demonstrated that the incidence of cognitive decline was 24% at six months after surgery, but it increased to 42% at five years. In the recently conducted Octopus Randomized Trial, cognitive decline at three months after surgery was present in 29% of the patients operated with CPB. In the patients operated without CPB, the incidence was 21%, i.e. only slightly better. Hypothesis: Improvement of cognitive outcome by avoiding cardiopulmonary bypass will become more apparent five years after surgery, compared to three months after surgery. Study objectives: The objective of the present study is to compare the effect of coronary bypass surgery with and without cardiopulmonary bypass on cognitive and clinical outcome, five years after surgery. Methods: The 281 participants of the Octopus Study, who were operated on between March 1998 and August 2000 and randomized to off-pump or on-pump coronary bypass surgery, will be invited for an additional assessment of their cognitive and clinical status and quality of life, five years after surgery. Patients will undergo a battery of ten neuropsychologic tests to determine their cognitive status. Clinical status will be assessed by an interview. Questionnaires will be used to measure quality of life.

Inclusion Criteria: indication for (first-time) coronary artery bypass surgery off-pump CABG considered technically possible Exclusion Criteria: concomitant valve surgery unable to complete neuropsychological testing life expectancy less than 1 year

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Van Dijk D, Jansen EW, Hijman R, Nierich AP, Diephuis JC, Moons KG, Lahpor JR, Borst C, Keizer AM, Nathoe HM, Grobbee DE, De Jaegere PP, Kalkman CJ; Octopus Study Group. Cognitive outcome after off-pump and on-pump coronary artery bypass graft surgery: a randomized trial. JAMA. 2002 Mar 20;287(11):1405-12. doi: 10.1001/jama.287.11.1405.

Nathoe HM, van Dijk D, Jansen EW, Suyker WJ, Diephuis JC, van Boven WJ, de la Riviere AB, Borst C, Kalkman CJ, Grobbee DE, Buskens E, de Jaegere PP; Octopus Study Group. A comparison of on-pump and off-pump coronary bypass surgery in low-risk patients. N Engl J Med. 2003 Jan 30;348(5):394-402. doi: 10.1056/NEJMoa021775.