The Choice of Conduits in Coronary Artery Bypass Surgery

Clinical and financial outcomes associated with the utilization of right internal mammary artery versus radial artery in multivessel coronary artery bypass grafting

BACKGROUND

Multi-arterial coronary bypass grafting with the left internal mammary artery as a conduit has been shown to offer superior long-term survival compared to single-arterial coronary bypass grafting. Nevertheless, the selection of a secondary conduit between the right internal mammary artery and the radial artery remains controversial. Using a national cohort, we examined the relationships between the right internal mammary artery and the radial artery with acute clinical and financial outcomes.

METHODS

Adults undergoing on-pump multivessel coronary bypass grafting with left internal mammary artery as the first arterial conduit were identified in the 2016 to 2020 Nationwide Readmissions Database. Patients receiving either the right internal mammary artery or the radial artery, but not both, were included in the analysis. Multivariable regression models were fitted to examine the association between the conduits and in-hospital mortality, as well as additional secondary outcomes.

RESULTS

Of an estimated 49,798 patients undergoing multi-arterial coronary bypass grafting, 29,729 (59.7%) comprised the radial artery cohort. During the study period, the proportion of multi-arterial coronary bypass grafting utilizing the radial artery increased from 51.3% to 65.2% (nptrend <0.001). Following adjustment, the radial artery was associated with reduced odds of in-hospital mortality (adjusted odds ratio 0.44), prolonged mechanical ventilation (adjusted odds ratio 0.78), infectious complications (adjusted odds ratio 0.69), and 30-day nonelective readmission (adjusted odds ratio 0.77, all P < .05).

CONCLUSION

Despite no definite endorsement from surgical societies, the radial artery is increasingly utilized as a secondary conduit in multi-arterial coronary bypass grafting. Compared to the right internal mammary artery, the radial artery was associated with lower odds of in-hospital mortality, complications, and reduced healthcare expenditures. These results suggest that whenever feasible, the radial artery should be the favored conduit over the right internal mammary artery. Nevertheless, future studies examining long-term outcomes associated with these vessels remain necessary.

Long-term observational angiographic patency and perfect patency of radial artery compared with saphenous vein or internal mammary artery in coronary bypass surgery

OBJECTIVES

It is uncertain if the long-term biological behavior of the radial artery as a conduit for coronary bypass surgery has a similar resistance to the development of atherosclerosis as for the internal mammary artery. We aimed to examine long-term angiographic patency and disease-free patency (perfect patency) for internal mammary artery, radial artery, and saphenous vein grafts.

METHODS

A retrospective, single-center, individual patient cohort study of angiographic observations from patients' latest postoperative angiogram from 1997 to 2020 was performed. Analysis was per anastomosis and assessed for patency and perfect patency. A generalized linear mixed model premised upon logistic regression was used to minimize confounding bias.

RESULTS

A total of 983 patients with 3064 grafts were included, with a median follow-up of 8.6 (interquartile range, 4.4-12.6) years after the operation. Multivariable analysis revealed differences for radial (patency, 86.9%; perfect patency, 86.4%) and internal mammary artery (patency, 93.9%; perfect patency, 93.5%) versus saphenous vein graft (patency, 72.8%; perfect patency, 46.2%). There were no differences between the 2 arterial conduits for patency (odds ratio, 1.40; 95% CI, 0.85-2.33; P = .189) and perfect patency (odds ratio, 1.14; 95% CI, 0.71-1.84; P = .578). If a conduit was patent, then 99.4% of radial artery, 99.6% of internal mammary artery, and 63.5% of saphenous vein graft were reported as perfectly patent.

CONCLUSIONS

Radial artery and internal mammary artery had similar patency and perfect patency while both were superior to saphenous vein graft.

Saphenous Vein Graft Failure: Current Challenges and a Review of the Contemporary Percutaneous Options for Management

The use of saphenous vein grafts (SVGs) in the surgical management of obstructive coronary artery disease remains high despite a growing understanding of their limitations in longevity. In contemporary practice, approximately 95% of patients receive one SVG in addition to a left internal mammary artery (LIMA) graft. The precise patency rates for SVGs vary widely in the literature, with estimates of up to 61% failure rate at greater than 10 years of follow-up. SVGs are known to progressively degenerate over time and, even if they remain patent, demonstrate marked accelerated atherosclerosis. Multiple studies have demonstrated a marked acceleration of atherosclerosis in bypassed native coronary arteries compared to non-bypassed arteries, which predisposes to a high number of native chronic total occlusions (CTOs) and subsequent procedural challenges when managing graft failure. Patients with failing SVGs frequently require revascularisation to previously grafted territories, with estimates of 13% of CABG patients requiring an additional revascularisation procedure within 10 years. Redo CABG confers a significantly higher risk of in-hospital mortality and, as such, percutaneous coronary intervention (PCI) has become the favoured strategy for revascularisation in SVG failure. Percutaneous treatment of a degenerative SVG provides unique challenges secondary to a tendency for frequent superimposed thrombi on critical graft stenoses, friable lesions with marked potential for distal embolization and subsequent no-reflow phenomena, and high rates of peri-procedural myocardial infarction (MI). Furthermore, the rates of restenosis within SVG stents are disproportionately higher than native vessel PCI despite the advances in drug-eluting stent (DES) technology. The alternative to SVG PCI in failed grafts is PCI to the native vessel, 'replacing' the grafts and restoring patency within the previously grafted coronary artery, with or without occluding the donor graft. This strategy has additional challenges to de novo coronary artery PCI, however, due to the high burden of complex atherosclerotic lesion morphology, extensive coronary calcification, and the high incidence of CTO. Large patient cohort studies have reported worse short- and long-term outcomes with SVG PCI compared to native vessel PCI. The PROCTOR trial is a large and randomised control trial aimed at assessing the superiority of native vessel PCI versus vein graft PCI in patients with prior CABG awaiting results. This review article will explore the complexities of SVG failure and assess the contemporary evidence in guiding optimum percutaneous interventional strategy.

A review on the treatment of intimal hyperplasia with perivascular medical devices: role of mechanical factors and drug release kinetics

INTRODUCTION

Intimal hyperplasia (IH) is a significant factor limiting the success of revascularization surgery for blood flow restoration. IH results from a foreign body response and mechanical disparity that involves complex biochemical reactions resulting in graft failure. The available treatment option utilizes either different pharmacological interventions or mechanical support to the vascular grafts with limited success.

AREAS COVERED

This review explains the pathophysiology of IH, responsible mechanical and biological factors, and treatment options, emphasizing perivascular devices. They are designed to provide mechanical support and pharmacology actions. The perivascular drug delivery concept has successfully demonstrated efficacy in various animal studies. Accurate projections of drug release mechanisms using mathematical modeling could be used to formulate prolonged drug elution devices. Numerical modeling aspects for the prediction of design outcomes have been given due importance that fulfills the unmet clinical need for better patient care.

EXPERT OPINION

IH could be effectively prevented by simultaneous mechanical scaffolding and sustained local drug delivery. Future perivascular medical devices could be designed to integrate these essential features. Numerical modeling for device performance prediction should be utilized in the development of next-generation perivascular devices.

Comparison of SYNTAX score strata effects of percutaneous and surgical revascularization trials: A meta-analysis

OBJECTIVES

The evidence supporting the use of the Synergy Between Percutaneous Coronary Intervention With TAXUS and Cardiac Surgery (SYNTAX) score for risk stratification is controversial. We performed a systematic review and meta-analysis of all the randomized controlled trials comparing percutaneous coronary intervention versus coronary artery bypass grafting that reported their outcomes stratified by SYNTAX score, focusing on between-strata comparisons.

