Long-term patency of saphenous vein and left internal mammary artery grafts after coronary artery bypass surgery: results from a Department of Veterans Affairs Cooperative Study

Nonlinear Elasticity of Blood Vessels and Vascular Grafts

The transplantation of vascular grafts has emerged as a prevailing approach to address vascular disorders. However, the development of small-diameter vascular grafts is still in progress, as they serve in a more complicated mechanical environment than their counterparts with larger diameters. The biocompatibility and functional characteristics of small-diameter vascular grafts have been well developed; however, mismatch in mechanical properties between the vascular grafts and native arteries has not been accomplished, which might facilitate the long-term patency of small-diameter vascular grafts. From a point of view in mechanics, mimicking the nonlinear elastic mechanical behavior exhibited by natural blood vessels might be the state-of-the-art in designing vascular grafts. This review centers on elucidating the nonlinear elastic behavior of natural blood vessels and vascular grafts. The biological functionality and limitations associated with as-reported vascular grafts are meticulously reviewed and the future trajectory for fabricating biomimetic small-diameter grafts is discussed. This review might provide a different insight from the traditional design and fabrication of artificial vascular grafts.

Evaluation of the Patients with Recurrent Angina After Coronary Artery Bypass Grafting

INTRODUCTION

In this study, we aimed to evaluate the most common causes of recurrent angina after coronary artery bypass grafting (CABG) and our treatment approaches applied in these patients.

METHODS

We included all patients who underwent CABG, with or without percutaneous coronary intervention after CABG, at our hospital from September 2013 to December 2019. Patients were divided into two groups according to the time of onset of anginal pain after CABG. Forty-five patients (58.16 ± 8.78 years) had recurrent angina in the first postoperative year after CABG and were specified as group I (early recurrence). Group II (late recurrence) comprised 82 patients (58.05 ± 8.95 years) with angina after the first year of CABG.

RESULTS

The mean preoperative left ventricular ejection fraction was 53.22 ± 8.87% in group I, and 54.7 ± 8.58% in group II (P=0.38). No significant difference was registered between groups I and II regarding preoperative angiographic findings (P>0.05). Failed grafts were found in 27.7% (n=28/101) of the grafts in group I as compared to 26.8% (n=51/190) in group II (P>0.05). Twenty-four (53.3%) patients were treated medically in group I, compared with 54 (65.8%) patients in group II (P=0.098). There was a need for intervention in 46.6% (n=21) of group I patients, and in 34.1% (n=28) of group II patients.

CONCLUSION

Recurrent angina is a complaint that should not be neglected because most of the patients with recurrent angina are diagnosed with either native coronary or graft pathology in coronary angiography performed.

Relationship between uric acid to albumin ratio and saphenous vein graft disease in patients with coronary artery bypass graft

OBJECTIVE

Saphenous vein graft disease (SVGD) remains a challenging issue for patients with coronary artery bypass grafting (CABG). It is associated with poor outcomes and atherosclerosis is the major cause of SVGD. Uric acid to albumin ratio (UAR) is a new marker which associated with cardiovascular mortality. We aim to evaluate the relationship between the SVGD and UAR.

METHODS

We retrospectively enrolled 237 patients who underwent elective coronary angiography (CAG) for stable angina or positive stress test results >1 year after CABG. The patients were divided into two groups; SVGD (+) patients and SVGD (-) patients. The SVGD was defined as presence of at least 50% stenosis in at least 1 SVG.

RESULTS

UAR were significantly higher in the SVGD (+) group (P < 0.001). Similarly, Hs-CRP, white blood cell count, and neutrophil count were significantly higher in SVGD (+) group (P = 0.03, P = 0.027 P = 0.01, respectively). In multivariate logistic regression analysis, time interval after CABG [OR = 1.161, 95% confidence interval (CI) 1.078-1.250; P < 0.001] and UAR (OR = 2.691, 95% CI 1.121-6.459; P < 0.001) were found to be independent predictors of SVGD.

CONCLUSION

Our results suggested that UAR could be a simple and available marker to predict SVGD in patients with CABG who underwent elective percutaneous coronary intervention.

The impact of perivascular tissue preservation on 5-year patency of saphenous vein composite grafts

OBJECTIVES

This retrospective study was conducted to evaluate the impact of saphenous vein (SV) harvesting with versus without perivascular tissue on the 5-year angiographic patency in coronary artery bypass grafting.

METHODS

Among the 944 patients who received coronary artery bypass grafting between 2010 and 2015, 579 patients who received off-pump coronary artery bypass grafting using 1 SV as a Y-composite graft based on the in situ left internal thoracic artery were enrolled. SV harvesting was performed using no-touch technique without perivascular tissue (the NoPVT group) in 342 patients and with perivascular tissue (the PVT group) in 237 patients. Follow-up duration was 84.0 months (interquartile range 66.5-105.4). Propensity score matching was performed, and long-term clinical outcomes and angiographic patency were compared.

RESULTS

The average number of distal anastomoses per patient was comparable between the groups, although more SV grafts were anastomosed to left anterior descending territory in the PVT group than in the NoPVT group. Overall survival and cumulative incidence of cardiac death were comparable between the groups, whereas cumulative incidence of target vessel revascularization (1.3% vs 4.3% at 5 year, P = 0.009) and that of major adverse cardiac events (7.3% vs 9.9% at 5 year, P = 0.035) were lower in the PVT group than in the NoPVT group. One-year and 5-year angiographic patency rates of the SV grafts were higher in the PVT group than in the NoPVT group [97.0% vs 91.7% (P = 0.004) and 96.3% vs 89.9% (P = 0.007), respectively].

CONCLUSIONS

SV grafts harvested using no-touch technique with perivascular tissue further improved the 5-year patency of SV composite grafts compared with those without perivascular tissue.

Hybrid Materials for Vascular Applications: A Preliminary In Vitro Assessment

The production of biomedical devices able to appropriately interact with the biological environment is still a great challenge. Synthetic materials are often employed, but they fail to replicate the biological and functional properties of native tissues, leading to a variety of adverse effects. Several commercial products are based on chemically treated xenogeneic tissues: their principal drawback is due to weak mechanical stability and low durability. Recently, decellularization has been proposed to bypass the drawbacks of both synthetic and biological materials. Acellular materials can integrate with host tissues avoiding/mitigating any foreign body response, but they often lack sufficient patency and impermeability. The present paper investigates an innovative approach to the realization of hybrid materials that combine decellularized bovine pericardium with polycarbonate urethanes. These hybrid materials benefit from the superior biocompatibility of the biological tissue and the mechanical properties of the synthetic polymers. They were assessed from physicochemical, structural, mechanical, and biological points of view; their ability to promote cell growth was also investigated. The decellularized pericardium and the polymer appeared to well adhere to each other, and the two sides were distinguishable. The maximum elongation of hybrid materials was mainly affected by the pericardium, which allows for lower elongation than the polymer; this latter, in turn, influenced the maximum strength achieved. The results confirmed the promising features of hybrid materials for the production of vascular grafts able to be repopulated by circulating cells, thus, improving blood compatibility.

Long Term Survival Benefits of Different Conduits Used in Coronary Artery Bypass Graft Surgery- A Single Institutional Practice Over 20 Years

Objective

This study determined hazard factors and long-term survival rate of total arterial coronary artery bypass graft surgery over 20 years in an extensively large, population-based cohort.

Methods

A total of 2979 patients who underwent isolated CABG from April 1999 to March 2020 were studied in 4 groups- Group-A (bilateral internal mammary artery ± radial artery), Group-B (single internal mammary artery + radial artery ± saphenous vein), Group-C (single internal mammary artery ± saphenous vein; no radial artery), and Group-D (radial artery ± saphenous vein; no internal mammary artery). The study endpoints analysed the correlation between the number and types of grafts with the survival time following isolated CABG surgery.

Results

The total arterial revascularization (Group A) group had an admirable mean long-term survival of ~19 years, compared to 18.6 years (Group B), 15.86 years (Group C), and 10.99 years (Group D). A Kaplan-Meier curve demonstrated confidence interval (CI) for study groups- (95% CI 18.33-19.94), (95% CI 18.14-19.06), (95% CI 15.40-16.32), and (95% CI 9.61-12.38) in Group A, B, C, D respectively. In the Holm-Sidak method analysis, significant associations existed between the number of arterial grafts and the long-term outcome. A statistically significant (P≤0.05) long-term survival advantage for arterial grafting was demonstrated, especially total arterial revascularisation over all other combinations except single internal mammary artery + radial artery grafting.

