Multiple versus single arterial grafting in coronary artery bypass grafting: A meta-analysis of randomized controlled trials and propensity score studies

Multiarterial grafting in redo coronary artery bypass grafting: Type of arterial conduit and patient sex determine benefit

OBJECTIVE

To evaluate whether multiarterial grafting provides an incremental benefit above single arterial grafting in isolated redo coronary artery bypass grafting (CABG).

METHODS

From January 1980 to July 2020, 6559 adults underwent a total of 6693 isolated CABG reoperations. Patients undergoing multiarterial grafting were propensity score-matched with those undergoing single arterial grafting with or without additional vein grafts, yielding 2005 well-matched pairs. Endpoints were in-hospital postoperative complications, hospital mortality, and long-term mortality. The median follow-up was 10 years, with 25% of patients followed for >17 years. Multivariable multiphase hazard models and nonparametric random survival forest models for survival were used to identify patients for whom multiarterial grafting was most beneficial.

RESULTS

Among propensity score-matched patients, postoperative complications in multiarterial versus single arterial grafting included any reoperation (50 [2.5%] vs 65 [3.2%]); renal failure (73 [3.6%] vs 55 [2.7%]), stroke (44 [2.2%] vs 38 [1.9%]), and deep sternal infection (36 [1.8%] vs 25 [1.2%]). In-hospital mortality was 1.7% (n = 35) in multiarterial grafting versus 2.8% (n = 56) in single arterial grafting (P = .03). Comparing multiarterial to single arterial grafting, overall survival was 95% versus 94% at 1 year, 92% versus 88% at 3 years, 87% versus 82% at 5 years, 49% versus 42% at 15 years, and 31% versus 25% at 20 years. Better survival after multiarterial grafting was confined to males with 2 patent internal thoracic artery grafts (P < .0001).

CONCLUSIONS

Redo CABG with multiarterial grafting can be performed with lower in-hospital mortality and similar major morbidity to single arterial grafting. It is associated with better long-term survival, particularly in males when 2 internal thoracic artery grafts are used.

Survival Benefit of Multiple Arterial Revascularization With and Without Supplementary Saphenous Vein Graft

BACKGROUND

It is unknown if the presence of saphenous vein grafting (SVG) adversely affects late survival following coronary surgery with multiple arterial grafting (MAG) versus single arterial grafting.

METHODS AND RESULTS

A retrospective, observational, multicenter cohort study from 2001 to 2020 was conducted using the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database linked to the National Death Index. Patients undergoing primary isolated coronary artery bypass grafting with ≥2 grafts were included, and exclusions were patients aged <18 years, reoperations, concomitant or previous cardiac surgery, and the absence of arterial grafting. Demographics, comorbidities, medication, and operative configurations were propensity score matched between cohorts. The primary outcome was all-cause late death. Of 59 689 eligible patients, 35 113 were MAG (58.8%), and 24 576 were single arterial grafting (41.2%). Of the MAG cohort, 17 055 (48.6%) patients did not receive supplementary SVG (total arterial revascularization). Matching separately generated 22 764 patient pairs for MAG versus single arterial grafting, and 11 137 patient pairs for MAG with total arterial revascularization versus MAG with ≥1 supplementary vein grafts. At a median follow-up duration of 5.0 years postoperatively, the mortality rate was significantly lower for MAG than single arterial grafting (hazard ratio [HR], 0.79 [95% CI, 0.76-0.83]; P<0.001). The stratified MAG analysis found that MAG with total arterial revascularization had a lower risk of late death (HR, 0.85 [95% CI, 0.80-0.91]; P<0.001) compared with MAG with ≥1 supplementary vein grafts. Sensitivity analyses produced consistent outcomes as the primary analysis. Following adjustment for the presence of SVG in the Cox model, the survival advantage of incremental number of arteries was lost.

CONCLUSIONS

Multiple arterial grafting has significantly improved long-term survival compared with single arterial grafting. A further incremental survival benefit exists when no SVG is used.