METHODS

A systematic review of MEDLINE, EMBASE, Cochrane Library databases was performed. Incidence rate ratios were pooled with a random effect model. Between-group statistical heterogeneity according to accepted SYNTAX score tertiles was computed in the main analysis. Ratios of incidence rate ratios were computed to appraise between-strata effect, as sensitivity analysis. Primary and secondary outcomes were major adverse cardiac and cerebrovascular events and all-cause mortality, respectively. Separate sub-analyses were performed for left main and multivessel disease.

RESULTS

From 425 citations, 6 trials were eventually included (8269 patients [4134 percutaneous coronary interventions, 4135 coronary artery bypass graftings]; mean follow-up: 6.2 years [range: 3.8-10]). Overall, percutaneous coronary intervention was associated with a significant increase in major adverse cardiac and cerebrovascular events (incidence rate ratio, 1.39, 95% confidence interval, 1.27-1.51) and nonsignificant increase in all-cause mortality (incidence rate ratio, 1.17, 95% confidence interval, 0.98-1.40). There was no significant statistical heterogeneity of treatment effect by SYNTAX score for major adverse cardiac and cerebrovascular events or mortality (P = .40 and P = .34, respectively). Results were consistent also for patients with left main and multivessel disease (major adverse cardiac and cerebrovascular events: P = .85 in left main, P = .78 in multivessel disease 0.78; mortality: P = .12 in left main; P = .34 in multivessel disease). Results of analysis based on ratios of incidence rate ratios were consistent with the main analysis.

CONCLUSIONS

No significant association was found between SYNTAX score and the comparative effectiveness of percutaneous coronary intervention and coronary artery bypass grafting. These findings have implications for clinical practice, future guidelines, and the design of percutaneous coronary intervention versus coronary artery bypass grafting trials.

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.

Angiographic Outcomes for Arterial and Venous Conduits Used in CABG

Coronary artery bypass grafting is the most commonly performed cardiac surgical procedure. Conduit selection is crucial to achieving early optimal outcomes, with graft patency being likely the main driver to long-term survival. We present a review of current evidence on the patency of arterial and venous bypass conduits and of differences in angiographic outcomes.

Coronary artery bypass with single versus multiple arterial grafts in women: A meta-analysis

OBJECTIVE

The study objective was to investigate the impact of multiple arterial grafting on long-term all-cause mortality in women undergoing isolated coronary artery bypass grafting.

METHODS

A comprehensive search was performed to identify observational studies reporting outcomes after coronary artery bypass grafting reported by sex and stratified into multiple arterial grafting versus single arterial grafting strategies. Articles were considered for inclusion if they were written in English and were propensity-matched observational studies. Included studies were then pooled in a meta-analysis performed using the generic inverse variance method. The primary outcome was long-term all-cause mortality. Secondary outcomes were operative mortality and spontaneous myocardial infarction. Meta-regression was used to explore the effects of preoperative and intraoperative variables on the primary outcome.

RESULTS

A total of 6 studies with 32,793 women (25,714 single arterial grafting and 7079 multiple arterial grafting) were included. Women who received multiple arterial grafting had lower long-term mortality (incidence rate ratio, 0.86; 95% confidence interval, 0.76-0.96; P = .007) and spontaneous myocardial infarction (incidence rate ratio, 0.80; 95% confidence interval, 0.68-0.93; P = .003) compared with women who received single arterial grafting, but the difference in mortality disappeared when including only the 3 largest studies. There was no difference between groups in operative mortality (odds ratio, 0.99; 95% confidence interval, 0.84-1.17; P = .91). Meta-regression did not identify any associations with the incidence rate ratio for long-term mortality.

CONCLUSIONS

The use of multiple arterial grafting in women undergoing coronary artery bypass grafting is associated with lower long-term mortality, although the difference is mostly driven by small series. Further studies, including randomized trials, are needed to evaluate the efficacy of multiple arterial grafting in women undergoing coronary artery bypass grafting.

Development of a dual-component infection-resistant arterial replacement for small-caliber reconstructions: A proof-of-concept study

Introduction: Synthetic vascular grafts perform poorly in small-caliber (<6mm) anastomoses, due to intimal hyperplasia and thrombosis, whereas homografts are associated with limited availability and immunogenicity, and bioprostheses are prone to aneurysmal degeneration and calcification. Infection is another important limitation with vascular grafting. This study developed a dual-component graft for small-caliber reconstructions, comprising a decellularized tibial artery scaffold and an antibiotic-releasing, electrospun polycaprolactone (PCL)/polyethylene glycol (PEG) blend sleeve. Methods: The study investigated the effect of nucleases, as part of the decellularization technique, and two sterilization methods (peracetic acid and γ-irradiation), on the scaffold's biological and biomechanical integrity. It also investigated the effect of different PCL/PEG ratios on the antimicrobial, biological and biomechanical properties of the sleeves. Tibial arteries were decellularized using Triton X-100 and sodium-dodecyl-sulfate. Results: The scaffolds retained the general native histoarchitecture and biomechanics but were depleted of glycosaminoglycans. Sterilization with peracetic acid depleted collagen IV and produced ultrastructural changes in the collagen and elastic fibers. The two PCL/PEG ratios used (150:50 and 100:50) demonstrated differences in the structural, biomechanical and antimicrobial properties of the sleeves. Differences in the antimicrobial activity were also found between sleeves fabricated with antibiotics supplemented in the electrospinning solution, and sleeves soaked in antibiotics. Discussion: The study demonstrated the feasibility of fabricating a dual-component small-caliber graft, comprising a scaffold with sufficient biological and biomechanical functionality, and an electrospun PCL/PEG sleeve with tailored biomechanics and antibiotic release.

Impact of low-density lipoprotein cholesterol and lipoprotein(a) on mid-term clinical outcomes following coronary artery bypass grafting: A secondary analysis of the DACAB trial

Purpose

The objective was to evaluate the influence of low-density lipoprotein cholesterol (LDL-C) and lipoprotein(a) [Lp(a)] on clinical outcomes in patients undergoing coronary artery bypass grafting (CABG).

Methods

This is a secondary analysis of a 5-year follow-up of the DACAB trial (NCT02201771), in which 500 patients who underwent primary isolated CABG were randomized to three-antiplatelet therapy for 1 year after surgery. Of them, 459 patients were recruited in this secondary analysis. Baseline LDL-C and Lp(a) levels were collected, and repeated measurement of LDL-C levels during the follow-up were recorded. Cut-off values for LDL-C were set at 1.8 and 2.6 mmol/L; thus, the patients were stratified into LDL-C <1.8, 1.8-<2.6, and ≥2.6 mmol/L subgroups. Cut-off value for Lp(a) was 30 mg/dL; thus, the patients were divided into Lp(a) <30 and ≥30 mg/dL subgroups. The primary outcome was 4-point major adverse cardiovascular events (MACE-4), a composite of all-cause death, myocardial infarction, stroke, and repeated revascularization. Median follow-up time was 5.2 (interquartile range, 4.2-6.1) years.

Results

During the follow-up, 129 (28.1%) patients achieved the attainment of LDL-C <1.8 mmol/L, 186 (40.5%) achieved LDL-C 1.8-<2.6 mmol/L, and 144 (31.4%) remained LDL-C ≥2.6 mmol/L. Compared with the postoperative LDL-C <1.8 mmol/L group, the risk of MACE-4 was significantly higher in the LDL-C 1.8-<2.6 mmol/L group [adjusted hazard ratio (aHR) = 1.92, 95% CI, 1.12-3.29; P = 0.019] and LDL-C ≥2.6 mmol/L group (aHR = 3.90, 95% CI, 2.29-6.64; P < 0.001). Baseline Lp(a) ≥30 mg/dL was identified in 131 (28.5%) patients and was associated with an increased risk of MACE-4 (aHR = 1.52, 95% CI, 1.06-2.18; P = 0.022).

