Risk factors for stroke and dementia after coronary artery bypass grafting (5-year observation)

Objective: We wished to study the state of the brain, the frequency of carotid artery stenosis, and the duration of hypertension in patients with ischemic strokes and dementia in the long-term period of coronary artery bypass grafting.

Methods: A total of 75 people were included, and their average age before surgery was 56 [52; 60] years. The operation was performed with the help of artificial blood circulation. The mean duration of the cardiopulmonary bypass was 86.0 [65.0; 105.0] min, and the surgery duration was 230.0 [190.0; 270.0] min. The follow-up period included hospital and five-year stages. Neuroimaging was performed on a Somatom Sensation 64 multispiral computed tomograph (MSCT) (Siemens, Germany). Color duplex scanning of the brachycephalic arteries was performed using an ultrasound scanner of the expert class "General Electric Vivid 7 Dimension LCD", USA.

Results: Within five years after coronary artery bypass grafting, four (5.3%) patients developed strokes, and two (2.7%) patients developed dementia. The duration of arterial hypertension in the group before coronary artery bypass grafting was 4 [1; 10] years. In patients with strokes, it was 8 [6; 15] years, and for those with dementia, it was 30 [20; 40] years. Before surgery, carotid artery stenoses of up to 50% according to the criteria of NASCET (North American Symptomatic Carotid Endarterectomy Trial) were detected in 37% of them, while after five years, they were found in 55% of patients, at p = 0.03. Among the stroke survivors, carotid artery stenosis was detected in four (100%) cases and dementia in one (50%) patient. Five years later, the expansion of the III ventricle of the brain was detected to range from 7.0 [5.5; 8.0] to 7.5 [6.0; 9.0] mm (p = 0.03). The number of people with leukoaraiosis increased from 25% to 71%, p=0.0001, as well as those with cysts and gliosis increasing from 4% to 20%, p=0.0001, indicating damage to the small cerebral arteries.

Conclusions: It can be assumed that the presence of prolonged arterial hypertension and carotid artery stenosis increases the likelihood of strokes and dementia within five years after coronary bypass surgery.