Incidence and impact of brain lesions and cognitive impairment after CABG with moderate or severe cerebral artery stenosis seen on low-field MRI.

Objective: The study aimed to assess the incidence and impact of brain lesions and cognitive impairment after coronary artery bypass grafting (CABG) in patients with moderate-to-severe cerebral artery stenosis using low-field MRI.

Methods: 110 patients with moderate-to-severe cerebral artery stenosis who underwent CABG between November 2023 and May 2024 were enrolled. Postoperative brain lesions were evaluated using low-field MRI. Cognitive decline was defined as a reduction of ≥3 points in the Montreal Cognitive Assessment score from baseline. Risk factors associated with postoperative brain lesions and cognitive impairment were identified in univariate and multivariate logistic regression analyses.

Results: A total of 110 patients were enrolled, with a mean age of 65±7 years and 22 (20.0%) were female. New brain lesions were identified in 24 patients (21.8%). Logistic regression analysis identified operation time (OR 1.014, 95% CI 1.003 to 1.025, p=0.013) to be independently associated with brain lesions. 22.2% of the patients (20/90) experienced postoperative cognitive decline. New brain lesions were independently associated with cognitive decline (OR 4.651, 95% CI 1.158 to 18.676, p=0.030), particularly the new brain lesions impairing orientation ability (OR 4.534, 95% CI 1.438 to 14.289, p=0.010).

Conclusions: Low-field MRI has proven effective in detecting new brain lesions after CABG. Both postoperative new brain lesions and CABG operation were significant contributors to cognitive decline.