Equipoise between radial artery and right internal thoracic artery as the second arterial conduit in left internal thoracic artery-based coronary artery bypass graft surgery: a multi-institutional study†

The Best Second Arterial Conduit for Coronary Artery Bypass Grafting: A Meta-Analysis of Reconstructed Individual Patient Data

Multiple arterial conduit revascularization in coronary bypass surgery is being advocated over the use of venous conduits. However, there is a critical gap regarding the optimal sequence of arterial conduit selection following the left internal thoracic artery. This study is the first individual patient data meta-analysis, which aimed to compare the right internal thoracic artery (RITA) versus the radial artery (RA) as a second-best arterial conduit. A comprehensive literature search was conducted in MEDLINE, Embase, Scopus, and CENTRAL. A forward-backward citation check was performed to identify other relevant studies. The study protocol was registered in the PROSPERO (CRD42023455543). Eligible studies included randomized controlled trials and propensity-score-matched cohort studies reporting long-term outcomes (>3 years) after coronary bypass surgery using the RITA versus RA as the second arterial conduit after left internal thoracic artery. Overall, long-term survival between the RITA and RA groups showed no significant difference. Landmark analyses demonstrated the superiority of RITA as a second arterial conduit at 1 [hazard ratio (HR): 0.86 (95% CI, 0.75-0.99), P = 0.036], 2 [0.83 (95% CI, 0.72-0.96), P = 0.011], and 5 years [HR: 0.80 (95% CI, 0.68-0.95), P = 0.036] post-surgery. Freedom from major cardiovascular events was significantly higher using the RITA conduit [HR: 0.72 (95% CI, 0.59-0.89), P = 0.002]. This study supports the use of RITA, especially when used in a skeletonized in situ fashion, as a second choice following the left internal thoracic artery as it has the potential to enhance long-term survival and outcomes. Further research with standardized surgical techniques is warranted.

Impact of Incomplete Revascularization on Long-term Survival Based on Revascularization Strategy

BACKGROUND

This study investigated the impact of complete revascularization (CR) and incomplete revascularization (IR) on long-term survival in patients undergoing isolated coronary artery bypass grafting (CABG) using multiple arterial graft (MAGs) or a single artery with saphenous vein grafts (SAGs).

METHODS

Between January 2006 and December 2020, 12,625 patients underwent CABG and were divided into 4 groups: MAG CR (n = 1066), MAG IR (n = 286), SAG CR (n = 8360), and SAG IR (n = 2913). Inverse probability of treatment weighting based on the generalized propensity score was used to minimize imbalance between the groups.

RESULTS

In the weighted cohort, median follow-up time was 8.35 years (interquartile range, 5.01-11.6 years). MAG CR was associated with similar long-term survival compared with MAG IR (hazard ratio [HR], 0.79; 95% CI, 0.60-1.03; P = .084). SAG CR was associated with improved long-term survival compared with SAG IR (HR, 0.67; 95% CI, 0.52-0.84; P = .01). MAG CR was associated with better long-term survival compared with SAG CR (HR, 0.45; 95% CI, 0.35-0.57; P < .001). Moreover, MAG IR was protective compared with SAG IR (HR, 0.62; 95% CI, 0.45-0.85; P = .033). Additional analysis was performed comparing perfect CR vs imperfect CR vs IR in MAG and SAG patients, separately. In the weighted sample of MAG, there were no differences in the long-term survival between perfect CR, imperfect CR, and IR. However, in the weighted sample of the SAG cohort, SAG perfect CR was associated with improved survival compared with SAG imperfect CR (HR, 0.81; 95% CI, 0.0.72-0.92; P = .001). Whereas, SAG perfect and imperfect CR were both associated with improved survival compared with SAG IR (HR, 0.51; 95% CI, 0.0.35-0.87; P = .006 and HR, 0.72; 95% CI, 0.64-0.82; P < .001), respectively.

