Surgical treatment of isolated left anterior descending coronary stenosis: Comparison of left internal mammary artery and venous autograft at 18 to 20 years of follow-up

The Predictive Value of Pan-Immune-Inflammation Value for Saphenous Vein Graft Disease in Post-Coronary Artery Bypass Grafting Patients

Background: Coronary artery bypass grafting (CABG) remains the gold standard treatment for patients with significant coronary artery disease (CAD) and high-risk profiles for percutaneous coronary intervention. Despite the frequent use of saphenous vein grafts (SVGs) in CABG, their patency rates are lower than those of arterial grafts. Identifying noninvasive methods to determine SVG patency is crucial. Aims: This study investigates the relationship between a novel inflammation marker, pan-immune-inflammation value (PIV), and SVG patency in post-CABG patients. Methods: The study included 507 patients who underwent coronary angiography (CAG) due to clinical indications between 2016 and 2023. Patients who had undergone CABG at least one year prior with at least one SGV used were divided into two groups based on the presence or absence of SVG stenosis (SGVS). Results: Among the 507 patients, 244 had SVGS. Patients with SVGS exhibited higher levels of diabetes mellitus and inflammatory markers such as NLR, SII, CAR, and PIV. Multivariate analysis identified PIV as an independent predictor of SVGS. ROC analysis showed that a PIV cut-off value > 315.5 predicted SVGS with 75.8% sensitivity and 68.6% specificity. Conclusions: PIV, a simple and easily measurable marker, demonstrated strong predictive value for SVGS in post-CABG patients.

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

BACKGROUND

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

MAIN BODY

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

CONCLUSION

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

Randomized comparison of HARVesting the Left Internal Thoracic Artery in a skeletonized versus pedicled technique: the HARVITA trial-study protocol

Latest research has indicated a potential adverse effect on graft patency rates and clinical outcomes with skeletonizing the left internal thoracic artery. We aim to provide a prospective, randomized, multicentre trial to compare skeletonized versus pedicled harvesting technique of left internal thoracic artery concerning graft patency rates and patient survival. A total of 1350 patients will be randomized to either skeletonized or pedicled harvesting technique and undergo surgical revascularization. Follow-up will be performed at 30 days, 1 year, 2 years and 5 years after surgery. The primary outcome will be death or left internal thoracic artery graft occlusion in coronary computed tomography angiography or invasive angiography within 2 years (+/- 3 months) after surgery. The secondary outcome will be major adverse cardiac events (composite outcome of all-cause death, myocardial infarction and repeated revascularization) within 1 year, 2 years and 5 years after surgery. The primary end point will be compared in the modified intention-to-treat population between the two treatment groups using Kaplan-Meier graphs, together with log-rank testing. Hereby, we present the study protocol of the first adequately powered prospective, randomized, multicentre trial which compares skeletonized and pedicled harvesting technique of left internal thoracic artery regarding graft patency rates and patient survival.

Left Internal Thoracic Artery versus Saphenous Vein Grafts to Left Anterior Descending Artery after Isolated Coronary Artery Bypass Surgery

BACKGROUND

This study compared perioperative outcomes and long-term survival of saphenous vein grafts (SVGs) versus left internal thoracic artery (LITA) to left anterior descending artery (LAD) in isolated coronary artery bypass graft surgery (CABG).

METHODS

In this retrospective, single-centre study, we included patients with primary isolated CABG from January 2001 to July 2022. Baseline demographics were compared between SVG-LAD and LITA-LAD. Univariable and multivariable regressions were performed for predictors of in-hospital death. Propensity score matching was performed for LITA-LAD vs. SVG-LAD. Kaplan-Meier survival curves were generated for comparison of survival. Cox proportional hazards model was used for predictors of survival.

RESULTS

A total of 8237 patients (1602 SVG-LAD/6725 LITA-LAD) were included. Median age was 67.9 years (LITA-LAD; 67.1 years vs. SVG-LAD; 71.7 years, p < 0.01). A total of 1270 pairs of SVG-LAD were propensity-matched to LITA-LAD. In matched cohorts, in-hospital mortality (0.8% vs. 1.6%, LITA-LAD and SVG-LAD respectively; p = 0.07), deep sternal wound infection, new cerebrovascular events, renal replacement therapy and hospital stay >30 days were similar. SVG-LAD did not adversely affect in-hospital mortality (OR; 2.03, CI; 0.91, 4.54, p = 0.08). Median long-term survival was similar between the groups (13.7 years vs. 13.1 years for LITA-LAD and SVG-LAD respectively, log rank p < 0.31). SVG-LAD was not a predictor of adverse long-term survival. (HR; 1.06, 95% CI; 0.92, 1.22, p < 0.40). Long-term survival was better with LITA-LAD for LVEF <30% (log rank p < 0.03).