Conclusion

In this series, over 20 years, total arterial CABG use has excellent long-term survival, achieving complete myocardial revascularisation. There is no significant difference between the BIMA group and SIMA with radial artery. However, there is a reduced survival with decreased use of arterial conduits.

No-touch saphenous vein: current understanding of the conduit 'less handled'

PURPOSE OF REVIEW

The no-touch technique is an established method to harvest the saphenous vein (NT-SV), which is the most commonly used conduit in coronary artery bypass grafting. Herein, we summarize the foundational evidence, as well as highlight recent innovations and ongoing clinical trials involving NT-SV.

RECENT FINDINGS

Through preservation of perivascular tissue for atraumatic handling and omission of manual distension, the NT-SV maintains endothelial nitrous oxide synthase levels and experiences less vascular smooth muscle cell activation, which translates to slower progression of atherosclerosis and less size mismatch of the graft and target vessel. These biomolecular advantages allow NT-SV to provide superior graft patency compared to conventional skeletonized saphenous vein and approximating that of the radial artery. Nonetheless, the clinical benefits of NT-SV for mortality and reduction in major adverse cardiac and cerebrovascular events are insufficiently studied in the long-term. The drawback of NT-SV is the short-term harvest site complications, which may potentially be addressed by the advent of endoscopic no-touch technique.

SUMMARY

NT-SV is a promising conduit, and its role will be further clarified in upcoming clinical trials and as follow-up lengthens. However, conduit selection and harvest technique should ultimately be personalized to the individual patient.

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.

Sex differences in long-term survival after total arterial coronary artery bypass grafting

OBJECTIVES

It is uncertain if the evidence on improved long-term survival of total arterial coronary artery bypass grafting applies to female patients. This study aims to compare the long-term survival outcomes of using total arterial revascularization (TAR) versus at least 1 saphenous vein graft separately for men and women.

METHODS

This retrospective analysis of the Australian and New Zealand Society of Cardiac-Thoracic Surgical Database had administrative linkage to the National Death Index. We identified all patients undergoing primary isolated coronary bypass from June 2001 to January 2020 inclusive. Following sex stratification, propensity score matching with 36 variables and Cox proportional hazard regression were used to facilitate adjusted comparisons. A Cox interaction-term analysis was performed to investigate the impact of sex on TAR survival benefit. The primary outcome was all-cause mortality.

RESULTS

Of the 69 624 eligible patients receiving at least 2 grafts, 13 019 (18.7%) were female patients. Matching generated 14 951 male and 3530 female pairs. Compared to vein-dependent procedures, TAR was associated with significantly reduced incidence of long-term all-cause mortality for both male (hazard ratio, 0.86; 95% confidence interval, 0.81-0.91; P < 0.001) and female (hazard ratio, 0.82; 95% confidence interval, 0.73-0.91; P < 0.001) cohorts. Interaction-term analysis indicated no significant subgroup effect from sex (P = 0.573) on the survival advantage of TAR. The treatment effect provided by TAR remained significant across most sex-stratified disease subgroups.

CONCLUSIONS

TAR, when compared to the use of at least 1 saphenous vein graft, provides comparable superior long-term survival outcomes in both females and males.

From a Position of Known Angiographic Perfect Patency: What Happens Next?

BACKGROUND AND AIM

The biological behaviour of coronary graft conduits over time may be considered by serial angiography.

METHODS

A single institution retrospective cohort received mostly clinically indicated angiography between 1997 and 2020, following coronary bypass surgery. Only perfectly patent grafts (absence of any lumen irregularity) for each conduit type at the first postoperative angiogram were selected for a later comparison. The latest angiograms were at least 5 years postoperatively, and at least 1 year after first postoperative angiogram. Analysis was done according to each graft (anastomosis). Comparisons used generalised estimating equations, adjusted for binary logistic regression.

RESULTS

Of 143 patients, there were 410 of 468 (87.6%) perfectly patent grafts at the first angiogram, analysed at 6.8±4.0 years postoperative, of which 157 were internal mammary arteries, 228 were radial arteries, and 25 were saphenous veins. At the latest angiogram (12.2±3.8 years postoperative), comparison with the first angiogram for each individual graft found preserved perfect patency for internal mammary arteries 156 of 157 (99.4%), and for radial arteries, 227 of 228 (99.6%) but saphenous veins deteriorated considerably 13 of 25 (52.0%). The two arterial grafts (internal mammary and radial) were superior to vein grafts (odds ratio 163; 95% confidence interval [CI] 22-1,211; p<0.001), but not different from each other (odds ratio 0.95; 95% CI 0.78-1.16; p=0.584).

CONCLUSIONS

From a position of known angiographic perfect patency post-CABG, internal mammary artery and radial artery grafts retained their perfect patency in the longer term, but saphenous vein grafts did not.

Single-Centre Registry Analysis of Patients Who Underwent Percutaneous Coronary Intervention on Their Coronary Bypass Grafts

Background

The study assessed the outcomes of patients undergoing percutaneous coronary intervention (PCI) to bypass grafts, focusing on all-cause mortality and target vessel failure (TVF) rates.

Methods

A single-centre registry analysis included 364 patients who underwent PCI on coronary bypass grafts between 2008 and 2019. The study analyzed all-cause mortality and TVF, which encompassed target lesion revascularization, target vessel revascularization, and medically treated occluded target graft post-PCI.

Results

The median age of the patients was 71 years (interquartile range: [IQR] 65-78), with 82.1% being male. Most patients (94.8%) received PCI on saphenous vein grafts, and the median graft age was 13.0 years (IQR: 8.4-17.6). Drug-eluting stents were used more frequently (54.4%) than bare-metal stents (45.6%), with a median stent diameter of 3.5 mm (IQR: 3-4) and length of 19 mm (IQR: 18-28). Outcome differences were not significant for PCI sites (aorto-ostial, graft body, anastomosis), use of drug-eluting stents, or use of protection devices. The 1-year mortality rate was 3.3%, whereas the combined rate of TVF or death was 20.3%. After 5 years, the mortality rate increased to 14.9%, and the combined TVF or death rate rose to 40.3%. Multivariable analyses revealed that chronic kidney disease was independently associated with mortality (hazard ratio [HR] 1.74, 95% confidence interval [CI] 1.16-2.61, P = 0.007), whereas hypertension (HR 2.42, 95% CI 1.32-4.42, P = 0.004) and increased stent length (HR 1.01, 95% CI 1.00-1.02, P = 0.007) were independently associated with the TVF-or-mortality outcome.

Conclusions

Patients undergoing PCI to bypass grafts experience considerable adverse outcomes over a 5-year period, highlighting the need for further strategies in managing this high-risk population.

Consensus statement-graft treatment in cardiovascular bypass graft surgery

Coronary artery bypass grafting (CABG) is and continues to be the preferred revascularization strategy in patients with multivessel disease. Graft selection has been shown to influence the outcomes following CABG. During the last almost 60 years saphenous vein grafts (SVG) together with the internal mammary artery have become the standard of care for patients undergoing CABG surgery. While there is little doubt about the benefits, the patency rates are constantly under debate. Despite its acknowledged limitations in terms of long-term patency due to intimal hyperplasia, the saphenous vein is still the most often used graft. Although reendothelialization occurs early postoperatively, the process of intimal hyperplasia remains irreversible. This is due in part to the persistence of high shear forces, the chronic localized inflammatory response, and the partial dysfunctionality of the regenerated endothelium. "No-Touch" harvesting techniques, specific storage solutions, pressure controlled graft flushing and external stenting are important and established methods aiming to overcome the process of intimal hyperplasia at different time levels. Still despite the known evidence these methods are not standard everywhere. The use of arterial grafts is another strategy to address the inferior SVG patency rates and to perform CABG with total arterial revascularization. Composite grafting, pharmacological agents as well as latest minimal invasive techniques aim in the same direction. To give guide and set standards all graft related topics for CABG are presented in this expert opinion document on graft treatment.

