Time-Varying Association of the Second Internal Thoracic Artery with Long-Term Survival after Coronary Artery Bypass Grafting

The survival advantages of bilateral internal thoracic artery (BITA) grafts in coronary artery bypass grafting (CABG) surgery remain unclear. Therefore, this study aims to systematically evaluate the time-dependent influence of BITA on long-term survival in elective CABG patients presenting with stable multivessel coronary artery disease.Data from 3,693 patients undergoing isolated CABG with single internal thoracic artery (SITA) or BITA, with or without additional vein grafts, between 2002 and 2012 were retrospectively analyzed. The entire cohort was divided into BITA and SITA groups (830 vs. 2,863 patients). A 1:3 propensity score matching was performed. Subsequent analysis of a subgroup meeting Randomized comparison of the clinical Outcome of single versus Multiple Arterial grafts (ROMA) trial criteria (n = 1,339) followed a 1:1 matching. Differences in restricted mean survival time (RMST) estimates were used to assess the time-varying association of BITA with long-term survival.In-hospital mortality (SITA 1.8% vs. BITA 1.1%, p = 0.2) and major postoperative complications were similar between the matched groups. However, long-term survival was significantly higher in BITA patients for the matched whole cohort (15-year survival: 64 vs. 51%, respectively; p < 0.001) and the ROMA-like population (76 vs. 60%, respectively; p < 0.001). RMST demonstrated an incremental survival advantage of BITA over SITA grafting over time for both the whole and ROMA-like populations (0.1, 0.5, and 1.1 years, and 0.1, 0.4, and 1.0 years at 5-, 10-, and 15-year follow-up, respectively)BITA grafting is safe and associated with superior long-term survival compared with SITA and vein grafts, with benefits extending beyond 5 years for the entire cohort and beyond 10 years for ROMA criteria patients.

Robot-Assisted Minimally Invasive Coronary Artery Bypass Grafting: Total Arterial Revascularization Using the Double-Docking Technique

OBJECTIVE

The right internal mammary artery is considered to be the second choice for arterial conduits for coronary artery bypass grafting (CABG). However, the widespread use of bilateral internal mammary artery (BIMA) grafting is limited owing to increased technical demands, lengthy procedure, and high incidence of sternal wound complications. We compared the early clinical outcomes of a novel robot-assisted double-docking technique (DDT) with an open sternotomy technique for total arterial revascularization using BIMA.

METHODS

Between June 2019 and June 2023, 445 patients with multivessel coronary artery disease underwent open sternotomy CABG using BIMA grafting and 145 patients underwent robot-assisted BIMA grafting using DDT. Comparative analysis of 104 pairs of matched patients obtained using propensity score matching was performed. Procedural characteristics, postoperative 30-day mortality, and composite outcome (major adverse cardiac and cerebrovascular events) at a median follow-up of 1.5 years were evaluated.

RESULTS

Preprocedural characteristics were well balanced between the groups after propensity matching. The number of distal anastomoses performed in the conventional group was statistically higher than that performed using DDT (P < 0.001). The durations of postsurgical ventilation, intensive care unit stay, and in-hospital stay were significantly lower with the DDT than with conventional CABG (P < 0.001). There was no significant difference in all-cause mortality or major adverse cardiac events between the DDT and conventional CABG groups at a median follow-up of 1.5 years.

CONCLUSIONS

The DDT is feasible and efficacious for revascularization of multiple coronary targets in select individuals. It is equivalent to open sternotomy in terms of early clinical outcomes and superior to open sternotomy with regard to rates of sternal infection and intensive care unit and in-hospital stay.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Early and late outcomes of single versus bilateral internal thoracic artery revascularization for patients in critical condition

OBJECTIVE

The optimal surgical approach for critically ill patients with complex coronary disease remains uncertain. We compared outcomes of bilateral internal thoracic artery (BITA) versus single ITA (SITA) revascularization in critical patients.

METHODS

We evaluated 394 consecutive critical patients with multi-vessel disease who underwent CABG during 1996-2001. Outcomes measured were early mortality, strokes, myocardial-infarctions, sternal infections, revisions for bleeding, and late survival. The critical preoperative state was acknowledged concisely by one or more of the following: preoperative ventricular tachycardia/fibrillation, aborted sudden cardiac death, or the need for mechanical ventilation or for preoperative insertion of intra-aortic-balloon counter-pulsation.

RESULTS

During the study period, 193 of our patients who underwent SITA and 201 who underwent BITA were in critical condition. The SITA group was older (mean 68.0 vs. 63.3 years, p = 0.001) and higher proportions were females (28.5% vs. 18.9% p = 0.025), after recent-MI (69.9% vs. 57.2% p = 0.009) and with left-main disease (38.3% vs. 49.3% p = .029); the median logistic EuroSCORE was higher (0.2898 vs. 0.1597, p<0.001). No statistically significant differences were observed between the SITA and BITA groups in 30-day mortality; and in rates of early CVA, MI and sternal infections (13.0% vs. 8.5%, p = 0.148; 4.1% vs. 6.0%, p = 0.49; 6.7% vs. 4.5%, p = 0.32 and 2.1% vs. 2.5%, p>0.99, respectively). Long-term survival (median follow-up of 15 years, interquartile-range: 13.57-15) was better in the BITA group (median 14.39 vs. 9.31± 0.9 years, p = 0.001). Propensity-score matching (132 matched pairs) also yielded similar early outcomes and improved long-term survival (median follow-up of 15 years, interquartile-range: 13.56-15) for the BITA group (median 12.49±1.71 vs. 7.63±0.99 years, p = 0.002). In multivariable analysis, BITA revascularization was found to be a predictor for improved survival (hazard-ratio of 0.419, 95%CI 0.23-0.76, p = 0.004).

