Single Internal Thoracic Artery Research Articles

Outcomes after coronary artery bypass graft surgery: systematic review and meta-analysis comparing bilateral versus single internal thoracic artery grafts

Abstract Background Patients with diabetes and/or obesity are at higher risk of adverse outcomes following coronary artery bypass grafting (CABG). The use of bilateral internal thoracic arteries (BITA) can potentially offer survival benefit in higher risk patients compared to single internal thoracic artery (SITA) in patients undergoing CABG, but the overall evidence base for BITA has not influenced guidelines, and there are concerns over increased risk of sternal wound complications. Methods We conducted a systematic review of the literature to identify observational studies and randomised controlled trials (RCT) comparing the efficacy (mortality) and safety (sternal wound infection) of BITA and SITA in diabetic and obese patients. Results We identified 18 observational studies and one RCT to obtain data comparing BITA and SITA in 19,589 diabetic patients, and two observational studies and one RCT comparing BITA and SITA in 6972 obese patients. Pooled analysis demonstrated significant mortality benefit of BITA compared to SITA in diabetic patients (risk ratio [RR] 0.79; 95% confidence interval [CI] 0.70, 0.90; Z=3.62, p=0.0003; I2=88%) (Figure 1a). Pooled analysis in obese patients found no significant difference in mortality rates between BITA and SITA (RR 0.73, 95% CI 0.47, 1.12; Z=1.43, p=0.15; I2=78%) (Figure 1b). A significantly higher rate of sternal wound complications following BITA was observed in diabetic (RR 1.53, 95% CI 1.23, 1.90; Z=3.86, p=0.0001; I2=4%) and obese patients (RR 2.24, 95% CI 1.63, 3.07; Z=5.00, p<0.00001; I2=0%). Conclusions BITA is associated with better long-term survival in diabetic patients, but most of the supportive data comes from observational studies. The effects of BITA grafting in patients who are obese is uncertain due to low numbers. BITA is associated with higher rates of sternal wound complications than SITA in both diabetic and obese patients. Further research is needed to understand if BITA has a role in higher risk patients undergoing CABG. Figure 1. Pooled all-cause mortality Funding Acknowledgement Type of funding source: None

Effects of diabetes and obesity in patients undergoing coronary artery bypass graft surgery: ten-year results from the Arterial Revascularisation Trial

Abstract Background Coronary artery bypass graft (CABG) surgery is an effective way to manage advanced coronary heart disease. Diabetes is associated with higher risk of mortality in patients undergoing CABG but the effects of obesity, and the interactions between diabetes and obesity in the context of CABG, have not been fully explored. Methods The Arterial Revascularisation Trial (ART) compared ten-year mortality in patients undergoing CABG randomised to single or bilateral internal thoracic arterial grafts. Effects of diabetes and obesity on mortality and risk (sternal wound complications) were explored. Diabetes was defined according to clinical history at baseline and combined insulin and non-insulin dependent patients, and obesity was defined as body mass index (BMI) ≥30kg/m2 at baseline. Results Information on diabetes, obesity and ten-year mortality were documented for 3094 patients who were included in the analysis. Mean age was 64 years, 86% male, mean weight 82kg and BMI 28. Diabetes was documented in 24% and obesity in 30% and as expected obese patients were more likely to be diabetic. The hazard ratios (95% confidence intervals) for ten-year mortality using the no diabetes, non-obese group as a reference were 1.33 (1.08, 1.64) (diabetes, non-obese), 0.93 (0.75, 1.16) (no diabetes, obese) and 1.18 (0.91, 1.54) (diabetes, obese) groups (Figure 1). Similar patterns of risk were observed whether patients were randomised to receive single or bilateral internal thoracic arteries and diabetes appeared to be the main driver of elevated risk of early sternal wound complications following CABG. Conclusions Obesity and diabetes are closely associated but our analysis shows that patterns of risk of death after CABG are not additive for these characteristics, and obesity may actually be associated with lower death rates in patients with and without diabetes. These findings will be explored further to understand mechanisms and interactions with other factors. Figure 1. Hazard ratios at 10 years Funding Acknowledgement Type of funding source: None

Single versus bilateral internal thoracic artery grafting in patients with low ejection fraction.