CONCLUSIONS

MAG CR is associated with better survival compared with SAG CR. If IR is inevitable, patients with MAG IR had better long-term survival compared with patients receiving SAG IR. Moreover, similar long-term survival is observed whether perfect CR, imperfect CR, or IR is achieved in the MAG population but not in SAG patients.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Radial artery vs right internal mammary artery as a second conduit during coronary artery bypass grafting

OBJECTIVE

To compare the clinical outcomes of radial artery (RA) grafts during CABG to those of right internal mammary artery (RIMA) grafts.

METHODS

This was a retrospective, single-institution cohort study of isolated CABG with multiple grafts between 2010-2022. To balance graft cohorts, propensity score matching (PSM) was performed using a 1:1 match ratio. Long-term postoperative survival was compared among RA and RIMA groups. Similarly, major adverse cardiac and cerebrovascular events (MACCE) were compared among both cohorts, with MACCE comprising death, myocardial infarction (MI), coronary revascularization, and stroke. Kaplan-Meier estimation was performed for mortality, while cumulative incidence estimation was utilized for MACCE.

RESULTS

A total of 8,774 patients underwent CABG. Of those, 1,674 (19.1%) patients who underwent multiarterial CABG were included in this analysis. 326 (19.5%) patients received RA grafts and 1,348 (80.5%) received RIMA grafts. PSM yielded a cohort of 323 RA patients and 323 RIMA patients. After matching, groups were well-balanced across all baseline variables. No significant differences were observed in immediate postoperative complications or long-term survival, with 5-year survival estimates of 89.5% for the RA group vs 90.1% for the RIMA group. There was a nonsignificant trend toward a higher incidence of MACCE at 5 years in the RA group compared to the RIMA group (31.3% in the RA group vs 24.1% in the RIMA group), especially after 1-year follow-up (21.6% in the RA group vs 15.1% in the RIMA group). Specifically, for RA patients, there were higher rates of repeat revascularization in the 5-year postoperative period (14.7% in the RA group vs 5.3% in the RIMA group), particularly in the territory revascularized by the RA during the index operation (45.7% in the RA group vs 10.3% in the RIMA group).

CONCLUSION

Overall, RA and RIMA secondary conduits for CABG were associated with comparable immediate postoperative complications, 5-year MACCE, and 5-year survival after PSM. RA grafting was associated with significantly higher rates of repeat coronary revascularization at 5 years, specifically in the territory revascularized by the RA during the index operation.

Single versus multiple arterial coronary artery bypass grafting in men and women: results from Polish National Registry of Cardiac Surgery Procedures

BACKGROUND

The objective of this multicenter study aimed to investigate the impact of sex on long-term survival among patients with multivessel coronary artery disease undergoing coronary artery bypass grafting (CABG) using multiple arterial grafting (MAG) or a single artery with saphenous vein grafts.

MATERIALS AND METHODS

Data were obtained from the Polish National Registry of Cardiac Surgery Procedures database. This study included 81 136 patients who underwent CABG for multivessel disease between January 2012 and December 2020 (22.9 were women and 77.1% were men). MAG was performed in 8.3 and 11.7% of female and male patients, respectively. A 1:1 propensity score (PS)-matching was performed. Long-term mortality was compared between matched groups of men and women. Subgroup analyses of patients aged <70 and ≥70 years, with an ejection fraction (EF) >40% and ≤40%, and with and without diabetes, obesity, peripheral artery disease (PAD), or chronic lung disease (CLD) were performed separately in women and men.

RESULTS

MAG was associated with lower long-term mortality than saphenous vein grafts in 1528 PS-matched female pairs [hazard ratio (HR): 0.74; 95% CI: 0.59-0.92; P =0.007) and 7283 PS-matched male pairs (HR: 0.80; 95% CI: 0.72-0.88; P <0.001). Subgroup analyses confirmed the results among female patients aged <70 years, with diabetes and EF >40%, and without PAD or CLD, and of male patients aged <70 and ≥70 years; with EF >40%; with or without diabetes, obesity, or PAD; and without CLD.

