Influence of diabetes and bilateral internal thoracic artery grafts on long-term outcome for multivessel coronary artery bypass grafting☆

Very Long-term Outcome of Bilateral Internal Thoracic Artery in Diabetic Patients: A Systematic Review and Reconstructed Time-To-Event Meta-analysis

The benefits of single (SITA) and bilateral internal thoracic arteries (BITA) in diabetics undergoing coronary bypass grafting (CABG) are conflicting. We undertook a study-level meta-analysis to compare early and long-term outcomes of both CABG configurations. PubMed, CENTRAL, and EMBASE were searched for studies comparing BITA versus SITA for isolated CABG surgery in diabetics. Randomized trials or observational studies were considered eligible for the analysis. Kaplan-Meier curves of long-term survival were reconstructed and compared with Cox linear regression; incidence rate ratios (IRR) with 95% confidence intervals (CI) for long-term survival were calculated. Landmark analysis and time-varying hazard ratio (HR) were analyzed. Odds ratios (OR) were extracted for early mortality, postoperative stroke, deep sternal wound infection (DSWI), and myocardial infarction (MI). A random effects meta-analysis was performed. Sensitivity analyses included leave-one-out-analyses and meta-regression. Thirteen studies (7332 patients) were included. Overall, at 20-year follow-up, BITA was associated with higher survival (HR = 0.77; 95% CI, 0.71-0.84; P < 0.0001). Time-varying HR and landmark analysis reported BITA was associated with a higher rate of 10-year survival (HR = 0.75, 95% CI 0.68-0.82, P < 0.0001), while from 10 to 20-year follow-up no difference was revealed (HR = 0.99, 95% CI 0.82-1.19, P = 0.93). There was no increase in early mortality, postoperative MI, stroke, or DSWI between the groups. At meta-regression, the higher the age, the higher the long-term overall survival in patients with BITA. In diabetics, the BITA approach is associated with improved 10-year survival with no increase in early mortality, MI, stroke, or DSWI. In the 10-20-year timeframe, BITA and SITA showed comparable survival.

Impact of diabetic versus non-diabetic patients undergoing coronary artery bypass graft surgery on postoperative wound complications: A meta-analysis

The effect of diabetes mellitus (DM) on the incidence of postoperative wound complications in patients with coronary artery bypass grafting (CABG) is still unclear. Thus, we performed a meta-analysis of CABG in DM patients to evaluate existing data from both prospective and historical cohorts. The objective of this trial was to assess the relevance and extent of the effect of diabetes on the outcome of previous CABG procedures. Data sources like Embase and Pubmed were found throughout the research, and the language was limited to English through manual search. The searches were performed up to August 2023. The data were extracted from the study of the inclusion/exclusion criteria, the features of the population, the statistical approach and the clinical results. A qualitative evaluation of the qualifying studies has been carried out. Out of the 1874 studies identified, 21 cohort studies were chosen for analysis. Meta-analyses were performed in 258 454 patients (71 351 diabetic and 187 103 non-diabetic). Twenty-one studies on deep sternal wound infections in CABG patients showed a lower rate of deep sternal wound infections in non-diabetes group compared with those with diabetes (OR, 2.13; 95% CI: 1.97, 2.31, p < 0.00001). And 16 studies of superficial wound infections in patients undergoing CABG were found to be associated with a lower rate of superficial injury (OR, 1.93; 95% CI: 1.53, 2.43, p < 0.00001) compared with those with diabetes; In five trials, perfusion time during CABG (MD, 2.31; 95% CI: -0.16, 4.79, p = 0.07) was observed, and there were no significant differences between diabetes and non-diabetes. Currently, there is a higher risk for CABG in diabetes than in non-diabetes patients with sternal infections and superficial injuries. Future randomized trials will concentrate on the treatment of such perioperatively related complications, which will lower the risk of postoperative wound infection in diabetes.

Bilateral versus single internal mammary artery in diabetic patients: systematic review and meta-analysis

OBJECTIVES

Data on bilateral internal mammary artery (BIMA) versus single internal mammary artery (SIMA) on diabetics were analyzed; This is the only meta-analysis, the last 7 years.