An Autopsy Case of Saphenous Vein Graft Rupture

ABSTRACT

Saphenous vein graft aneurysms are rare complications after coronary artery bypass grafting that carry serious complications. Less than 10 case reports of autopsy findings consistent with ruptured saphenous vein grafts exist in the literature. We report a case of a female presenting at autopsy who, after coronary artery bypass grafting 20 years prior, demonstrated findings of a saphenous vein graft aneurysm and rupture. With limited evidence from medical records, this case highlights a need for patients with previous coronary artery bypass grafting to be properly monitored to detect minute graft changes before aneurysm formation and rupture as seen in our decedent.

Single versus bilateral internal thoracic artery grafting in patients with impaired renal function

OBJECTIVE

The optimal strategy for surgical revascularization in patients with impaired renal function is inconclusive. We compared early and late outcomes between bilateral internal thoracic artery (BITA) and single ITA (SITA) grafting in patients with renal dysfunction.

METHODS

This is a retrospective analysis of all the patients with multivessel disease and impaired renal function (estimated glomerular filtration rate <60mL/min/1.73m2) who underwent isolated coronary artery bypass graft (CABG) in our center during 1996-2011, utilizing either BITA or SITA revascularization.

RESULTS

Of the 5301 patients with multivessel disease who underwent surgical revascularization during the study period, 391 were with impaired renal function: 212 (54.2%) underwent BITA, 179 (45.8%) underwent SITA. Patients who underwent BITA were less likely to have comorbidities. Statistically significant differences were not observed between the BITA and SITA groups in 30-day mortality (5.6% vs. 9.0%, p = 0.2) and in rates of early stroke, myocardial infarction, and sternal infection (4.5% vs. 6.1%, p = 0.467; 1.7% vs. 2.8%, p = 0.517; and 2.2% vs. 5.7%, p = 0.088, respectively). Long-term survival of the BITA group was better: median 8.36 vs. 4.14 years, p<0.001. In multivariable analysis, BITA revascularization was associated with decreased late mortality (HR = 0.704, 95% CI: 0.556-0.89, p = 0.003). In analysis of a matched cohort (134 pairs), early outcomes did not differ between the groups; however, in multivariable analysis, BITA revascularization was associated with decreased late mortality ‎‎(HR = 0.35 (95%CI 0.18-0.68), p = 0.002)‎.

CONCLUSIONS

BITA revascularization did not impact early outcome in patients with CRF, but demonstrated a significant protective effect on long-term survival ‎in the unmatched and matched cohorts.

Thirteen Years of Impactful, Minimally Invasive Coronary Surgery: Short- and Long-Term Results for Single and Multi-Vessel Disease

OBJECTIVES

Minimally invasive coronary surgery (MICS) via lateral thoracotomy is a less invasive alternative to the traditional median full sternotomy approach for coronary surgery. This study investigates its effectiveness for short- and long-term revascularization in cases of single and multi-vessel diseases.

METHODS

A thorough examination was performed on the databases of two cardiac surgery programs, focusing on patients who underwent minimally invasive coronary bypass grafting procedures between 2010 and 2023. The study involved patients who underwent either minimally invasive direct coronary artery bypass grafting (MIDCAB) for the revascularization of left anterior descending (LAD) artery stenosis or minimally invasive multi-vessel coronary artery bypass grafting (MICSCABG). Our assessment criteria included in-hospital mortality, long-term mortality, and freedom from reoperations due to failed aortocoronary bypass grafts post-surgery. Additionally, we evaluated significant in-hospital complications as secondary endpoints.

RESULTS

A total of 315 consecutive patients were identified between 2010 and 2023 (MIDCAB 271 vs. MICSCABG 44). Conversion to median sternotomy (MS) occurred in eight patients (2.5%). The 30-day all-cause mortality was 1.3% (n = 4). Postoperative AF was the most common complication postoperatively (n = 26, 8.5%). Five patients were reoperated for bleeding (1.6%), and myocardial infarction (MI) happened in four patients (1.3%). The mean follow-up time was six years (±4 years). All-cause mortality was 10.3% (n = 30), with only five (1.7%) patients having a confirmed cardiac cause. The reoperation rate due to graft failure or the progression of aortocoronary disease was 1.4% (n = 4).

CONCLUSIONS

Despite the complexity of the MICS approach, the results of our study support the safety and effectiveness of this procedure with low rates of mortality, morbidity, and conversion for both single and multi-vessel bypass surgeries. These results underscore further the necessity to implement such programs to benefit patients.

Long-term results of percutaneous coronary intervention in no-touch vein grafts are significantly better than in conventional vein grafts

INTRODUCTION

Conventional vein grafts have a high risk of thrombosis and early atherosclerosis. Percutaneous coronary intervention (PCI) in conventional vein grafts is associated with a higher incidence of late adverse cardiac events. The aim of this study was to evaluate the long-term results after PCI in saphenous vein grafts (SVG) harvested with the no-touch technique compared to the conventional technique.

METHODS

This was a single-center, retrospective, cohort study, based on data from the Swedeheart register. The inclusion criterion was individuals who underwent CABG using different vein graft techniques between January 1992 and July 2020, and who required a PCI in SVGs between January 2006 and July 2020. The primary end point was long-term in-stent restenosis. The secondary endpoints were long-term major adverse cardiac events (MACE) and 1-year re-hospitalization rates. The associations between the graft types and the endpoints were evaluated using the Fine and Gray competing-risk regression analysis.

RESULTS

The study included 346 individuals (67 no-touch, 279 conventional). The mean clinical follow-up time was 6.4 years with a standard deviation of 3.7 years. The long-term in-stent restenosis rate for the no-touch grafts was 3.2% compared to 18.7% for the conventional grafts (p < .01), with a subdistribution hazard ratio (SHR) of 0.16 (p = .010). The long-term MACE rate was 27.0% in the no-touch group and 48.3% in the conventional group (p < .01) with a SHR of 0.53 (p = .017). The short-term results were similar in both groups.

CONCLUSIONS

Percutaneous coronary intervention in a no-touch vein graft was associated with statistically significantly fewer in-stent restenoses and MACE at long-term follow-up compared to a conventional SVG.

Techniques and Technologies to Improve Vein Graft Patency in Coronary Surgery

Vein grafts are the most used conduits in coronary artery bypass grafting (CABG), even though many studies have suggested their lower patency compared to arterial alternatives. We have reviewed the techniques and technologies that have been investigated over the years with the aim of improving the quality of these conduits. We found that preoperative and postoperative optimal medical therapy and no-touch harvesting techniques have the strongest evidence for optimizing vein graft patency. On the other hand, the use of venous external support, endoscopic harvesting, vein preservation solution and anastomosis, and graft configuration need further investigation. We have also analyzed strategies to treat vein graft failure: when feasible, re-doing the CABG and native vessel primary coronary intervention (PCI) are the best options, followed by percutaneous procedures targeting the failed grafts.

Sternal wound infections following internal mammary artery grafts for a coronary bypass: A meta-analysis

The meta-analysis aims to evaluate and compare the sternal wound infections following internal mammary artery grafts for a coronary bypass. Examinations comparing bilateral internal mammary artery to single internal mammary artery for coronary artery bypass grafting were among the meta-analyses from various languages that met the inclusion criteria. Using dichotomous random- or fixed-effect models, the results of these investigations were examined, and the Odd Ratio (OR) with 95% confidence intervals (CIs) was computed. A total of 31 examinations from 2001 to 2023 were recruited for the current analysis including 181 503 personals with coronary artery bypass grafting. Bilateral internal mammary artery had significantly higher sternal wound infection (OR, 1.51; 95% CI, 1.37-1.68, p < 0.001), superficial sternal wound infection (OR, 1.72; 95% CI, 1.16-2.56, p = 0.007), deep sternal wound infection (OR, 1.62; 95% CI, 1.41-1.86, p < 0.001), sternal wound infection in diabetics (OR, 1.48; 95% CI, 1.16-1.90, p = 0.002), sternal wound infection in elderly (OR, 1.38; 95% CI, 1.22-1.57, p < 0.001), sternal wound infection in pedicled preparation (OR, 1.70; 95% CI, 1.30-2.23, p < 0.001) and sternal wound infection in skeletonized preparation (OR, 1.40; 95% CI, 1.09-1.81, p = 0.009) compared to single internal mammary artery in personals with coronary artery bypass grafting. Bilateral internal mammary artery grafting is linked to a higher risk of impaired wound healing, particularly in diabetic individuals, elderly, pedicled preparation, and skeletonized preparation. Nevertheless, caution should be exercised while interacting with its values since examinations were performed by different surgeons with different skills on different types of personals.