CONCLUSIONS

There was no difference in the propensity-matched cohorts for use of SVG vs. LITA to the LAD. Further contemporary long-term studies are needed for substantiation.

Use of the In Situ Right Internal Thoracic Artery as an Alternative Single-Inflow Source

Background

This study was conducted to evaluate whether the in situ right internal thoracic artery (RITA) can be an effective alternative to the left internal thoracic artery (LITA) as a single-inflow source in coronary artery bypass grafting (CABG).

Methods

Between 2006 and 2018, 73 patients underwent CABG with the composite grafting based on the in situ RITA as a single-inflow source (the RITA group). Angiographic patency and clinical outcomes were evaluated. These were compared with results after CABG using the composite grafting based on the in situ LITA (the LITA group) by 1:1 propensity score matching.

Results

Forty-three pairs were extracted by 1:1 propensity score matching. There were no significant intergroup differences in overall patency rates between the RITA and LITA groups at 1 year (92.2% [95/103] and 92.5% [111/120], respectively; P = .90) and 5 years (87.3% [48/55] and 90.4% [85/94], respectively; P = .58). There were no significant differences in the cumulative incidences of reintervention and major adverse cardiac events between the 2 groups (hazard ratio, 2.0 [95% CI, 0.33-11.97] and 1.50 [0.41-5.45], respectively).

Conclusions

Five-year graft patency and long-term clinical outcomes after CABG using the composite grafting based on the in situ RITA were not significantly different from those after CABG using the LITA.

Coronary artery bypass grafting using bilateral internal thoracic arteries in patients with diabetes and obesity: A systematic review and meta-analysis

Background

Patients with diabetes and obesity are at higher risk of adverse long-term outcomes following coronary artery bypass grafting. The use of bilateral internal thoracic arteries (BITA) can potentially offer survival benefit in higher risk patients compared to single internal thoracic artery (SITA), but BITA is not routinely used due to lack of clear evidence of efficacy and concerns over sternal wound complications.

Methods

Medline, Embase and the Cochrane Library were searched for studies comparing the efficacy and safety of BITA and SITA grafting in patients with diabetes and obesity. Meta-analysis of mortality and sternal wound complications was performed.

Results

We identified eight observational and ten propensity matched studies, and one RCT, comparing BITA and SITA which included patients with diabetes (n = 19,589); two propensity matched studies and one RCT which included patients with obesity (n = 6,972); mean follow up was 10.5 and 11.3 years respectively. Meta-analysis demonstrated a mortality reduction for BITA compared to SITA in patients with diabetes (risk ratio [RR] 0.79; 95% confidence interval [CI] 0.70-0.90; p = 0.0003). In patients with obesity there was a non-significant reduction in mortality in the BITA group (RR 0.73, 95% CI 0.47-1.12; p = 0.15). There was a significantly higher rate of sternal wound complications following BITA observed in patients with diabetes (RR 1.53, 95% CI 1.23-1.90; p = 0.0001) and obesity (RR 2.24, 95% CI 1.63-3.07; p < 0.00001).

Conclusions

BITA is associated with better long-term survival in patients with diabetes. The effects of BITA grafting in patients with obesity are uncertain. BITA is associated with higher rates of sternal wound complications compared to SITA in both patients with diabetes and obesity.

Bilateral versus Single Internal Thoracic Artery Grafting Strategies Supplemented by Radial Artery Grafting

PURPOSE

It is unclear if a second or third arterial graft can improve clinical outcomes in coronary artery bypass graft surgery. We compared the outcomes of bilateral internal thoracic artery (BITA) plus radial artery (RA) grafting versus left internal thoracic artery (LITA) plus RA grafting after off-pump coronary artery bypass grafting.

MATERIALS AND METHODS

Between January 2009 and December 2020, a total of 3007 patients with three-vessel coronary artery disease who underwent off-pump coronary artery bypass were analyzed. Among them, 971 patients received total arterial grafting using LITA. We divided the patients into two groups [group A, BITA+RA grafting (n=227) and group B, LITA+RA grafting (n=744)], and compared the survival and major adverse cardiac and cerebrovascular event (MACCE) rates between the two groups at 10 years.