METHODS

Medline through PubMed/EMBASE/CINHAL and the Cochrane Central Register of Controlled Trials; 179 articles were studied; 19 studies deemed suitable and were included in the analysis.

RESULTS

The mortality was 2.41% for BIMA versus 1.71% for SIMA (odds ratio [OR] =  0.95; 95% confidence interval [CI]: 0.74-1.22). Postoperative reopening for bleeding was higher at 3.75% for BIMA versus 2.91% for SIMA (OR =  1.49; 95% CI: 1.15-1.93). The incidence of MI was 0.87% for BIMA versus 0.83% for SIMA (OR =  0.73; 95% CI: 0.37-1.44). Deep sternal wound infection was 3.02% for BIMA and 1.95% for SIMA (OR =  1.57; 95% CI: 1.26-1.95). When skeletonized, the incidence of DSWI was 2.5% for BIMA versus 2.41% for SIMA. There was a significant difference at 5-year survival favoring the BIMA, 85.15% BIMA versus 80.77% SIMA (OR =  1.79; 95% CI: 1.60-2.01). The 10-year overall survival was 74.04% BIMA versus 61.57% SIMA (OR =  1.79; 95% CI: 1.61-1.98). The 15-year survival was 47.08% for BIMA versus 37.06% for SIMA (OR =  1.69; 95% CI: 1.52-1.88).

CONCLUSIONS

Postoperative bleeding was higher in BIMA group. Bilateral internal mammary artery in diabetic patients should be carried out in a skeletonize fashion, to reduce DSWI. There is a survival benefit of using BIMA in diabetics within 5 years of surgery; it remains significant up to 15 years.

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

Background

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

Methods

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

Results

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

Conclusions

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

Effect of bilateral internal thoracic artery harvesting on deep sternal wound infection in diabetic patients: Review of literature

Instead of its documented superiority of patency and long-term outcomes, the bilateral internal thoracic artery grafts are underused in the general population, and its use is controversial and debatable in diabetic patients due to long surgery duration, post-surgical bleeding, and sternal wound complications such as sternal wound infection, mediastinitis, and sternal wound dehiscence. This review article is particularly focused on deep sternal wound infection (DSWI) of bilateral internal thoracic artery (BITA) grafts in diabetic patients with comparison to single internal thoracic artery (SITA) graft.

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Bilateral internal thoracic artery grafting is superior to single internal thoracic artery grafting in terms of outcomes.

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Bilateral internal thoracic artery grafting is underused, especially in diabetic patients.

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The risk of DSWI in skeletonized BITA grafting in diabetic patients is almost similar to SITA grafting.

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Skeletonized BITA grafting should be encouraged in selected diabetic patients.

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.

Does Bilateral Internal Mammary Artery Grafting Better Suit Patients With Diabetes? - Two Different Ways to Explore Outcomes

BACKGROUND

This analysis compared short-term mortality, sternal wound infection (SWI), and long-term survival outcomes in diabetic patients who underwent coronary artery bypass grafting (CABG) with bilateral (BIMA) vs. single (SIMA) internal mammary artery, as well as in diabetic vs. non-diabetic patients undergoing BIMA grafting.Methods and Results:Nineteen studies were included in the study, covering 21,143 different patients. Of these patients, 6,464 underwent CABG with BIMA, 10,264 underwent CAGB with SIMA, 11,584 had diabetes, and 6,717 did not. Compared with SIMA, BIMA had a significantly lower risk of in-hospital mortality (odds ratio [OR] 0.73, P=0.02), but a significantly higher risk of SWI (OR 1.30, P=0.04). However, compared with non-diabetic patients who underwent CABG with BIMA, diabetic patients with BIMA grafting did not have significantly higher risks of either mortality (OR 1.22, P=0.53) or SWI (OR 1.10, P=0.72). No significant differences were detected with different harvesting techniques. Longer term, BIMA was associated with a significantly higher rate of survival than SIMA (hazard ratio [HR] 0.76, P<0.001).

CONCLUSIONS

Results from the 2 types of comparisons indicate that BIMA is a preferable option for diabetic patients, even though it has a higher risk of infection. CABG with BIMA is also associated with a long-term survival benefit.