Multi-slice CT coronary angiography versus invasive coronary angiography in the assessment of graft patency after coronary artery bypasses graft surgery

BACKGROUND

The long-term patency of arterial and venous grafts is crucial for the success of CABG. This study was designed to investigate graft patency using 128-slice coronary computed tomography angiography (CCTA) and compared the results with those obtained using invasive coronary angiography (ICA). In this observational cross-sectional study, we included 40 symptomatic post-CABG patients underwent CCTA and ICA within the same month.

RESULTS

Fifty-five percent were aged more than 60 years, and 80% were males. 67.5% had diabetes, 90% had hypertension, and 30% were smokers. Mean body mass index was 28.89 ± 5.17 kg/m2. Mean duration since CABG was 5.25 ± 4.04 years. In total, 124 native vessels and 97 grafts were assessed using CCTA and ICA. CCTA delineated 8 non-cannulated venous grafts and 6 non-cannulated left internal mammary artery grafts. CCTA required a significantly lower radiation dose (1165.77 ± 123.54 vs. 47,589.78 ± 6967.53, p < 0.001).

CONCLUSION

CCTA can be as accurate as ICA in assessing bypass grafts with less radiation dose, providing a non-invasive reliable tool for evaluation.

Dual-Antiplatelet Therapy After Coronary Artery Bypass Grafting: A Survey of UK Cardiac Surgeons

OBJECTIVE

Antiplatelet therapy after coronary artery bypass grafting (CABG) is important in postoperative medical management. Although cardiac surgeons are well-versed in the guidelines regarding discontinuation of dual-antiplatelet therapy (DAPT; aspirin and a P2Y12 antagonist) before CABG to minimize bleeding risk, there is considerable variability in DAPT dosing after CABG. The objective of this study was to explore the current trends in DAPT after CABG in the UK to improve understanding of the existing practice.

DESIGN

This study used an online survey with 9 questions about the use of DAPT after CABG. An invitation to participate was sent to all adult cardiac surgeons currently in practice in the UK and the Republic of Ireland.

SETTING

The study was conducted in the UK and the Republic of Ireland.

PARTICIPANTS

Participants in this study were adult cardiac surgeons currently in practice in the UK and the Republic of Ireland.

INTERVENTIONS

There were no interventions in this study.

MEASUREMENTS AND MAIN RESULTS

Responses were received from across the UK (85.4% UK; 4% each from Scotland and Northern Ireland, 1.3% from Wales) and 5.3% from the Republic of Ireland. Fifty-seven percent of the respondents performed between 50 and 100 CABGs per year. Ninety-one percent of the respondents prescribe DAPT postoperatively, but the choice of which patients receive it varied. Most responding surgeons used DAPT for selective patient cohorts, such as those with acute coronary syndrome (51%), diffuse coronary artery disease (42%), perioperative myocardial infarction (36%), coronary endarterectomy (31%), or when bypassing a stented coronary artery (23%). Thirty-eight percent of the respondents began all their patients with CABGs on DAPT. The most preferred P2Y12 antagonist was clopidogrel, used by 75% of respondents and introduced on day 1 after surgical revascularization (71%). The routine duration for DAPT is 12 months, which 78% of the respondents preferred. The main reason for not starting DAPT in those surveyed was the bleeding risk associated with DAPT (72%).

CONCLUSIONS

The survey uncovered variation in the use of DAPT after CABG. However, DAPT remains the preferred strategy after CABG in the UK. The study highlighted the need to develop standardized protocols for DAPT after CABG.

Endothelial damage inhibitor preserves the integrity of venous endothelial cells from patients undergoing coronary bypass surgery

OBJECTIVES

Despite the success of coronary artery bypass graft (CABG) surgery using autologous saphenous vein grafts (SVGs), nearly 50% of patients experience vein graft disease within 10 years of surgery. One contributing factor to early vein graft disease is endothelial damage during short-term storage of SVGs in inappropriate solutions. Our aim was to evaluate the effects of a novel endothelial damage inhibitor (EDI) on SVGs from patients undergoing elective CABG surgery and on venous endothelial cells (VECs) derived from these SVGs.

METHODS

SVGs from 11 patients participating in an ongoing clinical registry (NCT02922088) were included in this study, and incubated with both full electrolyte solution (FES) or EDI for 1 h and then examined histologically. In 8 of 11 patients, VECs were isolated from untreated grafts, incubated with both FES and EDI for 2 h under hypothermic stress conditions and then analysed for activation of an inflammatory phenotype, cell damage and cytotoxicity, as well as endothelial integrity and barrier function.

RESULTS

The EDI was superior to FES in protecting the endothelium in SVGs (74 ± 8% versus 56 ± 8%, P < 0.001). Besides confirming that the EDI prevents apoptosis in SVG-derived VECs, we also showed that the EDI temporarily reduces adherens junctions in VECs while protecting focal adhesions compared to FES.

CONCLUSIONS

The EDI protects the connectivity and function of the SVG endothelium. Our data suggest that the EDI can preserve focal adhesions in VECs during short-term storage after graft harvesting. This might explain the superiority of the EDI in maintaining most of the endothelium in venous CABG surgery conduits.

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.

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.

The VEST External Support for Saphenous Vein Grafts in Coronary Surgery: A Review of Randomized Clinical Trials

Saphenous vein grafts (SVGs) are the most frequently used conduits in coronary artery bypass grafting (CABG), but their higher rate of occlusion compared to arterial conduits remains a concern. Previous studies have shown that SVG failure is mainly driven by intimal hyperplasia, an adaptative response to higher pressures of the arterial circulation. The VESTTM device (Vascular Graft Solutions, Tel Aviv, Israel), an external support designed to mitigate intimal hyperplasia in SVGs, has been tested in few clinical trials (RCTs). Herein, we descriptively evaluated the randomized evidence on the VEST device.

Robotic Totally Endoscopic Coronary Bypass to the Left Anterior Descending Artery: Left Versus Right Internal Thoracic Artery Grafts

INTRODUCTION

The left internal thoracic artery (LITA) is most commonly used to bypass the left anterior descending artery (LAD) given its well-established mortality benefit. In some cases, the grafting strategy necessitates placing the right internal thoracic artery (RITA) on the LAD. We compared outcomes in our robotic beating-heart totally endoscopic coronary bypass surgery (TECAB) population between patients receiving LITA versus RITA-LAD grafts.

METHODS

We retrospectively reviewed patients undergoing robotic TECAB with skeletonized ITA conduits over 9 y. Outcomes were compared between those receiving LITA (Group-1) versus RITA (Group-2) grafts to the LAD (with/without other grafts). End points were early angiographic patency (in patients undergoing hybrid revascularization) and mid-term mortality/major adverse cardiac/cerebrovascular events. A propensity matched subanalysis was performed comparing only patients who received bilateral ITA grafting in each group.

RESULTS

Society of Thoracic Surgeons predicted mortality risk score was higher in Group-2. Group-1 patients had lower incidence of multivessel disease (75% versus 96%, P ≤ 0.001). Early overall graft patency (97% versus 96%, P = 0.718) and LAD graft patency (98% versus 95%, P = 0.372) were equivalent. At mean 42-mo follow-up (longest 8.5 y), Group-1 had lower all-cause mortality but no difference in cardiac mortality or repeat revascularization. In the propensity matched subanalysis, mid-term outcomes were equivalent.

CONCLUSIONS

Grafting the LAD with the LITA or RITA during robotic beating-heart TECAB resulted in similar early outcomes and angiographic patency. RITA-LAD patients were more likely to have multivessel disease and higher Society of Thoracic Surgeons risk and had higher all-cause mortality at mid-term analysis but no difference in major adverse cardiac/cerebrovascular events, including cardiac mortality.

