Multiarterial Grafting Research Articles

STS Adult Cardiac Surgery Database: 2021 Update on Outcomes, Quality, and Research

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It has been the foundation for quality measurement and improvement activities in cardiac surgery, facilitated the generation of accurate risk adjusted performance benchmarks and serves as a platform for novel research. Recent enhancements have added to the database's functionality, ease of use, and value to multiple stakeholders. This report is the sixth in a series of annual reports that provide updated volumes, outcomes, database-related developments, quality improvement initiatives, and research summaries using the Adult Cardiac Surgery Database in the past year.

The Growth Potential and Patency of Free Right Internal Thoracic Arteries Verified by Computed Tomography Angiography

BackgroundThe use of the left internal thoracic artery (LITA) is the gold standard in coronary artery bypass graft surgery (CABG). Multiarterial grafting for CABG is being increasingly emphasized. This study aimed to resolve the utility of the right internal thoracic artery (RITA) for multiple CABG as “free” RITA and described new evidence. MethodsOne hundred sixty-three patients received solo CABG with bilateral internal thoracic arteries between 2005 and 2018. The RITA was used as in situ RITA, group A (n = 62), and the composite graft created with saphenous vein graft (SVG), group B (n = 101). The patency rate and graft size of the composite free RITA and SVG were examined by coronary computed tomography angiography. ResultsThe average number of distal anastomoses per patient was 3.4 ± 1.0 in group A, and 4.2 ± 1.1 in group B (P < .001). The sequential grafting with free RITA was in 86 patients. The patency rate of both LITA and RITA was similar in both groups. In group B, 40 patients received late computed tomography angiography at a mean of 46 months (range, 17 to 175). The late patency rate was 95.1% in LITA and 96.9% in free RITA. The diameter of free RITA increased from 2.06 ± 0.34 mm to 2.37 ± 0.23 mm (P = .036); that of in situ LITA increased from 2.08 ± 0.51 mm to 2.44 ± 0.49 mm (P = .047); and that of composite SVG decreased from 4.1 ± 0.9 mm to 2.6 ± 0.7 mm (P < .001). ConclusionsMultiple bypass grafting can be sufficiently achieved with LITA and free RITA. The growth potential of free RITA and in situ LITA might play the important role of expected long-term patency.

Adverse events after coronary artery bypass grafting in patients with preoperative metabolic syndrome: A 10-year follow-up of the Veterans Affairs Database

IntroductionData regarding 10-year survival and adverse cardiovascular events in patients with metabolic syndrome (MET) after coronary artery bypass grafting (CABG) is limited. MethodsWe compared 10-year events rates for veterans undergoing isolated CABG (January 1, 2005, to December 31, 2014, follow-up October 31, 2019) stratified by presence of metabolic syndrome (MET+) versus without (MET–). A multivariable weighted Cox model was used to analyze all-cause mortality. Competing risk analysis was used to calculate cumulative event rates for congestive heart failure, myocardial infarction, and cerebrovascular events. The Fine-Gray subhazard model was used to determine adjusted association of MET with myocardial infarction and stroke. Congestive heart failure was modeled as a recurrent-event analysis. ResultsNationally, 9615 adults (median age, 60 years; 98.9% men) underwent isolated coronary artery bypass grafting at 41 centers); among them, 3121 out of 9615 (32.5%) had MET. The prevalence of MET increased from (27.88% in 2005 to 34.02% in 2014; P = .02). MET+ group members were likely younger (median age, 63 vs 64 years; P < .01), White (72% vs 68%), and had more peripheral vascular disease (30% vs 28%; P = .04). Multivessel (72% vs 70%; P = .23) and multiarterial (4% vs 4%; P = .14) grafting was performed equally. With a median follow-up of 6.5 years, survival was similar (P = .26); however, MET was associated with higher risks for myocardial infarction (21% vs 16%; hazard ratio, 1.3; P < .01) and recurrent admissions for congestive heart failure. ConclusionsPatients with metabolic syndrome undergoing coronary artery bypass grafting have higher 10-year cardiovascular event rates.