RESULTS

After risk adjustment with inverse probability treatment weighting methods, the freedom from all-cause mortality was 93.1% and 88.3% in groups A and B, respectively (p=0.140). The freedom from MACCE rates were 68.3% and 89.0%, respectively (p<0.0001). LITA plus RA grafting [hazard ratio (HR): 1.3, 95% confidence interval (CI): 1.05-2.37, p=0.025] and incomplete revascularization (HR 1.2, 95% CI: 0.70-2.15, p=0.046) were significant risk factors for MACCEs in multivariable Cox regression analysis.

CONCLUSION

The rates of MACCEs were lower with LITA plus RA grafting than with BITA plus RA grafting in total arterial revascularization. Furthermore, complete revascularization improved long-term outcomes following total arterial grafting.

Late Clinical Outcomes of Total Arterial Revascularization or Multiple Arterial Grafting Compared to Conventional Single Arterial with Saphenous Vein Grafting for Coronary Surgery

Coronary surgery provides better long-term outcomes than percutaneous coronary intervention. Conventional practice is to use a single arterial conduit supplemented by saphenous vein grafts. The use of multiple arterial revascularization (MAG), or exclusive arterial revascularization (TAR), however, is reported as having improved late survival. Survival is a surrogate for graft failure that may lead to premature death, and improved survival reflects fewer graft failures in the non-conventional strategy groups. The reasons for not using MAG or TAR may be due to perceived technical difficulties, a lack of definitive large-scale randomized evidence, a lack of confidence in arterial conduits, or resources or time constraints. Most people consider radial artery (RA) grafting to be new, with use representing approximately 2-5% worldwide, despite select centers reporting routine use in most patients for decades with improved results. In conclusion, the current body of evidence supports more extensive use of total and multiple arterial revascularization procedures in the absence of contraindications.

Doppler Ultrasound Selection and Follow-Up of the Internal Mammary Artery as Coronary Graft

The impact of coronary artery disease (CAD) on all-cause mortality and overall disabilities is well-established. Percutaneous and/or surgical coronary revascularization procedures dramatically reduced the occurrence of adverse cardiovascular events in patients suffering from atherosclerosis. Specifically, guidelines from the European Society of Cardiology on the management of myocardial revascularization promoted coronary artery by-pass graft (CABG) intervention in patients with specific alterations in the coronary tree due to the higher beneficial effects of this procedure as compared to the percutaneous one. The left internal mammary artery (LIMA) is one of the best-performing vessels in CABG procedures due to its location and its own structural characteristics. Nevertheless, the non-invasive assessment of its patency is challenging. Doppler ultrasonography (DU) might perform as a reliable technique for the non-invasive evaluation of the patency of LIMA. Data from the literature revealed that DU may detect severe (>70%) stenosis of the LIMA graft. In this case, pulsed-wave Doppler might show peak diastolic velocity/peak systolic velocity < 0.5 and diastolic fraction < 50%. A stress test might also be adopted for the evaluation of patency of LIMA through DU. The aim of this narrative review is to evaluate the impact of DU on the evaluation of the patency of LIMA graft in patients who undergo follow-up after CABG intervention.

It's not all about ISCHEMIA: the case for coronary artery bypass grafting in stable coronary artery disease

PURPOSE OF REVIEW

The recent American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions Guidelines for Coronary Artery Revascularization have raised concerns on the survival benefits of coronary artery bypass grafting (CABG) over guideline-directed medical therapy (GDMT) in stable coronary artery disease (CAD) and appropriate conduit selection for CABG. This review summarizes the evidence supporting CABG for stable CAD and use of the radial artery as a conduit for CABG.

RECENT FINDINGS

CABG has consistently demonstrated a survival benefit over GDMT for patients with stable multivessel CAD. These benefits were more pronounced in patients with diabetes and/or anatomically complex coronary artery disease. The recently published International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial was not designed to and did not include an appropriate patient population to compare revascularization with CABG to GDMT. These results should thus be viewed in the context of previously published studies. Furthermore, increasing evidence suggests that use of a radial artery in CABG is associated with reduced myocardial infarction and repeat revascularization. This should be considered when selecting the appropriate conduits based on underlying patient factors.

SUMMARY

Readers should be cautious when applying these guidelines broadly. Appropriate consideration of patient and anatomic factors, and in consultation with a multidisciplinary heart team, is important to achieve the best outcomes for patients.

