Association of Radial Artery Graft vs Saphenous Vein Graft With Long-term Cardiovascular Outcomes Among Patients Undergoing Coronary Artery Bypass Grafting: A Systematic Review and Meta-analysis

Off-pump vs. on-pump coronary artery bypass grafting in patients with chronic kidney disease: an updated systematic review and meta-analysis

BACKGROUND

In patients with chronic kidney disease (CKD), cardiovascular disease is found to be the primary cause of mortality, and after coronary artery bypass grafting (CABG), their prognosis deteriorates.

METHODS

We conducted a meta-analysis comparing off-pump CABG versus on-pump CABG in CKD patients. We searched electronic databases, including PubMed, Cochrane, and Google Scholar, using relevant keywords. We included studies comparing off-pump CABG with on-pump CABG in patients with chronic kidney disease, which was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m2. Effect estimates were synthesized using a random-effects model and expressed as risk ratios (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, with corresponding 95% confidence intervals (CIs). Our primary outcome was short-term mortality.

RESULTS

A total of 25 studies, of which 23 were observational and 2 were RCTs, were included in this meta-analysis, comprising 234,585 patients (66,591 in the off-pump group and 167,994 in the on-pump group). Our meta-analysis showed that there was a significantly higher mortality rate in the on-pump CABG group as compared to the off-pump CABG group (RR: 0.73, 95% CI [0.61, 0.88]; P = 0.0006, I2 = 60%).

CONCLUSION

Compared with OPCAB, short-term mortality was significantly higher in ONCAB.

Superior Outcomes of Dual-Arterial Coronary Artery Bypass Grafting Are Maintained in the Veterans Health Administration

INTRODUCTION

Controversy surrounds the long-term clinical benefit of coronary artery bypass grafting (CABG) using dual arterial grafts (DAGs) compared to single arterial grafts (SAGs). We investigated outcomes of DAG, using single internal thoracic artery and radial artery (DAG-RA) or bilateral internal thoracic artery grafts (DAG-BITA), compared to SAG, using the left internal thoracic artery and saphenous vein grafts, in the U.S. Veterans Health Administration (VA).

METHODS

We conducted a cross-sectional study of U.S. Veterans undergoing isolated on-pump CABG between 2005 and 2015 at 44 VA medical centers. The primary composite outcome was first occurrence of a major adverse cardiac and cerebrovascular event (MACCE), comprised of death from any cause, myocardial infarction, stroke, or repeat revascularization.

RESULTS

Among 25,969 Veterans undergoing isolated CABG, 1261 (4.9%) underwent DAG (66.8% DAG-RA and 33.2% DAG-BITA). Over a 5-y follow-up, DAG was associated with lower rates of all-cause death (adjusted hazard ratio [AHR] 0.70, 95% confidence interval [CI] 0.58-0.85), MACCE (AHR 0.80, 95% CI 0.71-0.91), and stroke (AHR 0.74, 95% CI 0.57-0.96) versus SAG. DAG-BITA was associated with lower rates of all-cause death (AHR 0.52, 95% CI 0.35-0.77) and MACCE (AHR 0.66, 95% CI 0.51-0.84) than SAG, while DAG-RA was associated with lower rates of all-cause death (AHR 0.79, 95% CI 0.64-0.99).

CONCLUSIONS

In the VA, DAG was associated with improved long-term MACCE outcomes compared to SAG. These results suggest that the practice of DAG in the VA benefits Veterans and should be promoted further.

Left ventricular recovery after total arterial coronary artery bypass grafting versus conventional coronary artery bypass grafting in patients with multivessel coronary artery disease and reduced left ventricular ejection fraction

BACKGROUND

We compared total arterial revascularization (TAR) versus conventional revascularization (CR) in terms of left ventricular function recovery in patients with multivessel coronary artery disease (CAD) and reduced left ventricular ejection fraction (LVEF).

METHODS

We conducted a retrospective cohort study of 162 consecutive patients with multivessel CAD and reduced LVEF who underwent isolated coronary artery bypass grafting at our institution between January 2013 and July 2022. We assessed left ventricular function by transthoracic echocardiography at admission, before discharge, and at follow-up of 3, 6, and 12 months, using LVEF, global longitudinal peak strain, end-diastolic volume index, and end-systolic volume index. We also evaluated mitral valve regurgitation and graft patency rate at 1 year.

RESULTS

The TAR group had a significantly higher increase in LVEF and global longitudinal peak strain, and a significantly lower decrease in end-diastolic volume index and end-systolic volume index than the CR group at 6 and 12 months after surgery. The TAR group also had a significantly lower degree of mitral valve regurgitation than the CR group at all-time points within 12 months after surgery. The TAR group had a significantly higher graft patency rate than the CR group at 12 months. There was no significant difference in hospital mortality or repeat revascularization between the groups.

CONCLUSIONS

TAR was associated with better recovery of left ventricular function than CR in patients with multivessel CAD and reduced LVEF. Further studies are needed to confirm these findings in this high-risk population.

Coronary Artery Bypass Graft Failure in Women: Incidence and Clinical Implications

BACKGROUND

Women have worse outcomes after coronary artery bypass surgery (CABG) than men.

OBJECTIVES

This study aimed to determine the incidence of CABG graft failure in women, its association with cardiac events, and whether it contributes to sex-related differences in outcomes.

