Outcomes Associated With Bilateral Internal Thoracic Artery Grafting: The Importance of Age

External stenting for saphenous vein grafts reduces early postoperative graft failure

OBJECTIVES

Multiple studies have shown that external stenting (ExSt) mitigates the progression of vein graft disease years after coronary artery bypass grafting (CABG). We used computed tomography to evaluate the effect of ExSt on perioperative vein graft patency.

METHODS

This study assessed graft patency rates of saphenous vein grafts (SVG) in consecutive patients with isolated coronary artery bypass grafting (CABG) between 2018 and 2021. Logistic regression analyses were conducted to compare the outcomes of supported and non-supported groups at both patient and graft levels, with age, EuroSCORE II, gender, diabetes and arterial grafts as covariates. Subgroup analyses were performed based on different covariates. The goal of the study was to provide valuable insights into the clinical outcomes of SVG in patients having CABG.

RESULTS

The study examined a total of 357 patients who met the inclusion criteria and evaluated 572 vein grafts. Of these, 150 patients (205 SVGs) received ExSt, whereas 207 patients (337 SVGs) did not receive ExSt. The study results indicated that the likelihood of overall SVG patency at discharge was higher in the stented group than in the non-stented group, both at the level of the grafts [93.8% vs 87.8%, odds ratio (OR) 2.1; 95% confidence interval (CI) 1.0-4.5; P = 0.05] and at the patient level (90.1% vs 83.5%, OR 1.8; 95% CI 0.9-3.6; P = 0.1). It is worth noting that the difference between the stented and non-stented groups was most significant in the subgroup that received 2 arterial grafts (96.5% vs 89.6%, OR 3.2; 95% CI 1.2-8.4; P = 0.02) and in the subgroup with a higher EuroSCORE II (median >1.1) (98.6% vs 88.6%, OR 8.8; 95% CI 1.1-72.7; P = 0.04).

CONCLUSIONS

The ExSt is associated with improved perioperative SVG patency at both the graft and the patient levels. Moreover, SVGs to the right territory and high-risk patients appear to have an advantage using ExSt.

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.

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.

Gender-Related Discrepancies in Short-Term Outcomes in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting Surgery

The sex differences in patients undergoing off-pump coronary artery bypass grafting (OPCAB) surgery are still unclear. Our aim was to investigate the impact of gender on short-term outcomes in males and females after off-pump bypass procedures. Our research was designed as a double-center retrospective analysis. Generally, 343 patients (men (n = 255) and women (n = 88)) who underwent an OPCAB procedure were included in our study. To provide a statistical analysis of unequal cohorts, we created a propensity score-based matching (PSM) analysis (men, n = 61; women, n = 61). The primary endpoint was all-cause in-hospital mortality. Dialysis, transient ischemic attack (TIA), low cardiac output syndrome (LCOS), reoperation due to postoperative bleeding, wound infection and duration of hospital stay were secondary outcomes in our analysis. No significant differences were detected within the male and female groups regarding age (p = 0.116), BMI (p = 0.221), diabetes (p = 0.853), cardiogenic shock (0.256), STEMI (p = 0.283), NSTEMI (p = 0.555) and dialysis (p = 0.496). Males underwent significantly more frequently (p = 0.005) total-arterial revascularization with T-graft technique (p = 0.005) than females. In contrast, temporary pacer use was significantly higher (p = 0.022) in females compared to males. The in-hospital mortality rate was not significantly higher (p = 0.496) in the female group compared to the male group. Likewise, secondary outcomes did not differ significantly between the non-adjusted and the adjusted groups. Based on our findings, gender has no impact on short-term outcomes after OPCAB surgery.

Single versus multiple arterial grafting in diabetic patients at 10 years: the Arterial Revascularization Trial

AIMS

To evaluate the impact of multiple arterial grafting (MAG) vs. single arterial grafting (SAG) in a post hoc analysis of 10-year outcomes in patients with diabetes mellitus (DM) from the Arterial Revascularization Trial (ART).

METHODS AND RESULTS

The primary endpoint was all-cause mortality and the secondary endpoint was a composite of major adverse cardiac events (MACE) at 10-year follow-up. Patients were stratified by diabetes status (non-DM and DM) and grafting strategy (MAG vs. SAG). A total of 3020 patients were included in the analysis; 716 (23.7%) had DM. Overall, 55.8% non-DM patients received MAG and 44.2% received SAG, while 56.6% DM patients received MAG and 43.4% received SAG. The use of MAG compared with SAG was associated with lower 10-year mortality for both non-DM [17.7 vs. 21.0%, adjusted hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.72-1.06] and DM patients (21.5 vs. 29.9%, adjusted HR 0.65, 95% CI 0.48-0.89; P for interaction = 0.12). For both groups, the rate of 10-year MACE was also lower for MAG vs. SAG. Overall, deep sternal wound infections (DSWIs) were uncommon but more frequent in the MAG vs. SAG group in both non-DM (3.3 vs. 2.1%) and DM patients (7.9 vs. 4.8%). The highest rates of DSWI were in insulin-treated patients receiving MAG (9.6 vs. 6.3%, when compared with SAG).

