Bilateral Internal Mammary Artery Use Research Articles

Association of HbA1c and utilization of internal mammary arteries with wound infections in CABG.

Deep sternal wound infection (DSWI) remains a serious complication after coronary artery bypass grafting (CABG). We herein aimed to stratify diabetic patients who underwent CABG using bilateral internal mammary artery (BIMA) for levels of glycated hemoglobin A1C (HbA1c) and compare postoperative outcomes. Between January 2010 and August 2020, 4,186 consecutive patients underwent isolated CABG at our center. In 3,229 patients, preoperative HbA1c levels were available. Primary endpoints were wound healing disorder (WHD), DSWI, and 30-day mortality. Patients were stratified according to preoperative HbA1c levels. Patients were further divided into subgroups according to utilization of BIMA. After adjustment, no differences in mortality and stroke rates were seen between group 1 (HbA1c < 6.5%) vs. group 2 (HbA1c ≥ 6.5%). WHD was more frequent in group 2 [2.8 vs. 5.6%; adjusted p = 0.002; adjusted odds ratio (OR), 1.853 (1.243-2.711)] but not DSWI [1.0 vs. 1.5%; adjusted p = 0.543; adjusted OR, 1.247 (0.612-2.5409)]. BIMA use showed a higher rate of WHD [no BIMA: 3.0%; BIMA: 7.7%; adjusted p = 0.002; adjusted OR, 4.766 (1.747-13.002)] but not DSWI [no BIMA: 1.1%; BIMA: 1.8%; adjusted p = 0.615; adjusted OR, 1.591 (0.260-9.749)] in patients with HbA1c ≥ 6.5%. Intraoperative utilization of BIMA is not connected with an increase of DSWI but higher rates of WHD in patients with poor diabetic status and HbA1c ≥ 6.5%. Therefore, application of BIMA should be taken into consideration even in patients with poor diabetic status, while identification of special subsets of patients who are at particular high risk for DSWI is of paramount importance to prevent this serious complication.

Why Are We Weighting? Understanding the Estimates From Propensity Score Weighting and Matching Methods.

Propensity score methods are used in observational studies to compensate for the lack of random allocation by balancing measured baseline characteristics between treated and untreated patients. We sought to explain the treatment effect estimates derived from different propensity score methods. We performed a retrospective analysis of long-term mortality after single internal mammary artery versus bilateral internal mammary artery (BIMA) conduit in 47 984 index isolated coronary artery bypass grafting procedures from 1992 to 2014 in the Northern New England Cardiovascular Disease Study Group registry using multivariable Cox regression, 1:1 propensity score matching, inverse probability weighting (IPW) among the treated, and IPW among the overall population treatment estimates. The mean duration of follow-up was 13.2 (interquartile range, 7.4-17.7) years. In multivariable Cox regression, the adjusted hazard ratio for mortality was 0.83 (95% CI, 0.75-0.92) in patients receiving BIMA compared with a single internal mammary artery. The 1:1 propensity matched (hazard ratio, 0.79 [95% CI, 0.69-0.91]) and IPW among the treated (hazard ratio, 0.83 [95% CI, 0.75-0.92]) estimates showed a protective treatment effect of BIMA use on mortality. However, the IPW estimate of treatment effect for the overall population showed an increased risk of mortality after BIMA that was not statistically significant (hazard ratio, 1.08 [95% CI, 0.94-1.24]). While the multivariable Cox regression, 1:1 propensity matching, and IPW treatment effect in the treated estimates demonstrate that BIMA was associated with a statistically significantly decreased risk of mortality, the IPW treatment effect in the average study population showed an increased risk of mortality associated with BIMA that was not statistically significant. This is attributed to the different populations (weighted to look like the overall study population versus treated group) represented by the 2 IPW approaches. Determining how the study population is balanced is a large driver of the treatment effect. Ultimately, the treatment effect estimate desired should drive the choice of the propensity score method.

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

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

Left or bilateral internal mammary artery employment in coronary artery bypass grafting: midterm results.