METHODS

A pooled analysis of individual patient data from randomized clinical trials with systematic imaging follow-up was performed. Multivariable logistic regression models were used to assess the association of graft failure with myocardial infarction and repeat revascularization between CABG and imaging (primary outcome) and death after imaging (secondary outcome). Mediation analysis was performed to evaluate the effect of graft failure on the association between female sex and risk of death.

RESULTS

Seven randomized clinical trials (N = 4,413, 777 women) were included. At a median imaging follow-up of 1.03 years, graft failure was significantly more frequent among women than men (37.3% vs 32.9% at the patient-level and 20.5% vs 15.8% at the graft level; P = 0.02 and P < 0.001, respectively). In women, graft failure was associated with an increased risk of myocardial infarction and repeat revascularization (OR: 3.94; 95% CI: 1.79-8.67) and death (OR: 3.18; 95% CI: 1.73-5.85). Female sex was independently associated with the risk of death (direct effect, HR: 1.84; 95% CI: 1.35-2.50) but the association was not mediated by graft failure (indirect effect, HR: 1.04; 95% CI: 0.86-1.26).

CONCLUSIONS

Graft failure is more frequent in women and is associated with adverse cardiac events. The excess mortality risk associated with female sex among CABG patients is not mediated by graft failure.

Application of the radial artery after angiography in patients undergoing total arterial coronary revascularization

OBJECTIVE

There is growing evidence supporting the utilization of the radial artery as a secondary arterial graft in coronary artery bypass grafting (CABG) surgery. However, debates continue over the recovery period of the radial artery following angiography. This study aims to evaluate the clinical outcomes and experiences related to the use of the radial artery post-angiography in total arterial coronary revascularization.

METHODS

A retrospective analysis was performed on data from patients who underwent total arterial CABG surgery at the University of Hong Kong Shenzhen Hospital from July 1, 2020, to September 30, 2022. Preoperative assessments included ultrasound evaluations of radial artery blood flow, diameter, intimal integrity, and the Allen test. Additionally, pathological examinations of the distal radial artery and coronary artery CT angiography were conducted, along with postoperative follow-up to assess the safety and efficacy of using the radial artery in patients undergoing total arterial CABG.

RESULTS

A total of 117 patients, compromising 102 males and 15 females with an average age of 60.0 ± 10.0 years, underwent total arterial CABG. The internal mammary artery was used in situ in 108 cases, while in 4 cases, it was grafted to the ascending aorta due to length limitations. Bilateral radial arteries were utilized in 88 patients, and bilateral internal mammary arteries in 4 patients. Anastomoses of the proximal radial arteries to the proximal ascending aorta included 42 cases using distal T-anastomosis and 4 using sequential grafts. The interval between bypass surgery and coronary angiography ranged from 7 to 14 days. Pathological examination revealed intact intima and continuous elastic membranes with no significant inflammatory infiltration or hyperplastic lumen stenosis in the radial arteries. There were no hospital deaths, 3 cases of perioperative cerebral infarction, 1 secondary thoracotomy for hemorrhage control, 21 instances of intra-aortic balloon pump (IABP) assistance, and 2 cases of poor wound healing that improved following debridement. CT angiography performed 2 weeks post-surgery showed no internal mammary artery occlusions, but 4 radial artery occlusions were noted.

CONCLUSION

Ultrasound may be used within 2 weeks post-angiography to assess the recovery of the radial artery in some patients. Radial arteries with intact intima may be considered in conjunction with the internal mammary artery for total arterial coronary CABG. However, long-term outcomes of these grafts require further validation through larger prospective studies.

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.

Comparison of Arterial and Venous Interposition Grafting for Arterial Defects in a Rat Model

BACKGROUND

 Interposition microvascular grafting may be required to bridge arterial defects during digital replantation or revascularization and has traditionally been performed utilizing a venous autograft. Arterial interposition grafting has been shown to be superior in maintaining patency in large vessel surgery; there are case reports of its use in microsurgery.

METHODS

 Six fellowship-trained hand and microsurgeons performed arterial and venous interposition grafts on the femoral arteries of 40 Wistar rats. After sectioning one femoral artery a segment of the contralateral femoral artery or vein was obtained. The time was recorded per graft and patency tested 10 minutes following grafting by an independent assessor. Each surgeon also completed a questionnaire detailing regular microsurgical volume, technical ease, and conceptual preference for either graft.

RESULTS

 Time for arterial interposition (median time 51.7 minutes) was longer than venous grafting (median time 45.9 minutes, p = 0.075). Arterial grafts were more likely to be patent or questionably patent (odds ratio [OR] = 6.77, p = 0.031). All surgeons found arterial interposition grafting technically easier and preferred it conceptually. Improvements were noted in patency rates (OR = 11.29, p = 0.018) and avoidance of anastomotic leak (OR = 0.19, p = 0.029) when surgeons performed moderate levels or greater of microsurgery within their regular practice.

CONCLUSION

 Greater immediate patency was noted with arterial interposition grafting in a rodent model when compared to venous grafting, although procedural time was greater. All surgeons found arterial grafting technically easier. Arterial microvascular grafting may be useful in the setting of digital replantation or revascularization with an arterial defect.

