The second best arterial graft: A propensity analysis of the radial artery versus the free right internal thoracic artery to bypass the circumflex coronary artery

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Current indications and surgical strategies for myocardial revascularization in patients with left ventricular dysfunction: a scoping review

BACKGROUND

Ischemic cardiomyopathy (ICM) accounts for more than 60% of congestive heart failure cases and is associated with high morbidity and mortality rates. Myocardial revascularization in patients with left ventricular dysfunction (LVD) and a left ventricular ejection fraction (LVEF) ≤35% aims to improve survival and quality of life and reduce complications associated with heart failure and coronary artery disease. The majority of randomized clinical trials have consistently excluded those patients, resulting in evidence primarily derived from observational studies.

MAIN BODY

We performed a scoping review using the Arksey and O'Malley methodology in five stages: 1) formulating the research question; 2) locating relevant studies; 3) choosing studies; 4) organizing and extracting data; and 5) compiling, summarizing, and presenting the findings. This literature review covers primary studies and systematic reviews focusing on surgical revascularization strategies in adult patients with ischemic left ventricular dysfunction (LVD) and a left ventricular ejection fraction (LVEF) of 35% or lower. Through an extensive search of Medline and the Cochrane Library, a systematic review was conducted to address three questions regarding myocardial revascularization in these patients. These questions outline the current knowledge on this topic, current surgical strategies (off-pump vs. on-pump), and graft options (including hybrid techniques) utilized for revascularization. Three independent reviewers (MAE, DP, and AM) applied the inclusion criteria to all the included studies, obtaining the full texts of the most relevant studies. The reviewers subsequently assessed these articles to make the final decision on their inclusion in the review. Out of the initial 385 references, 156 were chosen for a detailed review. After examining the full articles were examined, 134 were found suitable for scoping review.

CONCLUSION

The literature notes the scarcity of surgical revascularization in LVD patients in randomized studies, with observational data supporting coronary revascularization's benefits. ONCABG is recommended for multivessel disease in LVD with LVEF < 35%, while OPCAB is proposed for older, high-risk patients. Strategies like internal thoracic artery skeletonization harvesting and postoperative glycemic control mitigate risks with BITA in uncontrolled diabetes. Total arterial revascularization maximizes long-term survival, and hybrid revascularization offers advantages like shorter hospital stays and reduced costs for significant LAD lesions.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Effect of right internal mammary artery versus radial artery as a second graft vessel in coronary artery bypass grafting on postoperative wound infection in patients: A meta-analysis

Few studies have shown that radial artery (RA), which is used as a secondary arterial graft, offers superior results compared with right internal thoracic artery (RIMA) in coronary artery bypass grafting (CABG). In a meta-analysis of observational studies starting in 2023, we looked at the effect of re-operation on postoperative infection and haemorrhage in CABG with RA vs. RIMA. The electronic database up to October 2023 was examined in the course of the research. Analysis was carried out on the clinical trials of postoperative wound infections and haemorrhage re-surgery. Among 912 trials associated with CABG, we selected 8 trials to be included in the final data analysis. The main results were secondary wound infection and re-operation after surgery. The odds ratios (OR) and confidence intervals (CIs) were computed on the basis of a randomized or fixed-effect model of wound infection and re-operation. Seven trials showed a significant reduction in the risk of wound infection in RA treated as a secondary artery transplant compared with RIMA (OR, 1.60; 95% CI, 1.03, 2.47 p = 0.04); Four trials showed that RIMA was not significantly different from RA in the rate of re-operation for postoperative bleeding (OR, 1.31; 95% CI, 0.60, 2.88 p = 0.50). In CABG, RA is used as a secondary arterial conduit graft to lower the risk of wound infection in CABG patients.

Bilateral internal thoracic artery versus single internal thoracic artery plus radial artery: A double meta-analytic approach

OBJECTIVES

We explored the current evidence on the best second conduit in coronary surgery carrying out a double meta-analysis of propensity score matched or adjusted studies comparing bilateral internal thoracic artery (BITA) versus single internal thoracic artery plus radial artery.

METHODS

PubMed, Embase, and Google Scholar were searched for propensity score matched or adjusted studies comparing BITA versus single internal thoracic artery plus radial artery. The end point was long-term mortality. Two statistical approaches were used: the generic inverse variance method and the pooled meta-analysis of Kaplan-Meier-derived individual patient data.