In situ skeletonized bilateral thoracic artery for left coronary circulation: a 20-year experience

OBJECTIVES

Our goal was to analyse the outcomes in a patient population using a standardized technique for coronary artery bypass grafting (CABG) consisting of total arterial myocardial revascularization utilizing the in situ skeletonized bilateral thoracic artery for left coronary circulation. We also explored potential predictors of long-time unfavourable outcomes.

METHODS

Patients undergoing total arterial myocardial revascularization using in situ skeletonized bilateral thoracic artery for left coronary circulation between January 1997 and May 2017 were included prospectively in this study. The median follow-up (100% complete) was 103 months (interquartile range 61-189 months) and ranged from 1 to 245 months.

RESULTS

A total of 1325 consecutive patients were recruited. During the follow-up period, there were 131 deaths (9.8%), 146 repeat revascularizations (11.0%) and 229 major adverse cardiac events (17.2%). The 18-year freedom from major adverse cardiac events was 62.6 ± 9.3%, 62.5 ± 6.3% and 53.9 ± 11.0%, respectively. Multivariable models showed that a left ventricular ejection fraction ≤35%, chronic obstructive pulmonary disease, peripheral vascular disease (P < 0.001), chronic kidney disease and age ≥80 years (P = 0.002) were independent predictors of diminished long-term survival. Moreover, peripheral vascular disease and off-pump coronary artery bypass (both, P < 0.001) predicted repeat revascularization. Finally, age ≥80 years, peripheral vascular disease, left ventricular ejection fraction ≤35%, off-pump coronary artery bypass and chronic pulmonary obstructive disease were independent predictors of major adverse cardiac events during the long-term follow-up period (all, P < 0.001).

CONCLUSIONS

Coronary artery bypass using the in situ skeletonized bilateral thoracic artery for left coronary circulation configuration for total arterial myocardial revascularization resulted in satisfactory long-term results with a low incidence of death and late events and may represent a technique of choice in selected patients having CABG. Larger and long-term prospective studies are, however, warranted.

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.

Deep sternal infections after in situ bilateral internal thoracic artery grafting for left ventricular myocardial revascularization: predictors and influence on 20-year outcomes

Background

The incidence and potential factors influencing deep sternal wound infection (DSWI) in a cohort of patients undergoing coronary artery bypass grafting (CABG) using skeletonized bilateral internal thoracic artery (BITA) was explored. Furthermore, we studied influence of DSWI on long-term survival, major adverse cardiac events (MACEs) and repeat coronary revascularization (RCR).

Methods

The study cohort consisted of 1,325 consecutive patients who were divided in two groups: patients experiencing DSWI (n=33, group 1) and those who did not have sternal infection (n=1,292, group 2). A logistic regression model was employed to find predictors of DSWI whereas Cox regression and a competing risk models were carried out to test predictors of late death, MACE and RCR, respectively. Follow up was 100% complete and ranged from 1 to 245 months. Median follow-up was 103 months (IQR, 61 to 189 months). Cumulative follow-up was 16,430 patient years.

Results

The incidence of DSWI was 2.4%. Multivariable logistic regression analysis found any single independent predictor of DSWI. However, the association of peripheral vascular disease (PVD) and diabetes increased the risk by 1.4 and 1.6 times. When DM was associated with obesity the risk increased by 2.1 and 2.6 times compared to the single factors, respectively. Obese female patients were at a 1.6-fold higher risk when compared to the association of DM with obesity. DSWI was not an independent predictor of long-term survival (HR, 2.31; 95% CI: 0.59-9.12), RCR (SHR, 2.89; 95% CI: 0.65-10.12), or MACE (SHR, 1.98; 95% CI: 0.44-8.56).

Conclusions

With an accurate patient selection (i.e., exclusion of obese diabetic females) and strict DM control BITA represents a first choice for most of CABG patients, even at high risk for DSWI. The occurrence of DSWI does not influence long-term survival and late outcomes. Our findings should be confirmed by further larger research.

Bilateral internal thoracic artery grafting in India-Time to raise the bar

Objectives

Bilateral internal thoracic artery (BITA) grafting strategy is the current trend in coronary artery bypass grafting for multivessel coronary artery disease. Although better long-term outcomes have been shown, BITA grafting is underutilized as a main strategy for revascularization by most of the surgeons. The survey was conducted to ascertain the current usage and concerns of BITA grafting in India.