Coronary artery bypass grafting (CABG) is the standard of care for the treatment of complex coronary artery disease. However, the optimal surgical treatment for patients with reduced left ventricular function with low ejection fraction (EF) is inconclusive. In our center, left-sided coronary grafting with bilateral internal thoracic artery (BITA) is generally the preferred method for surgical revascularization, also for patients with low EF. We compared early and long-term outcomes between BITA grafting and single internal thoracic artery (SITA) grafting in patients with low EF.We evaluated short- and long-term outcomes of all patients who underwent surgical revascularization in our center during 1996 to 2011, according to EF ≥30% and <30%. Univariate and multivariate analyses were performed. In addition, patients who underwent BITA and SITA grafting were matched using propensity score matching.In total, 5337 patients with multivessel disease underwent surgical revascularization during the study period. Of them, 394 had low EF. Among these, 188 underwent SITA revascularization and 206 BITA grafting. Those who underwent SITA were more likely to have comorbidities such as chronic obstructive pulmonary disease, diabetes, congestive heart failure, chronic renal failure, and a critical preoperative condition including preoperative intra-aortic balloon pump insertion.Statistically significant differences were not observed between the SITA and BITA groups in 30-day mortality (8.5% vs 6.8%, P = .55), sternal wound infection (2.7% vs 1.0%, P = .27), stroke (3.7% vs 6.3%, P = .24), and perioperative myocardial infarction (5.9% vs 2.9%, P = .15). Long-term survival (median follow up of 14 years, interquartile range, 11.2–18.9) was also similar between the groups. Propensity score matching (129 matched pairs) yielded similar early and long-term outcomes for the groups.This study did not demonstrate any clinical benefit for BITA compared with SITA revascularization in individuals with low EF.

Bilateral internal thoracic artery grafting in elderly patients: Any benefit in survival?

The purpose of the present study was to compare survival outcomes in propensity score-matched patients aged 70years or greater receiving a bilateral internal thoracic artery graft with patients receiving a single internal thoracic artery graft. Among 4083 consecutive patients with isolated coronary artery bypass grafting who underwent operation between January 2001 and December 2018, we identified 1300 patients aged 70years or greater; of these, 968 received a bilateral internal thoracic artery (bilateral internal thoracic artery group) and 332 received a single internal thoracic artery (single internal thoracic artery group). Propensity score matching was used to reduce the preoperative patient differences. The 10-year survival and postoperative complications were compared between the 2 groups. A Kaplan-Meier curve at 10years of follow-up showed that crude survival was significantly superior in patients with bilateral internal thoracic artery grafts than in patients with single internal thoracic artery grafts (67.0%±2.5% vs 56.0%±3.4%, respectively; P<.016). In the actuarial survival, estimates for propensity score-matched patients with a bilateral internal thoracic artery showed a significantly higher rates of survival than patients with a single internal thoracic artery by the end of follow-up (66.0%±5.3% vs 53.0%±3.9%, respectively; hazard ratio, 0.64; 95% confidence interval, 0.44-0.94; P=.022, univariable Cox Model and multivariable analysis hazard ratio, 0.66; 95% confidence interval, 0.45-0.97; P=.036 Cox model). Postoperative complications were all similar between the single internal thoracic artery and bilateral internal thoracic artery groups. The use of bilateral internal thoracic artery grafting in older patients improves 10-year survival, with similar postoperative morbidity. This surgical technique might have beneficial effects in survival in patients aged more than 70years. Its use could be considered more frequently.

Is the Use of BITA vs SITA Grafting Safe and Beneficial in Octogenarians?

Bilateral internal thoracic artery (BITA) grafting is questionable in octogenarians because of shorter life expectancy and increased risk of perioperative complications. The aim of this study was to examine the safety and effectiveness of performing BITA and single internal thoracic artery (SITA) grafts in patients older than 80 years of age. This study compared outcomes in 201 consecutive octogenarians who underwent isolated BITA grafting with those of 280 consecutive octogenarians who underwent SITA and saphenous vein grafting during 1996 to 2011. Insulin-dependent diabetes, ejection fraction <30, and emergency operations were more common among patients who underwent SITA, and the prevalence of left main coronary artery disease was lower. Propensity score matching was used to control for these differences, thus generating well-matched groups of 190 patients each. There were no significant differences in early mortality between the unmatched groups: 3.2% in the BITA group and 8.6% in the SITA group (P= .12). Rates of sternal wound infection were also similar, 1.5% vs 1.7%, respectively. Differences were not observed in the occurrences of perioperative stroke (3.5% vs 2.5%; P= .999) and myocardial infarction (1.5% vs 3.6%; P= .166). The results were similar for the matched groups. Long-term survival between the unmatched groups and survival between the matched groups were not significantly different. This study shows equal long-term survival for BITA and SITA grafting in octogenarians. BITA is an acceptable alternative to SITA grafting in low-risk octogenarians and in the presence of a calcified aorta or poor-quality saphenous vein graft.