CONCLUSIONS

In patients undergoing CABG, MAG was associated with significantly improved survival in both sexes. The long-term benefits of MAG observed across subgroups of men and women support the consideration of a multiarterial revascularization strategy for a broader spectrum of patients.

Long-Term Outcomes of Coronary Artery Bypass Grafting Using an Internal Thoracic Artery versus a Radial Artery as a Second Arterial Graft

PURPOSE

To compare the outcomes of left circumflex artery (LCx) revascularization using an internal thoracic artery (ITA) or radial artery (RA) as the second arterial graft.

METHODS

Patients who underwent primary isolated coronary artery bypass grafting with left anterior descending artery revascularization using an ITA and LCx revascularization using another bilateral ITA (BITA group) or an RA (ITA-RA group) were included. All-cause mortality (primary endpoint), cardiac death, major adverse cardiac events, in-hospital death, and deep sternal wound infection (secondary endpoints) were evaluated.

RESULTS

Among 790 patients (BITA, n = 548 (69%); ITA-RA, n = 242 (31%)), no significant difference in all-cause mortality between the groups was observed (hazard ratio (HR): 0.87; 95% confidence interval (CI): 0.67-1.12; p = 0.27) during follow-up (mean, 10 years). Multivariate analysis revealed that the BITA group exhibited significantly lower rates of long-term all-cause mortality (HR: 0.63; 95% CI: 0.48-0.84; p = 0.01). In the propensity-matched cohort (n = 480, 240 pairs), significantly fewer all-cause deaths occurred in the BITA group (HR: 0.66; 95% CI 0.47-0.93; p = 0.02). There were no significant differences in secondary outcomes.

CONCLUSIONS

When used as second grafts for LCx revascularization, ITA grafts may surpass RA grafts in reducing all-cause mortality 10 years postoperatively.

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.

Coronary Artery Bypass Surgery: Comparing the Long-Term Impact of Total Arterial Grafting With Multiarterial Plus Saphenous Vein Grafting

INTRODUCTION

This study aimed to compare the long-term outcomes in a propensity matched population receiving total arterial grafting (TAG) and multiple arterial grafts (MAG) in addition to saphenous vein graft (SVG) following multivessel coronary artery bypass grafting requiring at least three distal anastomoses.

METHODS

In this retrospective study, 655 patients from two centers met the inclusion criteria and were divided into two groups: TAG group (n = 231) and MAG + SVG group (n = 424). Propensity score matching was performed resulting in 231 pairs.

RESULTS

No significant differences were observed between both groups in terms of early outcomes. Survival probabilities at 5, 10, and 15 y were 89.1% versus 94.2%, 76.2% versus 76.1%, and 66.7% versus 69.8% in the TAG and MAG + SVG groups, respectively (hazard ratio stratified on matched pairs: 0.90; 95% confidence interval [0.45-1.77]; P = 0.754). Freedom from major adverse cardiac and cerebral events (MACCE) in the matched cohort did not show any significant difference between both groups. Probabilities at 5, 10, and 15 y were 82.7% versus 85.6%, 62.2% versus 75.3%, and 48.8% versus 59.5% in the TAG and MAG + SVG groups, respectively (hazard ratio stratified on matched pairs: 1.12; 95% confidence interval [0.65-1.92]; P = 0.679). Subgroup analyses of the matched cohort showed no significant difference between TAR with three arterial conduits compared to TAR with two arterial conduits with sequential grafting and MAG + SVG in terms of long-term survival and freedom from MACCE.

CONCLUSIONS

Multiple arterial revascularizations in addition to SVG may yield comparable long-term outcomes in terms of survival and freedom from MACCE compared to total arterial revascularization.

Impact of Second Arterial Conduit on Outcomes Following Coronary Bypass Grafting

BACKGROUND

The aim of this study was to compare short-term outcomes and long-term survival in patients following coronary artery bypass grafting in whom second arterial conduit or saphenous vein was used as well as to find out the most optimal second arterial graft.