CONCLUSION

In this post hoc analysis of the ART, MAG was associated with substantially lower mortality rates at 10 years after coronary artery bypass grafting in patients with DM. Patients with DM receiving MAG had a higher incidence of DSWI, especially if insulin dependent.

Bilateral internal thoracic artery coronary grafting: risks and benefits in elderly patients

AIMS

Whether bilateral internal thoracic artery (BITA) grafting benefits elderly patients in coronary artery bypass grafting (CABG) remains unclear since they tend to have a limited life expectancy and severe comorbidities. We aim to evaluate the outcomes of BITA vs. single internal thoracic artery (SITA) grafting in elderly patients.

METHODS AND RESULTS

A meta-analysis was performed by database searching until May 2021. Studies comparing BITA and SITA grafting among elderly patients were included. One randomized controlled trial, nine propensity score matching, and six unmatched studies were identified, with a total of 18 146 patients (7422 received BITA grafting and 10 724 received SITA grafting). Compared with SITA grafting, BITA grafting had a higher risk of deep sternal wound infection (DSWI) [odds ratio: 1.67; 95% confidence interval (CI): 1.22-2.28], and this risk could not be significantly reduced by the skeletonization technique. Meanwhile, BITA grafting was associated with a higher long-term survival [hazard ratio: 0.83; 95% CI: 0.77-0.90], except for the octogenarian subgroup. Reconstructed Kaplan-Meier survival curves revealed 4-year, 8-year, and 12-year overall survival rates of 85.5%, 66.7%, and 45.3%, respectively, in the BITA group and 79.3%, 58.6%, and 34.9%, respectively, in the SITA group. No significant difference was observed in early mortality, perioperative myocardial infarction, perioperative cerebral vascular accidents, or re-exploration for bleeding.

CONCLUSION

Compared with SITA grafting, BITA grafting could provide a long-term survival benefit for elderly patients, although this benefit remained uncertain in octogenarians. Meanwhile, elderly patients who received BITA were associated with a higher risk of DSWI and such a risk could not be eliminated by the skeletonization technique.

Prediction of Long-Term Survival after Coronary Artery Bypass with Bilateral Internal Thoracic Artery Grafting: External Validation of A Contemporary Nomogram

Background: This study aimed to verify the external validation of a contemporary nomogram in predicting long-term survival after an isolated coronary artery bypass with bilateral internal thoracic artery grafting (CABG-BITA). Methods: Consecutive patients who underwent CABG-BITA at a single center were included in the study. All the predictors of the original risk score (age, diabetes mellitus, chronic obstructive pulmonary disease, congestive heart failure, chronic renal failure, old myocardial infarction, ejection fraction, intra-aortic balloon pump and peripheral arterial disease) were available for analysis. Results: Among the 2846 consecutive patients, a total of 1176 (41.3%) deaths were recorded during the 31,383 patient years of follow-up. The median EuroSCORE II was 2.35, and the median follow-up was 11.1 years. The risk score showed 72.7% overall discriminatory ability as measured by Harrell’s concordance statistic. It showed satisfactory calibration at 10, 15 and 20 years of follow-up. The risk score showed a time-varying nonlinear effect, and accordingly, adjusted long-term survival predictions were calculated. There were subgroups (scores < 50 points) with favorable 20-year survival rates ranging from 77% to 60%. Higher risk subgroups (scores > 90 points) showed poor 20-year survival rates ranging from 22% to 4%. Conclusions: The validated risk score represents a useful algorithm for the detection of patients who could benefit after CABG-BITA with respect to long-term survival. Although further multi-center studies are required worldwide to reveal the usefulness of this score in the clinical setting, its wide adoption may act as a motivation for cardiac surgeons resulting in higher numbers of CABG-BITA procedures.

Meta-Analysis of Bilateral Versus Single Internal Thoracic Artery Grafting in Patients ≥70 Years of Age

The optimal choice of graft material in patients ≥70 years of age undergoing coronary artery bypass grafting remains unknown. A systematic review of literature was conducted by searching PubMed, Embase, Web of Science, and Cochrane Library databases for original publications that compared bilateral internal thoracic artery (BITA) grafting with single internal thoracic artery grafting in patients ≥70 years of age. Data were extracted by 2 independent investigators and meta-analyzed with the use of random effects. A total of 10 studies, including 11,185 patients, met the inclusion criteria. No differences in early mortality and morbidity, with the exemption of sternal wound complications which were more frequently observed in the BITA group (odds ratio 1.72, 95% 1.00 to 2.96 confidence interval [CI], p = 0.05; propensity score-matched population odds ratio 1.58, 95% CI 1.09 to 2.29, p = 0.02), were observed. Overall survival was superior in the overall patient population (hazard ratio [HR] 0.76, 95% CI 0.66 to 0.86, p <0.001), after applying a blanking period of 3 months to the overall patient population (HR 0.77, 95% CI 0.64 to 0.92, p = 0.005) as well as in the matched population (HR 0.72, 95% CI 0.58 to 0.89, p = 0.002); in all cases, a benefit was readily seen within a few years after surgery. The difference in freedom from major adverse cardiac and cerebrovascular events failed to reach statistical significance (overall patient population HR 0.55, 95% CI 0.27 to 1.13, p = 0.10; matched population HR 0.52, 95% CI 0.23 to 1.16, p = 0.11). In conclusion, BITA grafting can be safely performed in patients ≥70 years of age as late clinical benefits are expected to manifest themselves readily within a few years after surgery.