RESULTS

Twelve matched populations comparing 6450 patients with BITA versus 9428 patients with single internal thoracic artery plus radial artery were included in our meta-analysis. The generic inverse variance method showed a statistically significant survival benefit of the BITA group (hazard ratio, 0.84; 95% CI, 0.74-0.95; P = .04). The Kaplan-Meier estimates of survival at 1, 5, 10, and 15 years of the BITA group were 97.0%, 91.3%, 80.0%, and 68.0%, respectively. The Kaplan-Meier estimates of survival at 1, 5, 10, and 15 years of the single internal thoracic artery plus radial artery group were 97.3%, 91.5%, 79.9%, and 63.9%, respectively. The Kaplan-Meier-derived individual patient data meta-analysis applied to very long follow-up time data, showed that BITA provided a survival benefit after 10 years from surgery (hazard ratio, 0.77; 95% CI, 0.63-0.94; P = .01). No differences in terms of survival between the 2 groups were detected when the analysis was focused on the first 10 years of follow-up (hazard ratio, 0.99; 95% CI, 0.91-1.09; P = .93).

CONCLUSIONS

The present meta-analysis suggests that double internal thoracic artery may provide, compared with single internal thoracic artery plus radial artery, a statistically significant survival advantage after 10 years of follow-up, but not before. VIDEO ABSTRACT.

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.

Bilateral Internal Thoracic Arteries Improve 10-Year Outcomes of Coronary Artery Bypass Grafting

BACKGROUND

This observational cohort study was designed by the PRIORITY (PRedictIng long-term Outcomes afteR Isolated coronary arTery bypass surgery) steering committee to evaluate the 10-year follow-up outcome of bilateral internal thoracic arteries (BITA) versus single internal thoracic artery.

METHODS

The PRIORITY project was designed to evaluate long-term outcome of 2 large prospective multicenter cohort studies of coronary artery bypass grafting. Clinical data on isolated coronary artery bypass grafting were merged with administrative data to collect follow-up information. The primary endpoint was the composite outcome of major adverse cardiac and cerebrovascular events at 10-year follow-up. Secondary endpoints were individual components of major adverse cardiac and cerebrovascular events at 10 years and surgical site complications or infections. A propensity score-based inverse probability treatment weighting (IPTW) was used to overcome the selection bias related to the observational nature of the study.

RESULTS

The study population consisted of 10,988 patients who underwent isolated coronary artery bypass grafting. BITA was used in 23.5%. The use of BITA is related to lower incidence of major adverse cardiac and cerebrovascular events at 10 years (adjusted hazard ratio [HR] 0.88, 95% CI 0.79-0.98, P < .001). BITA correlated with better 10-year survival (IPTW adjusted HR 0.87, 95% CI 0.78-1.00, P = .05), re-revascularization (IPTW adjusted HR 0.83, 95% CI 0.74-0.92, P < .001), and myocardial infarction (IPTW adjusted HR 0.86, 95% CI 0.77-0.95, P = .005) but to increased incidence of surgical site complications or infections (HR 2.12, 95% CI 1.39-3.24, P < .001).

CONCLUSIONS

In propensity-matched patients, use of BITA was associated with improved 10-year survival, freedom from repeat revascularization, and myocardial infarction but also higher incidence of surgical site complications.

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.

Long-term outcomes of patients receiving right internal thoracic artery or radial artery as a second arterial conduit. A propensity score matching study

OBJECTIVE

This study aimed to compare the long-term outcomes in propensity matched patients receiving right internal thoracic artery(RITA) or radial artery(RA) as second arterial conduit during coronary artery bypass grafting(CABG) with internal thoracic artery to the left anterior descending artery(LAD).

METHODS

In this retrospective study, propensity score matching was performed including 1198 patients from 3 centers resulting in 389-pairs who received either RITA or RA.

