Abstract 9865: Acute Infarcts on Brain MRI Following Aortic Arch Repair With Circulatory Arrest: Insights From the ACE Cardiolink-3 Randomized Trial

Abstract

Introduction: Our objective was to investigate the frequency and distribution of new ischemic brain lesions detected by diffusion-weighted imaging (DWI) on brain MRI after aortic arch surgery. Methods: This was an imaging sub-analysis of the ACE CardioLink-3 randomized controlled trial which compared the safety and efficacy of innominate vs axillary artery cannulation during elective proximal aortic arch surgery. All participants in the trial underwent pre- and post-operative MRI. New ischemic lesions were defined as lesions on post-operative DWI that were not visible on the pre-operative DWI. Results: Of 102 patients who underwent surgery, 71 (70%) had new ischemic lesions on DWI and the total lesion number across all participants was 391. The average lesion number in patients with at least one ischemic lesion was 5.5±4.9, and were similar in the right (3.3±2.7) or left (3.6±2.8) hemispheres (p=0.49). The most common lesion patterns were single or multiple cortical infarcts. Half of the lesions (n=183, 47%) were in the middle cerebral artery territory, while 24% were in the infratentorium. 42% of patients had lesions distributed in both anterior and posterior circulation, 21% in anterior circulation only, and 7% in posterior circulation only. Besides, 20% had lesions in watershed areas. There were no differences in distribution between patients in the innominate vs axillary artery cannulation groups. In multivariable regression models, more severe white matter hyperintensity on pre-operative MRI (odds ratio per 1-score increase of Fazekas scale 1.80; p=0.02) and lower nadir temperature during operation (odds ratio per 1°C decrease, 1.14; p=0.05) were associated with having any new ischemic lesion, while older age (risk ratio per 1-year increase 1.02; p=0.03) and lower nadir temperature (risk ratio per 1°C decrease, 1.06; p=0.06) were associated with higher lesion numbers. Conclusion: In patients who underwent elective proximal aortic arch surgery, new ischemic brain lesions were common, and mostly identified as scattered cortical infarcts in the middle cerebral artery territory. Advanced age, underlying small vessel disease, and lower nadir temperature during operation were risk factors of presence and burden of new ischemic lesions after surgery.