Sex differences in outcomes following coronary artery bypass grafting: a meta-analysis

OBJECTIVES

Previous reports have found females are a higher risk of morbidity and mortality following isolated coronary artery bypass grafting (CABG). Here, we describe the differences in outcomes following isolated CABG between males and females.

METHODS

Following a systematic literature search, studies reporting sex-related outcomes following isolated CABG were pooled in a meta-analysis performed using the generic inverse variance method. The primary outcome was operative mortality. Secondary outcomes included rates of stroke, repeat revascularization, myocardial infarction, major adverse cardiac events, and late mortality. Subgroup analyses were performed for studies published before and after the year 2000 and for the type of risk adjustment.

RESULTS

Eighty-four studies were included with a total of 903 346 patients. Females were at higher risk for operative mortality (odds ratio: 1.77, 95% confidence interval [CI]: 1.64-1.92, P < 0.001). At subgroup analysis, there was no difference in operative or late mortality between studies published prior and after 2000 or between studies using risk adjustment. Females were at a higher risk of late mortality (incidence rate ratio [IRR]: 1.16, 95% CI: 1.06-1.26, P < 0.001), major adverse cardiac events (IRR: 1.40, 95% CI: 1.19-1.66, P < 0.001), myocardial infarction (IRR: 1.28, 95% CI: 1.13-1.45, P < 0.001) and stroke (IRR: 1.31, 95% CI: 1.15-1.51, P > 0.001) but not repeat revascularization (IRR: 0.99, 95% CI: 0.76-1.29, P = 0.95). The use of the off-pump technique or multiple arterial grafts was not associated with the primary outcome.

CONCLUSIONS

Females undergoing CABG are at higher risk for operative and late mortality as well as postoperative events including major adverse cardiac events, myocardial infarction and stroke.

PROSPERO REGISTRATION

CRD42020187556.

Does Age Affect the Short- and Long-Term Outcomes of Coronary Bypass Grafting?

The etiology of coronary artery disease (CAD) is multifactorial, stemming from both modifiable and nonmodifiable risk factors such as age. Several studies have reported the effects of age on various outcomes of coronary artery bypass grafting (CABG). This article reviews age-related outcomes of CABG and offers direction for further studies in the field to create comprehensive, evidence-based guidelines for the treatment of CAD. Ninety-two primary sources were analyzed for relevance to the subject matter, of which 17 were selected for further analysis: 14 retrospective cohort studies, 2 randomized clinical trials, and 1 meta-analysis. Our review revealed four broad age ranges into which patients can be grouped: those with CAD (1) below the age of 40 years, (2) between the ages of 40 and 60 years, (3) between the ages of 60 and 80 years, and (4) at or above 80 years. Patients below the age of 40 years fare best overall with total arterial revascularization (TAR). Patients between the ages of 40 and 60 years also fare well with the use of multiarterial grafts (MAGs) whereas either MAGs or single-arterial grafts may be of significant benefit to patients at or above the age of 60 years, with younger and diabetic patients benefitting the most. Arterial grafting is superior to vein grafting until the age of 80 years, at which point there is promising evidence supporting the continued use of the saphenous vein as the favored graft substrate. Age is a factor affecting the outcomes of CABG but should not serve as a barrier to offering patients CABG at any age from either a cost or a health perspective. Operative intervention starts to show significant mortality consequences at the age of 80 years, but the increased risk is countered by maintenance or improvement to patients' quality of life.

Multiple versus single arterial grafting in the elderly: a meta-analysis of randomized controlled trials and propensity score studies

INTRODUCTION

The benefit of adding a second arterial conduit is still controversial, mainly in specific subgroups. We conducted a meta-analysis of randomized controlled trials (RCTs) and propensity score (PS) studies comparing survival and early results in elderly patients who underwent coronary artery bypass grafting (CABG) with multiple (MAG) versus single arterial grafting (SAG).

EVIDENCE ACQUISITION

MEDLINE, Web of Science and Cochrane Library were used to find relevant literature (1960-April 2020). Survival at a ≥ 1-year follow-up and early outcomes were evaluated. Outcomes were collected from matched samples or PS adjusted analysis: hazard ratio (HR) along with their variance, frequencies or odds ratios. Random effect models were used to compute combined statistical measures and 95% confidence intervals (CI) through generic inverse variance method (time-to-event) or Mantel-Haenszel method (binary events).

