Radial artery patency and clinical outcomes: five-year interim results of a randomized trial

Sequential Grafting of the Left Internal Thoracic Artery to the Left Anterior Descending Artery and Graft Failure

BACKGROUND

There is concern that left internal thoracic artery (LITA)-to diagonal (D)-to left anterior descending artery (LAD) grafts may be more susceptible to failure compared with single LITA-LAD grafts.

METHODS

Pooled individual patient data from 8 clinical trials with systematic graft imaging were analyzed to assess the incidence of sequential LITA-D-LAD vs single LITA-LAD grafts. Mixed-effects multivariable logistic regression, adjusting for patient characteristics and clustering within trials, was used.

RESULTS

Of 3969 patients with LITA-LAD grafts, 283 patients (7.1%) received sequential LITA-D-LAD grafts. Patients with sequential LITA-D-LAD grafts were older (66 vs 65 years, P = .009) and more often men (88% vs 83%, P = .03). Overall, graft failure occurred in 9.3% of patients with LITA-LAD grafts, with more graft failure occurring in single (9.5%) than in sequential LITA-D-LAD grafts (6.4%, P = .08) at a median time to imaging of 1.0 years (interquartile range, 1.0-1.1 years). After multivariable adjustment, sequential LITA-D-LAD grafting was not associated with graft failure (adjusted odds ratio, 1.22; 95% CI, 0.68-2.18; P = .55). There was no difference between groups in mortality (2.8% vs 5.3%, P = .06), myocardial infarction (1.4% vs 1.6%, P = .90), revascularization (4.5% vs 7.3%, P = .08), or stroke (1.7% vs 1.2%, P = .40).

CONCLUSIONS

In selected patients, LITA-D-LAD grafting was not associated with higher risk of graft failure or adverse clinical events at 1 year.

Coronary Artery Bypass Grafting Using the No-Touch Great Saphenous Vein Graft Harvesting Technique: A Retrospective Study

Background We focused on coronary artery bypass grafting using the great saphenous vein and compared the no-touch great saphenous vein and conventional great saphenous vein. Methods Coronary artery bypass grafting using the great saphenous vein was performed at our hospital over a 15-year period from 2007/04 to 2022/08. The primary endpoint was the patency of the great saphenous vein at discharge, and secondary endpoints were delayed healing of the great saphenous vein harvest wound, delayed healing of the mid-thoracic wound, and factors related to coronary artery bypass surgery. Results There were 183 patients who underwent coronary artery bypass surgery using the great saphenous vein during the study period. There were 131 male patients (72%) and 52 female patients (28%) with a mean age of 69 years (38-94 years). The method of harvesting the great saphenous vein was a no-touch great saphenous vein graft (NT-SVG) in 29 cases (16%) and conventional SVG in 154 cases (84%). Patients were divided into two groups: the NT-SVG group and the standard-collection saphenous vein graft (SVG) group. We compared graft patency at discharge, healing failure of the lower leg wound, healing failure of the mid-thoracic wound, and flow by transit-time flow measurement (TTFM). Conclusion There were no significant differences in perioperative outcomes between the NT-SVG and conventional SVG groups in this study.

It's not all about ISCHEMIA: the case for coronary artery bypass grafting in stable coronary artery disease

PURPOSE OF REVIEW

The recent American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions Guidelines for Coronary Artery Revascularization have raised concerns on the survival benefits of coronary artery bypass grafting (CABG) over guideline-directed medical therapy (GDMT) in stable coronary artery disease (CAD) and appropriate conduit selection for CABG. This review summarizes the evidence supporting CABG for stable CAD and use of the radial artery as a conduit for CABG.

RECENT FINDINGS

CABG has consistently demonstrated a survival benefit over GDMT for patients with stable multivessel CAD. These benefits were more pronounced in patients with diabetes and/or anatomically complex coronary artery disease. The recently published International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial was not designed to and did not include an appropriate patient population to compare revascularization with CABG to GDMT. These results should thus be viewed in the context of previously published studies. Furthermore, increasing evidence suggests that use of a radial artery in CABG is associated with reduced myocardial infarction and repeat revascularization. This should be considered when selecting the appropriate conduits based on underlying patient factors.

SUMMARY

Readers should be cautious when applying these guidelines broadly. Appropriate consideration of patient and anatomic factors, and in consultation with a multidisciplinary heart team, is important to achieve the best outcomes for patients.

Redo Coronary Artery Bypass Grafting in the era of Advanced PCI

OBJECTIVE

To review the evidence behind the role and relevance of redo coronary artery bypass grafting (CABG) in the current practice of percutaneous coronary intervention (PCI).

METHODS

A comprehensive electronic literature search was performed to identify articles that discuss the practice of PCI and redo CABG in patients that require coronary revascularization. All relevant studies are summarized in narrative manner to reflect current indications and preference.

RESULTS

The advancement in utilization of PCI has reduced the rate of redo CABG in patients with previous CABG that requires revascularization of an already treated coronary disease or a new onset of coronary artery stenosis. Redo CABG is associated with satisfactory perioperative outcomes but higher mortality at immediate postoperative period when compared to PCI.

CONCLUSION

Redo CABG patients are less likely to develop comorbidities associated with revascularisation, but the operative mortality is higher and long-term survival rates are similar in comparison to PCI. There is a need for further research into the role of redo CABG in the current advanced practice of PCI.

Utility of a smartphone application in assessing palmar circulation prior to radial artery harvesting for coronary artery bypass grafting: rationale and design of the randomised CAPITAL iRADIAL-CABG trial

INTRODUCTION

There is emerging evidence supporting the use of the radial artery (RA) as a preferred secondary conduit for coronary artery bypass grafting (CABG) as it is associated with higher rates of graft patency at 5 years when compared with saphenous vein grafts (SVG). The modified Allen's test (MAT) is traditionally regarded as the standard of care in the assessment of ulnar artery (UA) patency prior to RA harvesting. Unfortunately, due to high false-positive rates, a substantial number of pre-CABG patients are found to have an abnormal MAT despite normal UA patency, resulting in inappropriate exclusion from RA harvesting. The SVG is generally used in its place when this occurs, resulting in potentially lower rates of long-term graft patency.

