Impact of Multiarterial Revascularization on Long-term Major Adverse Cardiovascular Events After Coronary Bypass in 23,798 Patients

BACKGROUND

This study evaluated the association between bypass grafting with multiarterial grafts (MAG) and single arterial grafts (SAG) and all-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE), overall and across different patient subgroups from a Middle Eastern nation.

METHODS

This single-center retrospective cohort study included 23,798 patients. MAG and SAG groups were balanced using inverse probability weighting (IPW). Associations between MAG and outcomes were assessed using Cox regression. A series of covariate-adjusted Cox models were conducted to evaluate the effect of MAG on outcomes at different levels of independent variables, including age, sex, and cardiovascular risk factors.

RESULTS

In the study population (73.9% were men, 65.11 ± 9.94 years), 986 patients (4.1%) underwent MAG. Compared with the SAG group, MAG had lower crude mortality (14.1% vs 21.6%) and MACCE (28.8% vs 34.7%) rates during a median follow-up of 9.23 years (quartile 1-quartile 3, 9.13-9.33 years). Although MAG was significantly associated with reduced risk of study outcomes at the univariate level, these associations disappeared after matching (all-cause mortality (IPW hazard ratio, 0.90; 95% CI, 0.67-1.22) and MACCEs (IPW hazard ratio, 0.94; 95% CI, 0.76-1.15). However, covariate-adjusted models indicated that MAG was associated with a significantly reduced risk of adverse events, particularly MACCEs, in men, younger patients, and those without risk factors.

CONCLUSIONS

MAG was not associated with improved postsurgery outcomes among the total coronary artery bypass graft population. Our findings, however, should be interpreted in the context of a relatively low total institutional MAG burden. Choosing a second arterial conduit over saphenous vein grafts in specific patient subgroups might be reasonable. This hypothesis-generating finding should be investigated in future clinical trials in these patients.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Total Arterial Revascularization: Evaluating the Length of the Radial Artery in a Composite Graft Configuration

PURPOSE

Reimplanting the radial artery in the left internal thoracic artery as a composite graft allows total arterial revascularization (TAR) without aortic manipulation. The limitation of this strategy is the length of the radial artery required to reach distal right coronary artery (RCA) branches. Our analysis focuses on the feasibility of this strategy.

METHODS

A total of 169 patients underwent TAR using the radial artery in a composite grafting configuration. Length of the radial artery, number of sequential anastomoses, heart size, target location, length of the arm, patient height, body surface area, and flow in the composite graft were prospectively collected.

RESULTS

The mean length of the radial artery was 18.02 cm. Patients with a mean length of the radial artery of 15.9 cm needed an extension of the radial artery with another conduit to reach the RCA distal branches. When T-configuration is used, the length of the radial artery should be 0.53 cm per sequential anastomosis to reach the RCA distal branches.

CONCLUSIONS

Our study shows that an average length of 18.02 cm of radial artery is needed to reach targets on the RCA distal branches in composite grafting. In T-configuration, we need 0.53 cm more length per anastomosis to achieve TAR.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bilateral Internal Thoracic Arteries Improve 10-Year Outcomes of Coronary Artery Bypass Grafting

BACKGROUND

This observational cohort study was designed by the PRIORITY (PRedictIng long-term Outcomes afteR Isolated coronary arTery bypass surgery) steering committee to evaluate the 10-year follow-up outcome of bilateral internal thoracic arteries (BITA) versus single internal thoracic artery.

METHODS

The PRIORITY project was designed to evaluate long-term outcome of 2 large prospective multicenter cohort studies of coronary artery bypass grafting. Clinical data on isolated coronary artery bypass grafting were merged with administrative data to collect follow-up information. The primary endpoint was the composite outcome of major adverse cardiac and cerebrovascular events at 10-year follow-up. Secondary endpoints were individual components of major adverse cardiac and cerebrovascular events at 10 years and surgical site complications or infections. A propensity score-based inverse probability treatment weighting (IPTW) was used to overcome the selection bias related to the observational nature of the study.

RESULTS

The study population consisted of 10,988 patients who underwent isolated coronary artery bypass grafting. BITA was used in 23.5%. The use of BITA is related to lower incidence of major adverse cardiac and cerebrovascular events at 10 years (adjusted hazard ratio [HR] 0.88, 95% CI 0.79-0.98, P < .001). BITA correlated with better 10-year survival (IPTW adjusted HR 0.87, 95% CI 0.78-1.00, P = .05), re-revascularization (IPTW adjusted HR 0.83, 95% CI 0.74-0.92, P < .001), and myocardial infarction (IPTW adjusted HR 0.86, 95% CI 0.77-0.95, P = .005) but to increased incidence of surgical site complications or infections (HR 2.12, 95% CI 1.39-3.24, P < .001).

CONCLUSIONS

In propensity-matched patients, use of BITA was associated with improved 10-year survival, freedom from repeat revascularization, and myocardial infarction but also higher incidence of surgical site complications.