RESULTS

In the matched cohort, median follow-up time was 7.53 years(interquartile range, 4.35-11.81). Survival probabilities at 5, 10 and 15-years were 93.8% versus 94.5%, 81.2% versus 76.2% and 63.2% vs 62.5% in the RITA and RA groups, respectively(HR: 1.11; 95%CI;0.80-1.53; P = 0.533) Freedom from MACCE in the matched cohort at 5, 10 and 15-years were 92.0% versus 93.7%, 75.0% versus 73.8%, 72.2% and 46.9% vs 47.2% in the RITA and RA groups, respectively(HR: 0.96; 95%CI;0.74-1.26; P = 0.774). Subgroup analyses of the matched cohort showed comparable long-term outcomes in terms of MACCE at follow-up in patients with age older than 65-years, obese patients, diabetics, female patients and with impaired EF. As for target vessel revascularization, RITA and RA had comparable outcomes in terms of MACCE when the conduit was used to graft either the left coronary system or the right coronary system.

CONCLUSIONS

The use of RITA or RA as second arterial conduit during CABG with internal thoracic artery to the LAD is safe and associated with comparable long-term clinical outcomes. The choice of optimal second arterial conduit should be guided mainly by patients' characteristics and surgeons' preferences.

Diagnostic radiology methods for assessing coronary artery bypass graft viability

The review describes available modern radiological methods which are currently applied for a detailed and comprehensive anatomical and functional assessment of the viability of various coronary artery bypass grafts. In addition, it presents some aspects of the implementation of these methods and clinical interpretation of the results.

Impact of Conventional Cardiovascular Risk Factors on Left Internal Mammary Artery Graft Disease

Background:

The development of atherosclerosis was considered as the common cause of the stenosis of coronary artery grafts. Left internal mammary artery (LIMA) was the best artery graft for further effectiveness of coronary artery bypass grafting (CABG). We sought to assess the impact of known conventional cardiovascular risk factors (RFs) on LIMA graft stenosis.

Methods:

A retrospective study including 618 participants, who had recurrence of chest pain after CABG, aged ≥18 years, hospitalized for coronary angiography in Beijing Anzhen hospital between 2010 and 2017 was performed. All the participants were confirmed to have LIMA graft. Multivariate analysis was conducted to determine the relationship between conventional RFs and LIMA graft stenosis.

Results:

Of the study, 220 (35.6%) participants continued to smoke, 504 (81.6%) were overweight or obese, and 411 (66.5%) and 242 (39.2%) reported concomitant hypertension and diabetes, respectively. LIMA graft stenosis occurred in 161 participants (26.1%). Postoperative smoking, a CABG duration of ≥10 years and hyperglycemia without diabetes had an increased risk of LIMA graft stenosis, the odds ratio (OR) was 1.86 [95% confidence interval (CI): 1.26–2.78], 2.24 (95%CI:1.33–3.478), and 2.44(95% CI:1.39–4.32), respectively. Statin use (OR, 0.28; 95% CI: 0.25–0.5) and low-density lipoprotein cholesterol (LDL-C) &lt; 1.8 mmol/L (OR, 0.27; 95% CI: 0.14–0.53) had a significantly decreased risk of LIMA graft stenosis. While, only 15.4% (95/618) achieved the target LDL-C level.

Conclusions:

Postoperative smoking and hyperglycemia without diabetes had an increased risk of LIMA graft stenosis. Statin use and LDL-C &lt;1.8 mmol/L decreased the risk.

Additional survival benefit of bilateral in situ internal thoracic artery grafting with composite radial artery graft in total arterial off-pump coronary artery bypass grafting

OBJECTIVE

This study aimed to elucidate whether the use of bilateral internal thoracic arteries (BITAs) confers additional survival benefits compared with a single internal thoracic artery (SITA) in total arterial grafting with the radial artery.

METHODS

Between 2002 and 2016, 617 patients underwent a bilateral in situ internal thoracic artery grafting with the radial artery as a composite I-graft (BITA-I group) and 516 patients underwent single in situ internal thoracic artery grafting with the radial artery as a composite Y-graft (SITA-Y group). All anastomoses were performed without cardiopulmonary bypass and aortic manipulation. Propensity score matching was performed to adjust covariates and compared the outcomes between the 2 groups. Subanalysis was also performed to evaluate the effects of the BITA-I group on survival according to the covariates using Cox proportional hazards regression analysis.

RESULTS

Propensity score matching yielded 348 well-matched pairs. Early postoperative outcomes were similar in the 2 groups. The BITA-I group showed significantly better survival than the SITA-Y group (79.3% vs 70.2% at 10 years, P = .015). The subanalysis revealed a significantly better survival in the BITA-I group among overall patients (hazard ratio, 0.68; 95% confidence interval, 0.49-0.93). There was a significant positive effect on survival in the BITA-I group among patients without comorbidities or those aged <77 years.