METHODS AND ANALYSIS

The CAPITAL iRADIAL-CABG trial is currently enrolling participants 18 years of age or older undergoing CABG for whom the treating physician is considering the use of an RA conduit. Eligible patients will be randomised in a 1:1 fashion to MAT or smartphone-based photoplethysmography application assessment to assess collateral palmar circulation prior to RA harvesting. The primary outcome of the trial is the use of the RA as a conduit during CABG. The primary safety outcome is postoperative palmar ischaemia as determined by clinical assessment or requirement of vascular intervention. Secondary outcomes include vascular complications, early graft failure, need for rescue percutaneous coronary intervention during the index hospitalisation and a composite cardiovascular outcome of myocardial infarction, stroke and cardiovascular death prior to discharge from hospital. A total of 236 participants are planned to be recruited.

ETHICS AND DISSEMINATION

The study was approved by the Ottawa Heart Science Network Research Ethics Board (approval number 20180865-01H). The study results will be disseminated via conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03810729.

Off-Pump Coronary Artery Bypass Grafting; is it Still Relevant?

Off-pump Coronary Artery Bypass Grafting (OPCAB) experienced a resurgence in the 1980s -2000s and developed steadily with improvement of the instrumentation and techniques. However questions about graft patency and long-term survival of OPCAB patients still exist. This review attempts to explore the current relevance of OPCAB.

Survival effect of radial artery usage in addition to bilateral internal thoracic arterial grafting: A meta-analysis

OBJECTIVE

Little evidence shows whether the radial artery (RA) as third arterial graft provides superior outcomes compared with the use of the bilateral internal thoracic artery (BITA) and saphenous vein (SV) graft in patients undergoing coronary artery bypass grafting. A meta-analysis of propensity score-matched observational studies that compared the long-term outcomes of coronary artery bypass grafting with the use of BITA and the RA (BITA + RA) versus BITA and SV (BITA + SV) was performed.

METHODS

Electronic databases from January 2000 to November 2020 were screened. Studies that reported long-term mortality were analyzed. The primary outcome was long-term overall mortality. A secondary end point was in-hospital/30-day mortality. Pooled hazard ratio with 95% confidence interval (CI) were calculated for survival and time-to-event analysis according to a random effect model. Differences were expressed as odds ratio with 95% CI for in-hospital/30-day mortality.

RESULTS

Six propensity score-matched studies that reported on 2500 matched patients (BITA + RA: 1250; BITA + SV: 1250) were identified for comparison. The use of BITA + RA was not statistically associated with early mortality (odds ratio, 0.90; 95% CI, 0.36-2.28; P = .83). The mean follow-up time ranged from 7.5 to 12 years. The pooled analysis of long-term survival revealed a significant difference between the 2 groups favoring BITA + RA treatment (hazard ratio, 0.71; 95% CI, 0.50-0.91; P = .031). The survival rate for BITA + RA versus BITA + SV at 5, 10, and 15 years were: 96.2% versus 94.8%, 88.9% versus 87.4%, and 83% versus 77.9%, respectively (log rank test, P = .02).

CONCLUSIONS

In patients with coronary artery bypass grafting, BITA + RA usage is not associated with higher rates of operative risk and is associated with superior long-term overall survival.

The Use of Radial Artery for CABG: An Update

We used the radial artery as a second target conduit for coronary artery bypass grafting since 1971. However, randomized clinical studies have demonstrated differences in clinical outcomes between the radial artery and other grafts because these trials are underpowered. As we proceed toward 50 years of experience with radial artery grafting, we examined the literature to define the best second-best target vessel for coronary artery bypass grafting. The literature was reviewed with emphasis, and a large number of randomized controlled trials, propensity-matched observational series, and meta-analyses were identified with a large patient population who received arterial conduit and saphenous vein grafts. The radial artery has been shown to be effective and safe when used as a second target conduit for coronary artery bypass grafting. Results and patency rates were superior to those for saphenous vein grafting. It has also been shown that the radial artery is a safe and effective graft as a third conduit into the territory of the artery right coronary artery. However, there is little evidence based on a few comparable series limiting the use of the gastroepiploic artery. In its fifth decade of use, we can finally deduced that the aorto-to-coronary radial bypass graft is the conduit of choice for coronary operations after the left internal thoracic artery to the left anterior descending artery.

The Growth Potential and Patency of Free Right Internal Thoracic Arteries Verified by Computed Tomography Angiography

BACKGROUND

The use of the left internal thoracic artery (LITA) is the gold standard in coronary artery bypass graft surgery (CABG). Multiarterial grafting for CABG is being increasingly emphasized. This study aimed to resolve the utility of the right internal thoracic artery (RITA) for multiple CABG as "free" RITA and described new evidence.

METHODS

One hundred sixty-three patients received solo CABG with bilateral internal thoracic arteries between 2005 and 2018. The RITA was used as in situ RITA, group A (n = 62), and the composite graft created with saphenous vein graft (SVG), group B (n = 101). The patency rate and graft size of the composite free RITA and SVG were examined by coronary computed tomography angiography.

RESULTS

The average number of distal anastomoses per patient was 3.4 ± 1.0 in group A, and 4.2 ± 1.1 in group B (P < .001). The sequential grafting with free RITA was in 86 patients. The patency rate of both LITA and RITA was similar in both groups. In group B, 40 patients received late computed tomography angiography at a mean of 46 months (range, 17 to 175). The late patency rate was 95.1% in LITA and 96.9% in free RITA. The diameter of free RITA increased from 2.06 ± 0.34 mm to 2.37 ± 0.23 mm (P = .036); that of in situ LITA increased from 2.08 ± 0.51 mm to 2.44 ± 0.49 mm (P = .047); and that of composite SVG decreased from 4.1 ± 0.9 mm to 2.6 ± 0.7 mm (P < .001).

CONCLUSIONS

Multiple bypass grafting can be sufficiently achieved with LITA and free RITA. The growth potential of free RITA and in situ LITA might play the important role of expected long-term patency.

Second best conduit-is it the tag or patency that counts?

The Radial Artery Patency and Clinical Outcomes (RAPCO) trial compared radial artery (RA) with free right internal thoracic artery (RITA) and saphenous vein grafts (SVG). This was a prospective, randomized, single-center trial with two separate arms (RA-RITA and RA-SVG). The study showed that RA was superior to free RITA in terms of 10-year angiographic patency and provided a survival advantage as well. In contrast, RA-SVG comparison suggested a trend towards better outcomes with RA but no statistically significant difference in patency or survival. In this appraisal of the RAPCO trial, both the conduct and the findings have been critically evaluated. The concerns over using free RITA as aorto-coronary grafts as opposed to composite grafts and the insufficient sample size for the RA-SVG comparison have been highlighted. In the RAPCO trial that spanned almost quarter of a century, patency of all three conduits studied in the trial appears satisfactory.