Reconstruction Technique Options for Achieving Total Arterial Revascularization and Multiple Arterial Grafting

Ischemic heart disease is the leading cause of morbidity and mortality worldwide and may require coronary revascularization when more severe or symptomatic. Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure and can be performed with different bypass conduits and anastomotic techniques. Saphenous vein grafts (SVGs) are the most frequently used conduits for CABG, in addition to the left internal thoracic artery. Outcomes with a single internal thoracic artery and SVGs are favorable, and the long-term patency of SVGs may be improved through novel harvesting techniques, preservation methods, and optimal medical therapy. However, increasing evidence points towards the superiority of arterial grafts, especially in the form of multiple arterial grafting (MAG). Nevertheless, the uptake of MAG remains limited and variable, both as a result of technical complexity and a scarcity of conclusive randomized controlled trial evidence. Here, we present an overview of CABG techniques, harvesting methods, and anastomosis types to achieve total arterial revascularization and adopt MAG. We further narratively summarize the available evidence for MAG versus single arterial grafting to date and highlight remaining gaps and questions that require further study to elucidate the role of MAG in CABG.

Immediate Results after Multiple Arterial Grafts in Coronary Artery Bypass Graft Surgery in the São Paulo State: Cross Cohort Study

BACKGROUND

The short-term results after using arterial grafts still raise questions and doubts for medical society.

OBJECTIVE

To compare the immediate outcomes of patients undergoing single arterial graft versus multiple arterial grafts coronary artery bypass grafting surgery.

METHODS

Cross-sectional cohort study in the São Paulo Registry of Cardiovascular Surgery II (REPLICCAR II). Perioperative data from 3122 patients were grouped by the number of arterial grafts used, and their outcomes were compared: reoperation, deep sternal wound infection (DSWI), stroke, acute kidney injury, prolonged intubation (>24 hours), short hospital stay (<6 days), prolonged hospital stay (>14 days), morbidity and mortality. Propensity Score Matching (PSM) matched 1062 patients, adjusted for the mortality risk.

RESULTS

After PSM, the single arterial graft group showed patients with advanced age, more former smokers, hypertension, diabetes, stable angina, and previous myocardial infarction. In the multiple arterial grafts, there was a predominance of males, recent pneumonia, and urgent surgeries. After the procedure, there was a higher incidence of pleural effusion (p=0.042), pneumonia (p=0.01), reintubation (p=0.006), DSWI (p=0.007), and sternal debridement (p=0.015) in the multiple arterial grafts group, however, less need for blood transfusion (p=0.005), extremity infections (p=0.002) and shorter hospital stays (p=0.036). Bilateral use of the internal thoracic artery was not related to increased DSWI rate, but glycosylated hemoglobin >6.40% (p=0.048).

CONCLUSION

Patients undergoing the multiarterial technique had a higher incidence of pulmonary complications, and DSWI, where glycosylated hemoglobin ≥6.40%, had a greater influence on the infectious outcome than the choice of grafts.

Long-term outcomes of patients receiving right internal thoracic artery or radial artery as a second arterial conduit. A propensity score matching study

OBJECTIVE

This study aimed to compare the long-term outcomes in propensity matched patients receiving right internal thoracic artery(RITA) or radial artery(RA) as second arterial conduit during coronary artery bypass grafting(CABG) with internal thoracic artery to the left anterior descending artery(LAD).

METHODS

In this retrospective study, propensity score matching was performed including 1198 patients from 3 centers resulting in 389-pairs who received either RITA or RA.

RESULTS

In the matched cohort, median follow-up time was 7.53 years(interquartile range, 4.35-11.81). Survival probabilities at 5, 10 and 15-years were 93.8% versus 94.5%, 81.2% versus 76.2% and 63.2% vs 62.5% in the RITA and RA groups, respectively(HR: 1.11; 95%CI;0.80-1.53; P = 0.533) Freedom from MACCE in the matched cohort at 5, 10 and 15-years were 92.0% versus 93.7%, 75.0% versus 73.8%, 72.2% and 46.9% vs 47.2% in the RITA and RA groups, respectively(HR: 0.96; 95%CI;0.74-1.26; P = 0.774). Subgroup analyses of the matched cohort showed comparable long-term outcomes in terms of MACCE at follow-up in patients with age older than 65-years, obese patients, diabetics, female patients and with impaired EF. As for target vessel revascularization, RITA and RA had comparable outcomes in terms of MACCE when the conduit was used to graft either the left coronary system or the right coronary system.

CONCLUSIONS

The use of RITA or RA as second arterial conduit during CABG with internal thoracic artery to the LAD is safe and associated with comparable long-term clinical outcomes. The choice of optimal second arterial conduit should be guided mainly by patients' characteristics and surgeons' preferences.

Radial artery versus saphenous vein versus right internal thoracic artery for coronary artery bypass grafting

OBJECTIVES

We used individual patient data from 4 of the largest contemporary coronary bypass surgery trials to evaluate differences in long-term outcomes when radial artery (RA), right internal thoracic artery (RITA) or saphenous vein graft (SVG) are used to complement the left internal thoracic artery-to-left anterior descending graft.