Methods

Database of 856 Indian cardiac surgeons currently with predominantly adult practice was prepared and a questionnaire was sent about use of single and bilateral ITA grafts and BITA grafting strategy in different clinical scenarios.

Results

A total of 112 surgeons (13.08%) from 75 institutions responded and 92 surgeons (10.7%) completed the survey. Single ITA is used by 79% of surgeons in more than 90% of their patients. 31% and 29% of surgeons use BITA grafting in 5–10% and 11–98% of their patients respectively. 53% of surgeons avoided the usage of BITA grafting in patients with smoking, 35% of surgeons in chronic obstructive pulmonary disease, 58% of surgeons in obesity and 62% of surgeons in acute coronary syndrome, 36% of surgeons in patients with left ventricular dysfunction and 61% of surgeons in patients with poor coronary anatomy. The concerns for BITA usage are risk of deep sternal wound infection (DSWI) (40%), increased operative time (27%), unknown superiority (12%) and limited length of right ITA (5%).

Conclusions

The usage of BITA grafting is restricted to 10% in India and main concerns are DSWI and increased operative time.

Efficacy of multiple arterial coronary bypass grafting in patients with diabetes mellitus

OBJECTIVES

Use of the left internal mammary artery in patients with diabetes mellitus and multivessel coronary artery disease is known to improve survival after coronary artery bypass grafting (CABG); however, the survival benefit of multiple arterial grafts (MAGs) in diabetic patients is debated. We investigated the efficacy of CABG performed with MAGs in diabetic patients.

METHODS

The overall patient group comprised 2618 consecutive patients who underwent isolated CABG at our hospital between 1990 and 2014. Perioperative characteristics, in-hospital outcomes and long-term outcomes were compared between diabetic (n = 1110) and non-diabetic patients (n = 1508). The long-term outcomes of diabetic and non-diabetic patients were analysed between those who received a single arterial graft (SAG) and those who received MAGs. Both full unmatched patient population and propensity-matched patient population analyses (diabetic cohort = 431 pairs, non-diabetic cohort = 577 pairs) were performed.

RESULTS

Preoperative comorbidities were much more common in the diabetic patients than in the non-diabetic patients; however, comorbidities were not associated with in-hospital outcomes (diabetes versus non-diabetes group, in-hospital mortality: 2.2 vs 1.5%; deep sternal wound infection: 2.2 vs 1.8%, P > 0.05). Although survival and freedom from major cardiac and cerebrovascular events (MACCEs) at 15 years were lower in the diabetes group than in the non-diabetes group (survival: 48.6 vs 55.0%, P = 0.019; MACCE-free survival: 40.8 vs 46.1%, P = 0.02), cardiac death-free survival at 15 years was similar (81.7 vs 83.9%, P = 0.24). Overall, 12-year survival was higher in both diabetic and non-diabetic patients treated with MAGs than in those treated with an SAG (64.9 vs 56.8%, P = 0.006, and 71.9 vs 60.5%, P < 0.001). Propensity-matched patient cohort analysis revealed improved 12-year survival with MAGs versus SAG in both the diabetes group (64.9 vs 58.8%, P = 0.041) and non-diabetes group (71.4 vs 63.8%, P = 0.014). Similarly, MACCE-free survival was improved in both groups.

CONCLUSIONS

A long-term survival advantage, with no increase in perioperative morbidity, is conferred with the use of multiple arterial bypass grafts not only in non-diabetic patients but also in diabetic patients.

Impact of body mass index on outcome in patients undergoing coronary artery bypass grafting and/or valve replacement surgery

Objective

This study aimed to analyze the impact of body mass index on outcomes of 101 patients undergoing coronary artery bypass grafting, valve replacement, or combined valve/ coronary artery bypass grafting surgery in a private hospital in Belo Horizonte, Brazil.

Methods

This was a prospective cross-sectional study of patients undergoing cardiac surgery from May 2009 to December 2012. All patients were followed up from the first day of admission until discharge or death. Patients were divided into three groups according to BMI: normal weight, overweight, and obese. The main outcome measure was the association between BMI and postoperative morbidities and mortality.