Triglyceride-glucose index is associated with poor prognosis in acute coronary syndrome patients with prior coronary artery bypass grafting undergoing percutaneous coronary intervention

BACKGROUND

The triglyceride-glucose (TyG) index, which is a reliable substitute indicator for insulin resistance, has been considered an independent risk factor for long-term outcomes in patients with cardiovascular disease. However, it remains unknown whether the TyG index is associated with poor prognosis in acute coronary syndrome (ACS) patients with prior coronary artery bypass grafting (CABG) undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 1158 ACS patients with prior CABG undergoing PCI were retrospectively studied. The TyG index was calculated by ln[fasting triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2]. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), a composite of all-cause death, nonfatal myocardial infarction, nonfatal stroke, and unplanned repeat revascularization.

RESULTS

During a median of 42-month follow-up, 350 patients (30.2%) experienced at least one endpoint event. Based on the optimal cut-off value of the TyG index, patients were divided into the high TyG index group and the low TyG index group. Patients in the high TyG index group had higher risks of MACCE (35.3% vs. 25.3%, p < 0.001), major adverse cardiovascular events (MACE) (31.1% vs. 23.4%, p = 0.003), nonfatal stroke (4.2% vs. 1.9%, p = 0.022) and unplanned repeat revascularization (19.4% vs. 11.3%, p < 0.001) than those in the low TyG index group. Cox regression analysis demonstrated that there was an independent association between the TyG index and MACCE regardless of whether the TyG index was a continuous or categorical variable (HR 1.42, 95% CI 1.09-1.86, p = 0.009; HR 1.53, 95% CI 1.16-2.01, p = 0.003, respectively). Restricted cubic spline curve exhibited that the relationship between the TyG index and MACCE was linear (p for non-linear = 0.595, p for overall = 0.005). By incorporating the TyG index groups into baseline risk model, the accuracy of predicting MACCE was improved [AUC: baseline risk model, 0.618 vs. baseline risk model + TyG index groups, 0.636, p for comparison = 0.042].

CONCLUSIONS

The TyG index is independently associated with MACCE, suggesting that the TyG index may serve as a valid indicator for predicting poor prognosis in ACS patients with prior CABG undergoing PCI.

Internal thoracic artery graft failure and recurrence of symptoms following single-vessel coronary artery bypass graft surgery

OBJECTIVES

Coronary events and disease recurrence following coronary artery bypass (CABG) surgery could derive from either failure in the internal thoracic artery (ITA) graft, failure in other conduits or progressive disease in the coronaries. We aim to estimate the contribution of ITA graft failure to the recurrence of symptoms after CABG surgery.

METHODS

Within the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry, we identified patients who had coronary artery bypass grafting from 1997 to 2020 with a single-vessel ITA graft bypass. Deaths, postoperative incidence of coronary angiography and the presence of a failed graft at the time of the angiography were recorded.

RESULTS

The study population consisted of 1939 patients with a mean follow-up time (SD) of 17.2 (5.6) years. The cumulative incidence (95% CI) at 20 years for a first clinically-driven postoperative angiography was 38.6% (36.2-41.1). A failed ITA graft was reported in 16.4% of the angiographies.

CONCLUSIONS

A substantial part of recurrent symptoms of coronary artery disease do not seem to be related to ITA failure. Disease progression in the native coronary vessels may instead be the main driver of symptom recurrence.

Coronary Artery Bypass Surgery: Comparing the Long-Term Impact of Total Arterial Grafting With Multiarterial Plus Saphenous Vein Grafting

INTRODUCTION

This study aimed to compare the long-term outcomes in a propensity matched population receiving total arterial grafting (TAG) and multiple arterial grafts (MAG) in addition to saphenous vein graft (SVG) following multivessel coronary artery bypass grafting requiring at least three distal anastomoses.

METHODS

In this retrospective study, 655 patients from two centers met the inclusion criteria and were divided into two groups: TAG group (n = 231) and MAG + SVG group (n = 424). Propensity score matching was performed resulting in 231 pairs.

RESULTS

No significant differences were observed between both groups in terms of early outcomes. Survival probabilities at 5, 10, and 15 y were 89.1% versus 94.2%, 76.2% versus 76.1%, and 66.7% versus 69.8% in the TAG and MAG + SVG groups, respectively (hazard ratio stratified on matched pairs: 0.90; 95% confidence interval [0.45-1.77]; P = 0.754). Freedom from major adverse cardiac and cerebral events (MACCE) in the matched cohort did not show any significant difference between both groups. Probabilities at 5, 10, and 15 y were 82.7% versus 85.6%, 62.2% versus 75.3%, and 48.8% versus 59.5% in the TAG and MAG + SVG groups, respectively (hazard ratio stratified on matched pairs: 1.12; 95% confidence interval [0.65-1.92]; P = 0.679). Subgroup analyses of the matched cohort showed no significant difference between TAR with three arterial conduits compared to TAR with two arterial conduits with sequential grafting and MAG + SVG in terms of long-term survival and freedom from MACCE.

CONCLUSIONS

Multiple arterial revascularizations in addition to SVG may yield comparable long-term outcomes in terms of survival and freedom from MACCE compared to total arterial revascularization.

Revascularization Modalities in Acute Coronary Syndrome: A Review of the Current State of Evidence

Acute coronary syndrome (ACS) stands as a leading global cause of mortality, underscoring the importance of effective prevention, early diagnosis, and timely intervention. While medications offer benefits to many patients, revascularization procedures such as coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), and emerging hybrid approaches remain pivotal for ACS management. This review delves into the 2018 ESC/EACTS guidelines alongside an analysis of existing literature to shed light on the spectrum of revascularization methods. While both CABG and PCI demonstrate promising outcomes, the optimal choice between the two hinges on a comprehensive assessment of individual patient factors, anatomical complexity guided by advanced imaging, comorbidities, and age. The determination of whether to pursue culprit or total revascularization, as well as immediate or staged revascularization, is contingent upon various factors, including age, disease complexity, and clinical outcomes. This evidence-based decision-making process is orchestrated by a multidisciplinary heart team grounded in ongoing clinical evaluation. The primary objective of this review is to provide valuable insights into revascularization strategies and scrutinize the congruence of current guidelines with recent advancements in the field.

Hemodynamics of vascular shunts: trends, challenges, and prospects

Vascular bypass surgery takes a significant place in the treatment of vascular disease. According to various assessments, this type of surgery is associated with almost 20 % of all vascular surgery episodes (up to 23 % according to the Federal Neurosurgical Center of Novosibirsk). Even though the problem of using of vascular grafts is obvious and natural, many problems associated with them are not still elucidated. From the mechanics' point of view, a vascular bypass is a converging or diverging tee, and the functioning of such structures still does not have strict mathematical formulations and proofs in the general case, which forces many researchers to solve specific engineering problems associated with shunting. Mathematical modeling, which is the gold standard for virtual simulations of industrial and medical problems, faces great difficulties and limitations in solving problems for vascular bypasses. Complications in the treatment of the vascular disease may follow the difficulties in mathematical modeling, and the price can be a cardiac arrest or a stroke. This work is devoted to the main aspects of the medical application of vascular bypasses and their functioning as a mechanical system, as well the mathematical aspects of their possible setup.

Impact of quantitative flow ratio on graft function in patients undergoing coronary artery bypass grafting

Recent studies showed that preoperative functional assessment with fractional flow reserve (FFR) could predict a long-term patency of arterial bypass grafts in patients with coronary artery bypass grafting (CABG). Quantitative flow ratio (QFR) is a novel angiography-based approach to estimate FFR. This study aimed to investigate whether preoperative QFR could discriminate arterial bypass function at 1 year after surgery. The PRIDE-METAL registry was a prospective, multicenter observational study that enrolled 54 patients with multivessel coronary artery disease. By protocol, left coronary stenoses were revascularized by CABG with arterial grafts, whereas right coronary stenoses were treated with coronary stenting. Follow-up angiography at 1 year after surgery was scheduled to assess arterial graft patency. QFR was performed using index angiography by certified analysts, blinded to bypass graft function. The primary end point of this sub-study was the discriminative ability of QFR for arterial graft function, as assessed by receiver-operating characteristic curve. Among 54 patients enrolled in the PRIDE-METAL registry, index and follow-up angiography was available in 41 patients with 97 anastomoses. QFR were analyzed in 35 patients (71 anastomoses) with an analyzability of 85.5% (71/83). Five bypass grafts were found to be non-functional at 1 year. The diagnostic performance of QFR was substantial (area under the curve: 0.89; 95% confidence interval: 0.83 to 0.96) with an optimal cutoff of 0.76 to predict functionality of bypass grafts. Preoperative QFR is highly discriminative for predicting postoperative arterial graft function.Trial registration: Clinical.gov reference: NCT02894255.

