Preoperative blood–brain barrier disruption as a predictor of postoperative cognitive decline after CABG: a focus on brain reserve and long-term outcomes
Year: 2026
Type: article
Abstract: Dear Editor, We read with great interest the prospective cohort study by Wang et al, entitled “Preoperative blood–brain barrier disruption increased risk of postoperative cognitive decline after coronary artery bypass grafting” published in International Journal of Surgery[1]. The authors report that higher preoperative frontal permeability-surface (PS) values on computed tomography perfusion (CTP) imaging are independently associated with early postoperative cognitive decline (POCD) after coronary artery bypass grafting (CABG). This is an important contribution to the emerging understanding of blood–brain barrier (BBB) disruption as a factor in perioperative neurocognitive vulnerability. This study aligns with recent literature indicating that BBB disruption, assessed by various methods (e.g., cerebrospinal fluid-to-plasma albumin ratio [CPAR] and dynamic contrast-enhanced MRI [DCE-MRI]), is linked to postoperative cognitive dysfunction. In non-cardiac surgery patients, postoperative CPAR increases have been associated with delirium and longer hospital stays[2]. Furthermore, studies in cardiac surgery patients, including a recent report by Di et al, found that preoperative BBB permeability, measured by DCE-MRI, was associated with delirium in older patients undergoing off-pump CABG[3]. Together with Wang et al., these studies suggest that BBB dysfunction is an important factor in postoperative neurocognitive disorders. However, the findings by Di et al raise an important point: when baseline cognitive performance and brain structural measures (e.g., hippocampal volume) were accounted for, preoperative BBB permeability (measured by K_trans) was not independently associated with delirium, although it remained related to its severity[3]. In a cohort study by Wang et al, baseline Montreal Cognitive Assessment (MoCA) scores were relatively low, indicating a high burden of pre-existing cognitive impairment, and nearly half of the patients had cerebrovascular disease[1].Although several vascular risk factors were adjusted for, structural markers of brain reserve, such as white matter hyperintensities and hippocampal atrophy, were not considered. Future studies should incorporate such measures, potentially using multimodal MRI alongside CTP, to explore whether PS offers incremental value beyond traditional brain reserve markers. Additionally, the definition and timing of POCD require careful consideration. Wang et al defined POCD as a ≥20% decline in MoCA between baseline and 5–7 days postoperatively[1]. This early measure may capture transient postoperative effects such as pain, sleep disruption, or sedative exposure, and may not fully represent persistent cognitive decline[4]. Longitudinal studies incorporating BBB imaging with serial neuropsychological testing over 3–12 months would help clarify whether PS primarily reflects short-term cognitive vulnerability or identifies patients at risk for long-term cognitive decline. Lastly, Che et al have highlighted the multifactorial nature of POCD, with BBB disruption being one element of a cascade involving neuroinflammation, small vessel disease, and neurodegeneration[5]. While BBB biomarkers are promising, they may not fully account for long-term cognitive dysfunction after surgery, especially in patients with pre-existing brain pathologies. The study by Wang et al is a critical first step in incorporating BBB imaging into perioperative risk stratification, but we believe that future work should integrate PS measurements with structural brain reserve markers and detailed intraoperative data to define the true role of BBB vulnerability in postoperative cognitive decline. In conclusion, Wang et al provide valuable evidence linking preoperative frontal BBB disruption to early POCD after CABG. We encourage future studies to further examine the relationship between BBB permeability, brain reserve, and longitudinal cognitive outcomes to refine our understanding of perioperative neurocognitive vulnerability. We would be very interested in the authors’ views on these points and on the potential for incorporating structural and cognitive reserve variables into future models. Bedside adjustment flowchart in Figure 1. All this was observed regarding the transparency in the reporting of Artificial Intelligence – the TITAN guideline[6].Figure 1.: Bedside adjustment flowchart. Consent Not applicable.
Source: International Journal of Surgery
Authors: Zhang Liu, Weiqin Huang
Institution: Wuhan Asia Heart Hospital
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,450
OpenAlex ID: W7124212464