Quality improvement initiative to increase radial artery usage as a second arterial conduit in coronary artery bypass grafting

OBJECTIVES

Use of radial artery as a second arterial graft, compared to a saphenous vein, in coronary artery bypass grafting (CABG) can improve late outcomes. However, the radial artery remains underutilized. We initiated a quality improvement (QI) initiative to increase the usage of radial artery grafts.

METHODS

During our 4-month lead period, we disseminated evidence for radial artery graft usage to surgeons, developed a radial artery decision-making algorithm and adopted endoscopic harvesting. Our QI initiative was conducted over a 6-month period and included a postoperative survey of decision-making for graft selection and obstacles to radial artery usage.

RESULTS

Over the 6-month study period, 247 patients received isolated CABG which included 98 (40%) with radial arteries as a second arterial graft and 144 (58%) with greater saphenous veins. Radial artery usage increased with QI initiative implementation by 67% compared to 6 months prior to the study period (60 radial arteries/252 isolated CABG, 24%) (P = 0.006). The survey response rate was 93% (231/247). Barriers to radial artery graft usage were poor quality target vessel or stenosis <80% (24%), patient age >75 years (20%), ejection fraction ≤35% (8%) and renal insufficiency/dialysis (7%). No patients experienced significant complications from radial artery harvest.

CONCLUSIONS

Our institutional QI initiative was successful in (i) increasing the usage of radial artery as a second arterial graft and (ii) understanding barriers to radial artery graft usage. Implementation of a QI program can improve radial artery usage in CABG with low risk of patient morbidity from radial artery harvest.

Transient time flow measurement in arterial grafts

Coronary artery bypass grafting (CABG) is one of the foundations of treatment for coronary artery disease. While it has improved substantially since its inception more than 50 years ago, including a rising use of multiple arterial grafting, intraoperative quality assessment is yet to be disseminated as an integral part of the procedure. Herein we review the fundamentals of intraoperative quality assessment in CABG using transient time flow measurement (TTFM) with a focus on its use in arterial grafting.

Multiarterial vs Single-Arterial Coronary Surgery: 10-Year Follow-up of 1 Million Patients

BACKGROUND

Although many options exist for multivessel coronary revascularization, controversy persists over whether multiarterial grafting (MAG) confers a survival advantage over single-arterial grafting (SAG) with saphenous vein in coronary artery bypass grafting (CABG). This study sought to compare longitudinal survival between patients undergoing MAG and those undergoing SAG.

METHODS

All patients undergoing isolated CABG with ≥2 bypass grafts in The Society of Thoracic Surgeons Adult Cardiac Surgery Database (2008-2019) were linked to the National Death Index. Risk adjustment was performed using inverse probability weighting and multivariable modeling. The primary end point was longitudinal survival. Subpopulation analyses were performed and volume thresholds were analyzed to determine optimal benefit.

RESULTS

A total of 1,021,632 patients underwent isolated CABG at 1108 programs (100,419 MAG [9.83%]; 920,943 SAG [90.17%]). Median follow-up was 5.30 years (range, 0-12 years). After risk adjustment, all characteristics were well balanced. At 10 years, MAG was associated with improved unadjusted (hazard ratio, 0.59; 95% CI 0.58-0.61) and adjusted (hazard ratio, 0.86; 95% CI, 0.85-0.88) 10-year survival. Center volume of ≥10 MAG cases/year was associated with benefit. MAG was associated with an overall survival advantage over SAG in all subgroups, including stable coronary disease, acute coronary syndrome, and acute infarction. Survival was equivalent to that with SAG for patients age ≥80 years and those with severe heart failure, renal failure, peripheral vascular disease, or obesity. Only patients with a body mass index ≥40 kg/m2 had superior survival with SAG.

CONCLUSIONS

Multiarterial CABG is associated with superior long-term survival and should be the surgical multivessel revascularization strategy of choice for patients with a body mass index of less than 40 kg/m2.

Statistical primer: individual patient data meta-analysis and meta-analytic approaches in case of non-proportional hazards

Individual patient data (IPD) meta-analyses build upon traditional (aggregate data) meta-analyses by collecting IPD from the individual studies rather than using aggregated summary data. Although both traditional and IPD meta-analyses produce a summary effect estimate, IPD meta-analyses allow for the analysis of data to be performed as a single dataset. This allows for standardization of exposure, outcomes, and analytic methods across individual studies. IPD meta-analyses also allow the utilization of statistical methods typically used in cohort studies, such as multivariable regression, survival analysis, propensity score matching, uniform subgroup and sensitivity analyses, better management of missing data, and incorporation of unpublished data. However, they are more time-intensive, costly, and subject to participation bias. A separate issue relates to the meta-analytic challenges when the proportional hazards assumption is violated. In these instances, alternative methods of reporting time-to-event estimates, such as restricted mean survival time should be used. This statistical primer summarizes key concepts in both scenarios and provides pertinent examples.

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.