Meta-Analysis Comparing Multiple Arterial Grafts Versus Single Arterial Graft for Coronary-Artery Bypass Grafting

Observational studies and randomized controlled trials (RCTs) have shown conflicting outcomes for multiple arterial graft (MAG) coronary artery bypass graft surgery compared with single arterial grafts (SAGs). The predominant evidence supporting the use of MAGs is observational. The aim of this meta-analysis of RCTs is to compare outcomes following MAG and SAG. We searched multiple databases for RCTs comparing MAG versus SAG. The clinical outcomes studied were all-cause mortality, cardiac mortality, myocardial infarction (MI), revascularization, stroke, sternal wound complications, and major bleeding. We used hazard ratio (HR), relative risk (RR), and corresponding 95% confidence interval (CI) for measuring outcomes. Ten RCTs (6392 patients) were included. The average follow-up in the studies was 4.2 years. The average age of the patients in the studies ranged from 56.3 years to 74.6. No significant difference was seen between MAG and SAG groups for all-cause mortality (11.8% vs 12.7%, HR 0.94, 95% CI 0.81 to 1.09, p 0.36), cardiac mortality (4.1% vs 4.5%, HR 0.96 95% CI 0.74 to 1.26, p 0.77), MI (3.5% vs 5.1%, HR 0.87 95% CI 0.67 to 1.12, p 0.28), and major bleeding (3.3% vs 4.9%, RR 0.85 95% CI 0.64 to 1.13, p 0.26). Repeat revascularization in MAG showed a lower RR than SAG when one of the confounding studies was excluded (RR 0.63, 95% CI 0.4 to 0.99, p 0.04). The incidence of stroke was lower in MAG than SAG (2.9% vs 3.9%, RR 0.74 95% CI 0.56 to 0.98, p 0.03). MAG had higher incidence of sternal wound complications than SAG (2.9% vs 1.7%, RR 1.75 95% CI 1.19 to 2.55, p 0.004). In conclusion, MAG does not have a survival advantage compared with SAG but is better in revascularization and risk of stroke. This benefit may be set off by a higher incidence of sternal wound complications in MAG.

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

IMPORTANCE

Observational studies have suggested that the use of radial artery grafts for coronary artery bypass grafting may improve clinical outcomes compared with the use of saphenous vein grafts, but this has not been confirmed in randomized trials.

OBJECTIVE

To compare clinical outcomes between patients receiving radial artery vs saphenous vein grafts for coronary artery bypass grafting after long-term follow-up.

DESIGN, SETTING, AND PARTICIPANTS

Patient-level pooled analysis comparing radial artery vs saphenous vein graft in adult patients undergoing isolated coronary artery bypass grafting from 5 countries (Australia, Italy, Serbia, South Korea, and the United Kingdom), with enrollment from 1997 to 2009 and follow-up completed in 2019.

INTERVENTIONS

Patients were randomized to undergo either radial artery (n = 534) or saphenous vein (n = 502) grafts for coronary artery bypass grafting.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of death, myocardial infarction, or repeat revascularization and the secondary outcome was a composite of death or myocardial infarction.

RESULTS

A total of 1036 patients were randomized (mean age, 66.6 years in the radial artery group vs 67.1 years in the saphenous vein group; 376 [70.4%] men in the radial artery group vs 351 [69.9%] in the saphenous vein group); 942 (90.9%) of the originally randomized patients completed 10 years of follow-up (510 in the radial artery group). At a median (interquartile range) follow-up of 10 (10-11) years, the use of the radial artery, compared with the saphenous vein, in coronary artery bypass grafting was associated with a statistically significant reduction in the incidence of the composite outcome of death, myocardial infarction, or repeat revascularization (220 vs 237 total events; 41 vs 47 events per 1000 patient-years; hazard ratio, 0.73 [95% CI, 0.61-0.88]; P < .001) and of the composite of death or myocardial infarction (188 vs 193 total events; 35 vs 38 events per 1000 patient-years; hazard ratio, 0.77 [95% CI, 0.63-0.94]; P = .01).

CONCLUSIONS AND RELEVANCE

In this individual participant data meta-analysis with a median follow-up of 10 years, among patients undergoing coronary artery bypass grafting, the use of the radial artery compared with the saphenous vein was associated with a lower risk of a composite of cardiovascular outcomes.

RARAY Operation: Operative Description and Early Results for Achieving Total Arterial Coronary Revascularisation

BACKGROUND

Total arterial revascularisation may prolong postoperative survival following coronary surgery due to avoidance of late saphenous vein graft (SVG) failure leading to ischaemic cardiac events. The left internal mammary artery (LIMA) is routinely used for CABG but harvest may adversely affect lung function and reduce sternal vascular supply. Early experience of a novel reconstruction with exclusive reliance on two radial arteries (RA) joined as a Y graft (RARAY) is presented.

METHODS

One RA is anastomosed to the ascending aorta and used to revascularise the left anterior descending artery coronary territory; and a second RA is joined to the first 4-6 cm from the origin, approximating the lateral border of the pulmonary artery and used to revascularise the circumflex and right coronary territories. No LIMA is used. The radial artery was harvested open with diathermy and metal clips and since 2008, all patients received intravenous vasoconstrictors from the commencement of the anaesthetic.

RESULTS

From 2002 to 2019, 28 patients underwent RARAY for specific indications of prior use or reasons to avoid LIMA harvest, preservation of lung function, minimisation of bleeding risk from antiplatelet agents and extra length of RA to graft distal coronary targets beyond usual reach for LIMA. There was no RA spasm, no in-hospital death and no patient returned with symptoms of angina.

CONCLUSIONS

The early experience of the RARAY operation for three coronary territory revascularisations are satisfactory.

Direct angiography demonstrates equal 8-12 years patency rates of radial artery and saphenous vein grafts

Objectives: The benefits of coronary artery bypass surgery depend on lasting graft patency. To aid rational graft selection, the relative long-term merits of radial artery and saphenous vein grafts need to be determined by a gold standard method and with minimal clinically driven selection bias. Methods: The patency rates of various conduits were determined by direct angiography in 76 patients from a cohort of 119 undergoing coronary artery bypass grafting 7.6-12.1 (mean 8.9) years before. Results: 14 out of 76 radial artery and 10 out of 61 saphenous vein grafts were occluded (rates 0.18 and 0.16, respectively). Conclusion: The high long-term patency rate of saphenous vein grafts does not support a preferential use of the radial artery as a coronary artery bypass conduit. Clinical registration number: ISRCTN23118170.