EVIDENCE SYNTHESIS

Eleven PS cohorts and 1 RCT comprising > 18,800 patients older than 70 (>6200 MAG and >12,500 SAG) were included in this meta-analysis. MAG was associated with lower long-term mortality (pooled HR: 0.81, 95%CI: 0.72-0.91, p<0.01, I2=64%) in the absence of higher risk of early mortality (pooled OR: 0.74, 95%CI: 0.44 to 1.25, p=0.27, I2=0%). In a meta-regression, MAG survival advantage was more pronounced in studies with a higher MAG usage rate (β = -0.0052, p=0.021).

CONCLUSIONS

Current evidence suggests that advanced age should not limit MAG's use considering its benefits in long-term survival. Of note, an individualized patient selection for this approach is warranted.

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.

Association of Age With 10-Year Outcomes After Coronary Surgery in the Arterial Revascularization Trial

BACKGROUND

The association of age with the outcomes of bilateral internal thoracic arteries (BITAs) versus single internal thoracic arteries (SITAs) for coronary bypass grafting (CABG) remains to be determined.

OBJECTIVES

The purpose of this study was to evaluate the association between age and BITA versus SITA outcomes in the Arterial Revascularization Trial.

METHODS

The primary endpoints were all-cause mortality and a composite of major adverse events, including all-cause mortality, myocardial infarction, or stroke. Secondary endpoints were bleeding complications and sternal wound complications up to 6 months after surgery. Multivariable fractional polynomials analysis and log-rank tests were used.

RESULTS

Age did not affect any of the explored outcomes in the overall BITA versus SITA comparison in the intention-to-treat analysis and in the analysis based on the number of arterial grafts received. However, when the intention-to-treat analysis was restricted to the populations of patients between age 50 and 70 years, younger patients in the BITA arm had a significantly lower incidence of major adverse events (p = 0.03).

CONCLUSIONS

Our results suggest that BITA may improve long-term outcome in younger patients, although more randomized data are needed to confirm this hypothesis.

Differences in Long-term Outcomes After Coronary Artery Bypass Grafting Using Single vs Multiple Arterial Grafts and the Association With Sex

Importance

Sex-related differences in the outcome of using multiple arterial grafts during coronary artery bypass grafting (CABG) remain uncertain.

Objective

To compare the outcomes of the use of multiple arterial grafts vs a single arterial graft during CABG for women and men.

Design, Setting, and Participants

This statewide cohort study used data from New York's Cardiac Surgery Reporting System and New York's Vital Statistics file on 63 402 patients undergoing CABG from January 1, 2005, to December 31, 2014. Statistical analysis was performed from January 10 to August 20, 2020.

Exposures

Multiple arterial grafting or single arterial grafting.

Main Outcomes and Measures

Mortality, acute myocardial infarction (AMI), stroke, repeated revascularization, major adverse cardiac and cerebrovascular event (composite of mortality, AMI, and stroke), and major adverse cardiac event (composite of mortality, AMI, or repeated revascularization) were compared among propensity-matched patients and stratified by the risk of long-term mortality.

Results

Of the 63 402 patients (48 155 men [76.0%]; mean [SD] age, 69.9 [10.5] years) in the study, women had worse baseline characteristics than men for most of the explored variables. Propensity matching yielded a total of 9512 male pairs and 1860 female pairs. At 7 years of follow-up, mortality was lower among men who underwent multiple arterial grafting (adjusted hazard ratio, 0.80; 95% CI, 0.73-0.87) but not women who underwent multiple arterial grafting (adjusted hazard ratio, 0.99; 95% CI, 0.84-1.15). When stratified by the estimated risk of death, the use of multiple arterial grafts was associated with better survival and a lower rate of a major adverse cardiac event among low-risk, but not high-risk, patients of both sexes, and the risk cutoff was different for men and women.

Conclusions and Relevance

This study suggests that women have a worse preoperative risk profile than men. Multiple arterial grafting is associated with better outcomes among low-risk, but not high-risk, patients, and the risk cutoffs differ between sexes. These data highlight the need for new studies on the outcome of multiple arterial grafts in women.

Survival benefit from a second arterial conduit to the circumflex circulation persists in elderly after coronary artery bypass surgery

BACKGROUND

This retrospective propensity matched study investigated the impact of age on the survival benefit from a second arterial conduit to the left-sided circulation.

METHODS

Data for isolated coronary artery bypass surgery were collected from October 2004 to March 2014. All patients with an internal mammary artery graft to left anterior descending artery and additional arterial or venous graft to the circumflex circulation were included. Propensity matching was used to balance co-variates and generate odds of death for each observation. Odds ratios (venous vs. arterial) were charted against age.

RESULTS

The in-hospital mortality rate was 1.12% (arterial) vs. 1.24% (venous) (p = 0.77). The overall 10-year survival was 74.6% (venous) vs. 82.6% (arterial) (p = 0.001). A total of 1226 patients were successfully matched to the venous or arterial (second conduit to circumflex territory after left internal mammary artery to left anterior descending artery) cohorts. Odds ratio for death (venous to arterial) showed a linear decremental overall survival benefit for the second arterial graft to circumflex circulation with increasing age.