The gold standard for coronary artery bypass grafting to the left anterior descending artery is use of the left internal mammary artery. Better long-term survival has been reported using bilateral internal mammary arteries compared to left internal mammary artery only, but many surgeons are reluctant to employ bilateral internal mammary arteries in coronary artery bypass grafting. This study aimed to evaluate the effectiveness and safety of bilateral internal mammary artery use. From 2014 to 2017, 1703 patients underwent coronary artery bypass grafting in our institute. Of these, 772 met the inclusion criteria and were randomly assigned to receive bilateral (n = 387) or left (n = 385) internal mammary artery grafts. The mean age was 67.1 ± 6.0 years (range 48-85 years) and 474 (61.4%) were male. The mean number of diseased vessels was 3.1 ± 0.9, and mean EuroSCORE II was 3.4% ± 1.1%. Hospital mortality was 1.2% in the left internal mammary artery group vs. 1.8% in the bilateral internal mammary artery group (p = 0.55). There was no difference in procedure-related complications between groups. Mean follow-up was 65.9 months. Survival in the bilateral internal mammary artery group at 1, 3, and 5 years was 98.7%, 98.7%, and 94.8% vs. 98.1%, 98.1%, and 90.9%, respectively, in the left internal mammary artery group (p = 0.63). Application of bilateral internal mammary arteries in coronary artery bypass grafting is safe and effective, with comparable midterm results to those with the left internal mammary artery only.

Wound Infection after CABG Using Internal Mammary Artery Grafts: A Meta-Analysis.

Internal mammary arteries show better long-term patency rates than venous grafts. The use of both mammary arteries is associated with a higher risk of sternal wound infections. This meta-analysis was designed to assess the incidence of a wound healing disorder after bilateral compared with single mammary artery bypass grafting. Compared with existing meta-analysis this paper includes more current literature and one randomized controlled trial. A literature search was performed using PubMed and the Cochrane Library. The quality of the articles was assessed by the Newcastle Ottawa Scale. The odds ratio was used as a measure of the chance of developing a wound healing disorder after bilateral internal mammary artery (BIMA) surgery. Meta-analyses were performed for different subgroups. Twenty studies met the quality criteria, including one randomized controlled trial. The use of both mammary arteries significantly increased the risk of superficial (odds ratio [OR] 1.72) and deep (OR 1.75) wound healing disorder in the total population (OR 1.80) as well as in the diabetic subgroup (OR 1.38) and with both preparation techniques. The increased risk with BIMA grafting was present independently of the preparation technique (pedicled: OR 1.89, skeletonized: OR 1.37). Bilateral internal mammary artery grafting, especially in high-risk and diabetic patients, is associated with an increased risk of wound healing impairment. Skeletonized preparation does not eliminate the elevated wound healing disorder risk after BIMA use.

Sternal healing after bilateral internal mammary arteries use for Coronary artery bypass grafting in diabetic Patients; short-term results

Background: Bilateral internal mammary artery (BIMA) use may improve long-term outcomes after coronary artery bypass grafting (CABG); however, the risk of infection is high. Skeletonization of the internal mammary may decrease the risk of infection, especially in patients with diabetes. Our study aimed at evaluation of sternal healing in diabetic patients with different techniques of bilateral internal mammary artery harvesting.&#x0D; Methods: This prospective randomized study included 200 diabetic patients who underwent CABG using BIMA between 2017 and 2019. We divided patients into two groups; Group A had skeletonization of both internal mammary arteries, and Group B had pedicled left mammary and skeletonized right mammary. Patients were observed for three months, post-operatively for any sternal wound problems.&#x0D; Results: There was no significant difference regarding the baseline variables. Type I diabetes mellitus was present in 25% in group A (n= 24) and 13.64% in group B (n= 12) (p= 0.324). There was no difference in harvest time between groups (83 ±4 vs. 81 ±3 minutes in group A vs. B, respectively. P= 0.1). The mean number of grafts was 3± 0.5 in Group A and 3± 0.6 in Group B (p= 0.8). Postoperative drainage was 402.9 ± 174.1 ml in Group A vs. 387.2 ± 153.6 ml in Group B (p= 0.474). The duration of ICU stay did not differ significantly between groups (2± 0.7 in Group A vs. 2± 0.5 in Group B; p= 0.8). Deep sternal wound infection occurred in 4.17% in group A (n= 4) and 4.55% in group B (n= 4) (p= 0.705). Superficial wound infection occurred in eight patients in group A (8.33%) and eight patients in group B (9.1%) (p= 0.59). No patient had sternal dehiscence in group A vs. four patients in group B (4.55%) (p= 0.39).&#x0D; Conclusion: We did not find differences between bilateral mammary artery harvest with skeletonization of both arteries versus skeletonization of the right mammary only on sternal healing nor wound infection in diabetic patients undergoing CABG. A larger study is recommended.