Bacterial Nanocellulose Hydrogel: A Promising Alternative Material for the Fabrication of Engineered Vascular Grafts

Blood vessels are crucial in the human body, providing essential nutrients to all tissues while facilitating waste removal. As the incidence of cardiovascular disease rises, the demand for efficient treatments increases concurrently. Currently, the predominant interventions for cardiovascular disease are autografts and allografts. Although effective, they present limitations including high costs and inconsistent success rates. Recently, synthetic vascular grafts, made from artificial materials, have emerged as promising alternatives to traditional methods. Among these materials, bacterial cellulose hydrogel exhibits significant potential for tissue engineering applications, particularly in developing nanoscale platforms that regulate cell behavior and promote tissue regeneration, attributed to its notable physicochemical and biocompatible properties. This study reviews recent progress in fabricating engineered vascular grafts using bacterial nanocellulose, demonstrating the efficacy of bacterial cellulose hydrogel as a biomaterial for synthetic vascular grafts, specifically for stimulating angiogenesis and neovascularization.

Bypass Grafting to Circumflex: Left Internal Thoracic Artery versus Saphenous Vein

BACKGROUND

This study aimed to compare the short- and long-term outcomes of saphenous vein grafts (SVGs) and in situ left internal thoracic artery (LITA) grafts to the left circumflex artery (LCX) territory.

METHODS

This study included 678 patients who underwent LITA-left anterior descending (LAD) + SVG-LCX grafts and 286 patients who underwent right internal thoracic artery (RITA)-LAD + in situ LITA-LCX grafts from January 2002 to December 2020. Short-term and long-term clinical outcomes were compared using inverse probability of treatment weighting adjustment to reduce selection bias.

RESULTS

In-hospital mortality was significantly higher for the SVG-LCX group (p = 0.008), whereas deep sternal wound infection was significantly higher in the LITA-LCX group (p = 0.013).Survival rates at 5 and 10 years were 83.12 and 71.45% in the SVG-LCX group, whereas 75.24 and 65.54% in the LITA-LCX group (log-rank p = 0.114). Rates of freedom from cardiac events at 5 and 10 years were 92.82 and 85.24% in the SVG-LCX group, whereas 94.89 and 89.46% in the LITA-LCX group (log-rank p = 0.179).Univariate and multivariate logistic regression analysis showed that proximal severe stenosis was significantly protective against graft dysfunction before discharge (odds ratio, 0.43; 95% confidence interval, 0.23-0.81).

CONCLUSION

Deep sternal wound infection was significantly higher for LITA to LCX bypass whereas in-hospital mortality was higher for SVG to LCX. In situ LITA to LCX bypass grafting exhibited similar long-term outcomes with SVG to LCX bypass grafting in adjusted patient cohorts. Proximal severe stenosis of LCX was protective against graft dysfunction.

Multiple Arterial Graft Use in Coronary Artery Bypass Surgery: Surgeon Perspective vs Practice

BACKGROUND

Despite supportive evidence and guidelines, the use of multiple arterial grafts (MAGs) in coronary artery bypass grafting remains low. We sought to determine surgeon perception of personal MAG use and compare this with actual MAG use.

METHODS

We conducted a statewide surgeon survey of MAG use, presence of a hospital MAG protocol, and barriers for MAG use, with a response rate of 78% (n = 25). Surgeon survey responses were compared with actual Society of Thoracic Surgeons patient data from January 1, 2017, to December 31, 2020 using χ2 or Fisher's exact tests.

RESULTS

Of 5299 patients who had first-time, nonemergent, isolated coronary artery bypass grafting (≥2 grafts) by responding surgeons, 16% received MAG (n = 825). MAG use in patients whose surgeons self-designated as "routine" MAG users was 21% vs 7% for "nonroutine" users. Surgeons with a hospital protocol for MAG use utilized MAG more often (18% vs 14%, P = .001). Surgeons who were unconvinced by the data on the benefits of MAGs used MAGs in 11% vs 22% in surgeons who were convinced. MAG use increased over time, particularly from before to after the survey (13.1% vs 30.5%, P < .001).

CONCLUSIONS

Although MAG use increased over time, barriers to routine use remain. In surgeons who reported routine use, only 21% of their patients received MAGs. Hospital protocols, education, and increased awareness may reduce barriers to use and encourage evidence-based clinical practice.

Impact of Second Arterial Conduit on Outcomes Following Coronary Bypass Grafting

BACKGROUND

The aim of this study was to compare short-term outcomes and long-term survival in patients following coronary artery bypass grafting in whom second arterial conduit or saphenous vein was used as well as to find out the most optimal second arterial graft.

METHODS

Between January 2006 and June 2018, 7,857 patients met the inclusion criteria and were divided into two groups: single internal thoracic artery (SITA) + Vein group (n = 7,140) and second arterial conduit group (n = 717), of these 537 patients received right internal thoracic artery (RITA) and 180 patients received radial artery (RA). We obtained 701 propensity-matched pairs for final comparison. Short-term outcomes included: 30-day mortality and major adverse cardiac and cerebral events (MACCE), reoperation for bleeding, and deep sternal wound infection (DSWI). The long-term outcome was all-cause mortality.

RESULTS

No significant differences were observed between second arterial conduit versus SITA + Vein groups and between RITA versus RA groups in terms of 30-day mortality, 30-day MACCE, reoperation for bleeding, and incidence of DSWI in the matched cohort. The use of second arterial conduit was associated with a significant reduction in long-term mortality by 24% in the matched cohort (hazard ratio [HR]: 0.76; 95% confidence interval [CI]: 0.60-0.96; p = 0.02). RA and RITA as second arterial conduit had comparable long-term mortality (HR: 1.12; 95% CI: 0.69-1.82; p = 0.62).

CONCLUSION

The use of second arterial conduit, irrespective of type, is safe and associated with improved long-term survival compared with the second venous aortocoronary graft.

Unplanned postoperative catheterization during admission for coronary artery bypass grafting is neither cheap nor benign, but may rescue patients

OBJECTIVE

Literature describing outcomes of myocardial ischemia after coronary artery bypass grafting is sparse. We hypothesized these patients had more complications and incurred higher costs of care.

METHODS

Using adult cardiac surgery data and cardiac catheterization (CathPCI) data from the Virginia Cardiac Services Quality Initiative, we identified patients who underwent unplanned cardiac catheterization after coronary artery bypass grafting from 2018 to 2021. Adult cardiac surgery data were matched to CathPCI data examining earliest in-hospital catheterization. Patients not requiring catheterization served as the control group.

RESULTS

We identified 10,597 patients who underwent isolated coronary artery bypass grafting, of whom 41 of 10,597 underwent unplanned cardiac catheterization. A total of 21 of 41 patients (51%) received percutaneous coronary intervention, most commonly for non-ST-elevation myocardial infarction (n = 7, 33%) and ST-elevation myocardial infarction (n = 6, 29%). Postoperative cardiac arrest occurred in 14 patients (40%). In patients who underwent percutaneous coronary intervention, 14 (67%) had a single lesion, 4 (19%) had 2 lesions, and 3 (14%) had 3 lesions. The left anterior descending artery (38%) was the most frequently intervened upon vessel. Patients who underwent catheterization were more likely to require balloon pump support (26% vs 11%), to have prolonged ventilation (57% vs 20%), to have renal failure (17% vs 7.1%), and to undergo reintubation (37% vs 3.8%, all P < .04). There was no statistical difference in operative mortality (4.9% vs 2.3%, P = .2) or failure to rescue (4.9% vs 1.6%, P = .14). Total costs were higher in patients who underwent unplanned catheterization ($81,293 vs $37,011, P < .001).