Conclusions

For CABG patients, exposure to increased levels of postoperative LDL-C or baseline Lp(a) was associated with worse mid-term clinical outcomes. Our findings suggested the necessity of achieving LDL-C target and potential benefit of adding Lp(a) targeted lipid-lowering therapy in CABG population.

Improving service efficiency and throughput of cardiac surgery patients using Monte Carlo simulation: a queueing setting

Bed occupancy rate (BOR) is important for healthcare policymakers. Studies showed the necessity of using simulation approach when encountering complex real-world problems to plan the optimal use of resources and improve the quality of services. So, the aim of the present study is to estimate average length of stay (LOS), BOR, bed blocking probability (BBP), and throughput of patients in a cardiac surgery department (CSD) using simulation models. We studied the behavior of a CSD as a complex queueing system at the Farshchian Hospital. In the queueing model, customers were patients and servers were beds in intensive care unit (ICU) and post-operative ward (POW). A computer program based on the Monte Carlo simulation, using Python software, was developed to evaluate the behavior of the system under different number of beds in ICU and POW. The queueing simulation study showed that, for a fixed number of beds in ICU, BOR in POW decreases as the number of beds in POW increases and LOS in ICU increases as the number of beds in POW decreases. Also, based on the available data, the throughput of patients in the CSD during 800 days was 1999 patients. Whereas, the simulation results showed that, 2839 patients can be operated in the same period. The results of the simulation study clearly demonstrated the behavior of the CSD; so, it must be mentioned, hospital administrators should design an efficient plan to increase BOR and throughput of patients in the future.

Cost Analysis of Endoscopic Conduit Harvesting Technique Using a Non-Sealed System for Coronary Artery Bypass Surgery

Objective: Endoscopic vessel harvest (EVH) is evolving as the standard of care for coronary artery bypass grafting. However, the increase in upfront equipment-related costs has resulted in reluctance of uptake globally. We investigated the costs involving a non-sealed technique for EVH versus open vessel harvesting techniques (OVH) for both the greater saphenous vein and radial artery with a 6-month follow-up. Methods: From September 2016 to December 2018, 226 patients underwent OVH while 251 patients underwent EVH using a reusable non-sealed system and a single-use radiofrequency sealing system. Cumulative costs for OVH versus EVH were calculated as a summation of total operative and in-hospital stay costs. Costs related to harvest site complication management were also analyzed for up to 6 months. Results: Total operative costs were greater in the EVH group (Can$2,283.70 [Can$1,377.60 to $4,183.50] vs Can$1,742.40 [Can$998.50 to $3,628.10], P < 0.001). Total length of stay was significantly shorter for the EVH group (5.9 [4 to 43] days vs 6.8 [4 to 55] days, P = 0.018). Cumulative costs were comparable at the end of the hospitalization period (EVH, Can$6,534.70 [Can$2,076.50 to $33,087.70] vs OVH, Can$6,112.50 [Can$3,322.30 to $45,503.50], P = 0.06). After discharge, harvest site-related complications occurred more frequently in the OVH group (27% vs 4.4%, P < 0.001), resulting in increased use of antibiotics (2.2% vs 0.8%, P = 0.02) as well as more frequent requirement for home nursing assistance in the OVH group (5.7% vs 0.8%, P = 0.002) at 6 months of follow-up. Conclusions: Cumulative costs did not show a statistical difference between OVH and EVH, with higher intraoperative costs for EVH being offset by higher harvest site management costs in the OVH group.

Radial artery versus saphenous vein versus right internal thoracic artery for coronary artery bypass grafting

OBJECTIVES

We used individual patient data from 4 of the largest contemporary coronary bypass surgery trials to evaluate differences in long-term outcomes when radial artery (RA), right internal thoracic artery (RITA) or saphenous vein graft (SVG) are used to complement the left internal thoracic artery-to-left anterior descending graft.

METHODS

Primary outcome was all-cause mortality. Secondary outcome was a composite of major adverse cardiac and cerebrovascular events (all-cause mortality, myocardial infarction and stroke). Propensity score matching and Cox regression were used to reduce the effect of treatment selection bias and confounders.

RESULTS

A total of 10 256 patients (1510 RITA; 1385 RA; 7361 SVG) were included. The matched population consisted of 1776 propensity score-matched triplets. The mean follow-up was 7.9 ± 0.1, 7.8 ± 0.1 and 7.8 ± 0.1 years in the RITA, RA and SVG cohorts respectively. All-cause mortality was significantly lower in the RA versus the SVG [hazard ratio (HR) 0.62, 95% confidence interval (CI): 0.51-0.76, P = 0.003] and the RITA group (HR 0.59, 95% CI 0.48-0.71, P = 0.001). Major adverse cardiac and cerebrovascular event rate was also lower in the RA group versus the SVG (HR 0.78, 95% CI 0.67-0.90, P = 0.04) and the RITA group (HR 0.75, 95% CI 0.65-0.86, P = 0.02). Results were consistent in the Cox-adjusted analysis and solid to hidden confounders.

CONCLUSIONS

In this pooled analysis of 4 large coronary bypass surgery trials, the use of the RA was associated with better clinical outcomes when compared to SVG and RITA.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Design and characterization of small-diameter tissue-engineered blood vessels constructed by electrospun polyurethane-core and gelatin-shell coaxial fiber

Substitution or bypass is the most effective treatment for vascular occlusive diseases.The demand for artificial blood vessels has seen an unprecedented rise due to the limited supply of autologous blood vessels. Tissue engineering is the best approach to provide artificial blood vessels. In this study, a new type of small-diameter artificial blood vessel with good mechanical and biological properties was designed by using electrospinning coaxial fibers. Four groups of coaxial fibers vascular membranes having polyurethane/gelatin core-shell structure were cross-linked by the EDC-NHS system and characterized. The core-shell structure of the coaxial vascular fibers was observed by transmission electron microscope. After the crosslinking, the stress and elastic modulus increased and the elongation decreased, burst pressure of 0.11 group reached the maximum (2844.55 ± 272.65 mmHg) after cross-linking, which acted as the experimental group. Masson staining identified blue-stained ring or elliptical gelatin ingredients in the vascular wall. The cell number in the vascular wall of the coaxial group was found in muscle embedding experiment significantly higher than that of the non-coaxial group at all time points(p < 0.001). Our results showed that the coaxial vascular graft with the ratio of 0.2:0.11 had better mechanical properties (burst pressure reached 2844.55 ± 272.65 mmHg); Meanwhile its biological properties were also outstanding, which was beneficial to cell entry and offered good vascular remodeling performance.Polyurethane (PU); Gelatin (Gel); Polycaprolactone (PCL); polylactic acid (PLA);1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC); N-Hydroxy succinimide (NHS); 4-Morpholine-ethane-sulfonic (MES); phosphate buffered saline (PBS); fetal calf serum (FCS); Minimum Essential Medium (MEM); Dimethyl sulfoxide (DMSO); hematoxylin-eosin (HE).

Pilates method on pulmonary function and range of motion after coronary artery bypass grafting: A clinical trial

INTRODUCTION

Coronary artery bypass grafting (CABG) can compromise pulmonary function and range of motion (ROM) of the shoulder and knee joints due to median sternotomy and saphenectomy, the Pilates method being a strategy for reducing loss.

