What is the best graft to supplement the bilateral internal thoracic artery to the left coronary system? A meta-analysis

Preoperative Computed Tomography of the Right Gastroepiploic Artery for Coronary Artery Bypass Grafting

BACKGROUND

Grafting the right gastroepiploic artery (GEA) to the right coronary artery (RCA) is effective, but preoperative evaluation of arterial conduit availability has not been established. By comparing the midterm graft results, we aimed to assess the efficacy of preoperative evaluation of the GEA using computed tomography (CT).

METHODS AND RESULTS

We retrospectively examined patients who underwent isolated coronary artery bypass grafting surgery between April 2010 and December 2020, and those whose GEA was grafted to the RCA were selected: 55 patients were included in the study analysis. Postoperative evaluations were performed during the early phase, 1 year postoperatively, and at follow-up evaluations. The outer diameter of the proximal GEA was compared with the midterm graft patency grade on CT and patients were classified as Functional (Grade A) or Dysfunctional (Grades O or B). The proximal GEA outer diameters were significantly different between the Functional and Dysfunctional groups (P<0.001). Furthermore, multivariate Cox regression analysis revealed that this diameter was an independent predictor of graft functionality (P<0.001). Patients with outer proximal diameters larger than the cutoff value had superior graft results at 3 years postoperatively. The rate of freedom from a dysfunctional graft at 3 years postoperatively was 95.5% and 45.5% for the Larger and Smaller diameter subgroups, respectively (P<0.001).

CONCLUSIONS

Preoperative evaluation of the outer diameter of the proximal GEA, excluding calcified GEA, using CT is a minimally invasive and useful method, and may improve midterm results of in-situ GEA grafting, even in severe stenotic lesions.

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

PREAMBLE

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

Anterolateral territory coronary artery bypass grafting strategies: a non-inferiority randomized clinical trial: the AMI-PONT trial

OBJECTIVES

The main objective was to assess whether a composite coronary artery bypass grafting strategy including a saphenous vein graft bridge to distribute left internal mammary artery outflow provides non-inferior patency rates compared to conventional grafting surgery with separated left internal mammary artery to left anterior descending coronary graft and aorto-coronary saphenous vein grafts to other anterolateral targets.

METHODS

All patients underwent isolated grafting surgery with cardiopulmonary bypass and received ≥2 grafts/patients on the anterolateral territory. The graft patency (i.e. non-occluded) was assessed using multislice spiral computed tomography at 1 year.

RESULTS

From 2012 to 2021, 208 patients were randomized to a bridge (n = 105) or conventional grafting strategy (n = 103). Patient characteristics were comparable between groups. The anterolateral graft patency was non-inferior in the composite bridge compared to conventional grafting strategy at 1 year [risk difference 0.7% (90% confidence interval -4.8 to 6.2%)]. The graft patency to the left anterior descending coronary was no different between groups (P = 0.175). Intraoperatively, the bridge group required shorter vein length for anterolateral targets (P < 0.001) and exhibited greater Doppler flow in the mammary artery pedicle (P = 0.004). The composite outcome of death, myocardial infarction or target vessel reintervention at 30 days was no different (P = 0.164).

CONCLUSIONS

Anterolateral graft patency of the composite bridge grafting strategy is non-inferior to the conventional grafting strategy at 1 year. This novel grafting strategy is safe, efficient, associated with several advantages including better mammary artery flow and shorter vein requirement, and could be a valuable alternative to conventional grafting strategies. Ten-year clinical follow-up is underway.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01585285.

Saphenous Vein versus Arterial Graft to the Right System in Left-sided Arterial Revascularization

BACKGROUND

To investigate clinical outcomes of various arterial grafts (AGs) vs. saphenous vein grafts (VGs) to the right coronary system in patients who received left-side bilateral internal thoracic artery revascularization.

METHODS

We compared short- and long-term outcomes of all the patients operated in our center during 1996-2011, who received left-sided bilateral internal thoracic artery (left anterior descending and left circumflex) grafting and either a VG or an AG to the right coronary system.

RESULTS

Of 1691 patients, 983 received a VG and 708 received an AG to the right coronary system: 387 gastroepiploic arteries and 321 internal thoracic artery grafts. The median follow-up was 15.7 ± 0.32 years. For the VG and AG groups, early mortality (1.6% for VG and 1.3% for AG, p=0.55) and other early adverse outcomes did not differ. Long-term (up to 20 years) survival was similar (34.1 +/- 3.4% for VG vs. 36.0 +/-2% for AG, p=0.86). In multivariable analysis, VG to the right coronary artery was not found to be a predictor of inferior survival (hazard ratio: 0.99 95%CI 0.836-1.194, p=0.99). Comparing two propensity matched groups of 349 pairs with a VG or an AG, and accounting for the severity of the right coronary lesion, did not demonstrate differences in early outcome or late survival between the groups.

CONCLUSIONS

Early outcomes and long-term survival were comparable among patients who received left-sided bilateral internal thoracic artery revascularization, between various graft types to the right coronary system.

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.

Does the Addition of a Gastroepiploic Artery to Bilateral Internal Thoracic Artery Improve Survival?