CONCLUSIONS

BITA grafting with the radial artery provides better long-term survival than SITA grafting with the radial artery, which is enhanced among patients aged <77 years with minimum comorbidities.

Electrospun nanofiber scaffold for vascular tissue engineering

Due to the prevalence of cardiovascular diseases, there is a large need for small diameter vascular grafts that cannot be fulfilled using autologous vessels. Although medium to large diameter synthetic vessels are in use, no suitable small diameter vascular graft has been developed due to the unique dynamic environment that exists in small vessels. To achieve long term patency, a successful tissue engineered vascular graft would need to closely match the mechanical properties of native tissue, be non-thrombotic and non-immunogenic, and elicit the proper healing response and undergo remodeling to incorporate into the native vasculature. Electrospinning presents a promising approach to the development of a suitable tissue engineered vascular graft. This review provides a comprehensive overview of the different polymers, techniques, and functionalization approaches that have been used to develop an electrospun tissue engineered vascular graft.

Prediction value of EuroSCORE II in total arterial revascularization and its usage in the evaluation of postoperative complications: Single-center experience

BACKGROUND

Total arterial revascularization is the most durable and technically the most demanding type of coronary artery bypass grafting procedure. It has proven long-term supremacy in comparison to conventional coronary artery bypass grafting. In our study, we investigated the reliability of EuroSCORE II as a predictor of intrahospital death. We showed its impact on adverse perioperative events.

METHODS

In this nonrandomized prospective study, we analyzed 116 consecutive patients who underwent the total arterial revascularization procedure at our Institute from January 2011 until the present. For myocardial revascularization, the most suitable combinations with left internal mammary artery, right internal mammary artery, and radial artery grafts were used. Main fact in this research was intrahospital mortality value in comparison with the value predicted.

RESULTS

There were 104 (89.7%) males and 12 (10.3%) females. Mean preoperative EuroSCORE II prediction value was 1.98% and postoperative we obtained 1.72%. Postoperative redo for bleeding was 6%. Positive correlation was proven between the EuoroSCORE II value and intensive care unit stay (0.452; p < 0.001). Among patients who received two internal mammary arteries, the highest EuroSCORE II was among those with presternal wound infection (p = 0.005). Patients with bilateral internal mammary arteries and diabetes showed that they have the highest values of EuroSCORE II and, at the same time, that they are extremely prone to wound problems.

CONCLUSIONS

We achieved a lower intrahospital mortality level than it was predicted with preoperative EuroSCORE II value. This tool is a reliable method for preoperative death risk calculation in this group of patients.

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

BACKGROUND AND AIM OF THE STUDY

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Preventing spasm of the radial artery conduit during coronary artery bypass grafting: Nicardipine versus verapamil

BACKGROUND AND AIM OF THE STUDY

In vitro studies have shown a reduction in radial artery spasm with the use of calcium antagonists. The purpose of this study was to evaluate the efficacy of topical treatment of the radial artery conduit using either verapamil or nicardipine before the anastomoses.

METHODS

This prospective randomized study included 131 patients, who underwent coronary artery bypass grafting surgery with the use of the radial artery as a conduit. In 65 patients, the harvested radial artery was topically treated with verapamil and in 66 patients with nicardipine. After harvesting the radial artery, the direct flow through the conduit was measured in vitro before 5-minute incubation in nicardipine or verapamil and measured again after incubation. The flow before and after incubation was compared. Postincubation flow was also compared in the two groups. After performing the anastomosis, the flow through the radial artery was measured in vivo.

RESULTS

The mean flow after NaCl incubation was 19.93 ± 12.66 mL/min and after incubation in the Ca+ channel blocker 47.16 ± 14.58 mL/min (P < .001). No significant difference in postincubation free flow was found between verapamil (46.29 ± 15.43 mL/min) and nicardipine (48.01 ± 13.77 mL/min; P = .503).

CONCLUSION

Topical treatment with Ca+ channel blockers reduces radial artery spasm and significantly increases the free flow through the radial artery conduit. Nicardipine is a safe and effective alternative of verapamil in preventing spasm of radial artery conduit.

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.