OBJECTIVE

To evaluate the effect of applying the Pilates method on pulmonary function and ROM in patients undergoing CABG.

METHOD

ology: This is a clinical trial. Patients were evaluated preoperatively at discharge from the hospital for shoulder flexion and abduction and knee flexion-extension. In addition, vital capacity(VC), maximum inspiratory pressure(MIP), expiratory pressure(MEP) and peak expiratory flow(PEF) were evaluated. Upon discharge from the Intensive Care Unit (ICU), they were divided into a control group(CG) that received conventional assistance and Pilates(PG) was increased with Pilates method techniques.

RESULTS

40 patients were analyzed, 25 were men(61%), with a mean age of 66 ± 7 years. At the end, the left shoulder abduction in the CG was 105±9vs115 ± 8 in the PG(p = 0.03), the right shoulder abduction in the CG 104 ± 11vs116 ± 10 in the PG(p < 0.001) and right knee flexion in the CG 78 ± 13vs92 ± 9 in the PG(0.002). In relation to MIP, the CG had a loss of 32 ± 8 while the PG 18 ± 10cmH2O(p < 0.001), the worsening MEP was 31 ± 9(CG)vs29 ± 11cmH2O(PG)(p = 0.53), the VC in the CG reduced 8±9vs6±8 in the PG(p = 0.23) and the PEF reduced 107 ± 5 in the GCvs83 ± 88 in the PG(p = 0.09).

CONCLUSION

It is concluded that the Pilates method decreased the loss of ROM and maximum inspiratory pressure in patients undergoing coronary artery bypass grafting.

Quantification of adhesion of mesenchymal stem cells spread on decellularized vein scaffold

Purpose:

To evaluate methods that improve adipose-derived stem cells (ASCs) population in decellularized biological venous scaffold for tissue engineering in blood vessels, a model in rabbits.

Methods:

The ASC was expanded until the third passage. Inferior vena cava (IVC) was submitted to the decellularization process using 1% sodium dodecyl sulfate (SDS) or 2% sodium deoxycholate (SD) to compose 12 study groups (G): pure SD or SDS, exposed or not to 1% TritonX-100 (TX-100) and exposed or not to poly-l’lysine and laminin (PL). Scaffolds were covered with 1 × 10⁵ or 1 × 10⁶ ASCs diluted in 10 μL Puramatrix™. The histological analysis was done by cell counting in hematoxylin and eosin (HE) and nuclei count in immunofluorescence (IF) with 4’,6-Diamidine-2’-phenylindole dihydrochloride (DAPI).

Results:

The study of groups in HE and IF showed similar results. For both analyses,IVC-SD-1 × 10⁶ ASC and IVC-SD-PL-1 × 10⁶ ASC provided the best results. The IF technique showed better sensitivity than HE, with a weak agreement between them.

Conclusions:

Decellularizing agent and the number of ASC influence scaffolds cellularization response and the best protocols as those ones using SD with or without the addition of PL.

Hepatic artery reconstruction using interposition of autologous saphenous vein conduit for living donor liver transplantation: a case report

We have preferentially used the right gastroepiploic artery (RGEA) as an alternative for the recipient hepatic artery (HA) inflow during living donor liver transplantation (LDLT), but it was not always available. We herein present a case of adult LDLT with HA reconstruction using a greater saphenous vein (GSV) conduit because of the absence of the RGEA due to prior subtotal gastrectomy. A 55-year-old male patient diagnosed with hepatitis B virus-associated liver cirrhosis and secondary biliary cirrhosis underwent LDLT using a modified right liver graft. The upper abdominal cavity was heavily adhered due to prior abdominal surgeries, thus we had to sacrifice the common bile duct and the right HA completely. A 6-cm-long GSV segment was harvested from the left ankle and interposed between the recipient gastroduodenal artery and the graft HA. The patient recovered from LDLT and HA complications did not occur. However, 8 years after LDLT, chronic rejection occurred, thus repeated deceased donor liver transplantation was performed. This patient has been doing well for 2 years after retransplantation. In conclusion, we suggest that interposition of an autologous GSV conduit can be an alternative for establishing HA inflow in LDLT when other inflow source is not available.

Coronary revascularization in acute coronary syndrome: does the choice of the conduit matter?

BACKGROUND

Our retrospective study evaluates the impact on short - and long-term outcome according to the graft selection during emergency coronary revascularization surgery.

METHODS

339 Patients with acute coronary syndrome undergoing emergency coronary bypass surgery at our institution from 2008 until 2018 were analyzed using propensity score analysis. The primary endpoint was in-hospital survival. Secondary endpoints were postoperative bleeding, contractile dysfunction, postoperative percutaneous coronary intervention, myocardial infarction and wound infection. Patients were divided in two groups according to the bypass grafts received ((group 0, (n = 222): combined arterial and venous grafts for the and group 1 (n = 117): complete arterial revascularization).

RESULTS

There is significant improvement of left ventricular function postoperatively in patients undergoing emergency coronary revascularization for acute myocardial infarction where arterial grafts were used. Furthermore, there is significant difference between postoperative cardiac enzymes with lower values in group 1 (creatine kinase myocardial band p=0.0001; Troponin T p= 0,010). There was no significant difference in short and long-term survival between two groups. 5-years survival analysis between both groups did not show significant difference with Log-Rank test adjusted p-value = 0,49 (unadjusted p-value = 0.005). There was no significant difference in perioperative myocardial infarction, postoperative bleeding, and the need for postoperative coronary angiography.

CONCLUSIONS

Emergency coronary artery bypass grafting with arterial grafts shows significant improvement of left ventricular function postoperatively. However, utilization of bilateral internal mammary artery grafts in emergency coronary revascularization has no significant impact on short term or 5-year survival.

Whatever happens, two mammary is better than one

It is well known that the left internal mammary artery (LIMA) should be the first conduit of choice. Similarly, especially in patients younger than 70 years, other conduits should be search among arterial grafts, such as right internal mammary artery (RIMA) or radial artery (RA). If the RA can be harvested in the meanwhile of LIMA harvesting without time consuming, it is well established that former one has to be grafted only on presence of a good run-off. One of the main criticisms moved to the use of RIMA are linked to technical difficulties in its harvesting it.

Myocardial Revascularization Surgery: JACC Historical Breakthroughs in Perspective

Coronary artery bypass grafting (CABG) was introduced in the 1960s as the first procedure for direct coronary artery revascularization and rapidly became one of the most common surgical procedures worldwide, with an overall total of more than 20 million operations performed. CABG continues to be the most common cardiac surgical procedure performed and has been one of the most carefully studied therapies. Best CABG techniques, optimal bypass conduits, and appropriate patient selection have been rigorously tested in landmark clinical trials, some of which have resolved controversy and most of which have stoked further debate and trials. The evolution of CABG cannot be properly portrayed without presenting it in the context of the parallel development of percutaneous coronary intervention. In this Historical Perspective, we a provide a broad overview of the history of coronary revascularization with a focus on the foundations, evolution, best evidence, and future directions of CABG.

[Comparative study of vasa vasorum and neointima in conduits for coronary artery bypass grafting]

AIM

This study was undertaken to investigate the preoperative incidence and severity of intimal hypertrophy, as well as the level of blood supply of arterial and venous conduits for coronary artery bypass grafting.

MATERIAL AND METHODS

Segments of the internal thoracic artery and great saphenous vein (n=13) were harvested pairwise during coronary artery bypass grafting and were then visualized by scanning electron microscopy in back-scattered electrons. The analysis of the incidence and thickness of intimal hypertrophy, as well as the calculation of the number and the area of the vasa vasorum were performed using the programme ImageJ.