Abstract 171: User Beware: Understanding the Adjusted Estimates of Propensity Score Methods

Background: Propensity score methods are used in observational studies to compensate for the lack of random allocation by balancing measured baseline characteristics between treated and untreated patients. Yet default implementations of propensity score methods may lead to contradictory findings. Our goal was to illustrate differences in treatment effect estimates produced using propensity score methods such as matching and inverse probability weighting (IPW). Methods: We used data from a retrospective analysis of the Northern New England Cardiovascular Disease Study Group registry that studied reintervention after single internal mammary artery (SIMA) versus bilateral internal mammary artery (BIMA) conduit use in 41,481 coronary artery bypass grafting (CABG) procedures from 1992-2014. Results: The mean duration of follow-up was 13.2 (IQR: 7.4-17.7) years. In our standard multivariable Cox regression analysis, the adjusted HR for reintervention was 0.83 (95% confidence interval (CI): 0.75-0.92) in patients receiving BIMA compared to SIMA (Table). The 1:1 propensity matched analysis (HR=0.79, 95% CI: 0.69-0.91) and IPW estimate among the treated (HR=0.83, 95% CI: 0.75-0.92) show a similar protective treatment effect of BIMA use on reintervention. However, the IPW approach for the overall population effect unusually showed no difference between BIMA and SIMA on reintervention-free survival (HR=1.08, 95% CI: 0.94-1.24). Conclusions and Relevance: The adjusted HR for reintervention after BIMA versus SIMA use in CABG was remarkably different for the two IPW estimates. This difference is attributed to the population represented by the two IPW approaches- the IPW among the treated estimate represents the effect in the average study population, whereas the IPW in the treated represents the effect in the treated population alone. Determining how the study population is balanced (weighted to look like the overall study population versus treated group) is a large driver of treatment effect, and a key element of propensity score methods. Ultimately, the treatment effect estimate desired should drive the choice of propensity score adjustment method.

How do surgeons decide? Conduit choice in coronary artery bypass graft surgery in the UK†.

Conduits used in coronary artery bypass grafting may have significant impact on outcomes, but evidence is mixed and there is large variation in practice. This study provides insights into the opinions of the UK surgeons on conduit use and their decision-making processes. A questionnaire was created using the Ottawa Decision Support Framework to elicit the importance that surgeons placed on bilateral internal mammary artery grafting, skeletonization, total arterial revascularization and sequential anastomoses on a scale of 1-10. Scores ≥8 were deemed 'important' and ≤3 'not important'. Surgeons were asked to specify changes to practice in frail patients or emergencies. Additional questions included conduit type used, factors affecting decision-making and vein harvesting methods. Questionnaires were administered in person with data analysed centrally. Ninety-seven consultant cardiac surgeons from 25 centres responded. Thirty-two percent surgeons routinely used radial arteries and 36% used right internal mammary artery. High-quality evidence contributed most to decision-making receiving a total of 328/960 points, with consultant experience being the second (255/960 points). There was a bimodal distribution of perceived importance of bilateral internal mammary artery use, with 29 (30%) 'important' and 'not important' scores each. 23% of surgeons found total arterial revascularization important. Most surgeons (64%) preferred pedicled mammary arteries. Twenty-six percent of surgeons considered sequential grafting to be important. Low uptake of total arterial revascularization and bilateral internal mammary artery among the UK consultants may be due to the lack of high-quality evidence demonstrating a significant benefit. It is also possible that reluctance to use certain conduits may stem from low levels of exposure to conduits or inadequate training, particularly given the importance of consultant experience on decision-making.

Systematic bilateral internal mammary artery grafting: lessons learned from the CATHolic University EXtensive BIMA Grafting Study.

