This document summarizes neurological dysfunction that can occur after cardiac surgery. It notes that postoperative cognitive dysfunction and silent brain infarcts are common, occurring in 30-80% and 50% of patients respectively. The document reviews findings from several studies. One study found silent brain infarct rates of 0.71% after TAVR and 0.25% after CABG. Another study found early postoperative slowing on cognitive tests that normalized by 3 months post-op. The document recommends neuroprotective strategies like lidocaine and hypothermia to reduce neurological complications after cardiac surgery.

1. Neurological Dysfunction Post
Cardiac Surgery
Presenter: Nurul Hafiez bin Fijasri, MD
Supervisor: Prof Dato Sri Ramziham,
Mr Ishamuddin, Mr Hairulfaizi

2. Outlines
• Problem statement
• Incidence
• Journals
• Strategies, recommendation
• References

3. Problem statement
• Cerebral dysfunction after cardiac surgery remains a devastating
complication and is growing in importance in aging population.
• Examples are stroke, encephalopathy (including delirium), or postoperative
cognitive dysfunction (POCD, postoperative deterioration in memory,
attention, and speed of information processing)
• Aetiologies are caused primary by cerebral emboli, hypoperfusion, or
inflammation that has largely been attributed to the use of
cardiopulmonary bypass.
Tomoko Goto • Kengo Maekawa, Cerebral dysfunction after coronary artery bypass
surgery 24 August 2013 Japanese Society of Anesthesiologists 2013 J Anesth (2014)
28:242–248

4. Incidence
• Stroke following cardiac surgery occurs in 1.4 % to 3.8 % of patients
who undergo CABG and 8.7 % of patients after aortic repair.
• Postoperative cognitive dysfunction (POCD) is the most common
complication of cardiac surgery. It occurs in 30 % to 80 % of patients
at discharge and 20 % to 40 % after 6 months to 1 year.
• Postoperative DW-MRI finds new ischemic lesions in about 50 % of
patients undergoing cardiac surgery, and that there is a correlation
between new lesions and cognitive decline.
Selim M. Perioperative stroke. N Engl J Med. 2007;356:706–13.
Van Dijk D, et al, Neurocognitive dysfunction after coronary artery bypass
surgery: a systemic review. J Thorac Cardiovasc Surg. 2000;120: 632–9.
Knipp SC, et al, Cognitive outcomes three years after coronary artery bypass
surgery: relation to diffusion- weighted magnetic resonance imaging. Ann Thorac
Surg. 2008;85:872–9.

5. Neurological Dysfunction
• Exist in broad spectrum from major stroke/TIA to subclinical brain
injury such as postoperative cognitive dysfunction (POCD) and silent
brain infarct (SBI).
• SBI associated with significant morbidities; such as increase to
subsequent stroke to more than x5.
• Associated sequelae include cognitive dysfunction, increased risk of
dementia, psychiatric disturbances and reduced quality of life.
Indja, B., Woldendorp, K., Vallely, M.P. and Grieve, S.M. (2019). Silent
Brain Infarcts Following Cardiac Procedures: A Systematic Review and
Meta-Analysis. Journal of the American Heart Association, [online] 8(9),
p.e010920.

6. Journal 1
J Am Heart Assoc. 2019;8:e 010920. DOI: 10.1161/JAHA.118.010920.
42 studies with 49 separate intervention groups for a total of 2632 patients.
Studies are prospective cohort studies using diffused weighted imaging (DWI) in the early post operative
period following cardiac procedures, done within 14 days.
The prevalence of SBIs following transcatheter aortic valve implantation was
0.71, following aortic valve replacement 0.44, in a mixed cardiothoracic surgery
group 0.39;
coronary artery bypass graft 0.25; percutaneous coronary intervention 0.14;
and off-pump coronary artery bypass 0.14

10. • SBIs are very common following procedures involving the aortic valve
and manipulation of the aorta.
• In accordance with the aetiology of SBIs that are the microemboli as a
result of direct disruption of atherosclerotic plaque in the ascending
aorta.
• Increased levels of proximal thoracic aortic atheroma have been
shown to be associated with higher rates of intraoperative cerebral
embolism as evident by transcranial Doppler.
Djaiani G, Fedorko L, Borger M, Mikulis D, Carroll J, Cheng D, Karkouti K, Beattie S,
Karski J. Mild to moderate atheromatous disease of the thoracic aorta and new
ischemic brain lesions after conventional coronary artery bypass graft surgery. Stroke.
2004;35:e356–e358.

11. Journal 2
28 published studies, accumulating data from up to 2043 patients undergoing CABG surgery
Results were examined at ‘very early’ (<2 weeks), ‘early’ (3 months) and ‘late’ (6–12 months) time periods post-
operatively.
Neuropsychological Tests used
-Grooved Pegboard and Digit Symbol Test: assesses psychomotor speed.
-Trails A/B Test: assess psychomotor speed but requires a greater degree of planning and working
memory (executive functions).
-RAVLT – Rey Auditory Verbal Learning Test: assesses short-term memory for supraspan word lists.

12. Result
• Post-operative time point (<2 weeks post- surgery: ‘very early’)
data statistically significant slowing in the Digit Symbol (Z=−2.82;
p=0.005) and Grooved Pegboard tests (Z=−2.33, p=0.02).
• However after 3 months and 6-12 months; psychomotor speed had
normalised and that in fact all measures showed improvement
relative to baseline.

13. Recommendation
Lidocaine, low- dose magnesium, corticosteroids, beta-blockers, and ACE inhibitors have proven
neuroprotective capabilities.
Deep hypothermic circulatory arrest (DHCA) is a valuable method for neuroprotection, but care must be
taken in limiting its duration and effectively rewarming, while particle filters and anaesthetic monitoring
should both be employed in cardiac surgery.

14. Daniel G et al, Neuroprotection against stroke and encephalopathy after cardiac
surgery, December 10, 2018, Interventional Medicine & Applied Science, Vol. 11
(1), pp. 27–37

15. Tomoko Goto • Kengo Maekawa, Cerebral dysfunction after coronary artery bypass
surgery 24 August 2013 Japanese Society of Anesthesiologists 2013 J Anesth (2014)
28:242–248 DOI 10.1007/s00540-013-1699-0

16. References
1. Cormack, F., Shipolini, A., Awad, W.I., Richardson, C., McCormack, D.J., Colleoni, L.,
Underwood, M., Baldeweg, T. and Hogan, A.M. (2012). A meta-analysis of cognitive
outcome following coronary artery bypass graft surgery. Neuroscience and
Biobehavioral Reviews, [online] 36(9), pp.2118–2129.
2. Indja, B., Woldendorp, K., Vallely, M.P. and Grieve, S.M. (2019). Silent Brain Infarcts
Following Cardiac Procedures: A Systematic Review and Meta-Analysis. Journal of the
American Heart Association, [online] 8(9), p.e010920.
3. Goto, T. and Maekawa, K. (2013). Cerebral dysfunction after coronary artery bypass
surgery. Journal of Anesthesia, 28(2), pp.242–248.
4. Jovin, D.G., Katlaps, K.G., Ellis, B.K. and Dharmaraj, B. (2019). Neuroprotection against
stroke and encephalopathy after cardiac surgery. Interventional Medicine and Applied
Science, 11(1), pp.27–37.