Multiarterial coronary artery bypass grafting: is the radial artery fulfilling the unkept promise of the right internal thoracic artery?

PURPOSE OF REVIEW

The debate on the second best conduit for CABG is still intense. In this review, we discuss the role of the radial artery and the right internal thoracic artery (RITA) compared with saphenous vein grafts (SVG).

RECENT FINDINGS

The recent RADIAL STUDY has been the first evidence based on randomized trials of a clinical benefit using a second arterial graft in CABG.On the other hand, the definitive 10-year results of the ART trial failed to show a clinical advantage associated with the use of bilateral internal thoracic artery (BITA). A thorough and contextualized analysis of this and other studies, however, may offer a different perspective.

SUMMARY

Arterial conduits in CABG have shown better patency rates than SVG. Whether this leads to better clinical outcomes is still debated. In this setting, the radial artery and the RITA seem to offer a similar advantage, although with different indications and contraindications.

Bilateral internal thoracic artery versus single internal thoracic artery: a meta-analysis of propensity score-matched observational studies

The lack of benefit in terms of mid-term survival and the increase in the risk of sternal wound complications published in a recent randomized controlled trial have raised concerns about the use of bilateral internal thoracic artery (BITA) in myocardial revascularization surgery. For this reason, we decided to explore the current evidence available on the subject by carrying out a meta-analysis of propensity score-matched studies comparing BITA versus single internal thoracic artery (SITA). PubMed, EMBASE and Google Scholar were searched for propensity score-matched studies comparing BITA versus SITA. The generic inverse variance method was used to compute the combined hazard ratio (HR) of long-term mortality. The DerSimonian and Laird method was used to compute the combined risk ratio of 30-day mortality, deep sternal wound infection and reoperation for bleeding. Forty-five BITA versus SITA matched populations were included. Meta-analysis showed a significant benefit in terms of long-term survival in favour of the BITA group [HR 0.78; 95% confidence interval (CI) 0.71-0.86]. These results were consistent with those obtained by a pooled analysis of the matched populations comprising patients with diabetes (HR 0.65; 95% CI 0.43-0.99). When compared with the use of SITA plus radial artery, BITA did not show any significant benefit in terms of long-term survival (HR 0.86; 95% CI 0.69-1.07). No differences between BITA and SITA groups were detected in terms of 30-day mortality or in terms of reoperation for bleeding. Compared with the SITA group, patients in the BITA group had a significantly higher risk of deep sternal wound infection (risk ratio 1.66; 95% CI 1.41-1.95) even when the pooled analysis was limited to matched populations in which BITA was harvested according to the skeletonization technique (risk ratio 1.37; 95% CI 1.04-1.79). The use of BITA provided a long-term survival benefit compared with the use of SITA at the expense of a higher risk of sternal deep wound infection. The long-term survival advantage of BITA is undetectable when compared with SITA plus radial artery.

Right internal thoracic or radial artery as the second arterial conduit for coronary artery bypass surgery

PURPOSE OF REVIEW

To summarize the available evidence on the use of the right internal thoracic artery (RITA) and the radial artery as the second arterial graft in coronary artery bypass surgery.

RECENT FINDINGS

The current data support the equipoise of the two conduits in terms of clinical and angiographic outcomes. Both RITA and radial artery have better patency than saphenous vein grafts. The use of the RITA carries an increased risk of deep sternal wound infection (DSWI) if the artery is harvested as pedicle. Bilateral internal thoracic artery grafting is more technically demanding than radial artery use and there is a volume-outcome relationship in terms of mortality and incidence of DSWI. The radial artery is preferable over RITA in right-sided or distal circumflex artery targets with high-degree stenosis and in patients at higher risk for DSWI, whereas it is not recommended to graft vessels with moderate stenosis and in cases of insufficient collateralization from the ulnar artery or previous transradial procedures.

SUMMARY

The patency rate and clinical outcomes of radial artery and RITA are similar. The use of one or the other should be based on a careful evaluation of the patient's coronary anatomy and comorbidities, the conduit availability and the surgeon's and center's experience.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposures

Multiple arterial grafting or LITA+SVG.

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

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

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

The Risk Factor Analysis for the Late Graft Failure of Radial Artery Graft in Coronary Artery Bypass Grafting

Objective: The aim of this retrospective study was to investigate the early operative results and detect the factors influencing the fate of radial artery grafts (RAGs) by evaluating the mid-term patency.