METHODS

Between January 2006 and June 2018, 7,857 patients met the inclusion criteria and were divided into two groups: single internal thoracic artery (SITA) + Vein group (n = 7,140) and second arterial conduit group (n = 717), of these 537 patients received right internal thoracic artery (RITA) and 180 patients received radial artery (RA). We obtained 701 propensity-matched pairs for final comparison. Short-term outcomes included: 30-day mortality and major adverse cardiac and cerebral events (MACCE), reoperation for bleeding, and deep sternal wound infection (DSWI). The long-term outcome was all-cause mortality.

RESULTS

No significant differences were observed between second arterial conduit versus SITA + Vein groups and between RITA versus RA groups in terms of 30-day mortality, 30-day MACCE, reoperation for bleeding, and incidence of DSWI in the matched cohort. The use of second arterial conduit was associated with a significant reduction in long-term mortality by 24% in the matched cohort (hazard ratio [HR]: 0.76; 95% confidence interval [CI]: 0.60-0.96; p = 0.02). RA and RITA as second arterial conduit had comparable long-term mortality (HR: 1.12; 95% CI: 0.69-1.82; p = 0.62).

CONCLUSION

The use of second arterial conduit, irrespective of type, is safe and associated with improved long-term survival compared with the second venous aortocoronary graft.

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.

Differences in long-term survival outcomes after coronary artery bypass grafting using single vs multiple arterial grafts: a meta-analysis with reconstructed time-to-event data and subgroup analyses

OBJECTIVE

We reviewed the available literature on patients with coronary artery disease undergoing isolated coronary artery bypass grafting (CABG) with either single (SAG) or multiple arterial grafting (MAG).

METHODS

Original research studies that evaluated the long-term survival of MAG versus SAG were identified, from 1995 to 2022. The median overall survival (OS) and event-free OS were the primary endpoints. Comparison of median OS between the right internal mammary artery (RIMA) and radial artery (RA) as a second arterial conduit was the secondary endpoint. Subgroup analyses were performed regarding patients older than 70 years, with diabetes mellitus, and females. A sensitivity analysis was performed with the leave-one-out method.

RESULTS

Forty-four studies were included in the qualitative and thirty-nine in the quantitative synthesis. After pooling data from 180 to 459 patients, the MAG group demonstrated a higher OS (HR, 0.589; 95% CI, 0.58-0.60; p < 0.0001) and event-free OS compared with the SAG group (HR, 0.828; 95% CI, 0.80-0.86; p < 0.0001). In addition, RITA was associated with superior OS compared with RA as a second arterial conduit (HR, 0.936; 95% CI, 0.89-0.98; p = 0.009). MAG was also superior to SAG in patients over 70 years, females, and patients with diabetes mellitus. Sensitivity analysis demonstrated a small-size study effect on the female subgroup analysis.

CONCLUSION

The present meta-analysis indicates that MAG is associated with enhanced survival outcomes compared to SAG for patients undergoing isolated CABG.

Comparison of free arterial and saphenous vein grafting in outcomes after coronary bypass surgery

Objectives. The goal of this study was to examine whether the use of free arterial grafts could reduce the need for repeated revascularization and all-cause mortality in patients undergoing coronary artery grafting. Design. The cohort study included 17,354 consecutive adults with isolated coronary artery grafting from 2000 to 2016 in three cardiac surgery centers. Data were obtained from the Western Denmark Heart Registry. Propensity matching with 24 factors was used to establish comparable groups of patients receiving either vein grafts (n = 1019) or free arterial grafts (n = 1019) for outcome analysis. Results. The need for repeated revascularization and all-cause mortality was similar in both graft groups at 10 years of follow-up. Creatine-Kinase MB Isoenzyme >100 μg/L increased the risk of repeated revascularization rate after 1, 5 and 10 years. Conclusions. Long-term outcomes in revascularization and survival are comparable after free arterial or saphenous vein grafting.

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.

Long-term survival after coronary bypass surgery with multiple versus single arterial grafts

OBJECTIVES

This study sought to evaluate the long-term differences in survival between multiple arterial grafts (MAG) and single arterial grafts (SAG) in patients who underwent coronary artery bypass grafting (CABG) in the SYNTAX study.