Outcomes of Radial Artery Versus Saphenous Vein as A Second Conduit After Coronary Artery Bypass Grafting

Despite the advantages of multiarterial grafting, saphenous vein (SV) configurations predominate in coronary artery bypass grafting (CABG). In addition, the benefits of radial artery (RA) utilization in multivessel CABG remain unclear. This study aims to compare the clinical outcomes of patients who received RA grafts during CABG with those of patients who received SV grafts. A retrospective, single-institution cohort study was performed in 8,774 adults who underwent isolated CABG surgery with multiple grafts between 2010 and 2022. To balance graft cohorts, propensity score matching (PSM) was performed using a 1:2 (RA/SV) match ratio. Long-term postoperative survival was compared in RA and SV graft groups. Similarly, major adverse cardiac and cerebrovascular event (MACCE) rates were compared in the cohorts, with MACCE comprising death, myocardial infarction (MI), coronary revascularization, and stroke. Kaplan-Meier estimation was performed for both mortality and MACCE. A total of 7,218 patients (82.3%) who underwent multivessel CABG were included in this analysis. Of these patients, 341 (4.7%) received RA grafts, and 6,877 (95.3%) received SV grafts secondary to left internal mammary artery use. PSM yielded a cohort of 335 patients with RA and 670 patients with SV. After matching, groups were well balanced across all baseline variables. No significant differences were observed in either immediate postoperative morbidities or long-term survival. However, Kaplan-Meier estimates of long-term postoperative freedom from MACCE were significantly greater in matched patients with SV (73.3%) than in those with RA (67.4%) (p = 0.044, cluster log-rank), with patients with SV also possessing significantly greater freedom from coronary revascularization and MI. In conclusion, RA and SV secondary conduits for CABG were associated with comparable immediate postoperative complications and long-term survival after PSM. SV grafting was associated with significantly decreased rates of postoperative MACCE, likely owing to lower rates of coronary revascularization and MI than in RA grafting.

How to Omit the Potential Pitfalls in Distal Radial Access: Lessons From Cadaveric and CTA Analysis

OBJECTIVES

To verify the anatomical basis, ideal puncture sites, and potential pitfalls of the distal radial artery (dRA) in the anatomical snuffbox region for distal radial access (dTRA).

MATERIALS AND METHODS

Overall, 26 formalin-fixed upper limbs and computed tomography angiography (CTA) of the upper limbs of 168 consecutive patients were studied. Cadaveric dissection and dRA 3D reconstruction were used to evaluate the dRA route for dTRA. The puncture sites, dRA diameter, and angle of the dRA and tendons of the extensor pollicis brevis were also measured in the patients and cadavers.

RESULTS

The cadaver dissection provided more insights than did the dRA 3D reconstruction. However, preoperative evaluation had better diagnostic accuracy (p=0.024). Puncture sites 1 and 3 had a high success rate (63.2% possible success rate, 191/302). The DISFAVOR theory was put forward, in which 8 types of potential pitfalls that may interrupt puncture procedure or lead to a surgical failure were observed, including occlusion, stenosis, tortuosity, arteriovenous fistula, angioma, different radial artery (RA) ramifications, radial veins, and cephalic veins. The mean diameter of dRA based on cadaver dissection and CTA was 2.53 (SD=0.73) and 2.63 (SD=0.69) mm, respectively. Furthermore, the minimum distance from the outer layer of dRA to the skin was 5.71 (SD=2.0) mm based on CTA. The angle between the dRA and tendons of extensor pollicis brevis (TEPB) based on cadaver dissection and CTA was 58.0° (SD=21.5°) and 51.8° (SD=16.6°), respectively.

CONCLUSIONS

Puncture sites 1 and 3 were more suitable for the dTRA, and we put forward the DISFAVOR theory to summarize the 8 types of potential pitfalls during the use of dTRA.

Effectiveness and Safety of Left Distal Transradial Access in Coronary Procedures in the Caribbean

INTRODUCTION

This retrospective study investigated the effectiveness and safety of left distal transradial access (LDTRA) in patients with cardiovascular disease in Trinidad undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI).

METHOD

Procedural parameters, including technical success and safety outcomes such as vascular complications and radial artery occlusion (RAO), were assessed in 111 consecutive patients undergoing CAG or PCI from January 2023 to June 2023 at the Eric Williams Medical Sciences Complex, Trinidad and Tobago. Eighty-eight patients underwent LDTRA, while 23 received left transradial access (LTRA).

RESULTS

There was no difference in procedural success with LDTRA compared to LTRA, 90.9% vs. 100%, p-value 0.202, non-significant (ns). LDTRA was associated with shorter fluoroscopy times (8.4 ± 6.8 minutes vs. 12.4 ± 7.7 minutes, p-value = 0.02), procedural duration (26.7 ± 18 minutes vs. 35.8 ± 20 minutes, p-value = 0.04), and hemostasis time (142 ± 41 minutes vs. 186 ± 44 minutes, p-value < 0.05). There were no significant differences in procedural-related complications (8% for LDTRA vs. 4.3% for LTRA, p-value = 0.476, ns). There were no reported cases of RAO. In the subgroup of patients with prior coronary artery bypass grafting (CABG), the fluoroscopy and procedure times were similar for both access sites; however, LDTRA was associated with a shorter hemostasis time (128 ± 30 minutes vs. 194 ± 39 minutes, p-value = 0.01).

CONCLUSIONS

LDTRA is effective and safe for coronary procedures and is associated with a shorter hemostasis time. This study may prove clinically pertinent in a limited-resource Caribbean setting.

Percutaneous Coronary Intervention With a Drug-Eluting Stent Versus Coronary Artery Bypass Grafting in Patients Receiving Dialysis: A National Study From Taiwan

Rationale & Objective

We aimed to study the comparative effectiveness of percutaneous coronary intervention with drug-eluting stent and coronary artery bypass grafting in patients receiving dialysis.

