Care guided by tissue oxygenation and haemodynamic monitoring in off-pump coronary artery bypass grafting (Bottomline-CS): assessor blind, single centre, randomised controlled trial
BMJ 2025; 388 doi: https://doi.org/10.1136/bmj-2024-082104 (Published 24 March 2025) Cite this as: BMJ 2025;388:e082104Linked Editorial
Near-infrared spectroscopy in perioperative medicine
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Dear Editor
Han et al. 2025 explore the potential benefits of near-infrared spectroscopy (NIRS) for guiding clinical decision-making and improving patient outcomes. The outcomes underscore a significant reduction in perioperative complications and a trajectory towards enhanced graft patency in patients receiving targeted care based on real-time NIRS evaluation [1]. Thus, the findings suggest that integrating tissue oxygenation data can offer more precise management, especially in high-risk cardiovascular patients.
This study demonstrated that patients in the NIRS-guided cohort experienced fewer incidents of low oxygen saturation and metabolic derangements. Improved tissue perfusion culminates in reduced rates of organ dysfunction [2]. There is a serious need to optimise oxygen delivery and maintain hemodynamic stability, especially in off-pump CABG, where coronary flow is often compromised due to the lack of cardiopulmonary bypass [3].
Interestingly, the study equally explores the potential role of NIRS in predicting longer-term outcomes. Although the primary focus was on perioperative outcomes, the enhanced oxygenation and tissue perfusion observed in surgery could theoretically reduce postoperative morbidity [4]. The follow-up data, though limited, suggest that a well-oxygenated tissue environment may contribute to better long-term graft function.
Nevertheless, while the results are promising, there remains uncertainty regarding the widespread applicability of NIRS, particularly outside specialised centres. The single-centre design may limit the generalisability of the findings, and extra multicentre studies would be necessary to confirm whether these results can be replicated in diverse patient populations [5].
In conclusion, the findings from this trial offer compelling evidence for the integration of NIRS in off-pump CABG. By providing real-time insights into tissue oxygenation and hemodynamics, NIRS-guided care could reduce complications and optimise patient recovery.
References
[1] Han J, Zhai W, Wu Z, Zhang Z, Wang T, Ren M, et al. Care guided by tissue oxygenation and haemodynamic monitoring in off-pump coronary artery bypass grafting (Bottomline-CS): assessor blind, single centre, randomised controlled trial. BMJ. 2025 Mar 24;e082104.
[2] Parker T, Brealey D, Dyson A, Singer M. Optimising organ perfusion in the high-risk surgical and critical care patient: a narrative review. British Journal of Anaesthesia. 2019 Aug;123(2):170–6.
[3] Heusch G. Myocardial ischemia: lack of coronary blood flow, myocardial oxygen supply-demand imbalance, or what? American Journal of Physiology-Heart and Circulatory Physiology. 2019 Jun 1;316(6):H1439–46.
[4] Gurgel ST, do Nascimento P. Maintaining Tissue Perfusion in High-Risk Surgical Patients. Anesthesia & Analgesia. 2011 Jun;112(6):1384–91.
[5] Bellomo R, Warrillow SJ, Reade MC. Why we should be wary of single-center trials. Critical Care Medicine. 2009 Dec;37(12):3114–9.
Competing interests: No competing interests
Re: Care guided by tissue oxygenation and haemodynamic monitoring in off-pump coronary artery bypass grafting (Bottomline-CS): assessor blind, single centre, randomised controlled trial
Dear Editor
Not everything is equal, of course.
The work of Han et al, in a very large database, studies the incidence of complications associated with ‘guided care’ or ‘usual care’, as the authors mention (1). They choose cardiac surgery off-pump since this population has a great use for coronary surgery in their country and is associated with severe haemodynamic complications, similar to what occur in high-risk non-cardiac surgery (2).
The difference in ‘guided care vs usual care’ has to do with the use of specific monitoring to observe tissue and cerebral perfusion (NIRS). However, none of the complications they studied (cerebral, respiratory, infectious, renal and cardiac) showed a significant difference. The same is true for the secondary complications analysed.
All the techniques used to study different parameters in patients have evolved over the last 15 years, and although significant benefits occasionally appear with their use, there is still no robust information about the benefits of their use. The studies continue to evolve (3).
A second problem has to do with the setting in which these new devices are used. The risks and benefits of using them depends on: who is using them, what experience do they have, where are they being used. This is very difficult to evaluate (4). Health professionals (doctors, nurses, physiotherapist and many others), medical equipment, type of hospitals, they all have effect on the results we are looking for.
The authors mention the possibility of spurious results due to cofounding factors. It cannot be excluded.
More strong data is obviously needed.
Dr. Guillermo Lema
Professor
Division of Anaesthesia
Medical Faculty
Pontificia Universidad Católica de Chile
Email: glema@uc.cl Santiago, Chile
References.
1.- Han J., Zhai W., Wu Z., et al. Care guided by tissue oxygenation and haemodinamic monitoring in off-pump coronary artery bypass grafting (Bottomline-CS): assessor bling, single center, randomized controlled trial. BMJ 2025;388:e082104
2.- Park S, J., Jung Jo A., Jeon Kim H., et al. Real-World outcomes of on-vs Off-pump Coronary Bypass Surgery: Result from the Korean Nationwide cohort. Ann Thorac Surg. 2022 jun;113(6): 1989-1998.
3.- Ali J., Cody J., Maldonado Y. Near- Infrared Spectroscopy (NIRS) for Cerebral and Tissue Oximetry: Analysis of Evolving applications. Journal of cardiothoracic and vascular Anesthesia 36(2022) 2758-2766
4.- Lema G. Regarding article, “The value of preoperative assessment before Noncardiac surgery in the era of value-bases care”. Circulation 2028;137: 2425
Competing interests: No competing interests