METHODS

The present analysis included the randomized and registry-treated CABG patients (n = 1509) from the SYNTAX Extended Survival study (SYNTAXES). Patients with only venous (n = 42) or synthetic grafts (n = 1) were excluded. The primary end point was all-cause death at the longest follow-up. Multivariable Cox regression was used to adjust for differences in baseline characteristics. Sensitivity analysis using propensity matching with inverse probability for treatment weights was performed.

RESULTS

Of the 1466 included patients, 465 (31.7%) received MAG and 1001 (68.3%) SAG. Patients receiving MAG were younger and at lower risk. At the longest follow-up of 12.6 years, all-cause death occurred in 23.6% of MAG and 40.0% of SAG patients [adjusted hazard ratio (HR) 0.74, 95% confidence interval (CI) (0.55-0.98); P = 0.038], which was confirmed by sensitivity analysis. MAG in patients with the three-vessel disease was associated with significant lower unadjusted and adjusted all-cause death at 12.6 years [adjusted HR 0.65, 95% CI (0.44-0.97); P = 0.033]. In contrast, no significance was observed after risk adjustment in patients with the left main disease, with and without diabetes, or among SYNTAX score tertiles.

CONCLUSIONS

In the present post hoc analysis of all-comers patients from the SYNTAX trial, MAG resulted in markedly lower all-cause death at 12.6-year follow-up compared to a SAG strategy. Hence, this striking long-term survival benefit of MAG over SAG encourages more extensive use of multiple arterial grafting in selected patients with reasonable life expectancy.

TRIAL REGISTRATION

SYNTAXES ClinicalTrials.gov reference: NCT03417050; SYNTAX ClinicalTrials.gov reference: NCT00114972.

Multiarterial coronary grafting using the radial artery as a second arterial graft: how far does the survival benefit extend?

OBJECTIVES

Despite the 10-year results of the Arterial Revascularization Trial, the controversy regarding the survival benefit of multiarterial grafting (MAG) remains. Our goal was to present our long-term survival data in this propensity-matched observational study.

METHODS

A primary unmatched population of 4303 patients with first-time isolated coronary artery bypass grafts operated on between 2000 and 2018 were included. A total of 1187 post-matched patients were compared with matched controls. Multivariate logistic regression and Cox proportional hazard analyses were undertaken to assess the contribution of MAG and other covariates to the long-term survival of unmatched and propensity-matched populations.

RESULTS

MAG was associated with increased median survival in both the unmatched and the matched groups; difference: 962 and 1459 days, log-rank tests; P = 0.029 and 0.0004, respectively. MAG was associated with a reduced hazard of death in the unmatched as well as in the matched groups: hazard ratio [95% confidence interval (CI)]: 0.72 (0.62-0.83); P < 0.0001 and 0.75 (0.64-0.88); P ≤ 0.0001, respectively. In the matched group, the prosurvival factors were low logistic EuroSCORE, obesity, no intra-aortic balloon pump, an ejection fraction >30%, age 50-69 years, operation by an experienced surgeon, with and without diabetes, on-pump surgery and 3 distal anastomoses. In a cohort of 242 late-presenting patients with reinfarction or recurrent angina, both MAG and control populations were associated with reduced median survival; median (95% CI): MAG: 3026 (1138-3503); control: 3035 (2134-3991), log-rank P = 0.217 with superior patency of the left internal mammary artery but no difference between radial artery and saphenous vein grafts.

CONCLUSIONS

Multiarterial revascularization, especially using the radial artery as a second arterial conduit, is associated with a significant survival benefit and a lack of in-hospital morbidity.

Comparative Analysis Following Implementation of Two Types of Y-Composite Multiarterial Revascularization Strategies at a Single Academic Institution

Background

We compared early outcomes, at a single academic institution, of implementing full coronary revascularization in coronary artery bypass grafting using multiarterial Y‐composite grafts with multiple sequential anastomoses.