CONCLUSIONS

This study demonstrated long-term survival benefit for BITA revascularization in patients in a critical pre-operative state who presented for surgical revascularization.

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.

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.

Bilateral internal thoracic artery use in coronary artery bypass grafting in the post-ART era - Perspective

There is still lack of convincing evidence about the superiority of bilateral internal thoracic artery (BITA) use in coronary artery bypass grafting (CABG) and BITA grafts continue to be underutilized. Arterial Revascularization Trial (ART) did not demonstrate the superiority of BITA versus single ITA grafting after 10 years. We have reviewed the most recent literature, assessed the current status as well as indications of BITA grafting in the post-ART era. We believe that BITA grafting is not appropriate for all patients especially in light of the findings of ART. However, the use of BITA is justified in patients of younger age and those without comorbidities (poorly controlled diabetes, obesity, chronic obstructive pulmonary disease, previous mediastinal irradiation, long-term steroid use, elderly women). Further prospective randomized studies with long-term follow-up are needed to validate the benefits of BITA grafting.

Is gender a risk factor for bilateral internal thoracic artery grafting? A twenty-year follow-up

BACKGROUND

Although bilateral internal thoracic artery (BITA) grafting is associated with improved survival, many surgeons are reluctant to use this technique, especially in female patients, due to its greater complexity and potential increased risk of sternal infection. The aim of this study was to compare the outcomes of male and female patients who underwent BITA grafting.

METHODS

We evaluated at the early outcome and late mortality, 551 female versus 2525 male patients who underwent isolated BITA grafting between January 1996 and December 2011. To adjust for differences in demographic and clinical characteristics, a multivariate risk analysis and propensity score matching were performed. Kaplan-Meier analysis was performed for the entire cohort and for the matched cohort.

RESULTS

Female patients were older and were more likely than males to have congestive heart failure, unstable angina pectoris, and diabetes. Sternal infection was more frequent in females than males (3.3% vs. 1.8%; p = .04). Differences were not observed in operative mortality (2.9% vs. 1.9%; p = .15) and stroke incidence (3.4% vs. 2.6; p = .30). After multivariate risk analysis and propensity score matching, the female gender was not found to be a predictor of worse outcomes. There was no difference in median survival among female and male patients (14.3 and 14.2 years, respectively; p = .68).

CONCLUSION

Our results support the routine use of BITA grafting in proper selected female patients who undergo myocardial revascularization.

Sex differences after coronary artery bypass grafting with a second arterial conduit

OBJECTIVES

Double arterial conduit use during coronary artery bypass grafting is associated with improved clinical outcomes compared with single arterial conduits in the general population. However, the sex-specific outcomes of this strategy remain unknown and are needed to inform sex-specific revascularization guidelines.

METHODS

We conducted a population-based, retrospective cohort study of all Ontarians who underwent primary isolated coronary artery bypass grafting with single arterial conduits or double arterial conduits between October 2008 and September 2017. The primary outcome was all-cause mortality. Secondary outcomes included major adverse cardiac and cerebrovascular events, defined as a composite of myocardial infarction, heart failure hospitalization, repeat revascularization, and stroke. We used inverse probability of treatment weighting to account for group imbalances.

RESULTS

A total of 9135 women and 36,748 men underwent coronary artery bypass grafting. At 30 days, there was no between-group difference in mortality or major adverse cardiac and cerebrovascular events in men. However, among women, a double arterial conduit was associated with an increased rate of 30-day death (hazard ratio, 1.48; 95% confidence interval, 1.23-1.79) and major adverse cardiac and cerebrovascular events (hazard ratio, 1.32; 95% confidence interval, 1.14-1.51). The risk of medium-term mortality with double arterial conduits was less in men (hazard ratio, 0.88; 95% confidence interval, 0.84-0.92) and women (hazard ratio, 0.87; 95% confidence interval, 0.81-0.94), as was the medium-term risk of major adverse cardiac and cerebrovascular events (hazard ratio, 0.91; 95% confidence interval, 0.87-0.94) [men]; hazard ratio, 0.91; 95% confidence interval, 0.86-0.97) [women]). The incremental improvement in 9-year survival was 4.0% in women with a double arterial conduit and 0.9% in men.

CONCLUSIONS

Double arterial conduit is associated with better medium-term survival and cardiovascular outcomes in both sexes. Double arterial conduits are associated with increased perioperative risk in women, but the medium-term benefit is greater than in men.