Are all forms of total arterial revascularization equal? A comparison of single versus bilateral internal thoracic artery grafting strategies. J Thorac Cardiovasc Surg. 2015;150:1526-1533, 1534e1-1534e3, discussion 1533-1534. [PMID: 26211406 DOI: 10.1016/j.jtcvs.2015.05.074]

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.

Impact of Bilateral versus Single Internal Thoracic Artery Grafting on the Long-Term Survival in Adults: A Systematic Review

Objective

To analyse the survival of patients who had undergone bilateral internal thoracic artery grafting versus those with single internal thoracic artery grafting from the available literature. Moreover, this study will review the available literature regarding which of the two techniques seems to be the safest with long-term survival and reduced mortality rates.

Methods

A literature search of the databases was conducted to retrieve studies that fall under the study design of cohort and randomized controlled clinical trials in English from January 2015 to July 2021. Finally, seven studies were selected: four cohort studies and three other from a randomized trial.

Results

The cohort studies revealed that bilateral internal thoracic artery grafting is associated with lower mortality rates and better long-term survival outcomes than single internal thoracic artery grafting, while the ART randomized controlled clinical trials showed that there is no significant difference in mortality rates between both the coronary artery bypass grafting techniques. However, all studies concluded that bilateral internal thoracic artery grafting is associated with a higher frequency of deep sternal wound infections.

Conclusion

The discrepancy in results between the cohort studies and randomized controlled clinical trial remains persistent. However, the stated advantages of bilateral internal thoracic artery grafting are not strong enough to convince surgeons to alter their practice and the wide magnitude of expectations from the ART study was reckoned as inadequate. This may well be due to the presence of limited criteria for bilateral internal thoracic artery grafting in identifying the impact on survival of extended arterial revascularization, and there is a new colossal expectation from the ongoing randomized trial based on multiple arterial grafting versus single arterial grafting.

The use of free versus in situ right internal mammary artery in coronary artery bypass grafting

INTRODUCTION

Coronary artery bypass grafting (CABG) continues to be the most commonly performed cardiac surgical procedure in the world. The use of multiarterial grafting may confer a long-term survival benefit over the use of vein grafts. However, there is a paucity of data comparing the use of in situ versus free right internal mammary artery (RIMA) in isolated CABG.

METHODS

Patients that underwent isolated CABG between 2010 and 2018 where RIMA was used in addition to a left internal mammary artery graft. Patients with prior cardiac surgery or percutaneous coronary intervention were excluded. Propensity matching was used for subanalysis. Mortality and major adverse cardiac and cerebrovascular events (MACCE) were analyzed with Kaplan-Meier survival curves and Cox multivariable regression. Heart failure-specific readmissions were assessed with cumulative incidence curves with Fine and Gray competing risk regression.

RESULTS

A total of 667 patients underwent isolated CABG. Of those, 422 had free RIMA and 245 had in situ RIMA utilized. Mortality was similar between cohorts (p = 0.199) with 5-year mortality rates of 6.6% (free) and 4.1% (in situ). MACCE was similar between cohorts, with 5-year event rates of 33.6% and 33.9% (p = 0.99). RIMA style was not a significant predictor of any outcome.

CONCLUSION

There was no difference in long-term mortality, complications, MACCE, or heart failure readmissions when comparing a contemporary cohort of patients undergoing isolated CABG utilizing RIMA as a conduit. These data may allow surgeons to consider using RIMA either as an in situ or a free conduit.

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.

Application of bilateral internal mammary artery with different configurations in coronary artery bypass grafting

Background

A large number of studies have shown that BIMA grafting is superior to single internal mammary artery grafting in cardiac function protection and long-term survival after surgery. While, there is still no consensus on how is the best configuration to use BIMA. This study aims to compare intraoperative blood flow, early clinical results and early postoperative patency of different configurations of BIMA.

Methods

There were 74 patients who underwent CABGs with bilateral internal mammary artery with different configurations we included. According to the different target territories that RIMA grafted to, the patients were divided into bilateral group (group I) with 20 cases and left group (group II) with 54 cases. Intraoperative blood flow, early clinical results and early postoperative patency of different configurations of BIMA were compared.