Methods and Results

Clinical records of 425 consecutive patients who underwent coronary artery bypass grafting using Y‐grafting with left internal mammary artery and radial artery (Y‐RA group) or right internal mammary artery (Y‐RIMA group) from 2015 to 2019, were reviewed. These were compared with the institutional experience of isolated coronary artery bypass grafting cases (in situ on pump/off pump) for the same period of time. When comparing the 4 groups, the Y‐RIMA/RA groups revealed a higher number of distal anastomosis than the in situ on‐ or off‐pump groups. When the number of distal arterial anastomosis was analyzed, there was a superiority of using the Y‐configuration compared with the in situ approach. Moreover, there were no significant differences among groups for mortality and/or major adverse cardiac and cerebrovascular events in hospital or at 30‐day follow‐up. A subanalysis comparing the Y‐RIMA group with the Y‐RA group showed that complementary grafts to the Y‐construct were required to accomplish full revascularization more frequently in the Y‐RIMA group. Full‐arterial revascularization was achieved in 92.2% of the Y‐RA group and 72.0% of the Y‐RIMA group (P<0.001). In 82.8% of the Y‐RA group and 30.8% of the Y‐RIMA group, revascularization was completed as an anaortic procedure (P<0.001).

Conclusions

The 2 types of arterial Y‐composite grafting were able to be introduced in the routine practice of our institution showing comparable results to the established institutional practice. This procedure allowed for more arterial distal anastomosis to be performed safely without compromising outcomes.

Long-Term Results of the RAPCO Trials

Background:

An internal thoracic artery graft to the left anterior descending artery is standard in coronary bypass surgery, but controversy exists on the best second conduit. The RAPCO trials (Radial Artery Patency and Clinical Outcomes) were designed to compare the long-term patency of the radial artery (RA) with that of the right internal thoracic artery (RITA) and the saphenous vein (SV).

Methods:

In RAPCO-RITA (the RITA versus RA arm of the RAPCO trial), 394 patients <70 years of age (or <60 years of age if they had diabetes mellitus) were randomized to receive RA or free RITA graft on the second most important coronary target. In RAPCO-SV (the SV versus RA arm of the RAPCO trial), 225 patients ≥70 years of age (or ≥60 years of age if they had diabetes mellitus) were randomized to receive RA or SV graft. The primary outcome was 10-year graft failure. Long-term mortality was a nonpowered coprimary end point. The main analysis was by intention to treat.

Results:

In the RA versus RITA comparison, the estimated 10-year patency was 89% for RA versus 80% for free RITA (hazard ratio for graft failure, 0.45 [95% CI, 0.23–0.88]). Ten-year patient survival estimate was 90.9% in the RA arm versus 83.7% in the RITA arm (hazard ratio for mortality, 0.53 [95% CI, 0.30–0.95]). In the RA versus SV comparison, the estimated 10-year patency was 85% for the RA versus 71% for the SV (hazard ratio for graft failure, 0.40 [95% CI, 0.15–1.00]), and 10-year patient survival estimate was 72.6% for the RA group versus 65.2% for the SV group (hazard ratio for mortality, 0.76 [95% CI, 0.47–1.22]).

Conclusions:

The 10-year patency rate of the RA is significantly higher than that of the free RITA and better than that of the SV.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00475488.

Robustness of the Comparative Observational Evidence Supporting Class I and II Cardiac Surgery Procedures

Background

Current cardiac surgery guidelines give Class I and II recommendations to valve‐sparing root replacement over the Bentall procedure, mitral valve (MV) repair over replacement, and multiple arterial grafting with bilateral internal thoracic artery based on observational evidence. We evaluated the robustness of the observational studies supporting these recommendations using the E value, an index of unmeasured confounding.