RESULTS

Intimal hypertrophy was more characteristic for the great saphenous vein as compared with the internal thoracic artery (9/13 (69.2%) and 7/13 (55.8%), respectively), although this difference did not reach statistical significance. The maximal-to-minimal neointimal thickness ratio correlated with the percentage of stenosis (r=0.875, p<0.0001), the area (r=0.45, p=0.023) and the number (r=0.47, p=0.015) of the vasa vasorum in the conduits, thus confirming the hypothesis on possible participation of these vessels in the development of intimal hypertrophy, with the area of the vasa vasorum being greater in the vessels with >10% stenosis (p=0.051). The number of the vasa vasorum in the great saphenous vein exceeded that in the internal thoracic artery (p=0.0005), with this difference remaining significant after adjustment for the area of the adventitia (p=0.027). The number of the vasa vasorum per the percentage of stenosis in the great saphenous vein also exceeded that in the internal thoracic artery (p=0.039) and more strongly correlated with intimal hypertrophy in the great saphenous vein as compared with that in the internal thoracic artery (r=0.53 and r=0.27, respectively).

CONCLUSION

Intimal hypertrophy correlates with the area and number of the vasa vasorum in conduits. The great saphenous vein is characterised by a larger number and higher density of the vasa vasorum as compared with the internal thoracic artery. The number of the vasa vasorum is correlated with stenosis of the great saphenous vein more closely than with stenosis of the internal thoracic artery. This may be suggestive of significant predisposition of the great saphenous vein to the onset of adventitial inflammation followed by the development of intimal hypertrophy.

How to build a multi-arterial coronary artery bypass programme: a stepwise approach

Observational evidence shows that the use of multiple arterial grafts (MAG) is associated with longer postoperative survival and improved clinical outcomes. The current European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines on myocardial revascularization recommend the use of MAG in appropriate patients. However, a significant volume-to-outcome relationship exists for MAG, and lack of sufficient experience is associated with increased operative risk. A stepwise approach to building experience with MAG allows successful implementation of this technique into routine coronary surgery practice.

The Anaortic Technique with Bilateral Internal Thoracic Artery Grafting - Filling the Gap in Coronary Artery Bypass Surgery

Coronary artery bypass grafting (CABG) has consolidated its role as the most effective procedure for treating patients with advanced atherosclerotic coronary artery disease, reducing the long-term risk of myocardial infarction and death compared to other therapies and relieving angina. Despite the recognized benefits afforded by surgical myocardial revascularization, a subset of higher-risk patients bears a more elevated risk of perioperative stroke. Stroke remains the drawback of conventional CABG and has been strongly linked to aortic manipulation (cannulation, cross-clamping, and side-biting clamping for the performance of proximal aortic anastomoses) and the use of cardiopulmonary bypass. Adoption of off-pump CABG (OPCAB) is demonstrated to lower the risk of perioperative stroke, as well as reducing the risk of short-term mortality, renal failure, atrial fibrillation, bleeding, and length of intensive care unit stay. However, increased risk persists owing to the need for the tangential ascending aorta clamping to construct the proximal anastomosis. The concept of anaortic (aorta no-touch) OPCAB (anOPCAB) stems from eliminating ascending aorta manipulation, virtually abolishing the risk of embolism caused by aortic wall debris into the brain circulation. The adoption of anOPCAB has been shown to further decrease the risk of postoperative stroke, especially in higher-risk patients, entailing a step forward and a refinement of outcomes provided by the primeval OPCAB technique. Therefore, anOPCAB has been the recommended technique in patients with cerebrovascular disease and/or calcification or atheromatous plaque in the ascending aorta and should be preferred in patients with high-risk factors for neurological damage and stroke.

Gelatin coating promotes in situ endothelialization of electrospun polycaprolactone vascular grafts

Rapid endothelialization is crucial for in situ tissue engineering vascular grafts to prevent graft failure in the long-term. Gelatin is a promising nature material that can promote endothelial cells (ECs) adhesion, proliferation, and migration. In this study, the internal surface of electrospun polycaprolactone (PCL) vascular grafts was coated with gelatin. Endothelialization and vascular wall remolding were investigated by imaging and histological studies in the rat abdominal aorta replacement model. The endothelialization of heparinized gelatin-coated PCL (GP-H) vascular grafts was more rapid and complete than heparinized PCL (P-H) grafts. Intimal hyperplasia was milder in the GP-H vascular grafts than the P-H vascular grafts in the long-term. Meanwhile, smooth muscle cells (SMCs) and extracellular matrix (ECM) regeneration were better in the GP-H vascular grafts. By comparison, an aneurysm was observed in the P-H group in 6 months. Calcification was observed in both groups. All vascular grafts were patient after implantation in both groups. Our results showed that gelatin coating on the internal surface of PCL grafts is a simple and effective way to promote endothelialization. A more rapid endothelialization and complete endothelium can inhibit intimal hyperplasia in the long-term.

Coronary Artery Bypass: Review of Surgical Techniques and Impact on Long-Term Revascularization Outcomes

Coronary revascularization for multivessel disease remains a common and costly source of hospitalizations in the United States. Surgical techniques influence outcomes for coronary bypass and also affect the need for percutaneous coronary intervention in the future. As more radial access has been used for coronary angiography, consideration for use of the radial artery as a surgical conduit remains unclear. Saphenous vein grafts are commonly used for coronary bypass, however long-term patency remains suboptimal, and is also associated with a higher risk of adverse events with percutaneous coronary intervention. Thus, understanding the interplay between coronary bypass techniques and percutaneous coronary intervention has become increasingly important.

Use of the left radial artery as vascular access for coronary angiography and as a bypass conduit: A clinical dilemma?

PURPOSE

International coronary revascularization guidelines recommend both, transradial vascular access for coronary angiography/intervention and use of the radial artery as a conduit for coronary artery bypass grafting (CABG). These recommendations may pose a clinical dilemma, as transradial access exposes these arteries to vascular trauma which makes them potentially unsuitable as future grafts. In this study, we investigated the awareness and views of cardiologists on these guideline recommendations.

METHODS

We performed semi-structured interviews with 50 cardiologists from 19 centers, who regularly perform coronary angiographies or interventions, and outlined clinical scenarios to evaluate their preference of vascular access. In addition, we assessed whether preference was related to sub-specialization.

RESULTS

The interviewed cardiologists had 16 ± 9.3 years of professional experience. There were 23 (46%) cardiologists from 7 centers without percutaneous coronary intervention facilities, and 27 (56%) cardiologists from 12 interventional centers. All 50 (100%) cardiologists indicated familiarity with the guidelines, yet 28 (56%) said not to be familiar with the aforementioned dilemma, and 9 (18%) stated there was no dilemma at all. Responses did not differ significantly between interventional (n = 28) and non-interventional (n = 22) cardiologists; however, if the right radial artery was unavailable (e.g., occluded), interventional cardiologists more often said to prefer access via the left radial artery (18/28 (64%) vs. 5/22 (23%), p = 0.001).

CONCLUSION

More than half of the interviewed cardiologists indicated that they had not realized that left transradial access preceding CABG may preclude later use of this artery as a conduit. Notably, in case of unavailability of the right radial artery, interventional cardiologists preferred left transradial access more often than non-interventional cardiologists.