Effect of Calcium-Channel Blocker Therapy on Radial Artery Grafts After Coronary Bypass Surgery

BACKGROUND

Few studies have evaluated the effect of chronic calcium-channel blocker therapy (CCB) on the angiographic and clinical outcome of radial artery (RA) grafts used for coronary bypass surgery.

OBJECTIVES

The purpose of this study was to evaluate if CCB influences midterm clinical and angiographic outcomes of RA grafts.

METHODS

Patient-level data of 6 angiographic randomized trials evaluating RA graft status at midterm follow-up were joined in this observational analysis. Cox regression and propensity score methods were used to evaluate the effect of CCB on the incidence of a composite of major adverse cardiac events (MACE) (death, myocardial infarction, and repeat revascularization) and graft occlusion.

RESULTS

The study population included 732 patients (502 on CCB). The median clinical follow-up was 60 months. The cumulative incidence of MACE at 36, 72, and 108 months was 3.7% vs. 9.3%, 13.4% vs. 17.6%, and 16.8% vs. 20.5% in the CCB and no CCB groups, respectively (log-rank p = 0.003). Protocol-driven angiographic follow-up was available in 243 patients in the CCB group and 200 in the no CCB group. The median angiographic follow-up was 55 months. The cumulative incidence of RA occlusion at 36, 72, and 108 months was 0.9% vs. 8.6%, 9.6% vs. 21.4%, and 14.3% vs. 38.9% in the CCB and no CCB groups, respectively (log-rank p < 0.001). After controlling for known confounding, CCB therapy was found to be consistently associated with a significantly lower risk of MACE (multivariate Cox hazard ratio: 0.52; 95% confidence interval: 0.31 to 0.89; p = 0.02) and RA graft occlusion (multivariate Cox hazard ratio: 0.20; 95% confidence interval: 0.08 to 0.49; p < 0.001).

CONCLUSIONS

In patients with RA grafts CCB is associated with significantly better midterm clinical and angiographic RA outcomes.

Radial Artery Versus Right Internal Thoracic Artery Versus Saphenous Vein as the Second Conduit for Coronary Artery Bypass Surgery: A Network Meta-Analysis of Clinical Outcomes

Background

There remains uncertainty regarding the second‐best conduit after the internal thoracic artery in coronary artery bypass grafting. Few studies directly compared the clinical results of the radial artery (RA), right internal thoracic artery (RITA), and saphenous vein (SV). No network meta‐analysis has compared these 3 strategies.

Methods and Results

MEDLINE and EMBASE were searched for adjusted observational studies and randomized controlled trials comparing the RA, SV, and/or RITA as the second conduit for coronary artery bypass grafting. The primary end point was all‐cause long‐term mortality. Secondary end points were operative mortality, perioperative stroke, perioperative myocardial infarction, and deep sternal wound infection (DSWI). Pairwise and network meta‐analyses were performed. A total of 149 902 patients (4 randomized, 31 observational studies) were included (RA, 16 201, SV, 112 018, RITA, 21 683). At NMA, the use of SV was associated with higher long‐term mortality compared with the RA (incidence rate ratio, 1.23; 95% CI, 1.12–1.34) and RITA (incidence rate ratio, 1.26; 95% CI, 1.17–1.35). The risk of DSWI for SV was similar to RA but lower than RITA (odds ratio, 0.71; 95% CI, 0.55–0.91). There were no differences for any outcome between RITA and RA, although DSWI trended higher with RITA (odds ratio, 1.39; 95% CI, 0.92–2.1). The risk of DSWI in bilateral internal thoracic artery studies was higher when the skeletonization technique was not used.

Conclusions

The use of the RA or the RITA is associated with a similar and statistically significant long‐term clinical benefit compared with the SV. There are no differences in operative risk or complications between the 2 arterial conduits, but DSWI remains a concern with bilateral ITA when skeletonization is not used.

[Effect of the degree of stenosis of the right coronary artery on remote results of bypass grafting]

AIM

The purpose of this study was to assess the long-term results of right coronary artery bypass grafting and identify predictors of coronary artery bypass graft occlusion.

PATIENTS AND METHODS

Our retrospective single-centre study included a total of 245 patients subjected to isolated coronary artery bypass graft operations during the follow up period from 2010 to 2015. All patients endured bypass grafting of the right coronary artery (RCA) with either autovenous or autoarterial conduits. Control coronary bypass angiography was performed in all patients in connection with a relapse of angina pectoris. The duration of the follow up period amounted to 43.7±20.2 months. The patients were divided into two groups depending on the type of the conduit used to bypass the RCA. Group One patients (n=106) endured bypass grafting of the RCA and its branches using the internal thoracic artery. Group Two patients (n=139) underwent autovenous coronary artery bypass grafting of the RCA basin. By the main clinical, demographic and intraoperative parameters the groups were statistically homogeneous (p>0.05). The effect of the degree of proximal stenosis, the diameter of the grafted artery on the viability of bypass grafts was assessed.

RESULTS

During the follow-up period up to 84 months, 19 (17.9%) occluded arterial and 29 (20.9%) venous conduits were revealed. The Kaplan-Meier analysis showed that the probability of the absence of venous graft occlusion during the follow-up period up to 84 months was significantly lower than that of arterial grafts (log rank=0.012). The Cox regression analysis results revealed that shunt occlusion was influenced by the degree of proximal stenosis and the diameter of the shunted artery.

CONCLUSION

When shunting a moderate stenosis of the RCA (up to 70%), an advantage of autovenous conduits was revealed. When shunting the RCA with a critical stenosis and occlusion, advantages were revealed for the internal thoracic artery.

The RADial artery International ALliance (RADIAL) extended follow-up study: rationale and study protocol

It is generally accepted that radial artery (RA) grafts have better mid-term patency rate compared to saphenous vein grafts. However, the clinical correlates of the improved patency rate are still debated. Observational studies have suggested increased survival and event-free survival for patients who receive an RA rather than a saphenous vein, but they are open to bias and confounders. The only evidence based on randomized data is a pooled meta-analysis of 6 randomized controlled trial comparing the RA and the saphenous vein published by the RADial artery International Alliance (RADIAL). In the RADIAL database, improved freedom from follow-up cardiac events (death, myocardial infarction and repeat revascularization) was found at 5-year follow-up in the RA arm. The most important limitation of the RADIAL analysis is that most of the included trials had an angiographic follow-up in the first 5 years and it is unclear whether the rate of repeat revascularization (the main driver of the composite outcome) was clinically indicated due to per-protocol angiographies. Here, we present the protocol for the long-term analysis of the RADIAL database. By extending the follow-up beyond the 5th postoperative year (all trials except 1 did not have angiographic follow-up beyond 5 years), we aim to provide data on the role of RA in coronary artery bypass surgery with respect to long-term outcomes.