It is unclear whether the additional conduit to supplement bilateral internal thoracic arteries (BITA) influences the patient outcome in coronary surgery. This retrospective study compared long-term survival of patients undergoing left-sided BITA grafting in which the third conduit to the right coronary system (RCA) was either vein graft (SVG) or gastroepiploic artery (GEA). From 1989 to 2014, 1432 consecutive patients underwent left-sided revascularization with BITA associated with SVG (n = 599) or GEA (n = 833) to RCA. Propensity score was calculated by logistic regression model and patients were matched 1 to 1 leading to 2 groups of 320 matched patients. The primary end point was the overall mortality from any cause. GEA was used in significantly lower risk patients. The 30-day mortality was 1.6% without influence of the graft configuration. Postoperative follow-up was 13.6 ± 6.6 years and was 94% complete. The significant difference in patients' survival observed at 20 years in favor of GEA in unmatched groups (48 ± 4% vs 33 ± 6%, P < 0.001) was not confirmed in matched groups (41 ± 7% vs 36 ± 7%, P = 0.112). In multivariable Cox model analysis, the conduit used to RCA did not influence the long-term survival in matched groups, like no other graft configuration or operative parameter. Only complete revascularization remained predictor of survival (P = 0.016), with age (P < 0.0001), diabetes status (P = 0.007), and left ventricle ejection fraction (P < 0.0001). Long-term survival in patients undergoing BITA grafting is not affected by using GEA as third arterial conduit in alternative to SVG. Further studies are necessary to assess its impact on long-term cardiac events.

How decisive is the number of distal arterial anastomoses in coronary bypass surgery?

Background

The benefit of arterial revascularization in coronary surgery remains controversial. The incremental value of additional grafts to the left internal thoracic artery (ITA) has been mainly assessed according to the number of arterial grafts, possibly limiting the detection of its actual impact. We analyzed the influence of the number of distal arterial anastomoses (DAA) performed on late mortality in patients having received from one to three arterial grafts.

Methods

Retrospective review of 3685 primary isolated coronary artery bypass grafting (CABG) performed from 1989 to 2014 was conducted with a 13-year mean follow-up. One arterial graft (SITA) was used in 969 patients, two arterial grafts, ITA or gastroepiploic artery (GEA), in 1883 patients (BITA: 1644; SITA+GEA: 239), and three arterial grafts in 833 patients (BITA+GEA). Totally, 795 patients (22%) received one DAA, 1142 patients (31%) two, 1337 patients (36%) three, and 411 patients (11%) four or more. A sub-group analysis was done in the 2104 patients with 3-vessel disease who received at least 2 arterial grafts.

Results

In this series the early mortality was 1.6% and it was not influenced by the surgical technique. Late mortality was significantly influenced by age, gender, heart failure, LV ejection fraction, diabetes status, complete revascularization, number of arterial grafts, number of DAA, both ITA, sequential ITA graft, GEA graft. In multivariable analysis with Cox regression model, the number of DAA was the only technical significant independent prognosis factor of late survival (p < 0.0001), predominant over both ITA, complete revascularization and number of arterial grafts. The impact of the number of DAA on survival was found discriminant from 1 to 3; after 3 there was no more additional effect. In 3-vessel disease patients who received at least 2 arterial grafts, the number of DAA remained a significant independent prognosis factor of late survival (p < 0.0001).

Conclusions

The number of distal arterial anastomoses is an independent predictor of long-term survival, predominant over the number of arterial grafts and the completeness of the revascularization; higher the number, better the late survival. It is a strong support of the extensive use of arterial grafting in CABG.

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.

Total arterial revascularization strategies: A meta-analysis of propensity score-matched observational studies

BACKGROUND AND AIM OF THE STUDY

We explored the current evidence available on total arterial revascularization (TAR) carrying out a meta-analysis of propensity score-matched studies comparing TAR versus non-TAR strategy.

METHODS

PubMed, EMBASE, and Google Scholar were searched for propensity score-matched studies comparing TAR vs non-TAR. The generic inverse variance method was used to compute the combined hazard ratio (HR) of long-term mortality. The Der-Simonian and Laird method were used to compute the combined risk ratio (RR) of 30-day mortality, deep sternal wound infection, and reoperation for bleeding.

RESULTS

Eighteen TAR vs non-TAR matched populations were included. Meta-analysis showed a significant benefit in terms of long-term survival of the TAR group over the non-TAR group (HR: 0.73; 95% confidence interval [CI]: 0.68-0.78). Better long-term survival over non-TAR strategy was confirmed by both subgroups: TAR with the bilateral internal mammary artery (BIMA) and TAR without BIMA. Meta-regression suggests that TAR may offer a higher protective survival effect in diabetic patients (coefficient: -0.0063; 95% CI: -0.01 to 0.0006), when carried out with BIMA (coefficient: -0.15; 95% CI: -0.27 to -0.03) or using three arterial conduits (coefficient: -0.12; 95% CI: -0.25 to 0.007). A TAR strategy carried out using BIMA, differently from TAR without BIMA, increases the risk of deep sternal infection (RR: 1.44; 95% CI: 1.17-1.77).

CONCLUSIONS

TAR provides a long-term survival benefit compared with the non-TAR strategy. Also, compared with TAR without BIMA, TAR with BIMA may offer a higher protective long-term survival effect at the expense of a higher risk of sternal deep wound infection.