CONCLUSIONS

The survival benefit of a second arterial graft persists through all age groups with a gradual decline with increasing age over the decades. Elderly patients should not be denied a second arterial graft to the circumflex circulation based on age criterion alone.

Bilateral internal thoracic artery grafting in haemodialysis patients with diabetic nephropathy

OBJECTIVES

To compare postoperative outcomes in patients with diabetic nephropathy receiving haemodialysis and undergoing isolated coronary artery bypass grafting (CABG) using bilateral or single skeletonized internal thoracic artery (ITA).

METHODS

Among 1441 consecutive patients undergoing isolated CABG between 2002 and 2019 at our university hospital, we retrospectively analysed data for 107 patients with diabetic nephropathy receiving haemodialysis. After inverse probability of treatment weighting, we found no statistically significant differences regarding patients' preoperative characteristics.

RESULTS

All patients underwent myocardial revascularization using the off-pump technique. There was no statistical significance in postoperative deep sternal wound infection (P = 0.902) and 30-day mortality (P = 0.755). However, the bilateral ITA group had a lower rate of postoperative stroke versus the single group (0% vs 5.5%, respectively; P = 0.021). Follow-up was completed in 95.3% (102/107) of the patients, and the mean follow-up duration was 3.3 years. Thirty-eight deaths occurred in the bilateral ITA group and 18 in the single ITA group. There was no significant difference in all-cause death (P = 0.558) and cardiac death rates (P = 0.727). Multivariable Cox regression models showed that the independent predictors of all-cause death were age [hazard ratio (HR) 1.031; P = 0.010], previous percutaneous intervention (HR 1.757; P = 0.009) and gastroepiploic artery grafting (HR 0.582; P = 0.026).

CONCLUSIONS

Bilateral ITA grafting in patients with diabetic nephropathy receiving haemodialysis did not improve mid-term outcomes.

EFFECT OF PREOPERATIVE RESPIRATORY REHABILITATION IN PATIENTS UNDERGOING CARDIAC SURGERY

The aim of the study was to evaluate the effects of preoperative respiratory rehabilitation on functional capacity, length of stay in intensive care unit (ICU), duration of mechanical ventilation (MV) and total hospitalization, as well as to estimate arterial blood gas (ABG) values in patients undergoing cardiac surgery. Nineteen patients were included in the randomized observational study, divided into two groups: group A (intervention) and B (control). Preoperative and postoperative rehabilitation was performed in group A, and only postoperative rehabilitation in group B. Rehabilitation was carried out according to a predefined protocol. We used ABG to evaluate respiratory function, two-minute walk test (2MWT) and sit-to-stand test to assess functional capacity. The following data were obtained from medical documentation: duration of MV, length of stay at ICU, occurrence of postoperative pulmonary complications, and length of total hospitalization in both groups. Significant between-group difference was found for the length of total hospitalization and duration of MV (p<0.05 both). Analysis of the mean values of 2MWT on the last day of hospitalization (p=0.005), sit-to-stand test before surgery (p=0.022) and on the last day of hospitalization (p=0.008) showed statistically significant differences. The length of hospital stay significantly correlated with preoperative rehabilitation in group A (r=0.885; p<0.0001). There was no difference in ABG parameters between the groups. The study showed that preoperative respiratory rehabilitation had an effect on reducing duration of MV and length of total hospitalization, and improved functional capacity.

Outcomes following surgical revascularization with single versus bilateral internal thoracic arterial grafts in patients with left main coronary artery disease undergoing coronary artery bypass grafting: insights from the EXCEL trial†

OBJECTIVES

Observational data suggest that the use of a single internal thoracic artery (SITA) may result in inferior outcomes compared with bilateral internal thoracic artery (BITA) use for coronary artery bypass grafting (CABG)-a finding not yet supported by randomized trial outcomes. However, the optimal number of internal thoracic artery grafts in patients with left main coronary artery disease has not been investigated.

METHODS

The EXCEL trial randomized 1905 patients with left main coronary artery disease to percutaneous coronary intervention with everolimus-eluting stents versus CABG. Among the 905 patients undergoing CABG, 688 (76.0%) received SITA and 217 (24.0%) received BITA. Differences in clinical event rates were estimated using the Kaplan-Meier method and compared with the log-rank test. Multivariable Cox regression was used to adjust for differences in baseline covariates.

