Does off-pump coronary revascularization confer superior organ protection in re-operative coronary artery surgery? A meta-analysis of observational studies

Off-pump Versus On-pump Coronary Artery Bypass Grafting in Diabetic patients: A Meta-analysis of Observational Studies with a Propensity-Score Analysis

PURPOSE

The debate between off-pump coronary artery bypass grafting (OPCAB) and on-pump coronary artery bypass grafting (ONCAB) in diabetic patients remains. This meta-analysis aimed to investigate outcomes after OPCAB versus ONCAB for patients with diabetes.

METHODS

Literature research was conducted up to December 2023 using Ovid Medline, EMBASE, and the Cochrane Library. Eligible studies were observational studies with a propensity-score analysis of OPCAB versus ONCAB. The primary outcomes were early mortality and mid-term survival. The secondary outcomes were cerebrovascular accidents, reoperation for bleeding, incomplete revascularization, myocardial infarction, low cardiac output, and renal replacement therapy.

RESULTS

Our research identified seven observational studies with a propensity-score analysis enrolling 13,085 patients. There was no significant difference between OPCAB and ONCAB for early mortality, mid-term survival, myocardial infarction, low cardiac output, and renal replacement therapy. OPCAB was associated with a lower risk of cerebrovascular accidents (OR 0.43; 95% CI, 0.24-0.76, P = 0.004) and reoperation for bleeding (OR 0.60; 95% CI, 0.41-0.88, P = 0.009). However, OPCAB was associated with a higher risk of incomplete revascularization (OR 2.07; 95% CI, 1.60-2.68, P < 0.00001).

CONCLUSION

Among patients with diabetes, no difference in early mortality and mid-term survival was observed. However, OPCAB was associated with a lower incidence of morbidity, including cerebrovascular accidents and reoperation for bleeding.

Off-pump versus on-pump redo coronary artery bypass grafting: a systematic review and meta-analysis

Background:

Redo coronary artery bypass grafting (redo CABG) is associated with increased mortality and morbidity. The aim of this study was to systematically evaluate the evidence comparing the outcomes of off-pump with on-pump redo CABG.

Methods:

Studies were systematically searched and identified using PubMed, EMBASE, the Cochrane Library, and the International Clinical Trials Registry Platform (ICTRP) by two researchers independently. The primary outcome was 30-day mortality, and the secondary outcomes were in-hospital mortality, post-operative complications, completeness of revascularization, blood transfusion rate, duration of mechanical ventilation, intensive care unit and hospital stays.

Results:

The 21 studies including 4,889 patients were enrolled in our meta-analysis. Compared with on-pump, the off-pump technique was associated with significantly reduced 30-day mortality (odds ratio [OR] = 0.43, 95% confidence interval [CI] = 0.26-0.72, p = 0.001). Moreover, a notably decreased in-hospital mortality (OR = 0.55, 95% CI = 0.39-0.76, p = 0.0004) and incidence of post-operative new-onset atrial fibrillation, myocardial infarction, acute kidney injury, low cardiac output state, blood transfusion rate (OR = 0.46, 95% CI = 0.35-0.60, p < 0.00001; OR = 0.54, 95% CI = 0.38-0.78, p = 0.0007; OR = 0.51, 95% CI = 0.37-0.70, p < 0.0001; OR = 0.31, 95% CI = 0.20-0.47, p < 0.00001; OR = 0.29, 95% CI = 0.14-0.61, p = 0.001) and significantly shortened duration of mechanical ventilation, intensive care unit and hospital stays (mean difference [MD] = −8.21 h, 95% CI = −11.74 to −4.68, p < 0.00001; MD = −0.77 d, 95% CI = −0.81 to −0.73, p < 0.00001; MD = −2.24 d, 95% CI = −3.17 to −1.32, p < 0.00001) could be observed when comparing the outcomes of off-pump with on-pump redo CABG. There was nonsignificant difference between off-pump and on-pump redo CABG in completeness of revascularization.

Conclusion:

In patients undergoing redo CABG surgery, the off-pump technique was associated with decreased mortality, less post-operative complications when compared to on-pump.