Patency When Grafted to Coronary Stenosis More Than 50% in LIMA-RA-Y Grafts

BACKGROUND

Recent coronary surgery practice is to graft arterial conduits to more severely stenosed coronary targets than in the past. We aimed to investigate postoperative arterial graft patency with native coronary stenosis at the time of surgery, using the left internal mammary artery and radial artery (RA) as a composite Y graft (LIMA-RA-Y). In the study timeframe, it was routine clinical practice to graft coronary arteries with >50% stenosis.

METHODS

Of 464 patients previously reported 1996-1999, 346 who underwent LIMA-RA-Y at the Royal Melbourne Hospital, 76 had postoperative angiograms at the same institution. Each anastomosis was considered separately. For arterial grafts a "string sign" was analysed as being occluded. Predictor of patency was performed with a generalised linear mixed model (GLMM).

RESULTS

Seventy-six (76) patients had postoperative angiograms at 5.8±5.4 years (range 0.23-19.4; interquartile range 1.7-10.0) years postoperative; with age at operation 62.5±10.7 years and 3.4±0.8 grafts per patient, 82% were male. Of 256 anastomoses, 230 were to coronary targets >50% stenosis. Overall patency was 84.0% (214/256). For coronary stenosis >50%, patency was 88% (201/230) and varied by coronary territory left anterior descending (LAD) 94% (87/93), circumflex 90% (71/79) and right coronary artery (RCA) 74% (43/58). Interaction for coronary territory was significant (p=0.022). Higher preoperative coronary stenosis predicted higher patency; with odds ratio for improved patency of 1.83 (95% CI 1.51, 2.22), p<0.001 for each 10% increase in stenosis.

CONCLUSIONS

Late patency of composite arterial grafts is acceptable when grafted to coronary arteries of greater than 50% stenosis.

Long-Term Patency Rate of Radial Artery Conduits in Chinese Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

Consensus has yet to emerge among experts as to whether the radial artery (RA) conduit was superior to the saphenous vein (SV) graft for coronary artery bypass grafting (CABG) in terms of long-term patency. This study aimed to evaluate long-term patency of the RA conduit compared to the SV conduit for off-pump CABG, and to screen the independent predictors of long-term RA graft failure.Patients < 80 years of age with graftable triple-vessel disease undergoing non-emergent, primary, isolated off-pump CABG, using both the RA and the SV conduits, were reviewed. Graft patency, all-cause mortality and repeat revascularization were followed-up. The independent predictors of long-term RA graft failure were identified.A total of 296 out of 320 eligible patients (42 females, 61.3 ± 9.9 years old) received follow-up with an observed period of 93.4 ± 16.5 months. All-cause mortality was 14.5%, and repeat revascularization was conducted on 6 RA grafts and 9 SV grafts. Superior patency of the RA grafts compared to the SV grafts was observed (84.4% versus 78.5%, P = 0.035). Independent predictors of long-term RA graft failure included proximal stenosis of target right coronaries < 90% (OR = 2.35, 95%CI 1.41-5.82) and diabetes mellitus (OR = 1.66, 95%CI 1.17-4.26).The RA graft had a superior long-term patency than the SV graft. Long-term patency of the RA graft may be poor in diabetics or in the case of proximal stenosis of target right coronary <90%. (Trial registration: ChiCTR-OCH-1200212).

A comparative review of the outcomes of using arterial versus venous conduits in coronary artery bypass graft (CABG)

Nowadays one of the most frequent reasons of death in the world is coronary artery disease. CABG is a portion of a common revascularization mediation that is done to supervise CAD by applying vessels that are grafted to revascularize vessels distal from the blockage. Different sources of grafts are included veins (specifically saphenous) and arteries (include mammary and radial arteries). Multiple conduits are used to this end, but the most suitable is left internal mammary artery (LIMA) to the left anterior descending artery (LAD) as a golden standard. Saphenous vein grafts were the guiding approach applied by the vast majority of cardiac surgeons in the 1970s, even though all approaches were supported by doctors. Although the radial artery graft was introduced simultaneously, this approach due to its complications was not as prevalent. This article is aimed to define the pros and cons of applying each kind of grafts according to the results furnished by existent studies. It has also examined the benefits provided by total arterial coronary artery bypass graft against CABG including venous graft for patients with CAD from the perspective of surgeons.

Assessing the Long-term Patency and Clinical Outcomes of Venous and Arterial Grafts Used in Coronary Artery Bypass Grafting: A Meta-analysis

Introduction

The long-term patency of the grafts used during the coronary artery bypass grafting (CABG) is one of the most significant predictors of the clinical outcomes. The gold standard graft used during CABG with the best long-term patency rate and the better clinical outcomes is left internal thoracic artery (LITA) grafted to the left coronary artery (LCA). The controversy lies in choosing the second-best conduit for the non-left coronary artery (NLCA) with similar patency rate as LITA. This meta-analysis examines the long-term patency and clinical outcomes of all arterial grafts versus all venous grafts used during the CABG.

Methods

A comprehensive literature search of all published randomized control trials (RCTs) assessing long-term patency and clinical outcomes of grafts used in CABG was conducted using PubMed, Cochrane Central Registry of Controlled Trials, and Google Scholar (1966-2018). Keywords searched included combinations of “CABG”, “venous grafts in CABG”, “arterial grafts in CABG”, “radial artery grafts in CABG”, “gastroepiploic artery grafts in CABG”, “patency and clinical outcomes”. Inclusion criteria included: RCTs comparing the long-term patency, and clinical outcomes of radial artery, right internal thoracic artery, gastroduodenal artery, and saphenous vein grafts used in CABG. Long-term patency of the grafts and clinical outcomes were analyzed.

Results

Eight RCTs involving 2,091 patients with 1,164 patients receiving arterial grafts and 927 patients receiving venous grafts were included. There was no difference between the long-term patency rate (relative risk (RR) = 1.050, 95% confidence interval (CI) = 0.949 to 1.162, and p = 0.344), overall mortality rate (RR = 1.095, 95% CI = 0.561 to 2.136, and p = 0.790), rate of myocardial infarction (MI) (RR = 0.860, 95% CI = 0.409 to 1.812, and P = 0.692), and re-intervention rate (RR = 0.0768, 95% CI = 0.419 to 1.406, and P = 0.392) between arterial and venous grafts.