Co-Culture of Primary Human Coronary Artery and Internal Thoracic Artery Endothelial Cells Results in Mutually Beneficial Paracrine Interactions

Although saphenous veins (SVs) are commonly used as conduits for coronary artery bypass grafting (CABG), internal thoracic artery (ITA) grafts have significantly higher long-term patency. As SVs and ITA endothelial cells (ECs) have a considerable level of heterogeneity, we suggested that synergistic paracrine interactions between CA and ITA ECs (HCAECs and HITAECs, respectively) may explain the increased resistance of ITA grafts and adjacent CAs to atherosclerosis and restenosis. In this study, we measured the gene and protein expression of the molecules responsible for endothelial homeostasis, pro-inflammatory response, and endothelial-to-mesenchymal transition in HCAECs co-cultured with either HITAECs or SV ECs (HSaVECs) for an ascending duration. Upon the co-culture, HCAECs and HITAECs showed augmented expression of endothelial nitric oxide synthase (eNOS) and reduced expression of endothelial-to-mesenchymal transition transcription factors Snail and Slug when compared to the HCAEC–HSaVEC model. HCAECs co-cultured with HITAECs demonstrated an upregulation of HES1, a master regulator of arterial specification, of which the expression was also exclusively induced in HSaVECs co-cultured with HCAECs, suggestive of their arterialisation. In addition, co-culture of HCAECs and HITAECs promoted the release of pro-angiogenic molecules. To conclude, co-culture of HCAECs and HITAECs results in reciprocal and beneficial paracrine interactions that might contribute to the better performance of ITA grafts upon CABG.

Preventing treatment failures in coronary artery disease: what can we learn from the biology of in-stent restenosis, vein graft failure, and internal thoracic arteries?

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and the availability of percutaneous or surgical revascularization procedures significantly improves survival. However, both strategies are daunted by complications which limit long-term effectiveness. In-stent restenosis (ISR) is a major drawback for intracoronary stenting, while graft failure is the limiting factor for coronary artery bypass graft surgery (CABG), especially using veins. Conversely, internal thoracic artery (ITA) is known to maintain long-term patency in CABG. Understanding the biology and pathophysiology of ISR and vein graft failure (VGF) and mechanisms behind ITA resistance to failure is crucial to combat these complications in CAD treatment. This review intends to provide an overview of the biological mechanisms underlying stent and VGF and of the potential therapeutic strategy to prevent these complications. Interestingly, despite being different modalities of revascularization, mechanisms of failure of stent and saphenous vein grafts are very similar from the biological standpoint.

Outcomes following revascularization with radial artery bypass grafts: Insights from the PREVENT-IV trial

BACKGROUND

The optimal role of radial artery grafts in coronary artery bypass grafting (CABG) remains uncertain. The purpose of this study was to examine angiographic and clinical outcomes following CABG among patients who received a radial artery graft.

METHODS

Patients in the angiographic cohort of the PREVENT-IV trial were stratified based upon having received a radial artery graft or not during CABG. Baseline characteristics and 1-year angiographic and 5-year clinical outcomes were compared between patients.

RESULTS

Of 1,923 patients in the angiographic cohort of PREVENT-IV, 117 received a radial artery graft. These patients had longer surgical procedures (median 253 vs 228 minutes, P < .001) and had a greater number of grafts placed (P < .0001). Radial artery grafts had a graft-level failure rate of 23.0%, which was similar to vein grafts (25.2%) and higher than left internal mammary artery grafts (8.3%). The hazard of the composite clinical outcome of death, myocardial infarction, or repeat revascularization was similar for both cohorts (adjusted hazard ratio 0.896, 95% CI 0.609-1.319, P = .58). Radial graft failure rates were higher when used to bypass moderately stenotic lesions (<75% stenosis, 37% failure) compared with severely stenotic lesions (≥75% stenosis, 15% failure).

CONCLUSIONS

Radial artery grafts had early failure rates comparable to saphenous vein and higher than left internal mammary artery grafts. Use of a radial graft was not associated with a different rate of death, myocardial infarction, or postoperative revascularization. Despite the significant potential for residual confounding associated with post hoc observational analyses of clinical trial data, these findings suggest that when clinical circumstances permit, the radial artery is an acceptable alternative to saphenous vein and should be used to bypass severely stenotic target vessels.

Comparing Outcomes in Patients Undergoing Coronary Artery Bypass Grafting With and Without Using the Internal Mammary Artery in a Tertiary Care Hospital

Purpose

The left internal mammary artery in coronary artery bypass grafting (CABG) is considered to be an important intraoperative quality indicator with excellent long-term results. The purpose of this study is to compare the early outcomes of CABG with and without the left internal mammary artery (LIMA) in the South Asian population and to look for the utilization of LIMA as per the recommendations of the Society of Thoracic Surgeons in a developing country.

Materials and methods

A retrospective review was carried out for all patients who underwent CABG from 2010 to 2015. Patients were divided into two groups on the basis of whether LIMA was used (Group I) or not used (Group II) as a conduit. Both groups were further subdivided into elective and urgent. Preoperative, intraoperative, and postoperative variables were recorded and compared.

Results

After exclusion, a total of 2619 patients underwent isolated CABG surgery during the required duration. The LIMA was used in 94% of the patients (n=2472) while 147 patients underwent CABG without LIMA. The use of LIMA was associated with significantly lower mortality (2% LIMA vs 8.8% no LIMA), as well as a decrease in major comorbidity, stroke, and prolonged ventilation. In the subgroup analysis, LIMA usage in elective and urgent cases was associated with significantly lower mortality (elective 1.6% LIMA vs 7.4% No LIMA) (urgent 4.8% LIMA vs 15.7 % no LIMA)) and major morbidity.

Conclusion

The outcomes of CABG procedures without LIMA were not encouraging. Our results support compliance with standard adult cardiac surgery quality-of-care guidelines.

A novel biodegradable external stent regulates vein graft remodeling via the Hippo-YAP and mTOR signaling pathways

Coronary artery bypass graft (CABG) has been confirmed to effectively improve the prognosis of coronary artery disease, which is a major public health concern worldwide. As the most frequently used conduits in CABG, saphenous vein grafts have the disadvantage of being susceptible to restenosis due to intimal hyperplasia. To meet the urgent clinical demand, adopting external stents (eStents) and illuminating the potential mechanisms underlying their function are important for preventing vein graft failure. Here, using 4-axis printing technology, we fabricated a novel biodegradable and flexible braided eStent, which exerts excellent inhibitory effect on intimal hyperplasia. The stented grafts downregulate Yes-associated protein (YAP), indicating that the eStent regulates vein graft remodeling via the Hippo-YAP signaling pathway. Further, as a drug-delivery vehicle, a rapamycin (RM)-coated eStent was designed to amplify the inhibitory effect of eStent on intimal hyperplasia through the synergistic effects of the Hippo and mammalian target of rapamycin (mTOR) signaling pathways. Overall, this study uncovers the underlying mechanisms of eStent function and identifies a new therapeutic target for the prevention of vein graft restenosis.

Mapping decision making for bypass surgery in the era of interventional medicine: towards an integrative model of patient-centeredness

This article reviews the context and evidence of recent myocardial revascularization trials on PCI versus CABG with particular emphasis on patient selection and treatment of surgical patients. Moreover, one of our intended purposes is to identify the values underpinning the integrated care model, which incorporates decision to proceed with surgical myocardial revascularization in conjunction with established pillars of the use of optimal surgical techniques, and aggressive risk-factor modification through guideline-directed pharmacological therapies and lifestyle modifications.

Multi-arterial and total-arterial coronary revascularization: Past, present, and future perspective

BACKGROUND AND AIM OF THE STUDY

Although abundant biological, clinical, and scientific evidence exists on the superiority of multi-arterial (MAR) and total-arterial revascularization (TAR) over the conventional strategy with a single internal thoracic artery, only 10% of patients undergoing coronary artery bypass grafting (CABG) in the United States receives a second arterial conduit, and only 5% of patients receives TAR.