Study Design

This was a retrospective observational cohort study.

Setting & Participants

This population-based study identified patients receiving dialysis hospitalized for coronary revascularization between January 1, 2009 and December 31, 2015, in the Taiwan National Health Insurance Research Database.

Exposures

Patients received percutaneous coronary intervention with drug-eluting stent versus coronary artery bypass grafting.

Outcomes

The study outcomes were all-cause mortality, in-hospital mortality, and repeat revascularization.

Analytical Approach

Propensity scores were used to match patients. Cox proportional hazards models and logistic regression models were constructed to examine associations between revascularization strategies and mortality. Interval Cox models were fitted to estimate time-varying hazards during different periods.

Results

A total of 1,840 propensity score-matched patients receiving dialysis were analyzed. Coronary artery bypass grafting was associated with higher in-hospital mortality (coronary artery bypass grafting vs percutaneous coronary intervention with drug-eluting stent; crude mortality rate 12.5% vs 3.3%; adjusted OR, 5.22; 95% CI, 3.42-7.97; P < 0.001) and longer hospitalization duration (median [IQR], 20 [14-30] days vs 3 [2-8] days; P < 0.001). After discharge, repeat revascularization, acute coronary syndrome, and repeat hospitalization all occurred more frequently in the percutaneous coronary intervention with drug-eluting stent group. Importantly, with a median follow-up of 2.8 years, coronary artery bypass grafting was significantly associated with a higher risk of all-cause overall mortality (adjusted HR, 1.19; 95% CI, 1.05-1.35; P = 0.006) in the multivariable Cox proportional hazard model. Sensitivity and subgroup analyses yielded consistent results.

Limitations

This was an observational study with mainly Asian ethnicity.

Conclusions

Percutaneous coronary intervention with drug-eluting stent may be associated with better survival than coronary artery bypass grafting in patients receiving dialysis. Future studies are warranted to confirm this finding.

Less Invasive and Hybrid Surgical/Interventional Coronary Disease Management: The Future Is Now

Coronary artery bypass grafting (CABG) has evolved to become the criterion standard in elective revascularisation for coronary artery disease (CAD), particularly in patients with complex or multivessel CAD, left main involvement, diabetes mellitus, or left ventricular dysfunction. Despite the superiority of CABG in patients with the most advanced forms of CAD, a standard CABG operation, through a median sternotomy and with the use of cardiopulmonary bypass, carries well recognised challenges. In this article, we describe newer approaches, such as off-pump CABG, minimally invasive bypass grafting, robotic CABG, and hybrid coronary revascularisation, which we consider as necessary ways to minimise invasion, reduce recovery time, provide the benefits of arterial grafting to more patients, and offer alternatives to mitigate the adverse effects of conventional sternotomy and cardiopulmonary bypass.

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.

Designing the coronary artery bypass surgery operation of the future

PURPOSE OF REVIEW

This article discusses current shortcomings in coronary artery bypass surgery and ways to overcome them.

RECENT FINDINGS

Minimally invasive coronary bypass surgery, robotic coronary bypass, and hybrid approaches aim to avoid sternotomy, employ arterial grafts, and minimize the use of cardiopulmonary bypass. Other considerations such as bypass graft validation, the optimization of guideline-directed medical therapy, and the development of coronary surgery specialists are also crucial to further the benefits of coronary artery bypass grafting on future patients.

SUMMARY

Coronary artery bypass grafting must become less invasive, be better validated, and be carried out with an even higher emphasis on quality, including graft validation and preoperative/postoperative optimization, if it is to remain the best treatment for advanced, severe coronary artery disease.

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.

Sex differences in coronary artery bypass graft surgery outcomes: a narrative review

Background and Objective

Coronary artery bypass grafting (CABG) is the most commonly performed cardiac surgery globally and in the United States, however, women have worse outcomes than men. We aim to examine the possible drivers of this sex difference in CABG outcomes.

Methods

A narrative review using a current search of the most recent literature on this topic.

Key Content and Findings

The sex difference in outcomes after CABG has persisted despite advances in the field, with women having well-described worse operative mortality and morbidity than men. Several explanatory mechanisms have been proposed for these differences. These include, but are not limited to, preoperative factors such as the natural history of coronary artery disease in women, older age, and higher prevalence of comorbidities at the time of presentation for CABG surgery. Intraoperative factors have also been proposed to play a role, including the smaller coronary artery size and greater coronary artery reactivity in women, the degree of intraoperative hemodilution anemia, the type of grafting, and the completeness of revascularization. However, no definitive etiology has been identified to date.

Conclusions

The sex difference in outcomes after CABG remains present, and despite numerous proposed etiopathologies, the main driver remains unclear. Further research is needed to identify, and address, the root cause of this difference, and greater participation of women in cardiovascular and cardiac surgery trials is crucial.

Risk factors for major adverse cardiovascular events after coronary artery bypass grafting using radial artery grafts

Background

Coronary artery bypass grafting using radial artery grafts (RA-CABG) has improved long-term outcomes. However, major adverse cardiovascular events (MACE-4, including all-cause death, myocardial infarction, stroke, and repeat revascularization) after RA-CABG still occur and the predictors remain uncertain. This study aimed to detect independent risk factors of MACE-4 after RA-CABG.