Despite claims of feasibility, to date no study has examined the effect of systematic bilateral internal mammary artery (BIMA) use in a large cohort of real-world unselected patients. The CATHolic University EXtensive BIMA Grafting Study (CATHEXIS) registry was designed to assess the feasibility and safety of systematic BIMA grafting. The CATHEXIS was a single-centre, prospective, observational, propensity-matched study. The study was supposed to include 2 arms of 500 patients each: a prospective arm and a retrospective arm. The prospective arm included almost all patients referred for coronary artery bypass grafting (CABG) at our institution after the start of the CATHEXIS with very few exceptions. BIMA would have been used in all these patients. The retrospective arm included patients submitted to CABG before the start of the CATHEXIS and propensity matched to the prospective group (average BIMA use 50%; the radial artery was extensively used). Safety analyses were scheduled after enrolment of 200, 300 and 400 BIMA patients. After the first 226 patients, the BIMA use percentage was 88.5% (200 of 226). In 178 (89%) patients, mammary arteries were used as Y graft. Postoperative mortality was 2%, and incidence of perioperative myocardial infarction, graft failure and sternal complications were 3.5%, 3% and 5.5%, respectively. No perioperative stroke occurred. The incidence of major adverse cardiac events (particularly graft failure and sternal complications) in the BIMA arm were significantly higher than those in the propensity-matched cohort; the study was stopped for safety. In a real world setting the systematic use of BIMA was associated with a higher incidence of perioperative adverse events (particularly sternal complications). Individualization of the revascularization strategy and use of alternative arterial conduits are probably preferable to systematic use of BIMA.

Bilateral Versus Single Internal Mammary Artery Use in Coronary Artery Bypass Grafting: A Propensity Matched Analysis

Bilateral internal mammary artery (BIMA) grafts have demonstrated superior long-term outcomes compared with single internal mammary artery (SIMA) grafts. Despite this, BIMA remains widely underutilised due to perceived technical challenges and concerns regarding wound healing. We sought to examine the morbidity and mortality associated with BIMA use in a propensity-matched cohort of patients. From 2009 to 2016, 3,594 consecutive patients underwent coronary artery bypass surgery at three affiliated institutions. Thirty-day (30) mortality and morbidity data were collected prospectively. Propensity-score matched analyses were performed for BIMA versus SIMA use controlling for a number of preoperative characteristics. Overall, 29% of procedures were performed off pump, with a greater proportion in the BIMA group (43% vs. 21%, p<0.001). In the propensity-score analysis consisting of 820 matched pairs, there were similar rates of 30-day mortality (1.3% BIMA vs. 0.9% SIMA, p=0.48) and deep sternal wound infection (1.1% BIMA vs. 0.9% SIMA, p=0.84). The rate of superficial sternal wound infection trended towards being higher in the BIMA group (2.6% vs. 1.3%, p=0.077). The rates of red blood cell transfusions (27.4% vs. 27%, p=0.217), other blood product transfusions (18% vs. 20%, p=0.217), and reoperation for bleeding (2.9% vs. 2.1%, p=0.349) were similar. Bilateral internal mammary artery use was associated with similar rates of deep sternal wound infection compared to SIMA use, with a preponderance of superficial sternal wound infections that did not result in increased mortality or transfusion requirements. The use of BIMA should be more widely considered for coronary artery bypass surgery.

Cirugía de revascularización miocárdica versus stent farmacoactivos en pacientes con enfermedad de tronco común izquierdo: una revisión sistemática de ensayos clínicos aleatorizados y de metaanálisis de ensayos clínicos aleatorizados

ObjectiveThe aim of this systematic review is to analyze in the literature the clinical results of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention with drug-eluting stents in patients with left main stem disease. MethodsWe carried out a literature search using Pubmed, Google Scholar, Medline, Embase and Cochrane databases. We limited our search to randomized controlled trials or meta-analyses carried out on randomized controlled trials, with no year of publication or language restriction. ResultsEighty-two articles were found using the search methodology described. Of these, 14 articles were selected: 7 papers from 5 randomized non-inferiority clinical trials (SYNTAX, PRECOMBAT, study by Boudriot et al., NOBLE and EXCEL) and 7 meta-analyses. These trials have compared first generation drug-eluting stents (SYNTAX: stent with paclitaxel; Boudriot et al. and PRECOMBAT: stent with sirolimus) and second-generation drug-eluting stents (NOBLE: stent with biolimus; EXCEL: stent with cobalt-chromium everolimus) with CABG.With reference to the coronary revascularization procedure, bilateral internal mammary artery use ranged from 7.4% to 54.4%. All the included randomized trials reported a lower rate of repeated revascularization in the surgical population. According to the meta-analyses review, the risk, expressed as odds ratio, of requiring a new myocardial revascularization procedure by the percutaneous population compared with that one of the surgical population, ranged from 1.68 to 2.21. ConclusionsIndependently from the type of drug eluting stent used in the percutaneous procedures and despite low rate of bilateral internal mammary artery used in the surgical group, the risk of requiring a new myocardial revascularization procedure by the percutaneous population was twice that one of the surgical population.