RESULTS

Compared to SITA, patients treated with BITA were younger (66.1 ± 9.5 vs 64.5 ± 9.3 years, P = 0.020), were less likely female (24.3% vs 14.3%, P = 0.002) and diabetic (28.8% vs 15.2%, P < 0.001), and had a lower prevalence of peripheral vessel disease (10.2% vs 5.5%, P = 0.040). The unadjusted 3-year composite primary endpoint of death, stroke or myocardial infarction (MI) occurred in 15.6% of SITA vs 11.6% of BITA patients (P = 0.17). The SITA group tended to have a higher 3-year rate of all-cause death compared with the BITA group (6.7% vs 3.3%; P = 0.070). Stroke, MI and ischaemia-driven revascularization outcomes were not significantly different between groups. After adjusting for baseline differences, neither the composite of death, stroke or MI [hazard ratio (HR) 1.12, 95% confidence interval (CI) 0.71-1.78; P = 0.62] nor mortality (HR 1.36, 95% CI 0.60-3.12; P = 0.46) was significantly higher with SITA. The rehospitalization rate after 3 years was higher in the SITA group (35.8% vs 26.0%, P = 0.008), a difference which was no longer present after multivariable adjustment (HR 1.27, 95% CI 0.93-1.74; P = 0.13). Sternal wound dehiscence within 30 days did not occur more often in the BITA group compared to the SITA group (1.8% vs 2.2%, P > 0.99).

CONCLUSIONS

In the EXCEL trial, there were no clinical differences at 3 years between SITA or BITA revascularization in patients with left main coronary artery disease.

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

Background

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

Methods and Results

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

Conclusions

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

In situ skeletonized gastroepiploic artery grafting in hemodialysis patients

OBJECTIVES

There is no firm treatment strategy of coronary artery bypass grafting in hemodialysis patients. We investigated postoperative outcomes in hemodialysis patients undergoing isolated coronary artery bypass grafting using in situ skeletonized gastroepiploic artery.

METHODS

From January 2002 to December 2019, 143 hemodialysis patients underwent isolated coronary artery bypass grafting in our institution. Among them, 49 consecutive patients with gastroepiploic artery grafting were retrospectively analyzed.

RESULTS

No patient was converted from off-pump to on-pump surgery. The mean distal anastomoses were 3.6 ± 1.0 per patients. Seven patients (14.3%) required proximal anastomosis to aorta. Thirty-day mortality was 4.1% (2 of 49). The early (3-20 days after surgery) patency rate of the gastroepiploic artery was 96.9% (63 of 65 anastomoses). The adjusted rates of survival free from overall death at 1, 5 and 10 years after surgery were 91.7%, 72.6% and 32.5%, respectively. Multivariate Cox proportional hazard regression analysis showed that age (hazard ratio 1.131, 95% confidence interval 1.055-1.212, p < 0.001) and LVEF < 40% (hazard ratio 9.411, 95% confidence interval 1.963-45.919, p = 0.005) were independent predictors of mid-term death from all causes (Table 6).

CONCLUSIONS

Short and mid-term outcomes were acceptable. The use of in situ skeletonized gastroepiploic artery can decrease the time of touching aorta, so gastroepiploic artery grafting may be an important option for coronary artery bypass grafting in hemodialysis patients with limited conduits.

Second Generation Drug-Eluting Stent Implantation versus Coronary Artery Bypass Grafting in the Treatment of Young Patients with Left Main and/or Multivessel Coronary Disease

BACKGROUND

Many studies have compared the outcomes of coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI) for complex coronary artery disease (CAD). However, no trials have focused on young patients (<45 years) with complex CAD. We conducted a retrospective evaluation to compare the outcomes of a second-generation drug-eluting stent (DES) and CABG in young patients with LM or three-vessel disease.

METHODS

In young patients with complex CAD who underwent PCI or CABG, a Kaplan-Meier analysis and Cox regression before and after propensity score matching were used to compare major adverse cardiac and cerebrovascular events (MACCE), including myocardial infarction (MI), stroke, death, and repeat revascularization.

RESULTS

During follow-up, MACCE occurred in 20.5% of patients in the PCI group and 8.6% of patients in the CABG group (hazard ratio (HR): 3.263, 95% confidence interval (CI): 1.379 to 7.722, p=0.007). Repeat revascularization occurred more frequently in the PCI group (18.9% vs. 3.7%, respectively, HR: 6.968, 95% CI: 2.036 to 23.842, p=0.002). There were no significant differences in the other endpoints. After propensity score matching, no conclusions were modified.

CONCLUSIONS

In young patients with LM or three-vessel disease, PCI showed a higher incidence of MACCE, which was mainly driven by repeat revascularization. However, this did not translate into hard endpoint differences. Therefore, PCI is an alternative treatment to CABG in young patients with complex CAD.

Bilateral versus single internal thoracic artery grafting in hemodialysis patients

BACKGROUND

The use of the bilateral internal thoracic arteries (BITAs) during myocardial revascularization reportedly provides a survival benefit over using a single internal thoracic artery (SITA). However, the advantages in chronic hemodialysis patients, who generally have multiple comorbidities, is unclear.

METHODS

Outcomes of chronic hemodialysis patients who underwent isolated coronary artery bypass grafting (CABG) using a SITA with additional saphenous vein grafts (SVGs) (n = 33) or BITAs (n = 30) for left-side revascularization were retrospectively reviewed.