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

BackgroundCurrent 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 ResultsObservational 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.ConclusionsThe 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.

The Need for Randomized Trials in Cardiac Surgery

In this issue of The Annals of Thoracic Surgery, Zhu and colleagues1 report the results of a retrospective analysis of the Medicare database looking at patients undergoing isolated coronary artery bypass grafting (CABG) with single internal thoracic arteries (SITA) or bilateral internal thoracic arteries (BITA). Despite the large sample size and the use of propensity score matching (PSM), the study has the intrinsic limitations affecting all observational comparative studies.

The Power and the Pitfalls of Randomized Clinical Trials

In this issue of The Annals of Thoracic Surgery, the review article by Gaudino and colleagues1Gaudino M. Ruel M. Obadia J.-F. et al.Methodologic considerations on four cardiovascular interventions trials with contradictory results.Ann Thorac Surg. 2021; 111: 690-700Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar beautifully illustrates challenges associated with randomized clinical trials (RCTs) in surgery. The authors demonstrated the impact of differences in outcome definitions and patient populations—and potentially open-label design—on study results, calling for agreement on common outcomes definitions and duration of follow-up in study design and the involvement of statistical methodologists in guideline documents. Here, here! RCTs are widely accepted as the most objective method to evaluate treatment effect of an intervention by neutralizing known and unknown confounders. As such they stand at the top of the “evidence pyramid.” However they suffer significant limitations, particularly when related to interventional and operative procedures. First, bias is inescapable. The RCT design addresses “treatment selection bias” but inescapably substitutes “entry selectivity bias.” Despite complaints that the population studied in a given RCT are not representative of “real-world” clinical practice, such entry bias is necessary if one is to accurately study the treatment effect. This is analogous to using inbred mouse strains in basic science or when evaluating a specific pharmacologic agent for example. Appropriately these authors focus on the need to clarify and emphasize the impact of this bias rather than complain about its existence. Indeed they highlight the potential influence of heterogeneity in study population in the MITR-FR trial on study results. In fact in clever hands subtle manipulation of the study population (and other subtleties in RCT study design) can be used to demonstrate equivalence of empty backpacks to parachutes among individuals jumping from aircraft.2Yeh R.W. Valsdottir L.R. Yeh M.W. et al.Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial.BMJ. 2018; 363: k5094Crossref PubMed Scopus (65) Google Scholar The authors also emphasized the impact of differences in composite endpoints, perhaps notoriously including the definitions of their components, on study outcomes. It should be more broadly noted, however, that composite endpoints in all instances are potentially misleading. Used to increase the power of a study, they are commonly odd bedfellows chosen more as a matter of convenience than equivalence. Although repeat revascularization is indeed undesirable and potentially dangerous, would any of us seriously equate it with stroke or death? Among the challenges in surgical RCTs unaddressed by these authors is heterogeneity in the treatment administered (procedure performed). The consequences of this vulnerability is evident in the Arterial Revascularization Trial study, which demonstrated no impact of bilateral internal thoracic artery grafts when analyzed by intention to treat, but the opposite when considered by treatment received.3Taggart D.P. Benedetto U. Gerry S. et al.Arterial Revascularization Trial Investigators. Bilateral versus single internal thoracic artery grafts at 10 years.N Engl J Med. 2019; 380: 437-446Crossref PubMed Scopus (206) Google Scholar Operations are not drugs, and this impact increases with the complexity of the intervention. We are challenged to participate more enthusiastically in RCTs. I agree that it is incumbent on us to understand the nuances of their design and conduct. I also appreciate their call for statistical methodologists to participate in the construct of guidelines documents. Too often we call for “subject matter experts” to write these documents, which of course only serves to increase the impact of “expert opinion” which, despite our appetite, sits at the bottom of the aforementioned evidence pyramid. Methodologic Considerations on Four Cardiovascular Interventions Trials With Contradictory ResultsThe Annals of Thoracic SurgeryVol. 111Issue 2PreviewContradictory findings from randomized trials addressing similar research questions are not uncommon in medicine. Although differing results may reflect true differences in the treatment effects or in the deliverability of the intervention, more commonly it is as a consequence of small but important discrepancies in study design. Full-Text PDF