Sequential Versus Individual Saphenous Vein Grafting During Coronary Arterial Bypass Surgery

Although multiarterial grafting or bilateral mammary artery use is being increasingly emphasized for contemporary coronary artery bypass grafting (CABG) practice, saphenous vein graft (SVG) is still the most frequently used CABG conduit, and it accounts for 80% of all CABG conduits. Research focusing on modifiable surgical factors such as anastomosis technique, however, is scarce. This study aimed to compare clinical outcomes and graft patency according to anastomosis methods of vein grafting. From January 2005 through December 2016, patients who underwent CABG using SVG either by a sequential or an individual grafting technique were enrolled in this study. Graft patency was evaluated with coronary computed tomographic angiography. Propensity-score matching was used to compare the clinical outcomes and graft patency of these 2 grafting techniques to reduce treatment selection bias. Overall 2515 eligible patients, 1,037 in the sequential SVG graft group (41.3%) and 1478 (58.8%) in the individual SVG graft group were enrolled. After propensity-score matching, 901 matched pairs of patients and 891 matched pairs of grafts were included in the final outcome analysis. There were no significant differences in unadjusted (P= .83) and adjusted overall mortality (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.79 to 1.17; P= .67). The composite outcome of death, nonfatal myocardial infarction, and repeat revascularization also did not significantly differ between the sequential SVG and the individual SVG groups for both before (P= .20) and after matching (HR, 0.91; 95% CI, 0.75 to 1.09; P= .30). The sequential grafts showed superior patency as compared with the individual grafts for both before (P= .015) and after adjustment (HR, 0.61; 95% CI, 0.45 to 0.82; P < .001). The sequential grafting technique of SVG showed fairly acceptable safety and efficacy with superior long-term graft patency than individual grafts.Sequential SVG grafts perhaps can be a reasonable option as a second graft in CABG in some clinical situations.

Multiarterial grafting in coronary artery bypass grafting

Multiarterial grafting in coronary artery bypass grafting

Impact of preoperative fractional flow reserve on arterial bypass graft anastomotic function: the IMPAG trial.

Visual estimation is the most commonly used method to evaluate the degree of coronary artery stenosis prior to coronary artery bypass grafting. In interventional cardiology, the use of fractional flow reserve (FFR) to guide revascularization decisions has become routine. We investigated whether the preoperative FFR measurement of coronary lesions is associated with anastomosis function 6 months after surgical revascularization using a multiarterial grafting strategy. In this prospective double-blind study, 67 patients were enrolled from two institutions in Europe and Canada. From these patients, 199 coronary lesions were assessed visually and with FFR at the time of the preoperative angiogram. All patients received coronary revascularization using multiple arterial grafts. A post-operative 6-month angiogram was performed to assess anastomosis functionality using a described angiographic method. The primary outcome was the association between preoperative FFR values and anastomosis function 6 months after surgery. Preoperative FFR was significantly associated with 6-months anastomotic function for all conduits and for all targets (P < 0.001). An FFR value of ≤0.78 was associated with an anastomotic occlusion rate of 3%. We found a significant association between the preoperative FFR measurement of the target vessel and the anastomotic functionality at 6 months, with a cut-off of 0.78. Integration of FFR measurement into the preoperative diagnostic workup before multiarterial coronary surgical revascularization leads to improved anastomotic graft function. NCT02527044.

Disparities in Cardiovascular Risk Factors in Northern Plains American Indians Undergoing Coronary Artery Bypass Grafting.