METHODS

Primary outcome was all-cause mortality. Secondary outcome was a composite of major adverse cardiac and cerebrovascular events (all-cause mortality, myocardial infarction and stroke). Propensity score matching and Cox regression were used to reduce the effect of treatment selection bias and confounders.

RESULTS

A total of 10 256 patients (1510 RITA; 1385 RA; 7361 SVG) were included. The matched population consisted of 1776 propensity score-matched triplets. The mean follow-up was 7.9 ± 0.1, 7.8 ± 0.1 and 7.8 ± 0.1 years in the RITA, RA and SVG cohorts respectively. All-cause mortality was significantly lower in the RA versus the SVG [hazard ratio (HR) 0.62, 95% confidence interval (CI): 0.51-0.76, P = 0.003] and the RITA group (HR 0.59, 95% CI 0.48-0.71, P = 0.001). Major adverse cardiac and cerebrovascular event rate was also lower in the RA group versus the SVG (HR 0.78, 95% CI 0.67-0.90, P = 0.04) and the RITA group (HR 0.75, 95% CI 0.65-0.86, P = 0.02). Results were consistent in the Cox-adjusted analysis and solid to hidden confounders.

CONCLUSIONS

In this pooled analysis of 4 large coronary bypass surgery trials, the use of the RA was associated with better clinical outcomes when compared to SVG and RITA.

How to build a multi-arterial coronary artery bypass programme: a stepwise approach

Observational evidence shows that the use of multiple arterial grafts (MAG) is associated with longer postoperative survival and improved clinical outcomes. The current European Society of Cardiology/European Association for Cardio-Thoracic Surgery Guidelines on myocardial revascularization recommend the use of MAG in appropriate patients. However, a significant volume-to-outcome relationship exists for MAG, and lack of sufficient experience is associated with increased operative risk. A stepwise approach to building experience with MAG allows successful implementation of this technique into routine coronary surgery practice.

Angiographic Patency of Coronary Artery Bypass Conduits: A Network Meta-Analysis of Randomized Trials

Background Several randomized trials have compared the patency of coronary artery bypass conduits. All of the published studies, however, have performed pairwise comparisons and a comprehensive evaluation of the patency rates of all conduits has yet to be published. We set out to investigate the angiographic patency rates of all conduits used in coronary bypass surgery by performing a network meta-analysis of the current available randomized evidence. Methods and Results A systematic literature search was conducted for randomized controlled trials comparing the angiographic patency rate of the conventionally harvested saphenous vein, the no-touch saphenous vein, the radial artery (RA), the right internal thoracic artery, or the gastroepiploic artery. The primary outcome was graft occlusion. A total of 4160 studies were retrieved of which 14 were included with 3651 grafts analyzed. The weighted mean angiographic follow-up was 5.1 years. Compared with the conventionally harvested saphenous vein, both the RA (incidence rate ratio [IRR] 0.54; 95% CI, 0.35-0.82) and the no-touch saphenous vein (IRR 0.55; 95% CI, 0.39-0.78) were associated with lower graft occlusion. The RA ranked as the best conduit (rank score for RA 0.87 versus 0.85 for no-touch saphenous vein, 0.23 for right internal thoracic artery, 0.29 for gastroepiploic artery, and 0.25 for the conventionally harvested saphenous vein). Conclusions Compared with the conventionally harvested saphenous vein, only the RA and no-touch saphenous vein grafts are associated with significantly lower graft occlusion rates. The RA ranks as the best conduit. Registration URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42020164492.

Measures to Increase Use of Multiple Arterial Grafts for Isolated Coronary Artery Bypass Grafting

BACKGROUND

Use of multiple arterial grafts (MAGs) provides superior patency and long-term survival benefit compared with venous grafts during coronary artery bypass grafting (CABG). However, MAGs are used infrequently for CABG. We hypothesized that specific measures introduced at our institution would lead to an increase in the use of MAGs.

STUDY DESIGN

Use of MAGs before and after introduction of bundled measures was compared. Measures included increased education in arterial graft harvesting, inclusion as a quality metric, and hiring of surgeon champions. Patients younger than 70 years who underwent first time, isolated CABG using at least 1 arterial graft were included. Number and type of grafts used were compared between time periods using chi-square test. Secondary outcomes included postoperative complications. Complications were compared between time periods, as well as between MAG and non-MAG recipients before and after propensity score matching using Fisher exact test and univariate logistic regression. Multivariable logistic regression was used to determine patient characteristics associated with MAG use.

RESULTS

There were 2,169 patients included from 2012 to 2019. MAG use increased significantly after introduction of measures (21.1% to 41.9%; p < 0.001). Radial artery use with an internal mammary artery (0.3% to 16%; p < 0.001) and the use of triple arterial grafts increased significantly (0% to 2.4%; p < 0.001). MAG use in the entire cohort was associated with decreased 30-day mortality and postoperative cardiac arrest that was not significant after propensity matching.

CONCLUSIONS

A programmatic emphasis on the use of MAGs for CABG is an effective method to increase its use.

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

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