Multi-arterial and total-arterial coronary revascularization: Past, present, and future perspective.

Although abundant biological, clinical, and scientific evidence exists on the superiority of multi-arterial (MAR) and total-arterial revascularization (TAR) over the conventional strategy with a single internal thoracic artery, only 10% of patients undergoing coronary artery bypass grafting (CABG) in the United States receives a second arterial conduit, and only 5% of patients receives TAR. In January 2020, the authors performed comprehensive search to identify studies that evaluated MAR and TAR strategies through the MEDLINE database. In this paper, the authors reviewed the literature on the historical and current evidence in favor of MAR and TAR, thus underlying why current CABG practice needs qualitative improvement.

Bilateral internal thoracic artery grafting in patients with left main disease: a single-center experience.

We compared early and long-term outcomes between bilateral internal thoracic artery (BITA) grafting and single internal thoracic artery (SITA) grafting in patients with LM disease. We evaluated the outcomes of all patients with LM disease who underwent revascularization in our center during 1996-2011. Variables that were adjusted for in a multivariate analysis and in propensity matching included age, sex, comorbid diseases, repeat operation, the number of diseased vessels, other conduits used, the use of sequential grafting, the number of grafts constructed, and the operative era (1996-2000 vs. 2001-2011). In total, 949 patients with LM disease underwent BITA grafting and 564 underwent SITA grafting during the study period. SITA patients were more often female and more likely to have comorbidities such as chronic obstructive pulmonary disease, ejection fraction <30%, recent myocardial infarction, diabetes, congestive heart failure, chronic renal failure, and peripheral vascular disease, and to have undergone an emergency operation. We found no statistically significant difference between the SITA and BITA groups in 30-day mortality (4.8% vs. 3.3%, P = 0.136), sternal wound infection (2.0% vs. 2.4%, P = 0.548), and stroke (3.2% vs. 4.4%, P = 0.234). BITA patients had improved long-term survival (70.1% vs. 52.0% p<0.001), median follow-up of 15 years. In multivariate analysis, after propensity score matching (477 matched pairs), this finding was not statistically significant (P = 0.135). This study did not demonstrate a clear benefit of BITA grafts among patients with LM disease.

Effect of total arterial grafting in the Arterial Revascularization Trial

ObjectivesThe Arterial Revascularization Trial (ART) was designed to compare 10-year survival in bilateral versus single internal thoracic artery grafts. The intention-to-treat analysis has showed comparable outcomes between the 2 groups but an explanatory analysis suggested that those receiving 2 or more arterial grafts had better survival. Whether the exclusive use of arterial grafts provide further benefit is unclear. MethodsWe performed an exploratory analysis of the ART based on conduits actually received (as-treated principle). From ART cohort, only patients receiving at least 3 grafts were included. The final population consisted of 1084, 1010, and 390 patients in the single arterial graft (SAG) group, in the multiple arterial graft (MAG) group (2 or more arterial grafts with additional saphenous veins) and total arterial graft (TAG) group (3 or more arterial grafts only) respectively. Inverse probability of treatment weighting was used for comparison. ResultsWhen compared with the SAG group, there was a significant trend toward a reduction of 10-year mortality in the MAG and TAG group (test for trend P = .02). The TAG group was associated with the lowest risk of late mortality (hazard ratio, 0.68; 95% confidence interval, 0.48-0.96; P = .03) and with a significant risk reduction of the composite of death/myocardial infarction/stroke and repeat revascularization (hazard ratio, 0.71; 95% confidence interval, 0.53-0.94; P = .02). ConclusionsWhen compared with SAG, both MAG and TAG represent valuable strategies to improve clinical outcomes following coronary artery bypass grafting but TAG can potentially provide further benefit.