Multi-Omics Profiling of Human Endothelial Cells from the Coronary Artery and Internal Thoracic Artery Reveals Molecular but Not Functional Heterogeneity

Major adverse cardiovascular events occurring upon coronary artery bypass graft surgery are typically accompanied by endothelial dysfunction. Total arterial revascularisation, which employs both left and right internal thoracic arteries instead of the saphenous vein to create a bypass, is associated with better mid- and long-term outcomes. We suggested that molecular profiles of human coronary artery endothelial cells (HCAECs) and human internal mammary artery endothelial cells (HITAECs) are coherent in terms of transcriptomic and proteomic signatures, which were then investigated by RNA sequencing and ultra-high performance liquid chromatography-mass spectrometry, respectively. Both HCAECs and HITAECs overexpressed molecules responsible for the synthesis of extracellular matrix (ECM) components, basement membrane assembly, cell-ECM adhesion, organisation of intercellular junctions, and secretion of extracellular vesicles. HCAECs were characterised by higher enrichment with molecular signatures of basement membrane construction, collagen biosynthesis and folding, and formation of intercellular junctions, whilst HITAECs were notable for augmented pro-inflammatory signaling, intensive synthesis of proteins and nitrogen compounds, and enhanced ribosome biogenesis. Despite HCAECs and HITAECs showing a certain degree of molecular heterogeneity, no specific markers at the protein level have been identified. Coherence of differentially expressed molecular categories in HCAECs and HITAECs suggests synergistic interactions between these ECs in a bypass surgery scenario.

Reconstruction Technique Options for Achieving Total Arterial Revascularization and Multiple Arterial Grafting

Ischemic heart disease is the leading cause of morbidity and mortality worldwide and may require coronary revascularization when more severe or symptomatic. Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure and can be performed with different bypass conduits and anastomotic techniques. Saphenous vein grafts (SVGs) are the most frequently used conduits for CABG, in addition to the left internal thoracic artery. Outcomes with a single internal thoracic artery and SVGs are favorable, and the long-term patency of SVGs may be improved through novel harvesting techniques, preservation methods, and optimal medical therapy. However, increasing evidence points towards the superiority of arterial grafts, especially in the form of multiple arterial grafting (MAG). Nevertheless, the uptake of MAG remains limited and variable, both as a result of technical complexity and a scarcity of conclusive randomized controlled trial evidence. Here, we present an overview of CABG techniques, harvesting methods, and anastomosis types to achieve total arterial revascularization and adopt MAG. We further narratively summarize the available evidence for MAG versus single arterial grafting to date and highlight remaining gaps and questions that require further study to elucidate the role of MAG in CABG.

Differences in long-term survival outcomes after coronary artery bypass grafting using single vs multiple arterial grafts: a meta-analysis with reconstructed time-to-event data and subgroup analyses

OBJECTIVE

We reviewed the available literature on patients with coronary artery disease undergoing isolated coronary artery bypass grafting (CABG) with either single (SAG) or multiple arterial grafting (MAG).

METHODS

Original research studies that evaluated the long-term survival of MAG versus SAG were identified, from 1995 to 2022. The median overall survival (OS) and event-free OS were the primary endpoints. Comparison of median OS between the right internal mammary artery (RIMA) and radial artery (RA) as a second arterial conduit was the secondary endpoint. Subgroup analyses were performed regarding patients older than 70 years, with diabetes mellitus, and females. A sensitivity analysis was performed with the leave-one-out method.

RESULTS

Forty-four studies were included in the qualitative and thirty-nine in the quantitative synthesis. After pooling data from 180 to 459 patients, the MAG group demonstrated a higher OS (HR, 0.589; 95% CI, 0.58-0.60; p < 0.0001) and event-free OS compared with the SAG group (HR, 0.828; 95% CI, 0.80-0.86; p < 0.0001). In addition, RITA was associated with superior OS compared with RA as a second arterial conduit (HR, 0.936; 95% CI, 0.89-0.98; p = 0.009). MAG was also superior to SAG in patients over 70 years, females, and patients with diabetes mellitus. Sensitivity analysis demonstrated a small-size study effect on the female subgroup analysis.

CONCLUSION

The present meta-analysis indicates that MAG is associated with enhanced survival outcomes compared to SAG for patients undergoing isolated CABG.

Total arterial coronary artery bypass grafting in patients with preoperative anemia

OBJECTIVES

Blood transfusions after coronary artery bypass grafting (CABG) has been associated to adverse outcomes, especially in anemic patients. However, little is known about the influence of the modality of revascularization. Total arterial revascularization (TAR) was shown to reduce postoperative transfusion when compared to saphenous vein-based (SV)-CABG (LIMA plus one/more SV grafts). We, therefore, aimed to investigate the impact of TAR-CABG versus SV-CABG on blood products use and perioperative outcomes in patients with preoperative anemia, normally at higher risk for postoperative transfusions.