Results

Multivariate analysis identified obesity as an independent predictor of increased risk of surgical reintervention (odds ratio [OR] 13.6; 95%CI 1.1 - 162.9; P=0.046) and reduced risk of bleeding (OR 0.05; 95% CI 0.09 - 0.69; P=0.025). Univariate analysis showed that obesity was associated with increased frequency of wound dehiscence (P=0.021). There was no association between BMI and other complications or mortality in univariate analysis. There was also no association between body mass index and duration of cardiopulmonary bypass, aortic clamping, mechanical ventilation, and intensive care unit or hospital stay.

Conclusion

Obese individuals undergoing coronary artery bypass grafting, valve replacement, or combined surgery have a higher postoperative risk of surgical reintervention and lower chances of bleeding.

Risk factors for mortality of patients undergoing coronary artery bypass graft surgery

Introduction

Coronary artery bypass grafting is a safe procedure performed worldwide with low rates of mortality and morbidity in general population.

Objective

To investigate risk factors for mortality of patients undergoing coronary artery bypass grafting coronary artery bypass grafting surgery.

Methods

A total of 1,628 consecutive patients undergoing on-pump coronary artery bypass grafting were retrospectively studied from December 1999 to February 2012. Data analysis involved paired Student t test, Mann-Whitney test and Fisher’s exact test for the categorical data. Logistic regression, Odds Ratio and 95%CI were used for definition of risk factors for mortality.

Results

Of a total of 1,628 patients undergoing on-pump coronary artery bypass grafting, 141 (8.7%) died. The following risk factors for mortality were identified after logistic regression: dialysis (OR=7.61; 95%CI 3.58-16.20), neurologic dysfunction type I (OR=4.42; 95%CI 2.48-7.81), use of IABP (OR=3.38; 95%CI 1.98-5.79), cardiopulmonary bypass time (OR=3.09; 95%CI 2.04-4.68), serum creatinine on admission and peak values > 0.4mg/dL (OR=2.67; 95%CI 1.79-4.00), age > 65 years (OR=2.31; 95%CI 1.55-3.44), and time between hospital admission and and surgical procedure (OR=1.53; 95%CI 1.03-2.27).

Conclusion

Dialysis, type I neurologic dysfunction, use of IABP, cardiopulmonary bypass time (> 115 minutes), serum creatinine on admission and peak values>0.4mg/dL, age > 65 years and time between hospital admission and surgical procedure were considered as risk factors for mortality in patients undergoing on-pump coronary artery bypass grafting surgery.

Lessons learned from the use of 1,977 in-situ bilateral internal mammary arteries: a retrospective study

Background

We sought to determine the early and long-term results of in-situ bilateral internal mammary artery (BIMA) grafting in patients undergoing coronary artery bypass graft surgery (CABG).

Methods

Between 1992 and 2011, 16,364 patients underwent primary isolated CABG involving at least one in-situ IMA at our institution. Among these, 1,977 patients underwent in-situ BIMA grafting: the right IMA was used to revascularize the right coronary artery system in 1,279, the circumflex system in 454 patients, and the left anterior descending (LAD) in 244. Logistic and Cox regression analyses were used to predict in-hospital mortality and cumulative late death.

Results

Late survival among BIMA patients was negatively and independently influenced by chronic obstructive pulmonary disease (hazard ratio (HR) 2.4, 95% confidence interval (CI) 1.6-3.4, p = 0.0005), age (HR 1.2, 95% CI 1.1-1.3, p < 0.001), and mediastinitis (HR 2.1, 95% CI 1.1-4.2, p < 0.03). Gender, body mass index, diabetes, choice of target for the second (non-LAD) IMA, and conduit grafted to the LAD (RIMA vs. LIMA) did not influence late survival among BIMA patients. A BIMA grafting strategy was significantly beneficial for younger patients. However, it was not associated with superior late survival for patients aged 66 years and above at the time of CABG, and showed a trend to harm among octogenarians (HR 1.05, 95% CI 0.70-1.56, p = 0.80).