Results

There was no difference in the early postoperative death and major complications between group I and Group II(P>0.05). Compared with the LIMA in group II, the LIMA in group I had a slightly higher DF value (76.7 ± 6.2 vs 73.1 ± 6.8, P = 0.040). Compared with the RIMA in group II, the RIMA in group I had a slightly higher MGF (51.7 ± 34.4 ml/min vs 31.4 ± 21.4 ml/min, P = 0.024). There was no difference in the other TTFM parameters of LIMA and RIMA between group I and Group II(P>0.05). Further subgroup analysis revealed that compared with free RIMA in group II, in situ RIMA had a higher DF value (71.4 ± 7.8 vs 61.8 ± 18.1,P = 0.025). The PI of LIMA in free RIMA subgroup was higher than the PI of LIMA in in-situ RIMA subgroup (3.0 ± 1.6 vs 2.1 ± 1.0,P = 0.018). The results of early postoperative CTA examination showed that all IMAs grafts were completely patent.

Conclusions

The use of BIMA for CABG is safe and efficacious, RIMA used in right coronary artery received more satisfactory graft flow. BIMA with no stenosis and occlusion in the early stage, therefore is the ideal and stable coronary bypass graft.

Internal mammary artery: the primary conduit for surgical revascularization

Internal mammary artery, by far, is the gold standard and first conduit for surgical revascularization especially when it comes to bypassing a lesion in the left anterior descending coronary artery. Several factors behind using this artery have been established, including but not limited to, the anatomical location, the course and flow, the elastic nature of the artery as well as the physiological characteristics that make this conduit to yield excellent long-term patency rates. This review aims to thoroughly examine current literature and establish the facts behind using this conduit in our daily surgical revascularization practice.

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.

Bilateral Internal Thoracic Artery In Situ Versus Y-Composite Graftings: Long-term Outcomes

BACKGROUND

We compared 10-year graft patency rates and long-term clinical outcomes after off-pump coronary artery bypass grafting using bilateral internal thoracic arteries (ITAs) as in situ grafts with those using bilateral ITAs as Y-composite grafts.

METHODS

Of 509 patients who underwent off-pump coronary artery bypass grafting using bilateral ITAs, bilateral ITAs were used as in situ grafts in 172 patients (group I) and as Y-composite grafts in 337 patients (group Y). A propensity score-matched analysis was used to match group I patients (n = 153) with group Y patients (n = 153). Ten-year angiographic patency rates and long-term clinical outcomes were compared. The follow-up data were complete in 99.2% of patients (505/509) with a median follow-up duration of 175 months.

RESULTS

Ten-year overall patency rates and patency rates for distal anastomoses using bilateral ITAs were 87.5% (356/407) and 89.2% (297/333), respectively, in the propensity score-matched groups. No differences in overall patency rates (groups I vs Y, 84.9% vs 89.5%, P = .277) and bilateral ITA patency rates (groups I vs Y, 86.5% vs 91.1%, P = .282) were found between the propensity score-matched groups. There were no differences in the overall survival and cumulative incidence of cardiac death between the propensity score-matched groups (P = .312 and P = .812, respectively) up to 15 years after surgery. Cumulative incidences of target vessel revascularization (P = .606), reintervention (P = .849), and major adverse cardiac events (P = .672) were also similar between the propensity score-matched groups up to 15 years after surgery.

CONCLUSIONS

Off-pump coronary artery bypass grafting using bilateral ITAs as in situ versus Y-composite grafts demonstrated no differences in terms of 10-year patency rates and long-term clinical outcomes between the groups.

Short-term results of bilateral internal mammary arterial grafting for patients aged 60-75 years - a retrospective study

BACKGROUND

Bilateral internal mammary artery (BIMA) grafting has a good long-term survival rate and graft patency rate, but it is only recommended in young patients due to its high technical requirements and high incidence of sternal complications. Previous studies indicated that BIMA grafting has a significant benefit in patients aged 50-59 years, but this benefit does not extend to patients aged > 60 years. Thus, this study was designed to analyse the immediate artery graft function, short-term (3 months) results, and experience in preventing sternal complications for BIMA grafting in elderly patients (60-75 years old).

METHODS

Clinical records and echocardiographic and coronary artery computed tomography angiography data of 155 patients who underwent BIMA grafting for coronary artery disease between 2015 and 2017 in our hospital were analysed retrospectively to summarise the operative experience and short-term (3 months) results. Patients were divided into two groups: Group A (n = 95), aged < 60 years and Group B (n = 60), aged 60-75 years. The operation time, aortic clamp time, and cardiopulmonary bypass time of these two groups were compared to analyse the operation difficulty and the flow and pulsatility index were compared to analyse the immediate artery graft function. The left ventricular end-diastolic dimension (LVEDD) and left ventricular ejection fraction (LVEF) of these two groups were compared to analyse heart function.