Quality of life in patients after coronary artery bypass grafting with bilateral internal thoracic artery versus single internal thoracic artery.

IntroductionThe left internal thoracic artery to the left anterior descending artery graft is recognized as the gold standard for coronary revascularization. We compared quality of life (QoL) in patients who received bilateral internal thoracic arteries (BITA) and those with a single internal thoracic artery (SITA) graft.AimTo assess QoL during a 10-year follow-up in patients who underwent coronary artery bypass grafting (CABG) with BITA vs. SITA.Material and methodsWe recruited 300 patients with multivessel coronary artery disease who underwent CABG from January 2005 to October 2010. Mean duration (standard deviation – SD) of follow-up was 3568 ±409 days. QoL was measured subjectively using a Likert scale and objectively by the WHOQOL-BREF questionnaire. Patients were interviewed by telephone.ResultsBITA patients reported marked improvement and improvement more often than SITA patients (58% vs. 43.3%, p = 0.02). Marked deterioration was noted by 2% of BITA patients and 3.3% of SITA patients (p = 0.03). Summarized results of the WHOQOL-BREF questionnaire showed significantly better QoL in the BITA group (median: 15.0) vs. SITA group (median: 14.75) (p = 0.02). There were more angina-free patients in the BITA group (84%) compared to SITA patients (72.7%) (p = 0.006). QoL did not correlate with patients’ body mass index (p = 0.10) or residence status (p = 0.51), but there was a weak negative correlation between QoL and patients’ age (r = –0.14, p = 0.01).ConclusionsSurgical coronary revascularization using BITA improves QoL, particularly when measured by a Likert scale.

Bilateral versus single internal thoracic artery grafting in hemodialysis patients.

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. 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. 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). 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.

A simple-to-use nomogram to predict long term survival of patients undergoing coronary artery bypass grafting (CABG) using bilateral internal thoracic artery grafting technique.

BackgroundSeveral risk scores have been created to predict long term mortality after coronary artery bypass grafting (CABG). Several studies demonstrated a reduction in long-term mortality following bilateral internal thoracic arteries (BITA) compared to single internal thoracic artery. However, these prediction models usually referred to long term survival as survival of up to 5 years. Moreover, none of these models were built specifically for operation incorporating BITA grafting.MethodsA historical cohort study of all patients who underwent isolated BITA grafting between 1996 and 2011 at Tel-Aviv Sourasky medical center, a tertiary referral university affiliated medical center with a 24-bed cardio-thoracic surgery department. Study population (N = 2,935) was randomly divided into 2 groups: learning group which was used to build the prediction model and validation group. Cox regression was used to predict death using pre-procedural risk factors (demographic data, patient comorbidities, cardiac characteristics and patient's status). The accuracy (discrimination and calibration) of the prediction model was evaluated.Methods and findingsThe learning (1,468 patients) and validation (1,467 patients) groups had similar preoperative characteristics and similar survival. Older age, diabetes mellitus, chronic obstructive lung disease, congestive heart failure, chronic renal failure, old MI, ejection fraction ≤30%, pre-operative use of intra-aortic balloon, and peripheral vascular disease, were significant predictors of mortality and were used to build the prediction model. The area under the ROC curves for 5, 10, and 15-year survival ranged between 0.742 and 0.762 for the learning group and between 0.766 and 0.770 for the validation group. The prediction model showed good calibration performance in both groups. A nomogram was built in order to introduce a simple-to-use tool for prediction of 5, 10, and 15-year survival.ConclusionsA simple-to-use validated model can be used for a prediction of 5, 10, and 15-year mortality after CABG using the BITA grafting technique.

Arterial Grafts for Coronary Bypass: A Critical Review After the Publication of ART and RADIAL.