Methods and Results

Observational studies cited in the guidelines and in the 3 largest meta‐analyses comparing the procedures were evaluated for statistically significant effect measures. Two E values were calculated: 1 for the effect‐size estimate and 1 for the lower limit of the 95% CI. Thirty‐one observational studies were identified, and E values were computed for 75 effect estimates. The observed effect estimates for improved clinical outcomes with valve‐sparing root replacement versus the Bentall procedure, MV repair versus replacement, and grafting with bilateral internal thoracic artery versus single internal thoracic artery could be explained by an unmeasured confounder that was associated with both the treatment and outcome by a risk ratio of more than 16.77, 4.32, and 3.14, respectively. For MV repair versus replacement and grafting with bilateral internal thoracic artery versus single internal thoracic artery, the average E values were lower than the effect sizes of the other measured confounders in 33.3% and 60.9% of the studies, respectively. For valve‐sparing root replacement versus the Bentall procedure, no study reported effect sizes for associations of other covariates with outcomes.

Conclusions

The E values for observational evidence supporting the use of valve‐sparing root replacement, MV repair, and grafting with bilateral internal thoracic artery over the Bentall procedure, MV replacement, and grafting with single internal thoracic artery are relatively low. This suggests that small‐to‐moderate unmeasured confounding could explain most of the observed associations for these procedures.

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

Background

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

Methods and Results

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

Conclusions

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

Disagreement Between Randomized and Observational Evidence on the Use of Bilateral Internal Thoracic Artery Grafting: A Meta-Analytic Approach

Background

The ART (Arterial Revascularization Trial) showed no difference in survival at 10 years between patients assigned to the single versus bilateral internal thoracic artery grafting strategies. This finding is in contrast with the results of most observational studies, where the use of 2 internal thoracic arteries has been associated with improved survival.

Methods and Results

We selected propensity‐matched studies from the most comprehensive observational meta‐analysis on the long‐term outcomes of patients receiving 1 versus 2 internal thoracic arteries. Individual participant survival data from each study and the ART were reconstructed using an iterative algorithm that was applied to solve the Kaplan‐Meier equations. The reconstructed individual participant survival data were aggregated to obtain combined survival curves and Cox regression hazard ratios with 95% CIs. Individual participant survival data were obtained from 14 matched observational studies (24 123 patients) and the ART. The 10‐year survival of the control group of ART was significantly higher than that of the matched observational studies (hazard ratio, 0.86; 95% CI, 0.80–0.93). The 10‐year survival of the experimental group of ART was significantly lower than that of the bilateral internal thoracic artery group of the observational studies (hazard ratio, 1.11; 95% CI, 1.03–1.20).

Conclusions

Both the improved outcome of the control arm and the lower beneficial effect of the intervention had played a role in the difference between observational evidence and ART.

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.

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.

Unmeasured Confounders in Observational Studies Comparing Bilateral Versus Single Internal Thoracic Artery for Coronary Artery Bypass Grafting: A Meta-Analysis

Background

Observational studies suggest a survival advantage with bilateral single internal thoracic artery (BITA) versus single internal thoracic artery grafting for coronary surgery, whereas this conclusion is not supported by randomized trials. We hypothesized that this inconsistency is attributed to unmeasured confounders intrinsic to observational studies. To test our hypothesis, we performed a meta‐analysis of the observational literature comparing BITA and single internal thoracic artery, deriving incident rate ratio for mortality at end of follow‐up and at 1 year. We postulated that BITA would not affect 1‐year survival based on the natural history of coronary artery bypass occlusion, so that a difference between groups at 1 year could not be attributed to the intervention.

Methods and Results

We searched MEDLINE and Pubmed to identify all observational studies comparing the outcome of BITA versus single internal thoracic artery. One‐year and long‐term mortality for BITA and single internal thoracic artery were compared in the propensity‐score–matched (PSM) series, that is, the form of observational evidence less prone to confounders. Thirty‐eight observational studies (174 205 total patients) were selected for final comparison. In the 12 propensity‐score–matched series (34 019 patients), the mortality reduction for BITA was similar at 1 year and at the end of follow‐up (incident rate ratio, 0.70; 95% confidence interval, 0.60–0.82 versus 0.77; 95% confidence interval, 0.70–0.85; P for subgroup difference=0.43).

Conclusions

Unmeasured confounders, rather than biological superiority, may explain the survival advantage of BITA in observational series.

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.