Invited Commentary

Invited Commentary

National Trends and Geographic Variation in Bilateral Internal Mammary Artery Use in the United States

The goal of this study was to characterize the adoption rate and regional variation in bilateral internal mammary artery (BIMA) use during coronary artery bypass grafting (CABG) in the United States. Observational study of 100% sample of fee-for-service Medicare beneficiaries aged 65 years or older, continuously enrolled in Parts A and B from 2009 to 2014 (n= 162,860,439). Rates of beneficiaries receiving a BIMA versus single internal mammary artery (SIMA) during CABG are expressed per 1,000 beneficiaries and aggregated by Hospital Referral Region (HRR). An HRR is a validated unit for quantifying regional variation in health care. The absolute national rate of BIMA use declined during the study period from 0.21 claims per 1,000 beneficiaries in 2009 to 0.13 in 2014 (p < 0.001). When indexed to overall CABG volume, no change was seen in the frequency of BIMA use over time (p= 0.883). SIMA use ranged from 1.3 to 8.5 claims per 1,000 Medicare beneficiaries, whereas BIMA use ranged from 0 to 1.5 (p < 0.001). A significant correlation was found between regional volume of SIMA use and likelihood of BIMA use (correlation coefficient 0.673, p < 0.001). Although both SIMA and BIMA use correlated with regional volume of diagnostic cardiac catheterization, the correlation was stronger for SIMA use (correlation coefficient 0.962 versus 0.682, p < 0.001). Over the past 5 years, no growth was seen in BIMA use among Medicare beneficiaries, and the frequency of BIMA use during CABG remained low. There was significant regional variation in BIMA use, however, which demonstrates opportunity for continued growth of BIMA grafting.

Bilateral Internal Mammary Artery Use Can Be Safely Taught Without Increasing Morbidity or Mortality

Evidence shows a likely survival benefit with the use of bilateral internal mammary arteries (BIMA) compared with a single internal mammary artery (SIMA). Nonetheless, BIMA use is often not used or taught because of a perceived increase in operative time and complexity. This study aimed to evaluate operative time, morbidity, and mortality in both resident and nonresident cases using BIMA compared with SIMA. Consecutive patients undergoing isolated coronary artery bypass grafting (October 2012 to April 2015) at a single institution were reviewed. Cases were stratified on the basis of the use of SIMA versus BIMA and resident teaching versus nonresident teaching cases. Primary outcomes included operative time, postoperative morbidity, and mortality. A total of 416 patients were identified; 335 of 416 (81%) patients received a SIMA, and 81 of 416 (19%) patients received BIMA. A total of 184 of 416 (44%) were resident cases: 143 of the 335 (43%) SIMA cases and 41 of the 81 (51%) BIMA cases. Use of BIMA in resident cases was associated with a longer operative and cardiopulmonary bypass (CPB) time than resident SIMA cases, but this increased time did not affect morbidity or mortality. Use of SIMA versus BIMA in nonresident cases had no significant difference on total operative time, CPB time, postoperative morbidity, or mortality. Overall, operative and 1-year mortality rates were similar in the SIMA and BIMA groups (SIMA: 1.2%, 1.8%, respectively; BIMA: 0%, 0%, respectively; p= NS). In the hands of an experienced surgeon, BIMA use can be effectively performed without an increase in operative or CPB time. In resident teaching cases, BIMA use may increase operative time, but it can be safely taught without affecting morbidity or mortality.

Is bilateral internal thoracic artery grafting in poorly controlled diabetic obese patients a contraindication? A single center pilot study