Methods

This is a retrospective case-control study (NCT04935086) conducted among patients who underwent primary isolated RA-CABG between 2009 and 2019 in our center. Baseline characteristics, procedure characteristics, and medication use were compared to identify the independent predictors of MACE-4, all-cause death, and myocardial infarction (MI) with univariate and then multivariate logistic regression.

Results

A total of 370 patients were analyzed using a mean follow-up duration of 48.8 ± 41.0 months. MACE-4, all-cause death, and MI occurred in 102 (27.6%), 27 (7.3%), and 66 patients (17.8%), respectively. Multivariate analysis revealed prior MI (OR = 2.12, 95%CI 1.05-4.25, P = 0.04) and RA to the left anterior descending artery (LAD) (non-left internal mammary artery to LAD) (OR = 4.87, 95%CI 1.41-16.82, P = 0.01) as independent predictors of MACE-4 after surgery. Female (OR = 4.53, 95%CI 1.06-19.41, P = 0.04), left ventricular ejection fraction (LVEF) <40% (OR = 21.00, 95%CI 1.20-368.35, P = 0.04), and RA to LAD (OR = 8.55, 95%CI 1.35-54.10, P = 0.02) were independent predictors of all-cause death. Prior MI (OR = 3.11, 95%CI 1.40-6.94, P = 0.006) emerged as an independent predictor of MI.

Conclusion

Our data suggested that prior MI and RA to LAD were independent predictors of MACE-4 after RA-CABG. Being female, having an LVEF < 40% and RA to LAD indicated death. Prior MI indicated new MI.

Endothelial RIPK1 protects artery bypass graft against arteriosclerosis by regulating SMC growth

RIPK1 is crucial in the inflammatory response. The process of vascular graft remodeling is also involved in endothelial inflammation, which can influence the behavior of smooth muscle cells. However, the role of endothelial RIPK1 in arterial bypass grafts remains unknown. Here, we established an arterial isograft mouse model in wild-type and endothelial RIPK1 conditional knockout mice. Progressive vascular remodeling and neointima formation occurred in the graft artery, showing SMC accumulation together with endothelial inflammatory adhesion molecule and cytokine expression. Endothelial RIPK1 knockout exacerbated graft stenosis by increasing secretion of N-Shh. Mechanistically, RIPK1 directly phosphorylated EEF1AKMT3 at Ser26, inhibiting its methyltransferase activity and global protein synthesis, which further attenuated N-Shh translation and secretion. Consistently, treatment with the Hedgehog pathway inhibitor GDC0449 markedly alleviated RIPK1 knockout-induced graft stenosis. Our results demonstrated that endothelial RIPK1 played a protective role in arterial bypass graft vascular remodeling, highlighting that targeting Hedgehog pathway may be an attractive strategy for graft failure in the future.

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.

Multiple arterial coronary bypass grafting is associated with better survival compared with second-generation drug-eluting stents in patients with stable multivessel coronary artery disease

OBJECTIVE

We sought to compare the long-term outcomes of multiarterial graft (MAG) coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (DES) to treat stable multivessel coronary artery disease.

METHODS

This study was a multicenter population-based retrospective analysis of all residents of Ontario, Canada, from January 1, 2011, to December 31, 2019. We identified 3600 cases of elective primary isolated CABG with MAG and 2187 cases of PCI with second-generation DES.

RESULTS

After the application of propensity score-weighting using overlap weights, MAG was associated with better survival over 5 years compared with DES (96.8% vs 94.5%; hazard ratio [HR], 0.56; 95% CI, 0.37-0.85). MAG was also associated with better secondary outcomes including a composite of death, myocardial infarction, and stroke (94.3% vs 88.5%; HR, 0.49; 95% CI, 0.36-0.65). The rate of death, stroke, myocardial infarction, and repeat revascularization (91.2% vs 70.7%; HR, 0.24; 95% CI, 0.20-0.30), and the individual end points of myocardial infarction (1.4% vs 6.9%; HR, 0.22; 95% CI, 0.13-0.35), and repeat revascularization (4.1% vs 24.2%; HR, 0.14; 95% CI, 0.10-0.18) were lower with MAG. PCI with second-generation DES was associated with a lower rate of stroke up to 5 years (0.6% vs 1.8%; HR, 3.97; 95% CI, 1.45-10.88).

CONCLUSIONS

CABG with MAG was associated with better survival and fewer major cardiac adverse events compared with second-generation DES and might be considered the treatment of choice for patients with stable multivessel coronary artery disease. Further randomized controlled trials are needed to confirm this hypothesis.

Expert systematic review on the choice of conduits for coronary artery bypass grafting: endorsed by the European Association for Cardio-Thoracic Surgery (EACTS) and The Society of Thoracic Surgeons (STS)

PREAMBLE

The finalized document was endorsed by the EACTS Council and STS Executive Committee before being simultaneously published in the European Journal of Cardio-thoracic Surgery (EJCTS) and The Annals of Thoracic Surgery (The Annals) and the Journal of Thoracic and Cardiovascular Surgery (JTCVS).