Conclusion

The use of arterial conduits over the venous conduits has no significant superiority regarding the long-term graft patency, the rate of MI, overall mortality, and the rate of revascularization following CABG. Additional adequately powered studies are needed to further evaluate the long-term outcomes of arterial and venous grafts following the CABG.

Radial Artery Versus Saphenous Vein Grafts in Coronary Artery Bypass Surgery: a Literature Review

PURPOSE OF REVIEW

Coronary artery bypass grafting is a preferred strategy for complete coronary revascularization in patients who have multi-vessel coronary artery disease, left ventricular dysfunction, and/or diabetes. Both arterial (internal thoracic artery/radial artery) and venous grafts are utilized to bypass the obstruction in native vessels. Despite having radial arterial grafts as a preferred second conduit for bypass, venous grafts are more commonly used.

RECENT FINDINGS

We review the existing literature and report the preferred conduit based on a recently published meta-analysis of 6 randomized controlled trials. The analysis concluded that radial artery grafts are associated with fewer adverse cardiac events and better graft patency at 5 years of follow-up. Although saphenous vein grafting is the most commonly used conduit in addition to ITA, current data suggests that total arterial bypass (using RA conduit in addition to ITA) may be the better strategy. Both the US and European consensus guidelines advocate for the use of arterial over SV grafting for most patients.

Radial-Artery or Saphenous-Vein Grafts in Coronary-Artery Bypass Surgery

BACKGROUND

The use of radial-artery grafts for coronary-artery bypass grafting (CABG) may result in better postoperative outcomes than the use of saphenous-vein grafts. However, randomized, controlled trials comparing radial-artery grafts and saphenous-vein grafts have been individually underpowered to detect differences in clinical outcomes. We performed a patient-level combined analysis of randomized, controlled trials to compare radial-artery grafts and saphenous-vein grafts for CABG.

METHODS

Six trials were identified. The primary outcome was a composite of death, myocardial infarction, or repeat revascularization. The secondary outcome was graft patency on follow-up angiography. Mixed-effects Cox regression models were used to estimate the treatment effect on the outcomes.

RESULTS

A total of 1036 patients were included in the analysis (534 patients with radial-artery grafts and 502 patients with saphenous-vein grafts). After a mean (±SD) follow-up time of 60±30 months, the incidence of adverse cardiac events was significantly lower in association with radial-artery grafts than with saphenous-vein grafts (hazard ratio, 0.67; 95% confidence interval [CI], 0.49 to 0.90; P=0.01). At follow-up angiography (mean follow-up, 50±30 months), the use of radial-artery grafts was also associated with a significantly lower risk of occlusion (hazard ratio, 0.44; 95% CI, 0.28 to 0.70; P<0.001). As compared with the use of saphenous-vein grafts, the use of radial-artery grafts was associated with a nominally lower incidence of myocardial infarction (hazard ratio, 0.72; 95% CI, 0.53 to 0.99; P=0.04) and a lower incidence of repeat revascularization (hazard ratio, 0.50; 95% CI, 0.40 to 0.63; P<0.001) but not a lower incidence of death from any cause (hazard ratio, 0.90; 95% CI, 0.59 to 1.41; P=0.68).

CONCLUSIONS

As compared with the use of saphenous-vein grafts, the use of radial-artery grafts for CABG resulted in a lower rate of adverse cardiac events and a higher rate of patency at 5 years of follow-up. (Funded by Weill Cornell Medicine and others.).

Associations Between Adding a Radial Artery Graft to Single and Bilateral Internal Thoracic Artery Grafts and Outcomes: Insights From the Arterial Revascularization Trial

BACKGROUND

Whether the use of the radial artery (RA) can improve clinical outcomes in coronary artery bypass graft surgery remains unclear. The ART (Arterial Revascularization Trial) was designed to compare survival after bilateral internal thoracic artery (BITA) over single left internal thoracic artery (SITA). In the ART, a large proportion of patients (≈20%) also received an RA graft instead of a saphenous vein graft (SVG). We aimed to investigate the associations between using the RA instead of an SVG to supplement SITA or BITA grafts and outcomes by performing a post hoc analysis of the ART.

METHODS

Patients enrolled in the ART (n=3102) were classified on the basis of conduits actually received (as treated). The analysis included 2737 patients who received an RA graft (RA group; n=632) or SVG only (SVG group; n=2105) in addition to SITA or BITA grafts. The primary end point was the composite of myocardial infarction, cardiovascular death, and repeat revascularization at 5 years. Propensity score matching and stratified Cox regression were used to compare the 2 strategies.

RESULTS

Myocardial infarction, cardiovascular death, and repeat revascularization cumulative incidence was 2.3% (95% confidence interval [CI], 1.1-3.4), 3.5% (95% CI, 2.1-5.0), and 4.4% (95% CI, 2.8-6.0) in the RA group and 3.4% (95% CI, 2.0-4.8), 4.0% (95% CI, 2.5-5.6), and 7.6% (95% CI, 5.5-9.7) in the SVG group, respectively. The composite end point was significantly lower in the RA group (8.8%; 95% CI, 6.5-11.0) compared with the SVG group (13.6%; 95% CI, 10.8-16.3; P=0.005). This association was present when an RA graft was used to supplement both SITA and BITA grafts (interaction P=0.62).

CONCLUSIONS

This post hoc ART analysis showed that an additional RA was associated with lower risk for midterm major adverse cardiac events when used to supplement SITA or BITA grafts.

CLINICAL TRIAL REGISTRATION

URL: https://www.situ.ox.ac.uk/surgical-trials/art. Unique identifier: ISRCTN46552265.

Adjunctive Uses of the Radial Artery for Emergency Infrapopliteal Bypass in Patients Presenting With Acute Limb-Threatening Ischemia

Although the radial artery has proven to be a reliable conduit for arterial bypass procedures in cardiac surgery, its use in lower extremity revascularization has been limited due to its length. In patients who have undergone multiple cardiovascular procedures, venous conduit options can be limited, and infrapopliteal bypass with prosthesis has been shown to yield poor patency rates. In this report, the authors describe 3 different uses of the radial artery in patients with acute limb-threatening ischemia in the redo setting, which resulted in limb salvage.

Right internal thoracic artery versus radial artery as the second best arterial conduit: Insights from a meta-analysis of propensity-matched data on long-term survival

OBJECTIVE(S)

We conducted a meta-analysis of propensity score-matching (PSM) studies comparing long-term survival of patients receiving right internal thoracic artery (RITA) versus radial artery (RA) as a second arterial conduit for coronary artery bypass grafting.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and Web of Science to identify relevant articles. Primary endpoint was long-term mortality. Secondary endpoints were operative mortality, incidence of sternal wound infection, and repeat revascularization. Binary events were pooled using the DerSimonian and Laird method. For time-to-event outcomes, estimates of log hazard ratio (HR) and standard errors obtained were combined using the generic inverse-variance method.