Conclusions

Female gender, non-insulin dependent diabetes, and the site of second IMA anastomosis did not influence early and long-term outcomes in patients undergoing CABG with in-situ BIMA grafting. The right and left IMAs are equally effective conduits for the LAD. However, advanced age, chronic obstructive pulmonary disease, and insulin-treated diabetes mellitus have a negative impact on late survival among patients with BIMA grafts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0158-9) contains supplementary material, which is available to authorized users.

Internal thoracic artery: anatomical and biological characteristics revisited

The left internal thoracic artery has become the conduit of choice for coronary artery bypass grafting, due to its superior patency rates at 10 or more years with little or no evidence of atherosclerotic changes. Recent evidence indicates that a second internal thoracic artery graft provides improved results relative to overall survival and major cardiac and cerebrovascular event-free survival, and reduces the need for repeat revascularization. However, the routine use of bilateral internal thoracic arteries is limited due to a perceived higher incidence of deep sternal wound infection. The surgical anatomy, collateral blood supply to the sternum, and biological characteristics of internal thoracic artery conduits are reviewed.

Bilateral internal mammary artery grafting enhances survival in diabetic patients: a 30-year follow-up of propensity score-matched cohorts

BACKGROUND

The prevalence of diabetes mellitus is increasing at an unprecedented rate, affecting nearly 8% of the population. Previous studies have demonstrated a potential benefit for surgical over interventional revascularization in this group of patients. Similarly, studies have shown the superiority of bilateral internal mammary artery (BIMA) grafting over single internal mammary artery (SIMA) grafting in select populations. However, concerns about sternal wound infection have discouraged the use of BIMA grafting in diabetics. Therefore, we studied the long-term results of BIMA versus SIMA grafting in a large population of diabetic patients in whom BIMA grafting was broadly applied.

METHODS AND RESULTS

Between February 1972 and May 1994, 1107 consecutive diabetic patients underwent coronary artery bypass grafting with either SIMA (n=646) or BIMA (n=461) grafting. Optimal matching with the propensity score was used to create matched SIMA (n=414) and BIMA (n=414) cohorts. Cross-sectional follow-up (6 weeks to 30.1 years; mean, 8.9 years) determined long-term survival. There was no difference in operative mortality, sternal wound infection, or total complications between matched SIMA and BIMA groups (operative mortality, 10 of 414 [2.4%] versus 13 of 414 [3.1%]; P=0.279; sternal wound infection, 7 of 414 [1.7%] versus 13 of 414 [3.1%]; P=0.179); total complications, 71 of 414 [17.1%] versus 71 of 414 [17.1%]; P=1.000). Late survival was significantly enhanced with the use of BIMA grafting (median survival: SIMA, 9.8 years versus BIMA, 13.1 years; P=0.001). Use of BIMA was found to be associated with late survival on Cox regression (P=0.003).

CONCLUSION

Compared with SIMA grafting, BIMA grafting in propensity score-matched patients provides diabetics with enhanced survival without any increase in perioperative morbidity or mortality.

Clinical outcome of arterial myocardial revascularization using bilateral internal thoracic arteries in diabetic patients: a single centre experience

OBJECTIVES

The use of bilateral internal thoracic arteries (BITAs) grafting has been documented to be advantageous over left internal thoracic artery (LITA) grafting. It has been shown to significantly improve clinical outcomes and increase long-term survival in patients with diabetes. However, harvesting BITAs may result in a greater risk of superficial wound infection (SWI) or deep sternal wound infection (DSWI) and cardiovascular complications (major adverse cardiac and cerebrovascular events; MACCE) in such a patient group. The objective of this study was to compare the incidence of SWI or DSWI and cardiovascular events in a series of isolated coronary artery bypass grafting (CABG) patients who underwent BITA grafting vs LITA grafting.

METHODS

A total of 147 patients with coronary artery disease and diabetes underwent isolated CABG at John Paul II Hospital. Of these, 38 procedures were performed using BITA grafting and 109 with LITA-saphenous vein grafting.

RESULTS

MACCE were similar in bilateral groups (7.9%--BITA group and 9.2%--LITA group). No significant difference was found in mortality and length of stay between bilateral groups. The MACCE risk factor was age. The incidence of SWI and DSWI and sternal re-fixation did not differ between the BITA or LITA groups (5.2 vs 9.1%, 5.2 vs 7.3% and 5.2 vs 6.4%). The risk factors for DSWI were age (odds ratio 3.47, P = 0.032 for every 10 years) and body mass index >30 kg/m(2).