METHODS AND RESULTS

In January 2020, the authors performed comprehensive search to identify studies that evaluated MAR and TAR strategies through the MEDLINE database.

CONCLUSIONS

In this paper, the authors reviewed the literature on the historical and current evidence in favor of MAR and TAR, thus underlying why current CABG practice needs qualitative improvement.

Outcomes and Patency of Complex Configurations of Composite Grafts Using Bilateral Internal Thoracic Arteries

Background

It is generally agreed that using a bilateral internal thoracic artery (BITA) composite graft improves long-term survival after coronary artery bypass grafting (CABG). Although the left internal thoracic artery (LITA)-based Y-composite graft is widely adopted, technical or anatomical difficulties necessitate complex configurations. We aimed to investigate whether BITA configuration impacts survival or patency in patients undergoing coronary revascularization.

Methods

Between January 2006 and June 2017, 1,161 patients underwent CABG at Seoul National University Bundang Hospital, where the standard technique is a LITA-based Y-composite graft with the right internal thoracic artery (RITA) sequentially anastomosed to non-left anterior descending (LAD) targets. Total of 160 patients underwent CABG using BITA with modifications. Their medical records and imaging data were reviewed retrospectively to investigate technical details, clinical outcomes, and graft patency.

Results

Modifications of the typical Y-graft (group 1, n=90), LITA-based I-graft (group 2, n=39), and RITA-based composite graft (group 3, n=31) were used due to insufficient RITA length (47%), problems using LITA (28%), and target vessel anatomy (25%). The overall 30-day mortality rate was 1.9%. Among 116 patients who underwent computed tomography or conventional angiography at a mean interval of 29.9±33.1 months postoperatively, the graft patency rates were 98.7%, 95.3%, and 83.6% for the LAD, left circumflex artery, and right coronary artery territories, respectively. Patency rates for the inflow, secondary, and tertiary grafts were 98.2%, 90.5%, and 80.4%, respectively. The RITA-based graft (group 3) had the lowest patency rate of the various configurations (p<0.011).

Conclusion

LITA-based Y composite graft, showed satisfactory clinical outcomes and patency whereas modifications of RITA-based composite graft had the lowest patency and 5-year survival rates. Therefore, when using RITA-based composite graft, other options should be considered before proceeding atypical configurations.

Twenty-Five Years of No-Touch Saphenous Vein Harvesting for Coronary Artery Bypass Grafting: Structural Observations and Impact on Graft Performance

The saphenous vein is the most common conduit used in coronary artery bypass grafting (CABG) yet its failure rate is higher compared to arterial grafts. An improvement in saphenous vein graft performance is therefore a major priority in CABG. No-touch harvesting of the saphenous vein is one of the few interventions that has shown improved patency rates, comparable to that of the left internal thoracic artery. After more than two decades of no-touch research, this technique is now recognized as a Class IIa recommendation in the 2018 European Society of Cardiology and the European Association for Cardio-Thoracic Surgery guidelines on myocardial revascularization. In this review, we describe the structural alterations that occur in conventional versus no-touch saphenous vein grafts and how these changes affect graft patency. In addition, we discuss various strategies aimed at repairing saphenous vein grafts prepared at conventional CABG.

Mortality After Repeat Revascularization Following PCI or CABG for Left Main Disease: The EXCEL Trial

OBJECTIVES

The aim of this study was to investigate the incidence and impact on mortality of repeat revascularization after index percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for left main coronary artery disease (LMCAD).

BACKGROUND

The impact on mortality of the need of repeat revascularization following PCI or CABG in patients with unprotected LMCAD is unknown.

METHODS

All patients with LMCAD and site-assessed low or intermediate SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) scores randomized to PCI (n = 948) or CABG (n = 957) in the EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial were included. Repeat revascularization events were adjudicated by an independent clinical events committee. The effect of repeat revascularization on mortality through 3-year follow-up was examined in time-varying Cox regression models.

RESULTS

During 3-year follow-up, there were 346 repeat revascularization procedures among 185 patients. PCI was associated with higher rates of any repeat revascularization (12.9% vs. 7.6%; hazard ratio: 1.73; 95% confidence interval: 1.28 to 2.33; p = 0.0003). Need for repeat revascularization was independently associated with increased risk for 3-year all-cause mortality (adjusted hazard ratio: 2.05; 95% confidence interval: 1.13 to 3.70; p = 0.02) and cardiovascular mortality (adjusted hazard ratio: 4.22; 95% confidence interval: 2.10 to 8.48; p < 0.0001) consistently after both PCI and CABG (p_int = 0.85 for both endpoints). Although target vessel revascularization and target lesion revascularization were both associated with an increased risk for mortality, target vessel non-target lesion revascularization and non-target vessel revascularization were not.

CONCLUSIONS

In the EXCEL trial, repeat revascularization during follow-up was performed less frequently after CABG than PCI and was associated with increased mortality after both procedures. Reducing the need for repeat revascularization may further improve long-term survival after percutaneous or surgical treatment of LMCAD. (EXCEL Clinical Trial; NCT01205776).

The ROMA trial: why it is needed

PURPOSE OF REVIEW

We herein summarize the current evidence on the clinical outcome associated with the use of single and multiple arterial grafts for coronary bypass surgery and the role and importance of the Randomized comparison of the clinical Outcome of single versus Multiple Arterial grafts (ROMA) trial.

RECENT FINDINGS

Observational evidence suggests that the use of multiple arterial grafts is associated with better clinical outcomes compared to the use of a single arterial graft. Randomized evidence is inconclusive; the 5-year interim analysis of the largest randomized trial on the topic did not show any clinical benefit associated with the use of bilateral versus single internal thoracic arteries, whereas a pooled analysis of the trials comparing the radial artery and the saphenous vein as a second graft showed a significant reduction in follow-up cardiac events using the radial artery. Hidden confounders and treatment allocation biases as well as methodological flaws are the most likely explanation of this contradiction.

SUMMARY

ROMA was conceived based on the lessons learned from a critical analysis of the existing randomized and observational evidence with the aim to provide a definitive answer to the question of the potential clinical benefit of multiple arterial grafts for coronary bypass.

Long-term Outcomes of Multiple Arterial Coronary Artery Bypass Grafting: A Population-Based Study of Patients in British Columbia, Canada

Importance

Although the long-term survival advantage of multiple arterial grafting (MAG) vs the standard use of left internal thoracic artery (LITA) supplemented by saphenous vein grafts (LITA+SVG) has been demonstrated in several observational studies, to our knowledge its safety and other long-term clinical benefits in a large, population-based cohort are unknown.

Objective

To compare the safety and long-term outcomes of MAG vs LITA+SVG among overall and selected subgroups of patients.

Design, Setting, and Participants

In this population-based observational study, we included 20 076 adult patients with triple-vessel or left-main disease who underwent primary isolated coronary artery bypass grafting (MAG, n = 5580; LITA+SVG, n = 14 496) in the province of British Columbia, Canada, from January 2000 to December 2014, with follow-up to December 2015. We performed propensity-score analyses by weighting and matching and multivariable Cox regression to minimize treatment selection bias.

Exposures

Multiple arterial grafting or LITA+SVG.

Main Outcomes and Measures

Mortality, repeated revascularization, myocardial infarction, heart failure, and stroke.