Early home discharge after robot-assisted coronary artery bypass grafting

OBJECTIVES

Robot-assisted coronary artery bypass grafting (CABG) has been developed as a less invasive alternative for conventional CABG to enhance postoperative recovery, patient satisfaction and early discharge to home. Furthermore, it may provide a basis for hybrid coronary revascularization. To determine the feasibility of this procedure, we compared robot-assisted with conventional off-pump CABG.

METHODS

All consecutive patients undergoing a robot-assisted left internal mammary artery-to-left anterior descending coronary artery procedure were compared to consecutive patients undergoing conventional off-pump CABG for single-vessel disease from October 2016 to July 2019. The primary outcome was discharge to home within 5 days after the operation. Secondary outcomes were total hospital stay, reoperations within 48 h, transfusions, atrial fibrillation, 30-day mortality and quality of life 1 month postoperatively. A propensity matched cohort was assembled to correct for possible confounders.

RESULTS

A total of 107 patients who had robot-assisted CABG were compared to 194 patients who had conventional off-pump CABG. The primary outcome was reached in 51% of the robot-assisted group versus 19% of the conventional off-pump group (P < 0.01). The median postoperative hospital stay was 5 days for the robot-assisted group versus 7 days in the conventional off-pump group (P < 0.01). Other secondary outcomes did not differ significantly between the groups, and the quality of life 1 month after the operation was equal. The results after propensity matching were similar.

CONCLUSIONS

Early discharge to home is more frequent for patients who have robot-assisted CABG than in those who have conventional off-pump CABG, with no difference in health-related quality of life. Therefore, this approach may reduce healthcare resources and provide a solid basis for hybrid coronary revascularization.

Saphenous vein harvesting techniques for coronary artery bypass grafting: a systematic review and meta-analysis

The great saphenous vein (GSV) graft remains a frequently used conduit for coronary artery bypass graft (CABG) surgery. The optimal technique for GSV harvesting has been the subject of on-going controversy. We therefore sought to conduct a systematic review and meta-analysis of all available GSV harvesting techniques in CABG. A systematic search of 12 electronic databases was performed to identify all randomized controlled trials (RCTs) of any GSV harvesting technique, including conventional vein harvesting (CVH), no-touch, standard bridging technique (SBT) and endoscopic vein harvesting (EVH) techniques. We investigated safety and long-term efficacy outcomes. All outcomes were analyzed using the frequentist network meta-analysis. A total of 6480 patients from 34 RCTs were included. For safety outcomes, EVH reduced 91% and 77% risk of wound infection compared to no-touch and CVH, respectively. EVH and SBT also significantly reduced the risk of sensibility disorder and postoperative pain. The techniques were not significantly different regarding long-term efficacy outcomes, including mortality, myocardial infarction and graft patency. For GSV harvesting for CABG, EVH techniques are the most favorable, but in case of using an open technique, no-touch is more recommended than CVH. More effective and safer procedures should be investigated for GSV harvesting in CABG.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Hybrid approach for percutaneous mitral valve repair (MitraClip®) followed by minimally invasive direct coronary artery bypass (MIDCAB) in a patient with a high risk constellation

BACKGROUND

We present a 76-year-old poly-morbid male patient suffering from severe ischemic mitral valve regurgitation. A hybrid approach was suggested by the heart team to treat his multifaceted cardiac pathologies.

METHODS

At first percutaneous mitral valve repair with the mitraclip device was performed to reduce surgical risk. This was then followed by minimally invasive direct coronary artery bypass (MIDCAB).

RESULTS

At day 20 Post mitraclip intervention the patient suffered gastrointestinal bleeding which needed argon plasma coagulation (APC)-therapy and multiple blood transfusions. Stage II of the hybrid procedure was executed on post-intervention day 34 by minimally invasive direct coronary artery bypass (MIDCAB) to left anterior descending artery (LAD). Seven days later the patient was discharged. Up to two years of follow-up, the patient is in stable condition, without recurrent cardiac symptoms.

CONCLUSION

Hybrid approach of percutaneous mitral valve repair followed by MIDCAB is an effective minimally invasive treatment for severe ischemic mitral valve regurgitation and coronary artery disease.