CONCLUSIONS

Perioperative complications do not increase with the use of BITAs in this group of diabetic patients. There are no statistically significant differences in the number of superficial or deep wound infections or number of sternal resuturing between the BITA and LITA groups.

Surgical versus percutaneous revascularization of coronary artery disease in diabetic patients

Morbidity and mortality related to coronary artery disease (CAD) remain a great challenge in patients with diabetes mellitus. Revascularization of CAD is an important therapeutic intervention owing to its impact on both symptoms and prognosis. The optimal revascularization strategy continues to evolve due to the advent of new technologies and improved peri-procedural outcome with both percutaneous coronary interventions and coronary artery bypass grafting. Although clinical outcome following coronary artery bypass is worse in diabetic as opposed to non-diabetic patients, surgical revascularization tends to be associated with better outcome in stable patients with multivessel disease and reduced left ventricular function. The advent of drug-eluting stents has challenged the supremacy of coronary artery bypass grafting and has become a valuable alternative to surgery. The safety and efficacy of drug-eluting stents in the treatment of patients with diabetes and multivessel disease is currently under investigation in several ongoing randomized controlled trials. Percutaneous coronary intervention is the therapy of choice in patients with acute coronary syndromes, particularly ST-elevation myocardial infarction. The focus of this review is to present the current evidence, define the role of percutaneous and surgical revascularization in the treatment of diabetic patients with CAD, and propose a tailored approach for clinical decision-making.

Propensity-Score Analysis of Early Outcomes after Bilateral versus Single Internal Thoracic Artery Grafting

Objective

The use of bilateral internal thoracic arteries (BITAs) during coronary artery bypass grafting (CABG) improves long-term and event-free survival compared with single internal thoracic artery (SITA) grafting. It is controversial whether BITA grafting alters in-hospital adverse events after CABG.

Methods

Isolated CABG cases using BITA or SITA at a single US academic center between January 1, 1997 and June 30, 2006 were retrospectively reviewed. A propensity score was used as a covariate to balance the treatment groups (BITA and SITA) with respect to 44 preoperative risk factors. A multivariable logistic regression model tested whether treatment type was significantly associated with in-hospital death, deep sternal wound infection (DSWI), or hospital length of stay (LOS).

Results

There were 599 BITA and 10,212 SITA cases performed. Overall for all BITA versus SITA cases, adjusted mortality (0.8% vs. 1.7%, P = 0.85) was not different between the groups. However, adjusted incidence of DSWI (2.0% vs. 1.2%, P = 0.036) and LOS (6.7 vs. 6.1, P = 0.025) were significantly higher in BITA patients. Subsets analyses of obese patients and diabetic patients revealed no statistical differences for any of the outcomes between BITA and SITA.

Conclusions

The long-term benefits of BITA grafting do not come at the cost of increased adjusted risk of in-hospital death. BITA grafting was associated with an increased risk of DSWI and a longer adjusted LOS. Neither obesity, nor diabetes significantly increased the risk of poor outcomes after BITA.

Diabetes mellitus as a predictor for radial artery vasoreactivity in patients undergoing coronary artery bypass grafting

OBJECTIVES

Our purpose was to examine the impact of diabetes mellitus (DM) on vasoreactivity and endothelial function of radial artery (RA) grafts ex vivo.

BACKGROUND

The arteriopathy associated with DM may influence the surgeon's choice of conduits for revascularization. Arterial conduits and especially the RA are prone to vasospasm in the perioperative period.

METHODS

The study population consisted of 98 patients with coronary artery disease undergoing coronary artery bypass grafting by using RA grafts. The maximum contractions of RA segments induced by K+ (66 mmol/l) and clinically important vasoconstrictors such as adrenaline (5 x 10(-5) mol/l), angiotensin II (10(-6) mol/l), and prostaglandin F2alpha (PGF2alpha) (10(-6) mol/l) were recorded. Relaxation of RA rings to carbachol (10(-4) mol/l) was used as a measure of endothelial function. Multivariate analysis was then applied to determine the role of clinical characteristics on the vasomotor responses to these agents.