Results

Of 5580 participants who underwent MAG, 586 (11%) were women and the mean (SD) age was 60 (8.7) years. Of 14 496 participants who underwent LITA+SVG, 2803 (19%) were women and the mean (SD) age was 68 (8.9) years. The median (interquartile range) follow-up time was 9.1 (5.1-12.6) years and 8.1 (4.5-11.7) years for the groups receiving MAG and LITA+SVG, respectively. Compared with LITA+SVG, MAG was associated with reduced mortality rates (hazard ratio [HR], 0.79; 95% CI, 0.72-0.87) and repeated revascularization rates (HR, 0.74; 95% CI, 0.66-0.84) in 15-year follow-up and reduced incidences of myocardial infarction (HR, 0.63; 95% CI, 0.47-0.85) and heart failure (HR, 0.79; 95% CI, 0.64-0.98) in 7-year follow-up. The long-term benefits were coherent by all 3 statistical methods and persisted among patient subgroups with diabetes, obesity, moderately impaired ejection fraction, chronic obstructive pulmonary disease, peripheral vascular disease, or renal disease. Multiple arterial grafting was not associated with increased morbidity or mortality rates at 30 days overall or within patient subgroups.

Conclusions and Relevance

Compared with LITA+SVG, MAG is associated with reduced mortality, repeated revascularization, myocardial infarction, and heart failure among patients with multivessel disease who are undergoing coronary artery bypass grafting without increased mortality or other adverse events at 30 days. The long-term benefits consistently observed across multiple outcomes and subgroups support the consideration of MAG for a broader spectrum of patients who are undergoing coronary artery bypass grafting in routine practice.

State-of-the-Art Coronary Artery Bypass Grafting: Patient Selection, Graft Selection, and Optimizing Outcomes

Despite the progressive expansion of clinical indications for percutaneous coronary intervention and the increasingly high risk profile of referred patients, coronary artery bypass grafting (CABG) remains the mainstay in multivessel disease, providing good long-term outcomes with low complication rates. Multiple arterial grafting, especially if associated with anaortic techniques, might provide the best longer-term outcomes. A surgical approach individualized to the patients' clinical and anatomic characteristics, and surgeon and team experience, are key to excellent outcomes. Current evidence regarding patient selection, indications, graft selection, and potential strategies to optimize outcomes in patients treated with CABG is summarized.

Relaxation matters: comparison of in-vitro vasodilatory role of botulinum toxin-A and papaverine in human radial artery grafts

Background

Radial artery (RA) is widely used in coronary artery bypass (CABG) surgery and the prevention of spasm is crucial for graft patency. Botulinum toxin A (BTX-A) and B are commonly used for aesthetic reasons and neuromuscular disorders. They are proven to raise blood flow and increase survival of ischemic skin flaps. In this study we evaluated and compared the vasodilator effects of BTX-A and papaverine on human RA grafts.

Methods

After resting 60 min in isolated organ baths, human RA grafts were examined. Contraction responses for different doses of serotonin (5-HT) and endothelin-1 (ET-1) were evaluated as a percent of maximum contraction response elicited by 80 mM potassium chloride (KCl). The inhibitory effects of BTX-A and papaverine on contraction responses taken at the 0th hour were compared with the 1st and 2nd hour responses. Inhibitory effects of BTX-A and papaverine against the contractile agent were evaluated by comparing the results of the first and last (0th and 2nd hour) application.

Results

In low concentrations, when we compared the effects of BTX-A (10^− 8 M) and papaverine (10^− 6 M) on 5-HT, papaverine was found to be more effective at both the 0th and 2nd hour (p < 0.05). Both BTX-A and papaverine inhibited the maximum contractile effect of ET-1 to the same extent at the 0th hour; but, the inhibitory effect of BTX-A was significantly stronger at the 2nd hour (p < 0.05).

In high concentrations, when we compared the effects of BTX-A (10^− 6 M) and papaverine (10^− 4 M) on 5-HT, papaverine showed stronger inhibition (p < 0.05), whereas both agents had similar action of inhibition on ET-1 mediated maximum contraction responses.

Conclusion

BTX-A inhibits both ET-1 and 5-HT induced contractions and its effectiveness does not decrease over time as observed with papaverine. This study is the first in the literature using human RA for prevention of vasospasm by BTX-A.

On-Pump Coronary Artery Bypass Graft: The State of the Art

BACKGROUND

Coronary artery bypass grafting (CABG) remains the standard of care for patients with coronary artery disease (CAD). Debate exists concerning several factors, which include percutaneous coronary intervention (PCI) vs. CABG, single vs. bilateral mammary artery grafts, radial artery vs. saphenous vein grafts, right internal mammary artery vs. radial artery grafts, endoscopic vs. open vein-graft harvesting, and on-pump vs. off- pump surgery. Moreover, challenging is the management of diabetic patients with CAD undergoing CABG. This review reports current indications, practice patterns, and outcomes of CABG.

METHODS

Randomized controlled trials comparing CABG to other therapeutical strategies for CAD were searched through MEDLINE, EMBASE, Cochrane databases, and proceedings of international meetings.

RESULTS

Large multicenter randomized and observational studies (SYNTAX, BEST, PRECOMBAT, ASCERT) have reported excellent outcomes in CABG patients, with always fewer rates of operative mortality and major morbidity, than PCI. The 10-year follow-up of ARTS II trial showed no difference between single and bilateral mammary artery. BARI 2D, MASS II, CARDia, FREEDOM trials showed that CABG is the best choice for diabetic patients.

CONCLUSION

CABG still represents one of the most widespread major surgeries, with well-known benefits on symptoms and prognosis in patients with CAD. However, further studies and follow-up data are needed to validate these evidences.

Moderate-to-high intensity inspiratory muscle training improves the effects of combined training on exercise capacity in patients after coronary artery bypass graft surgery: A randomized clinical trial

BACKGROUND

The effects of adding moderate-to-high intensity inspiratory muscle training (IMT) to short-term aerobic and resistance exercise (combined training [CT]), after coronary artery bypass grafting (CABG) are not established. This study aimed to determine the effects of moderate-to-high intensity IMT + CT on exercise capacity, respiratory muscle strength, inspiratory muscle endurance, quality of life (QoL), and laboratory biomarkers in patients after CABG who were participants of a phase II cardiac rehabilitation program.

METHODS

Twenty-four patients were randomly assigned to either the IMT + CT group (n = 12), who performed moderate-to-high intensity IMT with CT or the sham-IMT + CT group (n = 12). Patients completed two sessions per week for 12 weeks. Each patient underwent a cardiopulmonary exercise test, six-minute walk test (6MWT), respiratory muscle strength and endurance evaluation, QoL questionnaire, and serum advanced oxidation protein products, ferric reducing antioxidant power [FRAP], nitrate/nitrate, and high-sensitivity C-reactive protein, before and after the 12-week intervention.

RESULTS

The IMT + CT group showed significantly greater improvements in peak oxygen uptake (1.3 mL∙kg^-1∙min^-1; 95% confidence interval [95% CI], 0.5 to 2.2), distance covered during the 6MWT (78.8 m; 95% CI, 28.1 to 129.5), maximal inspiratory pressure (23.0 cmH₂O; 95% CI, 9.3 to 36.7), QoL (-15.1 points; 95% CI, -26.9 to -3.3), and FRAP (83.7 μmol/L; 95% CI, 20.2 to 147.1) compared to the sham-IMT + CT group as a result of the intervention.

CONCLUSIONS

Short-term moderate-to-high intensity IMT with CT provided additional benefits in exercise capacity, inspiratory muscle strength, QoL, and antioxidant profile in patients after CABG. Trial Registration clinicaltrials.gov Identifier: NCT02885077.