CONCLUSIONS

Unplanned catheterization after coronary artery bypass grafting is infrequent but associated with more complications and a higher cost of care. Therefore, determination of an association with operative mortality in patients with suspected ischemia after coronary artery bypass grafting requires additional study.

Prognostic Value of Systemic Immune-Inflammation Index in Predicting Premature Saphenous Vein Graft Disease in Patients With Coronary Artery Bypass Grafting

BACKGROUND

Systemic inflammation is a risk factor for premature coronary artery disease (CAD), and systemic immune-inflammation index (SII), a new marker of systemic inflammation, is linked to the severity and prognosis of CAD. However, the prognosis of the SII in bypass patients' venous saphenous grafts has not been adequately evaluated. This study aimed to evaluate the prognostic value of SII in predicting premature saphenous vein graft disease (SVGD) in patients who underwent bypass surgery with venous saphenous grafts.

METHODS

We retrospectively included 422 patients who had saphenous vein grafts (SVG) at least one year after bypass surgery. Of these, 222 patients had SVGD, and 200 had patent SVG.

RESULTS

SII was higher in the SVGD group than in the control group (631.55 ± 397.84, 421.71 ± 351.07, P=0.001). A receiver operating characteristic (ROC) analysis was performed to identify the optimal cutoff point with the highest sensitivity and specificity. The optimal cutoff point for SII was defined as 430. Using a cutoff level of >430, SII predicted SVGD with a sensitivity of 73% and specificity of 56%.

CONCLUSION

Our study demonstrated that SII was substantially higher in patients with SVGD than in those with patent SVG. SII predicted SVGD in bypass surgery patients. SII may be a helpful parameter for identifying patients at high risk of SVGD and guiding preventive treatments.

Relationship between systemic immune-inflammation index and no-reflow in percutaneous coronary intervention for saphenous grafts

Objective: In this study, we investigated the occurrence of no-reflow (NR) in percutaneous coronary intervention (PCI) for saphenous vein grafts (SVGs) and its relationship with a new systemic immune-inflammation index (SII) that determines inflammation. Methods: We studied 303 patients with acute coronary syndrome without ST elevation who underwent PCI for SVG disease. Results: NR formation during SVG PCI was significantly higher in patients with high SII (p < 0.001). NR occurrence was 12.8% when SII was ≤548 and 41.9% when SII was >548. Conclusion: Our study is the first to investigate SII as the state of inflammation and its effect on the SVG PCI. Patients with higher SII have a higher risk of NR during an SVG for PCI.

A Contemporary Review of Antiplatelet Therapies in Current Clinical Practice

Antiplatelet therapy plays a crucial role in a number of cardiovascular disorders. We currently have a range of antiplatelet agents in our armamentarium. In this review, we aim to summarise the common antiplatelet agents currently available, and their use in clinic practice. We not only highlight recent trials exploring antiplatelet therapy in atherosclerotic cardiovascular disease, but also in trials related to transcatheter aortic valve implantation and coronavirus disease 2019. Inevitably, the antithrombotic benefits of these drugs are accompanied by an increase in bleeding complications. Therefore, an individualised approach to weighing each patient's thrombotic risk versus bleeding risk is imperative, in order to improve clinical outcomes.

Pathophysiology and management of saphenous vein graft disease

INTRODUCTION

The saphenous vein graft (SVG) is the most used conduit in CABG. With standardization of its use as a conduit came an understanding of its accelerated atherosclerosis, known as saphenous vein graft disease (SVGD). Given its extensive use, a review of the pathophysiology and management of SVGD is important as we optimize its use.

AREAS COVERED

For this review, an extensive literature search was completed to identify and examine the evolution of SVG in CABG, mechanisms driving SVGD, and methods developed to prevent and manage it. This includes a review of relevant major papers and trials in this space.

EXPERT OPINION

Eras of evolution in SVG usage in CABG include an experimental era, era of SVG dominance in CABG, and the current era of mixed venous and arterial grafting. As SVGD was studied, the mechanisms behind it became more understood, and prevention and management methods were developed. As advances in surgical techniques and pharmacotherapy continue to reduce occurrence and severity of SVGD, long-term patency of SV grafts continues to improve and remain excellent in optimized settings. With continued innovation and improvement in operative techniques, the SVG conduit is and will remain an important player in the field of coronary bypass.

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.

Multicentre, randomised, double-blind, parallel controlled trial to investigate timing of platelet inhibition after coronary artery bypass grafting: TOP-CABG trial study

INTRODUCTION

Dual antiplatelet therapy (DAPT), referred to as the combination of aspirin and P2Y12 receptor antagonist (clopidogrel or ticagrelor), potentially improves patency of saphenous vein grafts (SVG) after coronary artery bypass grafting (CABG), while it is further proposed that DAPT potentially increases bleeding risk. Compared with DAPT, de-escalated DAPT (De-DAPT) is an effective antiplatelet strategy for acute coronary syndrome treatment, which significantly reduces the risk of bleeding without increasing the incidence of major adverse cardiovascular events. However, insufficient evidence is available to determine the timing of DAPT after CABG.

METHODS AND ANALYSIS

ETHICS AND DISSEMINATION: The Ethics Committee in Fuwai hospital approved this study (2022-1774). Fifteen centres agreed to participate the TOP-CABG trial, and the study has been approved in these 15 centres by whose ethics committee. The results of the trial will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05380063.

The Role of TGF-β Signaling in Saphenous Vein Graft Failure after Peripheral Arterial Disease Bypass Surgery

Saphenous vein bypass grafting is an effective technique used to treat peripheral arterial disease (PAD). However, restenosis is the major clinical challenge for the graft vessel among people with PAD postoperation. We hypothesize that there is a common culprit behind arterial occlusion and graft restenosis. To investigate this hypothesis, we found TGF-β, a gene specifically upregulated in PAD arteries, by bioinformatics analysis. TGF-β has a wide range of biological activities and plays an important role in vascular remodeling. We discuss the molecular pathway of TGF-β and elucidate its mechanism in vascular remodeling and intimal hyperplasia, including EMT, extracellular matrix deposition, and fibrosis, which are the important pathways contributing to stenosis. Additionally, we present a case report of a patient with graft restenosis linked to the TGF-β pathway. Finally, we discuss the potential applications of targeting the TGF-β pathway in the clinic to improve the long-term patency of vein grafts.

Exploring new insights in coronary lesion assessment and treatment in patients with diabetes mellitus: the impact of optical coherence tomography

In this review, we summarise new insights into diagnostic approaches and treatment strategies for coronary artery disease (CAD) in patients with diabetes mellitus (DM). Despite the improvements in therapy, the clinical management of DM patients remains challenging as they develop more extensive CAD at a younger age and consistently have worse clinical outcomes than non-DM patients. Current diagnostic modalities as well as revascularisation treatments mainly focus on ischemic lesions. However, the impact of plaque morphology and composition are emerging as strong predictors of adverse cardiac events even in the absence of identified ischemia. In particular, the presence of vulnerable plaques such as thin-cap fibroatheroma (TCFA) lesions has been identified as a very strong predictor of future adverse events. This emphasises the need for an approach combining both functional and morphological methods in the assessment of lesions. In particular, optical coherence tomography (OCT) has proven to be a valuable asset by truly identifying TCFAs. New treatment strategies should consist of individualised and advanced medical regimens and may evolve towards plaque sealing through percutaneous treatment.

Resealable Antithrombotic Artificial Vascular Graft Integrated with a Self-Healing Blood Flow Sensor

Coronary artery bypass grafting is commonly used to treat cardiovascular diseases by replacing blocked blood vessels with autologous or artificial blood vessels. Nevertheless, the availability of autologous vessels in infants and the elderly and low long-term patency rate of grafts hinder extensive application of autologous vessels in clinical practice. The biological and mechanical properties of the resealable antithrombotic artificial vascular graft (RAAVG) fabricated herein, comprising a bioelectronic conduit based on a tough self-healing polymer (T-SHP) and a lubricious inner coating, match with the functions of autologous blood vessels. The self-healing and elastic properties of the T-SHP confer resistance against mechanical stimuli and promote conformal sealing of suturing regions, thereby preventing leakage (stable fixation under a strain of 50%). The inner layer of the RAAVG presents antibiofouling properties against blood cells and proteins, and antithrombotic properties, owing to its lubricious coating. Moreover, the blood-flow sensor fabricated using the T-SHP and carbon nanotubes is seamlessly integrated into the RAAVG via self-healing and allows highly sensitive monitoring of blood flow at low and high flow rates (10- and 100 mL min^-1, respectively). Biocompatibility and feasibility of RAAVG as an artificial graft were demonstrated via ex vivo, and in vivo experiment using a rodent model. The use of RAAVGs to replace blocked blood vessels can improve the long-term patency rate of coronary artery bypass grafts.