BackgroundIn spite of substantial evidence supporting a long-term survival benefit with bilateral internal mammary artery (BIMA) grafts in CABG, this technique remains grossly underutilized worldwide. The incidence of deep sternal wound infection (DSWI) following BIMA harvest ranges from 0.6% to 4.2%. The high incidence of obesity and diabetes among Kuwait population encouraged us to study the incidence of DSWI among our patients with BIMA. Methods101 patients who underwent CABG procedure with BIMA use in Al-Dabbous Cardiac center, Al-Adan Hospital, Kuwait. Between June 2014 and December 2016, were included and analyzed retrospectively. Results92 patients included in our study were males (91.1%) and were 9 females (8.9%). 86 patients had HbA1c > 7% (85.2%). 20 patients (19.8%) had Body Mass Index (BMI) > 30. Of all studied patients, 12 patients (11.9%) had both BMI > 30 and HbA1c > 7. DSWI occurred in 3 patients (3%) out of the studied 101 patients, 2 of them had BMI > 30 and HbA1c > 7. The multi-variable analysis showed a significant correlation between the occurrence of DSWI and female gender (p value = 0.001) as well as a combination of BMI > 30 and level of HbA1c > 7 (p value = 0.037). Age, HbA1c > 7 with BMI <30 and BMI >30 with HbA1c < 7, failed to show any statistically significant increase in the incidence of DSWI in our study group. ConclusionsBased on our results, BIMA grafting in poorly controlled diabetic obese patients especially of female gender shouldn't be used to avoid the higher incidence of DSWI among them.

Abstract 10938: Outcomes of Coronary Artery Bypass Grafting in 1.9 Million Medicare Patients From 1999-2010

Introduction: Coronary artery bypass grafting (CABG) remains a mainstay of treatment in patients with coronary artery disease. Outcomes of CABG from a large modern U.S. cohort (the Medicare database) were analyzed, with a focus on outcomes. Methods: Medicare patients undergoing CABG from 1999-2010 were assessed. ICD-9 and CPT codes were used to describe operative details. Survival distributions were estimated with the Kaplan-Meier method, and compared with an age-/sex-/race-matched general US population cohort. A Cox proportional hazards analysis determined variables associated with survival. Cubic-spline analyses were used to assess hospital and surgeon volume-outcome relationships. Results: Median survival following CABG for the entire cohort (n=1,902,315) was 9.43 years (95% confidence intervals [CI] 9.41-9.45) (Figure 1A), and was 10.02 years (95% CI: 10.00-10.04) in isolated CABG (n=1,523,529) recipients (Figure 1B). During the 12 year study period, Medicare patients underwent CABG at 1,391 U.S. hospitals and by 5,899 U.S. surgeons. Multivariable analysis identified multiple predictors of death including age, gender, race, patient comorbidities, prior cardiac surgery, year of operation, adjunct cardiac procedures (e.g. valve repair/replacement or aortic repair), the lack of internal mammary artery (IMA) use, the absence of billing for cardiopulmonary bypass, and both hospital and surgeon volume. A transition point was identified in the surgeon-volume and hospital-volume relationships suggesting a volume beyond which additional case numbers only improved outcomes minimally (Figures 1C/1D). Conclusions: Survival following CABG in Medicare patients is robust. Even in this elderly cohort, the use of a single IMA was associated with significantly improved outcomes, and bilateral IMA use was associated with an even lower hazard for death compared with single IMA. Both hospital and surgeon volume had strong associations with survival.

Bilateral Internal Mammary Artery Use for Coronary Artery Bypass Grafting Remains Underutilized: A Propensity-Matched Multi-Institution Analysis

Bilateral internal mammary arterial (BIMA) grafts have repeatedly demonstrated superior outcomes compared with single IMA (SIMA) after coronary artery bypass grafting (CABG). Despite known survival benefits with BIMA use, perceived perioperative challenges often preclude BIMA use. We hypothesized that the use of BIMA remains underutilized, even in low-risk patients. A total of 43,823 primary, isolated CABG patients in a regional Society of Thoracic Surgeons Database were evaluated. Patients were stratified by BIMA versus SIMA use. Surgical candidates considered "low risk" for BIMA use included the following: age less than 70 years; no or mild chronic lung disease; body mass index less than 30; and absence of diabetes. The BIMA patients (n = 1,333) were 1:1 propensity matched to SIMA patients (n = 1,333) and outcomes were compared. Overall, BIMA use was 3%; 24% (n = 10,327) of patients met "low-risk" criteria for BIMA use. Among "low-risk" patients, BIMA utilization was 6%. Propensity-matched comparisons revealed similar preoperative risk profiles between BIMA and SIMA patients (Predicted Risk of Mortality [PROM] 1.1% vs 1.1%, p > 0.05). The BIMA use was associated with longer cross-clamp time (71 vs 62 minutes, p < 0.05). Importantly, BIMA use was not associated with increased postoperative mortality, morbidity, or hospital length of stay (all p > 0.05). However, hospital readmission within 30 days was 41% greater for BIMA patients compared with SIMA patients (p = 0.01). Bilateral IMA graft use appears to remain underutilized in the modern surgical era, even in low surgical risk patients. The BIMA use does not appear to increase the risk of postoperative morbidity, although requires longer operative times and a higher risk for readmission. Efforts to more clearly understand surgeon motivators for the use of BIMA grafting are needed.