RESULTS

A total of 8 PSM studies were finally selected including 15,374 patients (RITA, 6739; RA, 8635) with 2992 matched pairs for final comparison. Mean follow-up time ranged from 45 to 168 months. When compared with RA, RITA was associated with a lower risk reduction of late death (HR, 0.75; 95% confidence interval [CI], 0.58-0.97; P = .028) and repeat revascularization (HR, 0.37; 95% CI, 0.16-0.85; P = .03). On the other hand, RITA did not increase operative mortality (odds ratio [OR], 1.53; 95% CI, 0.97-2.39; P = .07). RITA was associated with an increased risk of sternal wound complication when pedicled harvesting was used (OR, 3.18; 95% CI, 1.34-7.57), but not with skeletonized harvesting (OR, 1.07; 95% CI, 0.67-1.71).

CONCLUSIONS

The present PSM data meta-analysis suggests that the use of RITA compared with RA was associated with superior long-term survival and freedom from repeat revascularization, with similar operative mortality and incidence of sternal wound complication when the skeletonized harvesting technique was used.

SAPHENOUS VEIN GRAFT PATENCY AFTER GEOMETRY REMODELING

Tortuous saphenous vein graft (SVG) hemodynamics was investigated using computational fluid dynamics (CFD) techniques. Computed tomography (CT) technology is used for noninvasive bypass graft assessment seven days after surgery. CT investigation shows two regions with severe shape remodeling, one is an angle type contortion and the other one is a sharp curvature with tortuous area reduction. The numerical analysis carefully examines the effect of an SVG geometry remodeling through flow separation, particle deposition, and wall shear stress (WSS). During the cardiac cycle, overall pressure drop increases from 2.6[Formula: see text]mmHg to 4.4[Formula: see text]mmHg. In the accelerating part of the systolic phase, particles released in the inlet section move downstream toward the first narrowed part (elbow type contortion) with a helical motion. WSS range along the cardiac cycle varies from 2[Formula: see text]Pa to 42[Formula: see text]Pa, enough to damage the endothelial cells. Vessel torsion induced helical flow can reduce the flow disturbance and separation. Additionally, in the distal end of the graft, the high particle concentrations can promote the inflammatory processes in the vessels.

Radial artery vs saphenous vein graft used as the second conduit for surgical myocardial revascularization: long-term clinical follow-up

Background

There is ongoing debate regarding the efficacy of the radial artery (RA) as an aortocoronary conduit, with few solid data regarding long-term clinical results. We sought to determine if the use of the RA as the second arterial conduit, beside left internal thoracic artery (LITA), would improve long-term clinical outcome after CABG as compared to saphenous vein graft (SVG).

Methods

Between March 2001 and November 2003, 200 patients underwent isolated CABG and were randomized in 1:1 fashion to receive either LITA and RA grafts or LITA and SVGs. The primary end point was composite of cardiovascular mortality, non-fatal myocardial infarction and need for repeat myocardial revascularization (either surgical or percutaneous).

Results

There was no significant difference in absolute survival, with 12 deaths in each group during the study period (log rank = 0.01, p = 0.979). There were 3 and 2 cardiac deaths in RA and SVG groups, respectively. There was no difference in long-term clinical outcome between the groups (log rank = 0.450, p = 0.509). Eleven patients in RA group had one or more non-fatal events; 7 patients suffered a myocardial infarction, 9 patients underwent percutaneous coronary angioplasty, and 1 patient required redo coronary surgery. Likewise, 13 patients in SVG group had non-fatal event; 7 patients had myocardial infarction, 13 patients had percutaneous coronary intervention and 3 patients required redo coronary surgery. Angiograms were performed in 23 patients in RA group (patency rate 92 %) and 24 in SVG group (patency rate 86 %) (p = 0.67).

Conclusion

In this small randomised study our data indicate that there is no difference in the 8 year clinical outcomes in relatively young patients between those having a RA or a saphenous vein graft used as a second conduit, beside LITA, for surgical myocardial revascularisation.

Results of endoscopic radial artery harvesting in 1577 patients

OBJECTIVE

We reviewed 1577 consecutive patients undergoing coronary artery bypass grafting (CABG) using endoscopic harvesting of the radial artery (RA) to define our current results.

METHODS

Since 2000, we have performed endoscopic RA harvest on 1577 consecutive patients; 1476 patients had isolated CABG, and 101 patients had CABG and other procedures. The mean ± SD age was 59.4 ± 9.0 years; 80.2% were men and 40% had diabetes mellitus. All data were prospectively collected. All-cause mortality was determined using the Social Security Death Index.

RESULTS

There were nine in-hospital or 30-day deaths, for an operative mortality of 0.57%: mortality was 0.34% in isolated CABG and 3.85% in CABG/combined procedures. The overall estimated Kaplan-Meier survival at 1, 5, and 10 years was 99%, 95%, and 88%. In 37 patients, the RAs were not harvested or were not used for grafting because of a positive Allen test, extensive calcification or dissection, intramural hematoma, and scarring from previous arterial lines or catheterization. During postoperative follow-up, five patients (0.32%) were treated for incisional infection, and there were no ischemic hand complications. Three patients had a perioperative myocardial infarction in the RA graft distribution, and 15 patients had a coronary artery reintervention in the RA graft distribution. Two other patients had a percutaneous coronary intervention of their RAs. The overall RA patency at 10 years was 82%.

CONCLUSIONS

Endoscopic harvest of the RA is an excellent minimally invasive conduit harvesting technique with minimal morbidity.

Two questions on bilateral internal mammary artery usage

The use of a single internal mammary graft to the left anterior descending artery has been the gold standard in surgical coronary revascularization since its introduction. However, the take-up rate of use of bilateral internal mammary arteries has been slow despite emerging evidence. This has been partly due to the worry of postoperative complications, in particular, sternal wound complications. Skeletonization of the internal mammary has been proposed as a technique that can preserve the sternal microcirculation and therefore reduce this complication. In this article, we examine the evidence comparing the skeletonization technique versus the conventional pedicled technique for harvesting the internal mammary artery.

Which is the best graft for the right coronary artery?