Current Strategies for Engineered Vascular Grafts and Vascularized Tissue Engineering

Blood vessels not only transport oxygen and nutrients to each organ, but also play an important role in the regulation of tissue regeneration. Impaired or occluded vessels can result in ischemia, tissue necrosis, or even life-threatening events. Bioengineered vascular grafts have become a promising alternative treatment for damaged or occlusive vessels. Large-scale tubular grafts, which can match arteries, arterioles, and venules, as well as meso- and microscale vasculature to alleviate ischemia or prevascularized engineered tissues, have been developed. In this review, materials and techniques for engineering tubular scaffolds and vasculature at all levels are discussed. Examples of vascularized tissue engineering in bone, peripheral nerves, and the heart are also provided. Finally, the current challenges are discussed and the perspectives on future developments in biofunctional engineered vessels are delineated.

Operative Teaching of Coronary Bypass and Need for Repeat Catheterization: Does it Matter Who is Sewing?

OBJECTIVE

There are no studies to date comparing the patency of coronary bypass grafts constructed by attending surgeons versus trainees and the potential consequences of any such disparities. We explored this issue by comparing the patency of individual anastomoses performed by residents versus the attending surgeon.

DESIGN

We reviewed 765 continuous cases performed by a single surgeon which involved at least 1 coronary bypass anastomosis, totaling 2,173 distal anastomoses. At a median follow-up time of 36 months (interquartile range 20.5-47.3), 83 (10.9%) patients had undergone 110 cardiac catheterization procedures after their original operation for various indications. This angiographic information provided the data for our comparison cohorts.

SETTING

Cardiac surgery practice within an academic setting PARTICIPANTS: Adult patient undergoing coronary bypass grafting RESULTS: Of the 83 patients that underwent repeat catheterization, 23 (27.7%) were resident cases, 25 (30.1%) were attending cases and 35 (42.2%) were mixed. There were 4/83 (4.8%) patients with angiographic evidence of internal mammary artery graft compromise of which 3/4 (75%) had been constructed by the attending surgeon. Angiographic evidence of saphenous vein graft compromise was appreciated in 16/83 (19.3%) patients of which 9/16 (56.3%) of the grafts were constructed by the attending surgeon.

CONCLUSIONS

Liberal involvement of surgical trainees as primary operators in coronary revascularization cases led to equivalent rates of postoperative ischemic complications between the attending and resident groups. The outcome equivalence was also maintained when evaluated at the individual anastomosis patency level between the 2 groups. We conclude that academic programs should continue providing trainees significant experience as primary operating surgeons without fear of clinical outcome compromise.

Self-Expanding Versus Balloon Expanding Coronary Stents in Intervention of the Degenerated Saphenous Vein Graft: Memmingen Coronary Artery Bypass Stenosis Trial (MECAST)

Objectives. The aim of this retrospective analysis was to compare the patient outcome after interventional therapy of saphenous vein graft (SVG) stenoses in an all-comers population receiving either self-expanding drug-eluting stents (SExS) or balloon expanding drug-eluting stents (BExS). Background. The interventional therapy of degenerated SVGs remains challenging. Diameter variations of stenotic segments and friable plaques can lead to malapposition and distal embolization with increased major adverse cardiac event (MACE) rates. Methods. 107 patients with a total of 130 SVG interventions were separated into two groups according to either SExS (n = 51) or BExS (n = 56) treatment. Primary endpoint was the MACE rate, which is defined as the composite of cardiac death, myocardial infarction (MI), target vessel (TVR), and target lesion revascularization (TLR) at 30 days and at one-year follow-up. Results. Both patient groups did not differ significantly regarding patient characteristics. The patient outcome was significantly better in the SExS patient group: the MACE rate at 30 days was 1/51 (2.0%) in group SExS vs. 7/56 (12.5%) in group BExS; $p<0.05$ . At one-year follow-up, the MACE rate remained significantly lower in the SExS group 8/51(15.7%) vs. 20/56 (35.7%) in the BExS group, $p<0.02$ . Additionally, cardiac death occurred significantly later within the SExS patient group compared to the BExS group ( $p<0.05$ ). A better overall outcome of patients with de novo SVG-stenosis compared to patients with previous CABG (coronary artery bypass graft) intervention was noted in both groups. Conclusion. Our findings demonstrate that SVG treatment with SExS is safe and provides clinical benefits by comparatively improving short and especially long-term patient outcomes.

Early asymptomatic graft failure in coronary artery bypass grafting: a study based on computed tomography angiography analysis

BACKGROUND

Asymptomatic graft failure after coronary bypass grafting surgery (CABG) may have negative impact on the patients' short- and long-term outcomes. Cardiac computed tomography angiography (CTA) has been proved to be another choice to detect graft failure besides coronary artery angiography in several studies. We aimed to identify the rate and predictors of asymptomatic graft failure detected by CTA before discharge.

METHODS AND RESULTS

A total of 955 grafts of 346 consecutive asymptomatic patients who received CTA examination after CABGs were included in this retrospective study from July 2017 to Dec 2019. We divided 955 grafts into the patent group and occluded group by CTA results. Logistic regression model at graft-level were established to determine predictors of the early asymptomatic graft occlusion. The overall asymptomatic graft failure rate was 4.71% (45/955), and there was no difference between the arterial and venous conduits in different target territories (P > 0.05). The logistic regression at graft-level analysis showed that female (OR 3.181, CI 1.58-6.40, P = 0.001), composite grafting (OR 6.762, CI 2.26-20.28, P = 0.001), pulse index value (OR 1.180, CI 1.08-1.29, P < 0.001) and new postoperative atrial fibrillation (POAF) (OR2.348, CI 1.15-4.78, P = 0.018) were independent risk factors that affect graft failure, while early postoperative dual-antiplatelet treatment with aspirin and clopidogrel was a protective factor (OR 0.403, CI 0.19-0.84, P = 0.015).

CONCLUSIONS

Early asymptomatic graft failure is associated with both patient and surgical factors including female gender, high PI value, composite graft strategy and the new POAF. However, the early dual- antiplatelet therapy with aspirin and clopidogrel may be useful for preventing graft failure.

Symptomatic late saphenous vein graft failure in coronary artery bypass surgery

OBJECTIVES

Coronary artery bypass grafting for advanced coronary artery disease is a well-established procedure with excellent long-term results. The issue of saphenous vein graft (SVG) performance and its relation to clinical symptoms and thereby the potential for improvement by using superior grafts are still not fully understood. We aim to estimate the contribution of late SVG failure to the long-term outcome.

METHODS

A study population operated between 1997 and 2020, with an internal thoracic artery with a single distal anastomosis and 1, 2 or 3 distal SVG anastomoses, was isolated from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry. Data regarding postoperative clinically driven coronary angiography and status of bypass grafts were collected.

RESULTS

The study population consisted of 44 951 patients. Clinically driven angiography occurred in 10.1% (9.5-10.8), 7.9% (7.6-8.3) and 7.1% (6.7-7.5), respectively, of patients within 3 years and 23.6% (22.6-24.5), 20.0% (19.5-20.6) and 17.5% (16.9-18.2), respectively, of patients within 10 years after surgery. Excluding the first 3 postoperative years, no failed SVGs were found in >75%, 60% and 45%, respectively, of cases when an angiography was performed in the first 10 years after surgery.

CONCLUSIONS

The results suggest that the risk of symptomatic graft failure due to vein graft disease during the first 10 years after surgery is in the range of 1-2% for every grafted coronary vessel and provide an estimate for the upper limit of the improvements in results that could be achieved by replacing SVGs with superior grafts.