Staphylococcus aureus and repeat bacteremia in febrile patients as early signs of sternal wound infection after cardiac surgery.

BackgroundSternal wound infection is a devastating complication of cardiothoracic surgery that carries high postoperative morbidity and mortality rates. We explored whether our current program of extensive bacteriological examination including repeat blood cultures may contribute to the early diagnosis of sternal wound infection.MethodsWe retrospectively analyzed 112 patients who were subjected to our bacteriological examination protocol including within 90 days after cardiothoracic surgery. Univariate and multivariate analyses were made in order to identify risk factors for sternal infection.ResultsThe median patient age was 75 years, and 65 patients were male. In 35 cases (31.2%) the blood cultures showed the presence of bacterial infection with the following frequencies: Staphylococcus aureus, 18 cases; Coagulase-negative Staphylococcus, 7 cases; other organisms, 10 cases. Eleven patients presented repeat bacteremia on at least 2 different occasions. Twenty patients (17.8%) presented sternal wound infections. There was no difference in operative mortality between the patients with and without sternal wound infection. Univariate and multivariate analyses demonstrated that bilateral mammary artery use (OR, 13.68, 95% CI, 1.09-167.36, p = 0.043), positive blood culture for Staphylococcus aureus (OR, 19.51, 95% CI, 4.46-104.33, p < 0.0001), repeat bacteremia (OR, 17.98, 95% CI, 2.51-161.77, p = 0.004) were risk factors that were associated for sternal wound infection.ConclusionRepeat blood cultures in febrile patients appear to be useful for the early detection of Staphylococcus aureus and repeat bacteremia, and these were associated with sternal wound infection. Bilateral internal mammary artery use was another risk factor of sternal wound infection in febrile patients. These factors may identify patients suitable for expeditious radiological examination and aggressive treatments.

Bilateral internal mammary artery grafts, mortality and morbidity: an analysis of 1 526 360 coronary bypass operations

ObjectivesThe objective of this study was to investigate the impact of bilateral internal mammary artery (BIMA) on early outcomes after coronary artery bypass grafting.DesignRetrospective database analysis.SettingUS hospitals.Patients1 526 360 patients...

In-Hospital Outcomes of Pedicled Bilateral Internal Mammary Artery Use in Diabetic and Nondiabetic Patients Undergoing Off-Pump Coronary Artery Bypass Grafting: Single-Surgeon, Single-Center Experience

A common perception is that use of pedicled bilateral internal mammary arteries (BIMA) increases the risk of sternal wound complications in diabetic patients undergoing coronary artery bypass grafting (CABG). The purpose of this study was to compare the in-hospital outcomes of CABG using pedicled BIMA in diabetic and nondiabetic patients. From September 1998 to September 2010, 390 consecutive diabetic patients and 519 nondiabetic patients underwent isolated off-pump CABG using pedicled BIMA. The 2 groups had comparable preoperative demographics except for a higher prevalence of acute myocardial infarction (18.9% versus 6.1%, P = .01), peripheral vascular disease (17.2% versus 2.7%, P = .001), an ejection fraction <30% (17.7% versus 8.5%, P = .02), and chronic renal failure (4.5% versus 0.9%, P = .01) in the diabetic patients. The operative mortality rate of the diabetic patients was comparable to that of the nondiabetic patients (2.8% versus 2.1%, P = .87). The in-hospital outcomes, including occurrence of superficial and deep sternal wound infections, were similar except for an increased occurrence of wound infection at the vein harvest site (6.6% versus 1.1%, P = .04) and a need for hemofiltration (11.8% versus 2.1%, P = .02) in the diabetic patients. Pedicled BIMA use is associated with comparable incidences of sternal wound complications and other outcomes in diabetic patients and nondiabetic patients. Strict perioperative glycemic control, adherence to meticulous closure technique, and postoperative management of surgical wounds can make pedicled BIMA use a default strategy for diabetic patients.