Neural network imaging to characterize brain injury in cardiac procedures: the emerging utility of connectomics

Cognitive dysfunction is a poorly understood but potentially devastating complication of cardiac surgery. Clinically meaningful assessment of cognitive changes after surgery is problematic because of the absence of a means to obtain reproducible, objective, and quantitative measures of the neural disturbances that cause altered brain function. By using both structural and functional connectivity magnetic resonance imaging data to construct a map of the inter-regional connections within the brain, connectomics has the potential to increase the specificity and sensitivity of perioperative neurological assessment, permitting rational individualized assessment and improvement of surgical techniques.

The future of off-pump coronary artery bypass grafting: a North American perspective

Off-pump coronary artery bypass graft (OPCAB) is currently performed routinely in a minority of specialized centers and in many more centers, utilized only when a porcelain aorta mandates a no-touch aortic technique. The OPCAB literature can be summarized as follows: (I) large-scale randomized trials in relatively low risk patients that include surgeons with a range of experience demonstrating no consistent beneficial differences in major cardiovascular and cerebrovascular outcomes but lower transfusion rates and shorter length of stay, tempered by some reports of higher rates of incomplete revascularization and lower rates of long term graft patency; (II) smaller randomized controlled trials (RCTs) from highly specialized programs demonstrating equivalent or superior outcomes with OPCAB and similar completeness of revascularization and graft patency; and (III) observational data from large databases demonstrating a consistent benefit of OPCAB, especially in higher-risk patient subsets. Our rationale for OPCAB remains that if complete and precise revascularization can be safely and routinely accomplished, then the patient should benefit by avoiding the morbidities that can be attributed to aortic cannulation/clamping, cardiopulmonary bypass (CPB), hemodilution, hypothermia and global myocardial ischemia/cardioplegia. We further believe that OPCAB procedures should emphasize the use of arterial grafts to optimize long term patency and minimize aortic manipulation to limit the risk of stroke. Moving forward, the off-pump surgical community and specialty societies must address the challenge of training surgeons and their teams to master this technically demanding procedure. Furthermore, OPCAB opens the door to minimally-invasive surgical revascularization via hybrid coronary revascularization (HCR). A large NIH-funded RCT is currently underway to determine whether hybrid revascularization can offer a superior alternative to multi-vessel percutaneous coronary intervention for patients with low SYNTAX score and proximal LAD disease.

Developments in surgical revascularization to achieve improved morbidity and mortality

Coronary artery bypass graft surgery remains the main treatment modality for multivessel coronary artery disease and has consistently been demonstrated to have significantly lower rates of major adverse cardiac and cerebrovascular events in comparison to percutaneous coronary intervention. In this article we will explore the advances over time and the recent refinements in the techniques of surgical revascularization and how these contribute to the superior outcome profile associated with coronary artery bypass graft surgery. These include the current outcome status of coronary artery bypass grafting; the major landmark trials, registries and meta-analyses comparing coronary artery bypass grafting and percutaneous coronary intervention; the developments in coronary artery disease lesion classification; the techniques for the physiological assessment of coronary artery lesions; bypass grafting using arterial conduits; the role of off-pump coronary artery surgery; the outcomes of reoperative surgery; hybrid techniques for coronary revascularization; minimally invasive coronary artery surgery and finally robotic surgery.

Is the evidence from first time off-pump coronary artery bypass graft surgery transferable to re-operative off-pump surgery?

On-pump coronary artery surgery remains the gold standard treatment for multi-vessel disease. The technique of off-pump surgery has evolved since its first use; however, currently less than 20% of all cases worldwide are performed this way. This poor uptake has been both the cause and the effect of widespread scepticism regarding the validity of the data on the technique, as well as criticism regarding the conversion-related adverse outcomes, graft patency and completeness of revascularisation. Consequently, there has been focus on patient selection from subgroups most likely to benefit from the technique. Re-operative patients, by virtue of their advanced age, complex co-morbidities and the technical challenges of re-operation, fall into this category. In this review, the authors will discuss the outcomes of off-pump surgery in comparison to on-pump, explore the potential beneficial effects of off-pump in re-operative surgery and formulate a decision-making strategy in patients undergoing reoperative coronary artery surgery.