RESULTS

There were no significant differences in the operation time, aortic clamp time, and cardiopulmonary bypass time as well as the flow and pulsatility index between these two groups (P > 0.05). There was no significant difference in the incidence of sternal wound complications, graft occlusion, and other common complications 3 months post-BIMA grafting between these two groups (P > 0.05). Furthermore, there was no significant difference in LVEDD and LVEF between the groups 3 months post-operation (P > 0.05).

CONCLUSIONS

BIMA grafting was safe and effective for older patients (60-75 years). Similar to younger patients (< 60 years), BIMA grafting in elderly patients (60-75 years) can also achieve a satisfactory short-term (3 months) result. Thus, advanced age (60-75 years) should not be a contraindication for BIMA grafting.

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.

Immediate results of bypass grafting of the territory of the right coronary artery using the 'Penza Coronary Technology'

Coronary artery bypass grafting (CABG) is known to be an effective method of treatment for multivessel obstructive coronary disease with low rates of reintervention and excellent long-term survival and freedom from angina. Graft patency lies at the heart of its procedural success and durability, which in its turn largely depends on the appropriate choice of the conduit, as well as the target coronary artery (CA). It should be mentioned that patency of one and the same conduit used for bypass grafting of the territory of either the left or right coronary artery (LCA and RCA, respectively) may differ, which is probably determined by differences in physiology, size, territory of runoff, and local flow characteristics between different coronary targets. Previous reports have supported the use of bilateral internal thoracic arteries to revascularize the left coronary circulation. If this becomes standardized practice, the optimal conduit for the right coronary system remains to be established. Proposed in the present article is a variant of bypass grafting of the RCA territory using a composite I-graft formed from the proximal portion of the right internal thoracic artery (ITA) in situ and the great saphenous vein (GSV) harvested by the 'no-touch' technique. This technique is part of a CABG schematic algorithm worked out in our Clinic and called the 'Penza Coronary Technology'.

Left-Sided Complete Revascularization With Bilateral Internal Thoracic Arteries in Patients With Diabetes

BACKGROUND

Reports are few on the long-term patency of bilateral internal thoracic artery (BITA) grafts in patients with diabetes. We evaluated the relationship between the long-term patency of BITAs and the clinical outcomes in diabetes.

METHODS

We retrospectively identified 569 patients (321 with diabetes, 248 without diabetes) who underwent isolated BITA grafting for left-sided complete revascularization at our institution from 2000 to 2015. The primary end point was the incidence of major adverse cardiovascular events comprising death, re-revascularization, and myocardial infarction. The secondary end point was the patency of the BITAs.

RESULTS

No differences were found in the major adverse cardiovascular event rate (10-year: diabetic group, 33.7%; nondiabetic group, 22.3%; p = 0.15) or overall mortality rate (24.0% versus 12.2%, p = 0.066) between the patients with and without diabetes. The incidence of cardiac death (3.3% versus 1.8%, p = 0.80) or re-revascularization and myocardial infarction (11.4% versus 11.8%, p = 0.67) was similar between the groups. The patency of free internal thoracic artery (ITA) grafts to the left circumflex artery was associated with greater patency in patients with diabetes than in patients without diabetes (4 years: 99.3% versus 95.5%, p = 0.049); the patency of other ITA grafts did not differ between the groups.

CONCLUSIONS

All-cause death, re-revascularization, and myocardial infarction showed no differences between patients with and without diabetes who underwent left-sided revascularization with the BITAs. Although diabetes did not affect the patency of the ITA, free ITA grafts to the left circumflex artery showed good long-term patency in patients with diabetes.

The impact of the radial artery or the saphenous vein in addition to the bilateral internal mammary arteries on late survival: A propensity score analysis

BACKGROUND

Long-term survival benefits of full arterial revascularization with radial artery (RA) used in addition to bilateral internal mammary arteries (BIMA) compared with saphenous vein (SV) used in addition to BIMA has not been clearly defined.

METHODS

We retrospectively analyzed 660 3-vessel coronary artery disease subjects who received BIMA in addition to either RA (n = 206) or SV (n = 454) grafting in a period between June 1999 and November 2017. After propensity score matching, we obtained 190 matched pairs for analysis.

RESULTS

In the matched population, in-hospital mortality occurred in 4 patients (1%), with 2 deaths (1.1%) in the BIMA + RA group and 2 deaths (1.1%) in BIMA + SV group (P > .99). The median follow-up time was 9.2 years (interquartile range, 5.6-13 years) with a maximum follow-up time of 18.5 years. There was not a significant difference in long-term survival between the 2 groups over the follow-up period. Survival at 5, 10, and 15 years were 94.8 ± 1.7%, 83.7 ± 3.1%, and 78.6 ± 3.9% in the BIMA + RA group and 96.2 ± 1.4%, 85.1 ± 2.9%, and 80.4 ± 3.6% in the BIMA + SV group (stratified log-rank P = .78). Cox proportional hazard regression model was used to estimate that the use of RA in addition to BIMA did not affect the late mortality (propensity score adjusted hazard ratio, 1.05; 95% confidence interval, 0.62-1.79; P = .83).