Resilience of the Internal Mammary Artery to Atherogenesis: Shifting From Risk to Resistance to Address Unmet Needs

Fueled by the global surge in aging, atherosclerotic cardiovascular disease reached pandemic dimensions putting affected individuals at enhanced risk of myocardial infarction, stroke, and premature death. Atherosclerosis is a systemic disease driven by a wide spectrum of factors, including cholesterol, pressure, and disturbed flow. Although all arterial beds encounter a similar atherogenic milieu, the development of atheromatous lesions occurs discontinuously across the vascular system. Indeed, the internal mammary artery possesses unique biological properties that confer protection to intimal growth and atherosclerotic plaque formation, thus making it a conduit of choice for coronary artery bypass grafting. Its endothelium abundantly expresses nitric oxide synthase and shows accentuated nitric oxide release, while its vascular smooth muscle cells exhibit reduced tissue factor expression, high tPA (tissue-type plasminogen activator) production and blunted migration and proliferation, which may collectively mitigate intimal thickening and ultimately the evolution of atheromatous plaques. We aim here to provide insights into the anatomy, physiology, cellular, and molecular aspects of the internal mammary artery thereby elucidating its remarkable resistance to atherogenesis. We propose a change in perspective from risk to resilience to decipher mechanisms of atheroresistance and eventually identification of novel therapeutic targets presently not addressed by currently available remedies.

Review of Contemporary Techniques for Minimally Invasive Coronary Revascularization

Minimally invasive coronary revascularization techniques aim to avoid median sternotomy with its associated complications, while facilitating recovery and maintaining the benefits of surgical revascularization. The 3 most common procedures are minimally invasive coronary artery bypass grafting, totally endoscopic coronary artery bypass, and hybrid coronary revascularization. For a variety of reasons, including cost and technical difficulty, not many centers are routinely performing minimally invasive coronary revascularization. Nevertheless, many studies have assessed the safety and efficacy of each of these procedures in different clinical contexts. Thus far results have been promising, and with the evolution of procedural techniques, these approaches have the potential to redefine coronary revascularization in the future. This review highlights the current state of minimally invasive coronary revascularization techniques by exploring their benefits, identifying barriers to their adoption, and discussing future potential paradigms.

Graft Patency of a Second Conduit for Coronary Artery Bypass Surgery: A Network Meta-Analysis of Randomized Controlled Trials

It has been well documented that the use of the left internal thoracic artery (LITA) to graft the left anterior descending (LAD) artery has a significant benefit in coronary artery bypass graft (CABG) surgery. However, what graft is the best as a second conduit to complement LITA-LAD anastomosis remains uncertain. We thus conducted a network meta-analysis of RCTs to compare graft patency of the radial artery (RA), the right internal thoracic artery (RITA), the right gastroepiploic artery (RGEA), conventional saphenous vein (C-SVG), and no-touch saphenous vein (NT-SVG) as a second conduit in CABG. MEDLINE and EMBASE were searched through August 31, 2020 to identify randomized controlled trials (RCTs) that investigated graft patency of a second conduit in CABG. From each study, we extracted the incidence rate ratios of the outcome. A total of 13 RCTs were identified, including 3728 patients and 2773 angiographic results. The graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG and RGEA. There was no significant difference among the other comparisons. A sensitivity analysis restricting trials with ≥3 years angiographic follow-up time showed the graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG and RGEA, and a sensitivity analysis restricting trials with ≥5 years angiographic follow-up time showed the graft failure rates were significantly lower in NT-SVG and RA compared to C-SVG. In a network meta-analysis of the updated outcomes from RCTs, NT-SVG and RA have better graft patency compared to C-SVG and RGEA.

Hybrid Coronary Revascularization Versus Conventional Coronary Artery Bypass Surgery: Utilization and Comparative Outcomes

BACKGROUND

Hybrid coronary revascularization (HCR) treats multivessel coronary artery disease by combining a minimally invasive surgical approach to the left anterior descending artery with percutaneous coronary intervention for non-left anterior descending diseased coronary arteries. The objective of this study is to compare HCR and conventional coronary artery bypass graft (CABG) surgery medium-term outcomes.

METHODS

Data from multivessel disease patients in New York's cardiac surgery and percutaneous coronary intervention registries in 2010 to 2016 were used to compare mortality and repeat revascularization rates for HCR and conventional CABG after using propensity matching to reduce selection bias.

RESULTS

There was a total of 303 HCR (0.80%) patients and 37 556 conventional CABG patients after exclusions. After propensity matching, the respective median follow-up times were 3.72 years and 3.76 years. There was no difference between HCR and conventional CABG in survival at 6 years (80.9% versus 85.8%%, adjusted hazard ratio, 1.44 [0.90-2.31]), but HCR had higher mortality excluding deaths during the first year (adjusted hazard ratio, 1.88 [1.10-3.23]). Conventional CABG patients were more likely to be free from repeat revascularization at 6 years than HCR patients (88.2% versus 76.6%; hazard ratio, 2.22 [1.44-3.42]).