Methods: We retrospectively reviewed 410 patients who underwent isolated coronary artery bypass grafting using RAG. RAGs were anastomosed to 526 coronary arteries. Mid-term angiography was performed in 214 patients at an average 4.9 years after the operation.

Results: The early patency of RAGs was 97.6%. Cumulative 5-year patency was 86.5% for RAG, 94.1% for LITA graft, and 81.0% for saphenous vein graft (SVG). RAG was significantly superior to SVG in mid-term patency. Individual grafting (not sequential grafting) (hazard ratio [HR]: 2.535; 95% confidence interval [CI]: 1.293–5.281; p = 0.006) and grafting to the target coronary artery with ≤75% proximal stenosis (HR: 1.947; 95% CI: 1.090–3.484; p = 0.025) were found to be independent risk factors influencing late RAG patency.

Conclusions: The patency of RAGs was superior to that of SVGs in the studied population. When using RAGs, grafting to the target vessel with severe proximal stenosis is favorable. The RAG is suitable for sequential grafting.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The radial artery in coronary surgery, 2018

It is now 25 years since the radial artery (RA) was reintroduced in coronary surgery. It has evolved into being a significant coronary artery bypass conduit and ranks third in usage after the internal thoracic artery (ITA) and saphenous vein grafts (SVG). Its advantages are that it can be readily and efficiently harvested, is of good length and appropriate size for coronary artery bypass graft (CABG) surgery, is robust and easy to handle, and remains free of atheroma, and there is minimal wound morbidity. The RA must be used judiciously with attention to spasm prophylaxis because of its muscular wall, and by avoiding competitive flow. Its patency is equivalent to the ITAs when placed to similar coronary territories and under similar conditions (stenosis, size, quality) and RA patencies are always superior to those of SVG in both observational and randomized studies-88-90% versus 50-60% at 10 years, and 80-87% versus 25-40% at 20 years. Its use and excellent patencies result in survival results equivalent to bilateral internal thoracic artery (BITA) grafting and always superior to left internal thoracic artery (LITA) +SVG. Typical radial artery multiarterial bypass grafting (RA-MABG) 10-year survivals are 80-90% versus 70-80% for LITA-SVG. In general, for every 100 patients undergoing CABG, 10 more patients will be alive at 10 years post-operatively. The RA also is important in achieving total arterial revascularization, and several reports indicate a further survival advantage for patients having three arterial grafts over two. The RAs are especially useful in diabetic, morbidly obese patients, those with conduit shortage, and leg pathology, and in coronary reoperations. Although the RA has equivalent patencies to the right internal thoracic artery (RITA), it is much more versatile. RAs that have been instrumented by angiography or percutaneous coronary intervention should be avoided. The radial artery has proved to be an excellent arterial conduit, is equivalent to but more versatile than the RITA, and is always superior to SVG. Its use should be part of every coronary surgeon's skill set.

Long term outcomes of radial artery grafting in patients undergoing coronary artery bypass surgery

Single arterial left internal thoracic artery (LITA) based coronary artery bypass surgery (LITA-SABG) has been the principal revascularization strategy for over 25 years across all patient demographics. In line with the current emphasis being placed on personalized medicine, which tailors individual, patient-specific therapy to optimize outcomes, coronary artery bypass grafting (CABG) techniques have also evolved to achieve enhanced results among specific groups of patients with coronary artery disease. Most notable has been the development of multi-arterial bypass grafting (MABG) techniques, using either the radial artery (RA) or the right internal thoracic artery (RITA) in conjunction with the LITA, as both techniques have been shown to enhance long term survival of CABG patients. This article reviews the latest data on the long-term outcomes of RA-MABG and considers its impact in various sub-cohorts of CABG that are increasingly being treated by cardiac surgeons. The primary aim of this review is to highlight the advantages of RA-MABG over LITA-SABG and thereby potentiate its adoption into clinical practice. Our secondary aim is to summarize the results of RA-MABG in specific CABG sub-cohorts, to more closely align CABG surgery with the emerging consensus that personalized medicine enhances healthcare value.

Optimal management of radial artery grafts in CABG: Patient and target vessel selection and anti-spasm therapy

The current literature on radial artery grafting is reviewed focusing on the optimal deployment of radial artery grafts in coronary artery bypass surgery with specific attention to the selection of patients and target vessels for radial artery grafting.