Conduits and Strategies for Arterial Revascularization in CABG

Ischemic heart disease is the leading cause of death in the United States. Depending on the severity of the coronary artery disease, treatment options include percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). Although CABG has been performed since the 1970s, there is still debate onwhich conduit to use after the left internal thoracic artery. Currently, national registries report the left internal thoracic artery and the saphenous vein as the most commonly used conduits in CABG, while other arterial grafts, such as the radial artery, represent a minority, even though the current evidence suggests potential benefits of these arterial conduits. In this review, we aimed to describe the different types of arterial conduits used for CABG and summarize the evidence behind their use.

Percutaneous coronary intervention versus coronary artery bypass grafting among patients with left ventricular systolic dysfunction: a systematic review and meta-analysis

Current guidelines have shown the superiority of coronary artery bypass grafting (CABG) over medical therapy. However, there is a paucity of data evaluating the optimal revascularization strategy in patients with ischemic left ventricular systolic dysfunction (LVSD).

Objective

The authors aimed to evaluate the clinical outcomes of postpercutaneous coronary intervention (PCI) and CABG among patients with LVSD.

Methods

The authors performed a systematic literature search using the PubMed, Embase, Scopus, and the Cochrane Libraries for relevant articles from inception until 30 November 2022. Outcomes were reported as pooled odds ratio (OR), and their corresponding 95% CI using STATA (version 17.0, StataCorp).

Results

A total of 10 studies with 13 324 patients were included in the analysis. The mean age of patients in PCI was 65.3 years, and 64.1 years in the CABG group. The most common comorbidities included: HTN (80 vs. 78%) and DM (49.2 vs. 49%). The mean follow-up duration was 3.75 years. Compared with CABG, the PCI group had higher odds of all-cause mortality (OR 1.15, 95% CI 1.01-1.31, P=0.03), repeat revascularization (OR 3.57, 95% CI 2.56-4.97, P<0.001), MI (OR 1.92, 95% CI 1.01-3.86, P=0.048) while the incidence of cardiovascular mortality (OR 1.23, 95% CI 0.98-1.55, P=0.07), stroke (OR 0.73 95% CI: 0.51-1.04, P=0.08), major adverse cardiovascular and cerebrovascular events (OR 1.36, 95% CI 0.99-1.87, P=0.06), and ventricular tachycardia (OR 0.79, 95% CI 0.22-2.86, P=0.72) was comparable between both the procedures.

Conclusion

The results of this meta-analysis suggest that CABG is superior to PCI for patients with LVSD. CABG was associated with a lower risk of all-cause mortality, repeat revascularization, and incidence of myocardial infarction compared with PCI in patients with LVSD.

Current concepts in coronary artery revascularisation

Coronary artery revascularisation can be performed surgically or percutaneously. Surgery is associated with higher procedural risk and longer recovery than percutaneous interventions, but with long-term reduction of recurrent cardiac events. For many patients with obstructive coronary artery disease in need of revascularisation, surgical or percutaneous intervention is indicated on the basis of clinical and anatomical reasons or personal preferences. Medical therapy is a crucial accompaniment to coronary revascularisation, and data suggest that, in some subsets of patients, medical therapy alone might achieve similar results to coronary revascularisation. Most revascularisation data are based on prevalently White, non-elderly, male populations in high-income countries; robust data in women, older adults, and racial and other minorities, and from low-income and middle-income countries, are urgently needed.

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.

Extracranial-intracranial bypass surgery for intracranial aneurysm of the anterior cerebral circulation: A systematic review and meta-analysis

Background

The safety of extracranial–intracranial (EC–IC) bypass in the management of anterior circulation intracranial aneurysms (IAs) remains to be determined. This systematic review aims to summarize the existing evidence and provide guidance for the precise management of IAs.

Data source

We constructed search strategies and comprehensively searched Pubmed, Medline, Embase, Web of science, and Cochrane library.

Methods

This systematic review was actualized according to the PRISMA statement. We evaluated study quality using the methodological index for non-randomized study (MINORS). Effect sizes were pooled using a random-effects model. Heterogeneity between studies was assessed using the I2 test. Publication bias was assessed using the Egger's test. The registration number for this systematic review is CRD42023396730.

Result

This systematic review included a total of 21 articles, involving 915 patients. Postoperative bypass patency rate was 99% (95% CI 0.98–1.00); short-term follow-up was 98% (95% CI 0.94–1.00); long-term follow-up was 95% (95% CI 0.93–0.97). The long-term follow-up occlusion rate of saphenous vein was higher than that of radial artery (OR 6.10 95% CI 1.04–35.59). Short-term surgery-related mortality was 0.3% (95% CI 0.000–0.012); long-term follow-up was 0.4% (95% CI 0.000–0.013); The proportion of patients with a score of 0–2 on the modified Rankin Scale (mRS) during long-term follow-up was 92% (95% CI 0.86–0.98). The incidence rates of long-term follow-up complications were: ischemic 3% (95% CI 0.01–0.06); hemorrhagic 1% (95% CI 0.00–0.03); neurological deficit 1% (95% CI 0.00–0.03); other 3% (95% CI 0.01–0.06).

Limitation

Most of the included studies were retrospective studies. Studies reporting preoperative status were not sufficient to demonstrate postoperative improvement. Lack of sufficient subgroup information such as aneurysm rupture status.

Conclusion

EC–IC therapy for anterior circulation IAs has a high safety profile. Higher level of evidence is still needed to support clinical decision.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023396730, identifier: CRD42023396730.