Bilateral internal mammary arteries directed to the left coronaries are gaining popularity; an increasing level of evidence nowadays supports this surgical strategy. On the other hand, composite right internal mammary artery, radial artery, and gastroepiploic artery targeting high-grade stenotic lesions in the right coronary artery system may confer improved mid- and long-term patency compared to long saphenous veins. This analysis looks into the evidence comparing data of the third best available conduit for grafting the right coronary artery, and by extrapolating this report, compares total arterial revascularization vs. conventional coronary artery bypass grafting.

Radial artery as graft for coronary artery bypass surgery: Advantages and disadvantages for its usage focused on structural and biological characteristics

Radial artery (RA) is the most popular arterial graft after the left internal thoracic artery in both low- and high-risk patients undergoing coronary artery bypass grafting. Various arterial grafts such as the right internal thoracic artery, the right gastroepiploic artery, and the inferior epigastric artery have also gained ground over the past 30 years because of the intimal hyperplasia and atherosclerosis of the saphenous vein leading to late graft occlusion. In this review article we would like to present the utility of the RA as a graft, focused mainly on its structural and biological characteristics.

Impact of renal function in patients with multi-vessel coronary disease on long-term mortality following coronary artery bypass grafting compared with percutaneous coronary intervention

BACKGROUND

Comorbidities, such as diabetes, affect revascularization strategy for coronary disease. We sought to determine if the degree of renal impairment affected long-term mortality after percutaneous coronary intervention (PCI) compared to coronary artery bypass grafting (CABG) in patients with multi-vessel coronary disease (MVD).

METHODS AND RESULTS

8970 patients with MVD undergoing revascularization between 2004 and 2008, in two multi-center parallel PCI and CABG Australian registries were assigned to three groups based on their estimated glomerular filtration rate (eGFR)≥60 mL/min/1.73 m2 (n=1678:839), 30-59 mL/min/1.73 m2 (n=452:226) and <30 mL/min/1.73 m2 (n=74:37). We used 2:1 propensity matching to compare 3306 patients undergoing primary CABG versus PCI. Shock, myocardial infarction (MI)<24 h, previous CABG, valve surgery or PCI were exclusions. Long-term mortality (mean 3.1 years) was compared with Cox-proportional hazard-adjusted modeling. Observed long-term mortality rates (CABG vs. PCI) were 4.5% vs. 4.3% p=0.84, 12.8% vs. 17.3% p=0.12, and 23.0% vs. 40.5% p=0.05 in the three strata, respectively. In patients with eGFR≥60 mL/min/1.73 m2, long-term mortality between PCI and CABG (HR 0.99, 95% CI 0.65-1.49, p=0.95) was similar. However, amongst patients with eGFR 30-59 mL/min/1.73 m2, there was a significant mortality hazard with PCI (HR 2.00, 95% CI 1.32-3.04, p=0.001). In patients with eGFR<30 mL/min/1.73 m2, there was a trend for hazard with PCI (HR 1.66, 95% CI 0.80-3.46, p=0.17).

CONCLUSION

Long-term mortality in MVD patients with preserved renal function was very low and similar between PCI and CABG. However there was a long-term mortality hazard associated with PCI amongst patients with moderate renal impairment.

Regression of coronary disease after bypass surgery: Urban myth or common finding?

OBJECTIVES

Coronary artery disease has been viewed as a relentless, progressive disease. We sought to describe the prevalence and distribution of regression of native vessel disease in coronary artery bypass patients and characterize its relationship with bypass grafting.

METHODS

Among 619 patients who underwent bypass surgery in a radial artery trial, 405 had follow-up angiography available a mean of 6.2 ± 3.1 years (range, 0-14) after surgery. The percentage of diameter stenosis of each major native coronary vessel was reported by 3 cardiac specialists and classified into grades of nonflow limiting (0%-39%), moderate (40%-69%), flow limiting (70%-80%), severely stenosed (81%-99%), and occluded (100%). Native vessel disease regression was defined as decrease in 1 or more grades of stenosis between the pre- and postoperative angiograms.

RESULTS

A total of 1742 native coronary arteries had preoperative stenosis of at least 40% and were included in the present analysis, receiving 753 arterial grafts and 391 saphenous vein grafts. Overall, the prevalence of disease regression was 19.7%, and 45% of patients demonstrated regression in 1 or more vessels. The presence of an arterial graft increased the likelihood of disease regression (21.3% compared with 16% for venous bypassed vessels, P = .012) as did the location in the left circulation (22.6% compared with 13.9% for the right circulation, P < .001) and having a flow-limiting (≥70%) lesion (21.9% compared with 9.8% for moderate lesions, P < .001).

CONCLUSIONS

Native coronary artery disease regression after coronary artery bypass grafting is common and affected by conduit type, vessel location, and lesion severity. Surgeons must consider these factors when assessing the requirement for bypass grafts in a borderline lesion.

Composite versus conventional coronary artery bypass grafting strategy for the anterolateral territory: study protocol for a randomized controlled trial

Background

In severe coronary artery disease, coronary artery bypass grafting (CABG) surgery is indicated to re-establish an adequate blood supply to the ischemic myocardium. Effectiveness of CABG surgery for symptom relief and mortality decrease should therefore depend on bypass graft patency. As bypass using a left internal mammary artery (LIMA)-to-left anterior descending coronary artery (LAD) anastomosis allows the best results in terms of graft patency, we designed a new surgical technique using a saphenous vein graft as a venous bridge to distribute the LIMA flow to the cardiac anterolateral territory. This novel strategy could extend the patency benefits associated to the LIMA. Other potential benefits of this technique include easier surgical technique, possibility to use saphenous vein grafts as vein patch angioplasty, shorter saphenous vein grafts requirement and reduced or eliminated manipulations of the ascendant aorta (and associated stroke risk).

Methods/Design

Between July 2012 and 2016, 200 patients undergoing a primary isolated CABG surgery using cardiopulmonary bypass with a LAD bypass graft and at least another target on the anterolateral territory will be randomized (1:1) according to 1) the new composite strategy and 2) the conventional strategy with a LIMA-to-LAD anastomosis and revascularization of the other anterolateral target(s) with a separated aorto-coronary saphenous vein graft. The primary objective of the trial is to assess whether the composite strategy allows non-inferior anterolateral graft patency index (proportion of non-occluded CABGs out of the total number of CABGs) compared to the conventional technique. The primary outcome is the anterolateral graft patency index, evaluated at one year by 256-slice computed tomography angiography. Ten years of clinical follow-up is planned to assess clinical outcomes including death, myocardial infarction and need for revascularization.

Discussion

This non-inferiority trial has the potential to advance the adult cardiac surgery field, given the potential benefits associated with the composite grafting strategy.

Trial registration

ClinicalTrials.gov: NCT01585285.