The Surgical Treatment of Coronary Artery Occlusive Disease: Modern Treatment Strategies for an Age Old Problem

Coronary artery disease remains a formidable challenge to clinicians. Percutaneous interventions and surgical techniques for myocardial revascularization continue to improve. Concurrently, in light of emerging data, multiple practice guidelines have been published guiding clinicians in their therapeutic decisions. The multidisciplinary Heart Team concept needs to be embraced by all cardiovascular providers to optimize patient outcomes.

Right internal thoracic artery or radial artery? A propensity-matched comparison on the second-best arterial conduit

OBJECTIVES

We conducted propensity score matching to determine whether the use of the right internal thoracic artery (RITA) confers a survival advantage when compared with the radial artery (RA) as second arterial conduit in coronary artery bypass grafting.

METHODS

The study population included a highly selected low-risk group of patients who received the RITA (n = 764) or the RA (n = 1990) as second arterial conduit. We obtained 764 matched pairs that were comparable for all pretreatment variables. A time-segmented Cox regression model that stratified on the matched pairs was used to investigate the effect of treatment on late mortality.

RESULTS

After a mean follow-up of 10.2 ± 4.5 years (maximum 17.3 years), survival probabilities at 5, 10, and 15 years were 96.4% ± 0.7% versus 95.4% ± 0.7%, 91.0% ± 1.1% versus 89.1% ± 1.2%, and 82.4% ± 1.9% versus 77.2% ± 2.5% in the RITA and RA groups, respectively. During the first 4 years, RITA and RA were comparable in terms of mortality (hazard ratio [HR], 1.00; 95% confidence interval [CI], 0.56-1.78; P = .98). However, after 4 years RITA was associated with a significant reduction in late mortality (HR, 0.67; 95% CI, 0.48-0.95; P = .02). RITA was superior to RA when the experimental conduit was used to graft the left coronary system (HR, 0.69; 95% CI, 0.47-0.99; P = .04) but not the right coronary system (HR, 0.98; 95% CI, 0.59-1.62; P = .93).

CONCLUSIONS

In a highly selected low-risk group of patients, the use of the RITA as second arterial conduit instead of the RA was associated with better survival when used to graft the left but not the right coronary artery.

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.

Multiple arterial grafting for coronary revascularization: "A guide for the perplexed"

The surgical literature abounds with articles extolling the benefits of arterial grafting for patients with advanced coronary artery disease in need of surgical revascularization. However, examination of clinical performance demonstrates that extensive use of arterial grafting is highly selective and generally uncommon. Rather than to merely repeat multiple excellent recent literature reviews, the goal herein is to provide the reader with a guide to the evaluation of the current literature as well as to suggest fruitful areas for further research. More circumspect understanding of the strengths and weaknesses of our current knowledge base will not only help to explain the current apparent disparity between theory and practice but will hopefully inform future decision-making and patient care.

The Choice of Conduits in Coronary Artery Bypass Surgery

Coronary artery bypass grafting is the most common cardiac surgery operation performed worldwide. It is the most effective revascularization method for several categories of patients affected by coronary artery disease. Although coronary artery bypass grafting has been performed for more than 40 years, no detailed guidelines on the choice of coronary artery bypass grafting conduits have been published and the choice of the revascularization strategy remains more a matter of art than of science. Moreover, there is a clear contradiction between the proven benefits of arterial grafting and its very limited use in everyday clinical practice. In the hope of encouraging wider diffusion of arterial revascularization and to provide a guide for clinicians, we discuss current evidence for the use of different conduits in coronary artery bypass surgery and propose an evidence-based algorithm for the choice of the second conduit during coronary artery bypass operations.

Long-term outcome of revascularization with composite T-grafts: Is bilateral mammary grafting better than single mammary and radial artery grafting?

OBJECTIVE

Bilateral internal mammary artery (BIMA) grafting is associated with improved survival. However, many surgeons are reluctant to use this technique, owing to the potentially increased risk of sternal infection. The composite T-graft with radial artery (RA) attached end-to-side to the left internal mammary artery (IMA) provides complete arterial revascularization without increased risk of sternal infection. The purpose of this study is to compare outcomes of these 2 strategies.