Objectives: Heart disease is the leading cause of death in American Indians (AIs). For AI patients with severe coronary artery disease requiring coronary artery bypass graft (CABG) surgery, little data exist. The purpose of this study was to evaluate short-term outcomes of Northern Plains AI undergoing CABG and identify variations in patient presentation.Methods: All patients undergoing isolated CABG between June 2012 and June 2017 were studied. Seventy-four AI and 1236 non-American Indian (non-AI) patients were identified. Risk factors, preoperative characteristics, cardiac status, procedural information, and outcomes were collected. Univariate analysis comparing short-term clinical outcomes between AI and non-AI populations was performed. Multivariable logistic regression models were constructed and outcome differences assessed. Unadjusted Kaplan–Meier survival estimates were produced using 5-year survival data.Results: AI patients presented with increased risk factors, including higher rates of diabetes mellitus (AI 63.5% vs. non-AI 38.7% p=< 0.001) and smoking/tobacco use (AI 60.8% vs. non-AI 20.0% p=> 0.001). Seventy-nine percent of AI patients resided on or near federal reservations and presented from rural locations. Internal mammary artery (IMA) graft use in both groups was high (AI 95.9% vs. non-AI 94.9% p=0.904), and multiarterial grafting with left internal mammary artery and radial artery use was common in both groups (AI 67.6% vs. non-AI 69.6% p=0.814). No significant differences in unadjusted 30-day mortality or short-term outcomes were detected. Adjusted Kaplan–Meier survival curves were similar between race groups up through 5 years after CABG (p-value=0.38).Conclusion: AIs presented with significantly more risk factors for cardiovascular disease compared with the general population, with especially high rates of insulin-dependent diabetes and active tobacco use. Despite this, outcomes were similar between groups. In propensity-matched groups, AIs were at decreased risk for prolonged length of stay and combined morbidity/mortality. In contrast to previous reports, AI racial identity did not adversely affect survival up to 5 years after CABG.

Why Don’t We Kill 2 Birds with 1 Stone?

Article, see p 1698 In this issue of Circulation , Goldstone and colleagues1 report the early and midterm outcomes of more than 59 000 patients who underwent primary isolated multivessel coronary artery bypass grafting (CABG) at 126 nonfederal hospitals in California from 2006 to 2011. They found that after propensity matching, receipt of a second arterial conduit was associated with significantly lower all-cause mortality, myocardial infarction, and coronary reintervention at a median follow-up of more than 5 years. It is interesting to note that compared with radial artery (RA) grafting, right internal thoracic artery (RITA) grafting did not confer a survival or cardiovascular advantage, but was associated with increased risk of sternal wound infection. During the study period, use of a second arterial conduit decreased from 10.7% to 9.1%, mirroring a national trend reported by the Society of Thoracic Surgeons Adult Cardiac Surgery Database (11.6% in 2000–2009 versus 6.7% in 2010–2013).2 Notably, 30% of cardiac surgeons in California did not use a second arterial graft for the duration of the study. So why is there a reluctance to use multiple arterial grafts in multivessel CABG despite the potential benefit? As for the 70% of California’s surgeons who use 2 arteries, why do they do so only in a small percentage of patients? The answers to those questions are complex but not elusive. Barriers to multiarterial grafting are diverse, ranging from perceptions about available scientific evidence, to surgical expertise, to health economics and more (Table). View this table: Table. Barriers to Multiarterial Grafting, Proposed Solutions, and Responsible Parties Starting with the scientific evidence, the California study is the largest study to date and an important addition to other large …

Effectiveness of radial artery–based multiarterial coronary artery bypass grafting: Role of body habitus

BackgroundThe multiarterial grafting survival advantage noted in the overall population undergoing coronary artery bypass grafting is not well defined in the obese. We investigated the early to late survival effects of the radial artery in left internal thoracic artery–based multiarterial bypass grafting (radial artery-multiarterial bypass grafting) versus single arterial bypass grafting (left internal thoracic artery-single arterial bypass grafting) in obese patients. MethodsWe analyzed 15-year Kaplan–Meier survival in 6102 patients receiving primary, left internal thoracic artery–based coronary artery bypass grafting with 2 or more grafts divided into body mass index groups: nonobese (<30 kg/m2) and all-obese, comprised of mildly obese (30-35 kg/m2) and morbidly obese (>35 kg/m2). Risk-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of radial artery-multiarterial bypass grafting versus left internal thoracic artery-single arterial bypass grafting were derived via Cox regression and applied separately for early (<0.5 years), intermediate (0.5-5 years), and late (5-15 years) follow-up in each body mass index cohort. Propensity score matching between radial artery-multiarterial bypass grafting and left internal thoracic artery-single arterial bypass grafting cohorts within the body mass index groups was performed as a corroborating analysis. ResultsRadial artery-multiarterial bypass grafting was more frequently used in obese patients who were younger (62 ± 10 years; mild/morbid: 45.4%/54.4% radial artery-multiarterial bypass grafting) compared with nonobese patients (66 ± 10 years; 37.4% radial artery-multiarterial bypass grafting). Unadjusted 15-year survival was significantly better for radial artery-multiarterial bypass grafting in all body mass index groups. Multivariate analysis showed a survival benefit of radial artery-multiarterial bypass grafting over the entire 0- to 15-year study period in the all-obese cohort (HR, 0.85; 95% CI, 0.74-0.98) and was more pronounced in the mildly obese (HR, 0.79; 95% CI, 0.66-0.96) versus morbidly obese (HR, 0.88; 95% CI, 0.69-1.13). The radial artery-multiarterial bypass grafting survival benefit was realized between 0.5 and 5 years postoperatively and was comparable for all-obese (HR, 0.69; 95% CI, 0.51-0.94) and nonobese (HR, 0.68; 95% CI, 0.52-0.88) groups. Propensity score matching was confirmatory. ConclusionsRadial artery-multiarterial bypass grafting confers a long-term survival advantage in both obese and nonobese patients.

