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Published on: March 27, 2018
Long-Term Neurophysiological Outcomes in Patients Undergoing Coronary Artery Bypass Grafting
Irina V Tarasova1, Olga A Trubnikova1, Irina D Syrova1
1Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia.
Insights
Long-term cognitive decline affects over half of patients after coronary artery bypass grafting (CABG). This decline is linked to lasting changes in brainwave patterns, specifically increased theta and decreased alpha rhythms.
Area of Science:
- Neuroscience
- Cardiology
- Cognitive Psychology
Background:
- Coronary artery bypass grafting (CABG) is a common procedure for coronary artery disease.
- Postoperative cognitive dysfunction (POCD) is a recognized complication, but long-term outcomes require further investigation.
Purpose of the Study:
- To evaluate late neurophysiological outcomes in patients undergoing CABG.
- To identify predictors of long-term cognitive decline after CABG.
Main Methods:
- Neuropsychological and electroencephalographical assessments were performed before CABG and 5-7 years post-procedure in 45 male patients.
- Cognitive decline was defined as a 20% decrease in cognitive indicators.
- Multiple regression analysis identified associated demographic, clinical, and electroencephalographical variables.
Main Results:
- Cognitive decline was observed in 54% of patients 5-7 years after CABG.
- All patients exhibited increased theta rhythm and decreased alpha rhythm in specific brain areas.
- Slower mean alpha frequency and altered theta rhythms were significant predictors of cognitive impairment.
Conclusions:
- A significant proportion of patients experience long-term cognitive decline following CABG.
- Persistent alterations in brainwave activity (theta and alpha rhythms) are associated with this decline.
- Identifying predictors can aid in understanding and potentially mitigating long-term cognitive impairment after CABG.
Introduction:
This study aims to evaluate late postoperative neurophysiological outcomes in patients after coronary artery bypass grafting (CABG).
Methods:
Forty-five male patients with stable coronary artery disease aged 45-69 years underwent extended neuropsychological assessment using the software Status PF and electroencephalographical examination 3-5 days before CABG and 5-7 years after CABG. Postoperative decline in cognitive functions was determined by a 20% decrease in the cognitive indicator compared to that at baseline on 20% of the tests included in the Status PF battery. Statistical analysis was performed using the software STATISTICA 10.0. Multiple regression was used to identify demographic, clinical, and electroencephalographical variables associated with adverse cognitive outcomes.
Results:
Cognitive decline was observed in 54% of the patients in the long-term postoperative period. Five to seven years after CABG, all patients have shown an increase in the theta rhythm power compared to the preoperative values, which is most pronounced in the frontal and temporal areas of the right hemisphere (P=0.04), along with a decrease in the alpha rhythm in the posterior areas of the cortex (P=0.005). Multiple regression has reported that the main predictors of cognitive impairment are slower mean alpha frequency, decreased theta-2 rhythm with eyes closed in the right temporal area, and increased theta-2 rhythm with eyes open in the left temporal area (F(5.39)=8.81; P<0.00007; adjusted R-squared=0.57).
Conclusion:
Our findings indicate that 54% of the patients suffer from postoperative cognitive decline associated with increased theta and decreased alpha rhythms 5-7 years after CABG.