METHODS

Patients who underwent BIMA grafting using the composite T-graft technique, between 1996 and 2010 (n = 1329), were compared with 389 patients who underwent composite grafting with a single IMA + RA during the same time period.

RESULTS

Patients undergoing single IMA grafting were older, more often women, and more likely to have diabetes, peripheral vascular disease, and COPD, and to need an emergency operation. Congestive heart failure, left main disease, and recent myocardial infarction were more prevalent with bilateral grafting. Propensity-score matching was used to account for differences between groups in preoperative patient characteristics. The 268 matched pairs had similar characteristics. The median follow-up time was 14.19 (95% confidence interval 13.43-14.95) years. Operative mortality and Kaplan-Meier 10-year survival of the 2 matched groups were similar (3.4% vs 3.7%, and 61.6% vs 64%, for the groups treated with BIMA and single IMA, respectively). Cox-adjusted survival was similar (P = .514). Age, chronic renal failure, and performance of <3 bypass grafts were independent predictors of decreased survival.

CONCLUSIONS

This study suggests that long-term outcomes of arterial revascularization with a composite T-graft constructed using left IMA and RA are not inferior to outcomes after BIMA grafting.

Effect of modified proximal anastomosis of the free right internal thoracic artery: piggyback and foldback techniques

OBJECTIVES

Few studies have reported the free right internal thoracic artery (RITA) being used in an aorto-coronary fashion. This study aimed to evaluate the free RITA with modified proximal anastomosis in an aorto-coronary fashion.

METHODS

Between January 2000 and December 2012, 282 patients underwent coronary artery bypass grafting with bilateral internal thoracic arteries for complete revascularization of the left coronary system at our institution. The left internal thoracic artery (LITA) was anastomosed to the left anterior descending artery (LAD) and the RITA was anastomosed to the left circumflex branches (LCX). The RITA was used as a free graft in 213 patients (free group) and as an in situ graft in 69 patients (in situ group). Proximal anastomosis of the free RITA onto the ascending aorta was performed in two different ways. We compared early and late results and graft patency of the free RITA with those of the in situ RITA retrospectively.

RESULTS

The numbers of anastomoses per patient and anastomoses of the RITA were larger in the free group than in the in situ group (P < 0.01). There was no significant difference in postoperative survival between the groups (free group: 93.3% vs in situ group: 90.0%, P = 0.82). The 5-year patency of the free RITA was higher than that of the in situ RITA (97.0 vs 80.3%, P = 0.01). The 5-year patency of the free RITA was comparable with that of the in situ LITA anastomosed to the LAD (97.0 vs 92.9%, P = 0.28).

CONCLUSIONS

The free RITA anastomosed to the LCX might have better late patency than the in situ RITA. The free RITA with modified proximal anastomosis in an aorto-coronary fashion enables complete revascularization of the left coronary system with the in situ LITA to the LAD.

The Society of Thoracic Surgeons Clinical Practice Guidelines on Arterial Conduits for Coronary Artery Bypass Grafting

Internal thoracic arteries (ITAs) should be used to bypass the left anterior descending (LAD) artery when bypass of the LAD is indicated (class of recommendation [COR] I, level of evidence [LOE] B). As an adjunct to left internal thoracic artery (LITA), a second arterial graft (right ITA or radial artery [RA]) should be considered in appropriate patients (COR IIa, LOE B). Use of bilateral ITAs (BITAs) should be considered in patients who do not have an excessive risk of sternal complications (COR IIa, LOE B). To reduce the risk of sternal infection with BITA, skeletonized grafts should be considered (COR IIa, LOE B), smoking cessation is recommended (COR I, LOE C), glycemic control should be considered (COR IIa, LOE B), and enhanced sternal stabilization may be considered (COR IIb, LOE C). As an adjunct to LITA to LAD (or in patients with inadequate LITA grafts), use of a RA graft is reasonable when grafting coronary targets with severe stenoses (COR IIa, LOE: B). When RA grafts are used, it is reasonable to use pharmacologic agents to reduce acute intraoperative and perioperative spasm (COR IIa, LOE C). The right gastroepiploic artery may be considered in patients with poor conduit options or as an adjunct to more complete arterial revascularization (COR IIb, LOE B). Use of arterial grafts (specific targets, number, and type) should be a part of the discussion of the heart team in determining the optimal approach for each patient (COR I, LOE C).