RESULTS

With the exception of the rate of diabetes mellitus (SITA vs. BITA: 84.8% vs. 50.0%; p = 0.003), the two groups showed similar patient characteristics. Using the off-pump technique, revascularization was completed without manipulation of the ascending aorta in 45.7% of patients in the BITA group, whereas all patients in the SITA group required aortic manipulation (p < 0.001). Of note, the incidence of extensive aortic calcification (>50% of ascending aorta circumference) was not uncommon (14.3%). The in-hospital mortality (3.0% vs. 0%, p = 0.336) and complication rates (including deep wound infection, re-exploration and stroke) were similar in both groups. The 5-year estimated survival rates for freedom from overall death in the SITA and BITA groups were 42.4% and. 57.4%, respectively (p = 0.202).

CONCLUSIONS

BITA grafting was able to achieve revascularization with minimal manipulation of the diseased ascending aorta without increasing the complication rate. The long-term survival benefit of BITA grafting, however, was unclear in dialysis patients, especially because such patients have a relatively short life expectancy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Long-term Outcomes of Multiple Arterial Coronary Artery Bypass Grafting: A Population-Based Study of Patients in British Columbia, Canada

Importance

Although the long-term survival advantage of multiple arterial grafting (MAG) vs the standard use of left internal thoracic artery (LITA) supplemented by saphenous vein grafts (LITA+SVG) has been demonstrated in several observational studies, to our knowledge its safety and other long-term clinical benefits in a large, population-based cohort are unknown.

Objective

To compare the safety and long-term outcomes of MAG vs LITA+SVG among overall and selected subgroups of patients.

Design, Setting, and Participants

In this population-based observational study, we included 20 076 adult patients with triple-vessel or left-main disease who underwent primary isolated coronary artery bypass grafting (MAG, n = 5580; LITA+SVG, n = 14 496) in the province of British Columbia, Canada, from January 2000 to December 2014, with follow-up to December 2015. We performed propensity-score analyses by weighting and matching and multivariable Cox regression to minimize treatment selection bias.

Exposures

Multiple arterial grafting or LITA+SVG.

Main Outcomes and Measures

Mortality, repeated revascularization, myocardial infarction, heart failure, and stroke.

Results

Of 5580 participants who underwent MAG, 586 (11%) were women and the mean (SD) age was 60 (8.7) years. Of 14 496 participants who underwent LITA+SVG, 2803 (19%) were women and the mean (SD) age was 68 (8.9) years. The median (interquartile range) follow-up time was 9.1 (5.1-12.6) years and 8.1 (4.5-11.7) years for the groups receiving MAG and LITA+SVG, respectively. Compared with LITA+SVG, MAG was associated with reduced mortality rates (hazard ratio [HR], 0.79; 95% CI, 0.72-0.87) and repeated revascularization rates (HR, 0.74; 95% CI, 0.66-0.84) in 15-year follow-up and reduced incidences of myocardial infarction (HR, 0.63; 95% CI, 0.47-0.85) and heart failure (HR, 0.79; 95% CI, 0.64-0.98) in 7-year follow-up. The long-term benefits were coherent by all 3 statistical methods and persisted among patient subgroups with diabetes, obesity, moderately impaired ejection fraction, chronic obstructive pulmonary disease, peripheral vascular disease, or renal disease. Multiple arterial grafting was not associated with increased morbidity or mortality rates at 30 days overall or within patient subgroups.

Conclusions and Relevance

Compared with LITA+SVG, MAG is associated with reduced mortality, repeated revascularization, myocardial infarction, and heart failure among patients with multivessel disease who are undergoing coronary artery bypass grafting without increased mortality or other adverse events at 30 days. The long-term benefits consistently observed across multiple outcomes and subgroups support the consideration of MAG for a broader spectrum of patients who are undergoing coronary artery bypass grafting in routine practice.

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.

Coronary artery bypass grafting-fifty years of quality initiatives since Favaloro

Coronary artery bypass grafting (CABG) remains one of the most commonly performed major surgical procedures worldwide and the most common procedure performed by cardiac surgeons. Rene Favaloro is widely credited with recognizing the true potential of CABG and subsequently popularizing the technique in a broad manner. Since the era of Favaloro in the late 1960s, the evolution of CABG can be understood through a series of quality initiatives that have defined which patients can benefit from the procedure and via which technique(s) they will derive the greatest benefit. Herein, we will review some of the key developments in CABG over the last 50 years with a focus on ongoing quality initiatives that will continue to refine the optimal applications and outcomes of CABG for the next 50 years.

Scoring system to guide decision making for the use of bilateral internal mammary arteries: The BIMA score

OBJECTIVE

Currently, surgeons are unable to estimate whether the survival benefit from bilateral internal mammary artery (BIMA) grafting outweighs the increased deep sternal infection (DSWI) risk in the individual cases. As a consequence BIMA grafting is still largely underutilized. We aimed to develop and validate a scoring system to predict the individual risk for DSWI and 10 year survival probability to guide surgeons in decision making process for the use of BIMA over single internal mammary artery (SIMA).

METHODS

Fast backward elimination on predictors was performed using Lawless and Singhal method. BIMA score was reported as a partial nomogram that can be used to manually obtain predicted individual risk of DSWI and 10 year survival probability from the regression models. Bootstrapping validation of the regression models was performed.