RESULTS

Vessels from patients with DM had greater contractions in response to adrenaline (p < 0.05), angiotensin (p < 0.05), and PGF2alpha (p < 0.01) compared with non-DM vessels, despite the similar vasoconstrictions induced by high K+ (p = NS). Diabetes mellitus was also associated with smaller vasorelaxations in response to carbachol (p < 0.001). In multivariate analysis, DM was an independent predictor of RA contractions in response to adrenaline (beta [SE] 3.085 [1.410], p = 0.031), angiotensin II (beta [SE] 3.838 [1.552], p = 0.015), and PGF2alpha (beta [SE] 4.609 [1.908], p = 0.018) but not K+ (p = NS). Diabetes mellitus was also independently associated with the vasorelaxations in response to carbachol (beta [SE] -15.645 [2.622], p = 0.0001).

CONCLUSIONS

Diabetes mellitus is associated with impaired endothelial function and greater contractions of RA grafts in response to all of the clinically relevant vasoconstrictors. These findings suggest that the RA of diabetic patients may be more prone to spasm in response to endogenous vasoconstrictors, an observation with important implications for surgeons' choice of conduits in this cohort of patients.

Techniques and Benefits of Multiple Internal Mammary Artery Bypass at 20 Years of Follow-Up

BACKGROUND

In patients with multivessel coronary artery disease, performing multiple internal mammary artery (MIMA) grafts to two coronary systems during coronary artery bypass grafting (CABG) improves clinical outcome. Few databases have decades of follow-up, however, and the optimal configuration is still in question. The purpose of this study was to assess 20-year clinical benefits of MIMA grafting and to evaluate the possible effects of two different MIMA configurations.

METHODS

From 1984 to 1986, 867 patients with multivessel coronary disease underwent CABG. Single (SIMA) IMA grafts were used in 490 and multiple (MIMA) IMA grafts in 377, along with concomitant saphenous veins. Generally, MIMAs were placed to the two largest coronary systems. Among baseline characteristics, only smoking, diabetes, and hypertension were significantly higher for MIMA versus SIMA. Multivariable Cox model analysis was used to assess outcome differences between groups.

RESULTS

During a median follow-up of 20 years, the composite of mortality, myocardial infarction, percutaneous coronary intervention, and redo CABG was significantly reduced after MIMA versus SIMA (p = 0.013). Event-free survival was extended by almost 1 year (p = 0.018), and redo CABG was reduced by 59% (p = 0.005). A comparison within the MIMA group was made between 235 patients receiving IMA grafts to left anterior descending/left circumflex territories versus 122 with grafts to left anterior descending/right coronary artery systems. No significant difference in composite outcome was observed between these configurations (p = 0.88).

CONCLUSIONS

These data confirm the clinical benefits of MIMA grafting in multivessel coronary disease to 20 years of follow-up. As long as MIMAs are placed to the two largest coronary systems, no significant differences in long-term results are evident between left anterior descending/left circumflex and left anterior descending/right coronary artery configurations.

[Arterial grafts in coronary surgery for diabetic patients]

Surgical revascularization allows especially for the diabetic patient with coronary multi-vessel disease a superior long-termperspective compared to percutaneous coronary interventions. However, the specific advantages and also risks associated with the expanded use of arterial grafts as coronary conduits in diabetics are not clearly answered. A systemic analysis of the current literature underlines the following statements: The radial artery is, compared to the internal mammary artery, to a higher extent prone to atherosclerosis, especially in diabetic patients. Better long-term survival for patients with bilateral IMA-grafts has also been assessed for diabetic patients. The risk of thoracic wound infections is not obligatory increased for diabetics with double IMA-grafts. Revascularization with radial arteries can be performed with low perioperative risks. Long-term results or studies on radial artery bypass grafting especially in diabetics are not available. In our own experience (3,548 isolated coronary operations, 01/2001 until 05/2005), diabetic patients have no increased perioperative mortality, even when using more complex arterial grafting. Conclusively, diabetic patients should also significantly benefit from the use of the second mammary artery. Regarding conduit quality, a second IMA appears favorable over the radial artery.