Minimally invasive cardiac surgery coronary artery bypass grafting (MICS CABG): a review of technique and literature

Minimally invasive cardiac surgery has emerged as a safe alternative to standard cardiac surgery. Minimally invasive coronary surgery (MICS CABG) is developed to allow adequate exposure and complete revascularization in CABG from a small thoracotomy incision without cardiopulmonary bypass. The literature of the technique and evidence of the MICS CABG procedure is reviewed. In its earlier phase, MICS CABG required the adherence to a number of absolute and relative contraindications. The technique continues to evolve, and in addition to multi-vessel revascularization, bilaterally internal thoracic artery take down are currently feasible to allow for multi-arterial grafting. The success of an MICS CABG procedure also requires cooperation between the surgeon, anesthesiologist, and perfusionist and diligent management of hemodynamics. To date, 11 articles have been published on experiences with MICS CABG. MICS CABG is a safe alternative to sternotomy CABG in early and long-term post-operative mortality and morbidity, and has significantly shorter length of hospital stay and earlier post-operative physical recovery compared to sternotomy CABG. Evidences are emerging that MICS CABG maintains equivocal safety profile to sternotomy CABG, while providing superior morbidity profile and post-operative recovery. Further randomized control trials involving the comparison between MICS CABG and PCI or traditional CABG would widen the applicability and utilization of the procedure.

Right Internal Mammary Artery Use in 140 Robotic Totally Endoscopic Coronary Bypass Cases: Toward Multiarterial Grafting

Right Internal Mammary Artery Use in 140 Robotic Totally Endoscopic Coronary Bypass Cases: Toward Multiarterial Grafting

Right Internal Mammary Artery Use in 140 Robotic Totally Endoscopic Coronary Bypass Cases: Toward Multiarterial Grafting.

Benefits of adding a second arterial graft in coronary bypass are well documented. In patients requiring mulitvessel grafting robotic totally endoscopic coronary bypass (TECAB) has allowed for routine harvesting and use of the right internal mammary artery (RIMA). We retrospectively reviewed the technical considerations and target choice in 140 cases of beating heart TECAB where a RIMA graft was used. In 2008, we introduced beating heart TECAB with anastomotic connectors into our practice, first with single IMA and then with bilateral internal mammary artery. A robotic stabilizer was used not only to facilitate exposure of the coronary targets but also to aid the RIMA harvest using a skeletonized approach. Flow measurements were obtained routinely. We reviewed the technical aspects, target choice, and intraoperative flows in our TECAB patients who underwent grafting with RIMA grafts. From February 2008 to January 2015, a total of 404 patients underwent beating heart TECAB with anastomotic connectors, of which 194 (48%) were mulitvessel procedures. One hundred forty patients (35%) had a RIMA graft and constitute the patient population for this review. One hundred thirty-one RIMA grafts were harvested via left-sided ports and grafted to left coronary targets, and nine RIMA grafts were harvested via right-sided ports and grafted to the right coronary artery. Flow was greater than 25 mL/min (pulsatility index < 2) in 95% of grafts. Perioperative mortality was 0.7% and mean ± standard deviation length of hospital stay was 3.1 (1.5) days. The RIMA was used as an in situ graft in 124 cases (84%) and as a free T-graft in 24 cases (16%) cases. Right internal mammary artery graft use in all TECABS increased from 23% in the first 5 years to 53% in the last 2 years. Robotic TECAB allows the routine harvesting and use of the RIMA graft in a safe and reproducible manner. Skeletonization and sternal sparing allow the RIMA to reach various coronary targets. Further studies are needed for this approach to impact the adaption of multiarterial grafting.