CONCLUSIONS

HCR is rarely performed for patients with multivessel coronary artery disease. HCR and conventional CABG had no different 6-year mortality rates, but HCR had higher mortality after 1 year and higher rates of subsequent revascularization that were caused by both the need for repeat revascularization in the left anterior descending artery where minimally invasive CABG was performed, and in the coronary arteries where percutaneous coronary intervention was performed. Graphic Abstract: A graphic abstract is available for this article.

Beyond patency: Functional assessment of adequacy using internal mammary artery grafting to the left anterior descending artery

INTRODUCTION

Arterial graft physiology influences the long-term outcome of coronary artery bypass grafting (CABG). We studied factors that can affect the overall resistance to flow using internal mammary artery grafting to the left anterior descending artery.

METHODS

This was a prospective, nonrandomized observational study of 100 consecutive patients who underwent elective on-pump isolated or combined valve surgery and CABG. Coronary stenoses were assessed using conventional and quantitative coronary angiography assessment. The flow and pulsatility index (PI) of the grafts were assessed by transit-time flowmetry during cardioplegic arrest and at the end of the operation. Fractional polynomials were used to explore linearity, followed by multivariable regression analysis.

RESULTS

Univariate analysis demonstrated higher flows at the end of the operation in patients who had higher flows with the cross-clamp on (P < .001), in males (P = .004), in patients with a low PI at the end of the operation (P = .04), and in patients with a larger size of the recipient artery (P = .005). Multivariable regression analysis showed that the graft flow at the end of the operation was significantly associated with the mean flow with the cross-clamp on (P < .001), sex (P = .003), and PI at the end of the operation (P = .003). Concomitant valve surgery did not influence flows. Male patients had 18 mL/min higher flow.

CONCLUSIONS

The graft flow at the end of the operation can be determined by the flow with the cross-clamp on, the PI with the cross-clamp off and coronary artery. We reported differences in the graft flows between sexes, and for first the time, we introduced the concepts of "adequate flow" and "resistance-to-forward-flow" for patent coronary grafts.

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

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

Short- and long-term cause of death in patients undergoing isolated coronary artery bypass grafting: A nationwide cohort study

OBJECTIVES

Knowledge of the association between time and causes of death after coronary artery bypass grafting is sparse. We examined short- and long-term mortality and cause of death in patients undergoing coronary artery bypass grafting.

METHODS

With the use of Danish nationwide registries, we identified all patients undergoing isolated coronary artery bypass grafting from 1998 to 2014. Cause of death was classified as cardiovascular or noncardiovascular according to death certificates. Landmark analyses of the cumulative incidences of cardiovascular and noncardiovascular mortality after 1, 3, and 5 years after coronary artery bypass grafting were performed. Multivariable cause-specific Cox regression models were used to evaluate changes over time in the risk of all-cause, cardiovascular, and noncardiovascular mortality after 1 and 7 years after coronary artery bypass grafting, respectively.

RESULTS

Among 37,495 included patients, 12,230 (32.6%) died during a median follow-up of 7.4 years. Causes of death were classified as cardiovascular in 6459 patients (52.8%) and noncardiovascular in 5771 patients (47.2%). Within the first year, the incidence of cardiovascular death was higher compared with noncardiovascular death (3.9% vs 1.1%, P < .001). The cumulative incidences of cardiovascular and noncardiovascular were deaths similar in the periods 1 to 3 years (2.3% vs 2.6%, P = .004), 3 to 5 years (3.1% vs 3.2%, P = .75), and 5 to 7 years postsurgery (3.7% vs 4.0%, P = .07). The crude rates and adjusted risks of short- and long-term all-cause and cardiovascular mortality decreased during the study period despite an increase in age and burden of comorbidities.

CONCLUSIONS

In patients undergoing coronary artery bypass grafting, cardiovascular causes were responsible for the majority of deaths within the first year. Deaths due to noncardiovascular causes gained importance over time elapsed since coronary artery bypass grafting.