CONCLUSIONS

In a relatively small population of triple-vessel coronary artery disease, the use of RA as a third arterial conduit with BIMA did not confer a long-term survival benefit.

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.

Three Arterial Grafts Improve Late Survival: A Meta-Analysis of Propensity-Matched Studies

BACKGROUND

Little evidence shows whether a third arterial graft provides superior outcomes compared with the use of 2 arterial grafts in patients undergoing coronary artery bypass grafting. A meta-analysis of all the propensity score-matched observational studies comparing the long-term outcomes of coronary artery bypass grafting with the use of 2-arterial versus 3-arterial grafts was performed.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and Web of Science to identify relevant articles. Long-term mortality in the propensity score-matched populations was the primary end point. Secondary end points were in-hospital/30-day mortality for the propensity score-matched populations and long-term mortality for the unmatched populations. In the matched population, time-to-event outcome for long-term mortality was extracted as hazard ratios, along with their variance. Statistical pooling of survival (time-to-event) was performed according to a random effect model, computing risk estimates with 95% confidence intervals.

RESULTS

Eight propensity score-matched studies reporting on 10 287 matched patients (2-arterial graft: 5346; 3-arterial graft: 4941) were selected for final comparison. The mean follow-up time ranged from 37.2 to 196.8 months. The use of 3 arterial grafts was not statistically associated with early mortality (hazard ratio, 0.93; 95% confidence interval, 0.71-1.22; P=0.62). The use of 3 arterial grafts was associated with statistically significantly lower hazard for late death (hazard ratio, 0.8; 95% confidence interval, 0.75-0.87; P<0.001), irrespective of sex and diabetic mellitus status. This result was qualitatively similar in the unmatched population (hazard ratio, 0.57; 95% confidence interval, 0.33-0.98; P=0.04).

CONCLUSIONS

The use of a third arterial conduit in patients with coronary artery bypass grafting is not associated with higher operative risk and is associated with superior long-term survival, irrespective of sex and diabetic mellitus status.

Physiology of in-situ arterial revascularization in coronary artery bypass grafting: Preoperative, intraoperative and postoperative factors and influences

Surgical revascularization with coronary artery bypass grafting (CABG) has become established as the most effective interventional therapy for patients with moderately severe and severe stable ischemic heart disease (SIHD). This recommendation is based on traditional 5-year outcomes of mortality and avoidance of myocardial infarction leading to reintervention and/or cardiac death. However, these results are confounded in that they challenge the traditional CABG surgical tenets of completeness of anatomic revascularization, the impact of arterial revascularization on late survival, and the lesser impact of secondary prevention following CABG on late outcomes. Moreover, the emergence of physiologic-based revascularization with percutaneous cardiovascular intervention as an alternative strategy for revascularization in SIHD raises the question of whether there are similar physiologic effects in CABG. Finally, the ongoing ISCHEMIA trial is specifically addressing the importance of the physiology of moderate or severe ischemia in optimizing therapeutic interventions in SIHD. So it is time to address the role that physiology plays in surgical revascularization. The long-standing anatomic framework for surgical revascularization is no longer sufficient to explain the mechanisms for short-term and long-term outcomes in CABG. Novel intraoperative imaging technologies have generated important new data on the physiologic blood flow and myocardial perfusion responses to revascularization on an individual graft and global basis. Long-standing assumptions about technical issues such as competitive flow are brought into question by real-time visualization of the physiology of revascularization. Our underestimation of the impact of Guideline Directed Medical Therapy, or Optimal Medical Therapy, on the physiology of preoperative SIHD, and the full impact of secondary prevention on post-intervention SIHD, must be better understood. In this review, these issues are addressed through the perspective of multi-arterial revascularization in CABG, which is emerging (after 30 years) as the “standard of care” for CABG. In fact, it is the physiology of these arterial grafts that is the mechanism for their impact on long-term outcomes in CABG. Moreover, a better understanding of all of these preoperative, intraoperative and postoperative components of the physiology of revascularization that will generate the next, more granular body of knowledge about CABG, and enable surgeons to design and execute a better surgical revascularization procedure for patients in the future.

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.