RESULTS

The study population consisted of 5234 patients of which a total of 960 (18%) received BIMA and the remaining 4274 (82%) underwent conventional strategy using SIMA. A total of 119 patients experienced DSWI (2.3%). A total of 489 deaths were recorded after a median follow-up time of 5.68 years (interquartile range 2.7-8.8, range 0-12.1). BIMA grafting was found to have effect on both risk of DSWI and 10 year survival probability and was included into partial nomograms. Bootstrapping validation confirmed a good discriminative power of the models.

CONCLUSION

The BIMA score provides an impartial assessment of the decision making process for clinicians to establish the optimum revascularization strategy for individual patients.

Bilateral Versus Single Internal Thoracic Artery Grafts

Purpose of Review

Several advances have been made in recent years to improve outcome for patients with coronary artery disease. One of the most debated topics regarding surgical treatment with coronary artery bypass grafting (CABG) is graft selection. This review aims to present the current status and scientific evidence for bilateral internal thoracic artery (BITA) grafting.

Recent Findings

Observational studies and pooled analyses suggest that BITA grafting is associated with improved survival. Early results from a large randomized controlled trial report safety and efficacy of the method. The improved survival might be amplified in select groups, but with an increase in sternal wound-related complications. The benefit of BITA grafts seems to remain to an approximate age of 69 years at surgery.

Summary

CABG with BITA grafts is likely associated with improved long-term survival at a cost of an increase in sternal wound infections. Ten-year results from the Arterial Revascularization Trial are expected in 2018, providing the best evidence regarding the method yet. Early results show it is a safe method in most patient categories considerable for CABG.

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

Background

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

Methods and Results

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

Conclusions

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

Coronary Artery Bypass Grafting with Arterial Conduits in the Elderly

Although improved long-term outcomes obtained with the use of arterial grafts for coronary revascularization in comparison with the traditional association of a single arterial and saphenous vein grafts have been demonstrated in the overall population, the efficacy of this newer technique in the elderly is difficult to prove because their shorter life expectancy due to advanced heart disease, associated with severe comorbidities. Moreover, more widespread use of this technique is limited by the concerns on the potential morbidity, particularly the longer time required to perform the operation and the possibility of deep sternal wound infection in case of bilateral internal thoracic artery harvesting due to the decreased blood supply to the sternum and surrounding tissues.The review of the recent literature indicates that the use of bilateral internal thoracic arteries in very elderly patients should not be considered routinely. It seems reasonable to avoid it in octogenarians in the presence of well-known predictors of sternal complications such as diabetes, morbid obesity, and severe chronic lung disease.There is also still controversy about the superiority of the radial artery over the saphenous vein graft as a second or third conduit for surgical myocardial revascularization, although the majority of recent studies seem to support more liberal use of the radial artery as second arterial conduit in the elderly. Although a clinical benefit of arterial graft revascularization cannot be formally excluded for elderly patients, the increased complexity of this technique suggests that careful clinical judgment is necessary to select grafts for individual patients.

Randomized Trial of Bilateral versus Single Internal-Thoracic-Artery Grafts

BACKGROUND

The use of bilateral internal thoracic (mammary) arteries for coronary-artery bypass grafting (CABG) may improve long-term outcomes as compared with the use of a single internal-thoracic-artery plus vein grafts.

METHODS

We randomly assigned patients scheduled for CABG to undergo single or bilateral internal-thoracic-artery grafting in 28 cardiac surgical centers in seven countries. The primary outcome was death from any cause at 10 years. The composite of death from any cause, myocardial infarction, or stroke was a secondary outcome. Interim analyses were prespecified at 5 years of follow-up.

RESULTS

A total of 3102 patients were enrolled; 1554 were randomly assigned to undergo single internal-thoracic-artery grafting (the single-graft group) and 1548 to undergo bilateral internal-thoracic-artery grafting (the bilateral-graft group). At 5 years of follow-up, the rate of death was 8.7% in the bilateral-graft group and 8.4% in the single-graft group (hazard ratio, 1.04; 95% confidence interval [CI], 0.81 to 1.32; P=0.77), and the rate of the composite of death from any cause, myocardial infarction, or stroke was 12.2% and 12.7%, respectively (hazard ratio, 0.96; 95% CI, 0.79 to 1.17; P=0.69). The rate of sternal wound complication was 3.5% in the bilateral-graft group versus 1.9% in the single-graft group (P=0.005), and the rate of sternal reconstruction was 1.9% versus 0.6% (P=0.002).

CONCLUSIONS

Among patients undergoing CABG, there was no significant difference between those receiving single internal-thoracic-artery grafts and those receiving bilateral internal-thoracic-artery grafts with regard to mortality or the rates of cardiovascular events at 5 years of follow-up. There were more sternal wound complications with bilateral internal-thoracic-artery grafting than with single internal-thoracic-artery grafting. Ten-year follow-up is ongoing. (Funded by the British Heart Foundation and others; ART Current Controlled Trials number, ISRCTN46552265 .).