The relationship between lymphocyte-to-monocyte ratio and saphenous vein graft patency in patients with coronary artery bypass graft

AIM

A lower lymphocyte count and a high monocyte count give important clues about the prognosis of various cardiovascular diseases. We hypothesized that lymphocyte-to-monocyte ratio (LMR) was associated with the saphenous vein graft disease (SVGD) in patients with coronary artery bypass graft (CABG).

PATIENTS & METHODS

A total of 218 patients with previous history of CABG surgery, who underwent coronary angiography due to stable angina symptoms, were investigated, retrospectively.

RESULTS

LMR levels were significantly lower in the SVGD group. Multiple logistic regression analyses showed that LMR levels were independent predictors of SVGD (OR: 0.648; 95% CI: 0.469-0.894; p = 0.008).

CONCLUSION

Our results suggested that LMR levels may provide useful information for the relevant risk evaluation of SVGD in CABG patients.

Vein graft failure: from pathophysiology to clinical outcomes

Occlusive arterial disease is a leading cause of morbidity and mortality worldwide. Aside from balloon angioplasty, bypass graft surgery is the most commonly performed revascularization technique for occlusive arterial disease. Coronary artery bypass graft surgery is performed in patients with left main coronary artery disease and three-vessel coronary disease, whereas peripheral artery bypass graft surgery is used to treat patients with late-stage peripheral artery occlusive disease. The great saphenous veins are commonly used conduits for surgical revascularization; however, they are associated with a high failure rate. Therefore, preservation of vein graft patency is essential for long-term surgical success. With the exception of 'no-touch' techniques and lipid-lowering and antiplatelet (aspirin) therapy, no intervention has hitherto unequivocally proven to be clinically effective in preventing vein graft failure. In this Review, we describe both preclinical and clinical studies evaluating the pathophysiology underlying vein graft failure, and the latest therapeutic options to improve patency for both coronary and peripheral grafts.

Frequency and Predictors of Internal Mammary Artery Graft Failure and Subsequent Clinical Outcomes: Insights From the Project of Ex-vivo Vein Graft Engineering via Transfection (PREVENT) IV Trial

BACKGROUND

The internal mammary artery (IMA) is the preferred conduit for bypassing the left anterior descending (LAD) artery in patients undergoing coronary artery bypass grafting. Systematic evaluation of the frequency and predictors of IMA failure and long-term outcomes is lacking.

METHODS AND RESULTS

The Project of Ex-vivo Vein Graft Engineering via Transfection (PREVENT) IV trial participants who underwent IMA-LAD revascularization and had 12- to 18-month angiographic follow-up (n=1539) were included. Logistic regression with fast false selection rate methods was used to identify characteristics associated with IMA failure (≥75% stenosis). The relationship between IMA failure and long-term outcomes, including death, myocardial infarction, and repeat revascularization, was assessed with Cox regression. IMA failure occurred in 132 participants (8.6%). Predictors of IMA graft failure were LAD stenosis <75% (odds ratio, 1.76; 95% confidence interval, 1.19-2.59), additional bypass graft to diagonal branch (odds ratio, 1.92; 95% confidence interval, 1.33-2.76), and not having diabetes mellitus (odds ratio, 1.82; 95% confidence interval, 1.20-2.78). LAD stenosis and additional diagonal graft remained predictive of IMA failure in an alternative model that included angiographic failure or death before angiography as the outcome. IMA failure was associated with a significantly higher incidence of subsequent acute (<14 days of angiography) clinical events, mostly as a result of a higher rate of repeat revascularization.

CONCLUSIONS

IMA failure was common and associated with higher rates of repeat revascularization, and patients with intermediate LAD stenosis or with an additional bypass graft to the diagonal branch had increased risk for IMA failure. These findings raise concerns about competitive flow and the benefit of coronary artery bypass grafting in intermediate LAD stenosis without functional evidence of ischemia.

CLINICAL TRIAL REGISTRATION

URL: http:/www.clinicaltrials.gov. Unique identifier: NCT00042081.

Searching for the second best graft for coronary artery bypass surgery: a network meta-analysis of randomized controlled trials†

OBJECTIVES

There is a lack of unequivocal evidence basis for selecting the best second conduit in coronary artery bypass grafting (CABG). We thus aimed to perform head-to-head relative effect estimate on angiographic outcomes for second conduits, including the right internal mammary artery (RIMA), radial artery (RA), right gastroepiploic artery (RGEA) and saphenous vein graft (SVG) by means of network meta-analysis of randomized controlled trials (RCTs).