Long-Term Survival of Multiple Versus Single Arterial Coronary Bypass Grafting in Elderly Patients

Multiple arterial grafting (MAG) utilizes more than one arterial graft with any additional grafts being saphenous vein grafts (SVG). It remains an infrequently used coronary surgical revascularization technique, especially in elderly patients. Our study aims to evaluate the age-related association with the relative outcomes of multiple versus single arterial grafting (SAG). The Australian and New Zealand national registry was used to identify adult patients undergoing primary isolated CABG with at least two grafts. Exclusion criteria included reoperations, concomitant or previous cardiac surgery, and the absence of arterial grafting. Propensity score matching was used to match patient groups. The primary outcome was all-cause late mortality and the secondary outcomes were 30-day mortality and 30-day hospital readmission. We selected 69,624 eligible patients with a mean (standard deviation) age of 65.0 (10.2) years old. Matching between MAG and SAG generated 16,882 pairs of patients < 70 years old and 10,921 pairs of patients ≥ 70 years old. At a median [interquartile range] follow-up duration of 5.9 [3.2-9.6] years, MAG was associated with significantly reduced mortality compared to SAG (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.68-0.78; p < 0.001) in the younger subgroup as well as the elderly subgroup (HR, 0.84; 95% CI, 0.79-0.88; p < 0.001). In conclusion, MAG offers a survival benefit over SAG, in both younger and elderly patients.

Late Clinical Outcomes of Total Arterial Revascularization or Multiple Arterial Grafting Compared to Conventional Single Arterial with Saphenous Vein Grafting for Coronary Surgery

Coronary surgery provides better long-term outcomes than percutaneous coronary intervention. Conventional practice is to use a single arterial conduit supplemented by saphenous vein grafts. The use of multiple arterial revascularization (MAG), or exclusive arterial revascularization (TAR), however, is reported as having improved late survival. Survival is a surrogate for graft failure that may lead to premature death, and improved survival reflects fewer graft failures in the non-conventional strategy groups. The reasons for not using MAG or TAR may be due to perceived technical difficulties, a lack of definitive large-scale randomized evidence, a lack of confidence in arterial conduits, or resources or time constraints. Most people consider radial artery (RA) grafting to be new, with use representing approximately 2-5% worldwide, despite select centers reporting routine use in most patients for decades with improved results. In conclusion, the current body of evidence supports more extensive use of total and multiple arterial revascularization procedures in the absence of contraindications.

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.

The Role of Preservation Solutions upon Saphenous Vein Endothelial Integrity and Function: Systematic Review and UK Practice Survey

The long saphenous vein is the most used conduit in cardiac surgery, but its long-term patency is limited by vein graft disease (VGD). Endothelial dysfunction is a key driver of VGD; its aetiology is multi-factorial. However emerging evidence identifies vein conduit harvest technique and preservation fluids as causal in their onset and propagation. This study aims to comprehensively review published data on the relationship between preservation solutions, endothelial cell integrity and function, and VGD in human saphenous veins harvested for CABG. The review was registered with PROSPERO (CRD42022358828). Electronic searches of Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE databases were undertaken from inception until August 2022. Papers were evaluated in line with registered inclusion and exclusion criteria. Searches identified 13 prospective, controlled studies for inclusion in the analysis. All studies used saline as a control solution. Intervention solutions included heparinised whole blood and saline, DuraGraft, TiProtec, EuroCollins, University of Wisconsin (UoW), buffered, cardioplegic and Pyruvate solutions. Most studies demonstrated that normal saline appears to have negative effects on venous endothelium and the most effective preservation solutions identified in this review were TiProtec and DuraGraft. The most used preservation solutions in the UK are heparinised saline or autologous whole blood. There is substantial heterogeneity both in practice and reporting of trials evaluating vein graft preservation solutions, and the quality of existing evidence is low. There is an unmet need for high quality trials evaluating the potential for these interventions to improve long-term patency in venous bypass grafts.

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.

Sirolimus-Embedded Silk Microneedle Wrap to Prevent Neointimal Hyperplasia in Vein Graft Model

We investigated the role of a sirolimus-embedded silk microneedle (MN) wrap as an external vascular device for drug delivery efficacy, inhibition of neointimal hyperplasia, and vascular remodeling. Using dogs, a vein graft model was developed to interpose the carotid or femoral artery with the jugular or femoral vein. The control group contained four dogs with only interposed grafts; the intervention group contained four dogs with vein grafts in which sirolimus-embedded silk-MN wraps were applied. After 12-weeks post-implantation, 15 vein grafts in each group were explanted and analyzed. Vein grafts applied with the rhodamine B-embedded silk-MN wrap showed far higher fluorescent signals than those without the wrap. The diameter of vein grafts in the intervention group decreased or remained stable without dilatation; however, it increased in the control group. The intervention group had femoral vein grafts with a significantly lower mean neointima-to-media ratio, and had vein grafts with an intima layer showing a significantly lower collagen density ratio than the control group. In conclusion, sirolimus-embedded silk-MN wrap in a vein graft model successfully delivered the drug to the intimal layer of the vein grafts. It prevented vein graft dilatation, avoiding shear stress and decreasing wall tension, and it inhibited neointimal hyperplasia.