METHODS

From a cohort of 936 patients with mild preoperative anemia undergoing primary elective on-pump CABG, 166 matched pairs of patients undergoing either TAR- or SV-CABG were obtained. Anemia was defined as hemoglobin level <13 g/dl for men and <12 g/dl for women. The primary endpoint was the evaluation of red packed cells (RPC) use over the entire hospital stay.

RESULTS

TAR patients showed significantly reduced RPC usage compared with SV (mean difference 0.45 units). TAR patients had a reduced intubation time (mean difference 7.6 h) and were discharged 1.24 days earlier than SV patients. Pneumonia and acute kidney injury were doubled among SV patients. Adjusted regression showed that TAR technique is a predictor of reduced RPC unit use regardless of age and EuroSCORE II (odds ratio: 0.63, p < .01).

CONCLUSION

Patients with preoperative anemia might benefit from TAR regardless of age or calculated operative risk. TAR-CABG was associated to reduced postoperative use of blood products and postoperative length of stay in comparison with SV-CABG in this subset of patients.

Tissue-Engineered Carotid Artery Interposition Grafts Demonstrate High Primary Patency and Promote Vascular Tissue Regeneration in the Ovine Model

Tissue-engineered vascular graft for the reconstruction of small arteries is still an unmet clinical need, despite the fact that a number of promising prototypes have entered preclinical development. Here we test Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)Poly(ε-caprolactone) 4-mm-diameter vascular grafts equipped with vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and stromal cell-derived factor 1α (SDF-1α) and surface coated with heparin and iloprost (PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo, n = 8) in a sheep carotid artery interposition model, using biostable vascular prostheses of expanded poly(tetrafluoroethylene) (ePTFE, n = 5) as a control. Primary patency of PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo grafts was 62.5% (5/8) at 24 h postimplantation and 50% (4/8) at 18 months postimplantation, while all (5/5) ePTFE conduits were occluded within the 24 h after the surgery. At 18 months postimplantation, PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo grafts were completely resorbed and replaced by the vascular tissue. Regenerated arteries displayed a hierarchical three-layer structure similar to the native blood vessels, being fully endothelialised, highly vascularised and populated by vascular smooth muscle cells and macrophages. The most (4/5, 80%) of the regenerated arteries were free of calcifications but suffered from the aneurysmatic dilation. Therefore, biodegradable PHBV/PCL[VEGF-bFGF-SDF]^Hep/Ilo grafts showed better short- and long-term results than bio-stable ePTFE analogues, although these scaffolds must be reinforced for the efficient prevention of aneurysms.

Multiple versus single arterial grafting in the elderly: a meta-analysis of randomized controlled trials and propensity score studies

INTRODUCTION

The benefit of adding a second arterial conduit is still controversial, mainly in specific subgroups. We conducted a meta-analysis of randomized controlled trials (RCTs) and propensity score (PS) studies comparing survival and early results in elderly patients who underwent coronary artery bypass grafting (CABG) with multiple (MAG) versus single arterial grafting (SAG).

EVIDENCE ACQUISITION

MEDLINE, Web of Science and Cochrane Library were used to find relevant literature (1960-April 2020). Survival at a ≥ 1-year follow-up and early outcomes were evaluated. Outcomes were collected from matched samples or PS adjusted analysis: hazard ratio (HR) along with their variance, frequencies or odds ratios. Random effect models were used to compute combined statistical measures and 95% confidence intervals (CI) through generic inverse variance method (time-to-event) or Mantel-Haenszel method (binary events).

EVIDENCE SYNTHESIS

Eleven PS cohorts and 1 RCT comprising > 18,800 patients older than 70 (>6200 MAG and >12,500 SAG) were included in this meta-analysis. MAG was associated with lower long-term mortality (pooled HR: 0.81, 95%CI: 0.72-0.91, p<0.01, I2=64%) in the absence of higher risk of early mortality (pooled OR: 0.74, 95%CI: 0.44 to 1.25, p=0.27, I2=0%). In a meta-regression, MAG survival advantage was more pronounced in studies with a higher MAG usage rate (β = -0.0052, p=0.021).

CONCLUSIONS

Current evidence suggests that advanced age should not limit MAG's use considering its benefits in long-term survival. Of note, an individualized patient selection for this approach is warranted.