The Racial Paradox in Multiarterial Conduit Utilization for Coronary Artery Bypass Grafting

It has been established that outcomes for black patients undergoing coronary artery bypass graft surgery (CABG) are inferior to those of their white counterparts. The purpose of this study was to determine (1) whether rates of multiarterial grafting are different among black patients and white patients, and (2) whether racial differences exist in postoperative outcomes after accounting for grafting strategy. A retrospective review of black patients (n=2,810) and white patients (n= 13,569) who underwent isolated, primary CABG from January 2002 to June 2014 at a US academic institution was performed. A modified predicted risk of mortality (M-PROM) score was calculated for each patient using all The Society of Thoracic Surgeons variables for CABG excluding race. Multivariable linear, logistic, and Cox regression analyses were used to assess between-group differences, adjusted for M-PROM. Overall, 16,379 patients underwent CABG, and 2,441 (14.9%) received more than one arterial graft. When adjusted for M-PROM, the odds of blacks undergoing multiarterial CABG were 10% greater than for whites (p=0.05). Blacks had worse inhospital outcomes, including higher odds of stroke (odds ratio 2.41, 95% confidence interval [CI]: 1.80 to 3.25) and prolonged intubation (odds ratio 2.01, 95% CI: 1.77 to 2.28). The increase in postoperative complications did not translate to a difference in inhospital mortality (p= 0.10) between racial cohorts. Moreover, among patients who underwent multiarterial grafting strategies, blacks had a hazard of mortality that was 34% higher (95% CI: 22% to 51%)) than that of their white counterparts. Among black patients, those who underwent multiarterial grafting strategies showed better long-term survival than those undergoing single grafting strategies (hazard ratio 0.86, 95% CI: 0.78 to 0.96). Despite similar rates of arterial grafting for black patients and white patients in this large single-center cohort, black patients continued to have significantly worse late survival when compared with white patients. Continued evaluation as to the causes of this disparity is warranted.

The current status of multi-arterial off-pump coronary artery bypass grafting.

Off-pump coronary artery bypass surgery has not become widespread because of its technical difficulty. However, especially in Asia, pioneer surgeons continue with efforts to develop the off-pump technique. By reviewing past studies, mainly retrospective single-center reports, an up-to-date profile of off-pump surgery was assembled. Many of the past randomized trials failed to demonstrate the advantages of off-pump surgery. Although many of these were single-center retrospective studies, the data presented, mostly from world-famous surgeons, show that off-pump surgery does have advantages in high-risk patients and results in reduced rates of postoperative morbidity and equal rates of mortality in both the short- and long terms. Moreover, almost all experienced off-pump surgeons noted the benefit of multiple uses of arterial grafts, skeletonization harvesting of arterial conduits and the aorta no-touch technique. The off-pump procedure has not become a standard technique performed by the average surgeon in daily practice. However, off-pump surgery will continue to provide a significant benefit to high-risk patients with coronary disease.

Multi-arterial Grafting is Effective but Underused

This article reviews the facts that support multiarterial bypass grafting and circumstances for favorable outcomes, as well as discusses complications for this procedure.