METHODS

Databases were searched for RCTs comparing angiographic outcomes (≥4 weeks) of second conduits in CABG. Odds ratios (95% confidence intervals) were computed with Markov Chain Monte Carlo simulation.

RESULTS

A total of nine RCTs were identified, including 2780 patients and 1620 angiographic results available for analysis to compare RIMA (n=145) versus RA (n=871) versus RGEA (n=92) versus SVG (n=845). The mean time to angiographic follow-up ranged from 1 to 7.7 years. An SVG was significantly associated with a 4-fold (1.67-16.00) and 3-fold (0.78-22.20) increased risk of late (≥4 years) functional graft occlusion when compared with the RIMA and RA, respectively. A RIMA was associated with a non-significant 27% absolute risk reduction for functional graft occlusion when compared with the RA.

CONCLUSIONS

The present network meta-analysis consistently demonstrated an angiographic superiority of RIMA and RA over SVG. The RIMA is expected to achieve a better patency rate than the RA, but further studies are needed.

Hybrid revascularization for multivessel coronary artery disease

OBJECTIVES

The aim of this study was to assess the feasibility of hybrid coronary revascularization (HCR) in patients with multivessel coronary artery disease (MVCAD) referred for standard coronary artery bypass grafting (CABG).

BACKGROUND

Conventional CABG is still the treatment of choice in patients with MVCAD. However, the limitations of standard CABG and the unsatisfactory long-term patency of saphenous grafts are commonly known.

METHODS

A total of 200 patients with MVCAD involving the left anterior descending artery (LAD) and a critical (>70%) lesion in at least 1 major epicardial vessel (except the LAD) amenable to both PCI and CABG and referred for conventional surgical revascularization were randomly assigned to undergo HCR or CABG (in a 1:1 ratio). The primary endpoint was the evaluation of the safety of HCR. The feasibility was defined by the percent of patients with a complete HCR procedure and the percent of patients with conversions to standard CABG. The occurrence of major adverse cardiac events such as death, myocardial infarction, stroke, repeated revascularization, and major bleeding within the 12-month period after randomization was also assessed.

RESULTS

Most of the pre-procedural characteristics were similar in the 2 groups. Of the patients in the hybrid group, 93.9% had complete HCR and 6.1% patients were converted to standard CABG. At 12 months, the rates of death (2.0% vs. 2.9 %, p = NS), myocardial infarction (6.1% vs. 3.9%, p = NS), major bleeding (2% vs. 2%, p = NS), and repeat revascularization (2% vs. 0%, p = NS) were similar in the 2 groups. In both groups, no cerebrovascular incidents were observed.

CONCLUSIONS

HCR is feasible in select patients with MVCAD referred for conventional CABG. (Safety and Efficacy Study of Hybrid Revascularization in Multivessel Coronary Artery Disease [POL-MIDES]; NCT01035567).

The STS AVR+CABG composite score: a report of the STS Quality Measurement Task Force

BACKGROUND

The Society of Thoracic Surgeons (STS) is developing a portfolio of composite performance measures for the most commonly performed adult cardiac procedures. This manuscript describes the third composite measure in this series, aortic valve replacement (AVR) combined with coronary artery bypass grafting surgery (CABG).

METHODS

We identified all patients in the STS Adult Cardiac Surgery Database who underwent AVR+CABG during recent 3-year (July 1, 2009, through June 30, 2012) and 5-year (July 1, 2007, through June 30, 2012) periods. Variables from the STS risk model for AVR+CABG were used to adjust morbidity and mortality outcomes. Evidence for internal mammary artery use in AVR+CABG was examined. We compared composite measures constructed using 3 or 5 years of outcomes with Bayesian credible intervals of 90%, 95%, or 98%. The final STS AVR+CABG composite performance measure is based on 3 years of data and 95% credible intervals. It includes risk-adjusted mortality and morbidity but not internal mammary artery use.

RESULTS

Median composite score is 91.0% (interquartile range, 89.5% to 92.2%). There were 2.6% (24 of 915) one-star (lower performing) and 6.5% (59 of 915) three-star (higher performing) programs. Morbidity and mortality decrease monotonically as star ratings increase. The percentage of three-star programs increased substantially among programs that performed more than 150 procedures over 3 years compared with those performing 25 to 50 procedures (32.8% versus 1.6 %). Measure reliability was 0.51.

CONCLUSIONS

The STS has developed a composite performance measure for AVR+CABG based on 3-year data samples and 95% credible intervals. This composite measure identified 9.1% of STS participants as having higher or lower than expected performance.