Coronary Artery Bypass Grafting for Dialysis Patients: Usefulness of Multiarterial Bypass

This study assessed the efficacy of multiarterial bypass in coronary artery bypass grafting (CABG) in dialysis patients. Eighty dialysis patients who underwent CABG were divided into 2 groups. Group A consisted of 38 patients in whom the left internal thoracic artery and additional saphenous vein graft (SVG) had been used. Group B consisted of 42 patients in whom 2 or 3 arterial grafts and additional SVGs had been used. No mediastinitis was shown in either group. Actuarial survival rates, including all deaths, and estimated by cardiac deaths at 8 years, were 28% and 83%, respectively, in Group A and 93% and 100%, respectively, in Group B with a significant difference (p = 0.014 and 0.016, respectively). Cardiac event-free rates at 8 years were 43% and 96% in Groups A and B, respectively, with a significant difference (p = 0.0016). Multiarterial grafting improved long-term results after CABG for dialysis patients compared with single internal thoracic artery grafting with minimal complications related to graft harvesting.

Coronary Bypass with Arterial Conduits

To assess the efficacy of arterial revascularization 368 patients were studied who underwent myocardial revascularization with two or more arterial conduits (group M) and compared with 2092 patients in whom a single internal mammary artery ± veins (group S), and to a third group in which only saphenous vein conduits (group V, n = 602) were used. Group M patients were younger (aged 54.0(9.5) years: 4.1% aged &gt; 70 years) than either group V (67.6(8.9) years, 40.7% &gt; 70 years, P &lt; 0.0001) or group S patients (62.0(8.5) years. 15.7% &gt; 70 years, P &lt; 0.0001). Furthermore, this cohort group had the lowest percentage of females (8.4%), of urgent cases (21.7%), of preoperative myocardial infarction (6.0%), and of redo surgery (0.8%). In contrast, patients who received only saphenous vein conduits had the highest proportion of female patients (29.2%), of urgent cases (47.4%), of preoperative myocardial infarction (16.5%), and of redo surgery (5.5%). By multivariate logistic regression analysis (odds ratio in parentheses), redo surgery (6.06, P = 0.0001), preoperative intra-aortic balloon pump assist (6.11, P = 0.0001), diabetes (1.97, P = 0.03), urgent surgery (1.80, P = 0.05), and advanced age (2.14, P = 0.01) were all predictors of operative mortality. In contrast, while choice of conduit appeared to influence outcome by univariate analysis (4.2% mortality in group V, P &lt; 0.001), it was not found to be a predictor of either mortality or morbidity by regression analysis. The present results indicate that, in carefully selected patients, despite increased technical demands with longer periods of aortic occlusion and longer pump times, multi-arterial grafting (compared with conventional revascularization) is a safe and efficacious procedure. Whether or not this approach to revascularization will increase long-term survival and freedom from reoperation will require further study.

Coronary bypass with arterial conduits

To assess the efficacy of arterial revascularization 368 patients were studied who underwent myocardial revascularization with two or more arterial conduits (group M) and compared with 2092 patients in whom a single internal mammary artery±veins (group S), and to a third group in which only saphenous vein conduits (group V, n=602) were used. Group M patients were younger (aged 54.0(9.5) years; 4.1% aged >70 years) than either group V (67.6(8.9) years, 40.7% >70 years, P<0.0001) or group S patients (62.0(8.5) years, 15.7% >70 years, P<0.0001). Furthermore, this cohort group had the lowest percentage of females (8.4%), of urgent cases (21.7%), of preoperative myocardial infarction (6.0%), and of redo surgery (0.8%). In contrast, patients who received only saphenous vein conduits had the highest proportion of female patients (29.2%), of urgent cases (47.4%), of preoperative myocardial infarction (16.5%), and of redo surgery (5.5%). By multivariate logistic regression analysis (odds ratio in parentheses), redo surgery (6.06, P=0.0001), preoperative intra-aortic balloon pump assist (6.11, P=0.0001), diabetes (1.97, P=0.03), urgent surgery (1.80, P=0.05), and advanced age (2.14, P=0.01) were all predictors of operative mortality. In contrast, while choice of conduit appeared to influence outcome by univariate analysis (4.2% mortality in group V, P<0.001), it was not found to be a predictor of either mortality or morbidity by regression analysis. The present results indicate that, in carefully selected patients, despite increased technical demands with longer periods of aortic occlusion and longer pump times, multi-arterial grafting (compared with conventional revascularization) is a safe and efficacious procedure. Whether or not this approach to revascularization will increase long-term survival and freedom from reoperation will require further study.