Observational and randomized evidence shows that arterial grafts have better patency rates than saphenous vein grafts (SVGs) in coronary artery bypass grafting. Observational studies suggest that the use of multiple arterial grafts is associated with longer postoperative survival, but this must be interpreted in the context of treatment allocation bias and hidden confounders intrinsic to the study designs. Recently, a pooled analysis of 6 randomized trials comparing the radial artery with the SVG as the second conduit and the largest randomized trial comparing the use of single and bilateral internal thoracic arteries have provided apparently divergent results about a clinical benefit with the use of >1 arterial conduit. However, both analyses have methodological limitations that may have influenced their results. At present, it is unclear whether the well-documented increased patency rate of arterial grafts translates into clinical benefits in the majority of patients undergoing coronary artery bypass grafting. A large randomized trial testing the arterial grafts hypothesis (ROMA [Randomized Comparison of the Clinical Outcome of Single Versus Multiple Arterial Grafts]) is underway and will report the results in a few years.

P4586Bilateral internal thoracic artery grafting neutralizes detrimental effect of diabetes on survival in patients with ischemic cardiomyopathy

Abstract Background In ischemic cardiomyopathy patients requiring coronary artery bypass grafting (CABG), the association of diabetic status with outcomes after surgery as well as survival benefit with bilateral internal thoracic artery (ITA) grafting remain largely unknown. Purpose We evaluated the associations of diabetic status with postoperative LV reverse remodeling, change in renal function, and late outcome following surgical revascularization, with focus on cases with severely impaired LV function. We also attempted to determine the survival benefit of bilateral ITA grafting over single ITA grafting according to diabetic status. Methods We classified 188 patients (mean age 67±9 years) with left ventricular (LV) ejection fraction ≤40% who underwent isolated initial CABG into non-diabetic (n=64), non-insulin-dependent DM (NIDM, n=74), and insulin-dependent DM (IDM, n=50) groups. Results At baseline, there were no differences between the diabetic and non-diabetic patients in terms of age, LV function parameters and degree of coronary artery disease, while the diabetic patients were more likely to present chronic kidney disease and peripheral vascular disease. During follow-up (68±47 months), the 5-year survival rate was 84% and 65% in the non-diabetic and diabetic patients respectively (p=0.034). After adjusting for all covariates, both NIDM and IDM were independently associated with increased mortality (NIDM: adjusted hazard ratio 1.9, 95% confident interval 1.0–3.7, p=0.049; IDM: adjusted hazard ratio 2.4, 95% confident interval 1.2–4.8, p=0.016) and composite adverse events defined as mortality and/or heart failure readmission (NIDM: hazard ratio 1.7, 95% confident interval 1.0–2.8, p=0.038; IDM: hazard ratio 3.0, 95% confident interval 1.7–5.1, p&lt;0.001). Diabetic patients showed less improvements in LV dimensions and ejection fraction (interaction effect p&lt;0.05 for all), and steady decrease in the estimated glomerular filtration rate over time after surgery (group effect p&lt;0.05). Among non-diabetic patients, there was no difference in survival rate between single ITA and bilateral ITA grafting (5-year: 86% vs. 80%, p=0.95), whereas among diabetic patients, survival of those who received the latter was better (57% vs. 81%, p=0.004). Multivariate analysis revealed that use of bilateral ITA was significantly associated with decreased risk of mortality (hazard ratio 0.3, 95% confident interval 0.1–0.8, p=0.024). Conclusion Non-insulin- and insulin-dependent diabetes was significantly associated with worse long-term clinical outcome after CABG for ischemic cardiomyopathy. Bilateral ITA grafting has potential to improve survival in diabetic patients with ischemic cardiomyopathy.

Bilateral internal thoracic artery coronary bypass grafting

The OBJECTIVEof the study was to assess the immediate results of the use of two internal thoracic arteries during coronary bypass surgery.MATERIAL AND METHODS. 200 patients with coronary artery disease underwent coronary artery bypass grafting in Samara cardiology dispensary from 2016 to 2018. Patients were divided into 2 groups. Group 1 (100 people) used both internal thoracic arteries (ITA) and the radial artery as conduits; group 2 (100 people) used the left ITA and the great saphenous vein as conduits. The duration of the operation, complications in the early postoperative period, and hospital mortality were evaluated.RESULTS. Groups (1 – 73 % of men, average age (59±12) years, average number of conduits – (3.1±0.4), 2 – 62 % of men, average age (67±7) years, average number of conduits – (3.3±0.6)) were significantly different only in age. The average duration of the operation in the group 1 was (174±25) min, in 2 – (165±18) min (p&lt;0.05). Hospital mortality in the group 1 – 0 %, in 2 – 1 % (p&gt;0.05). The number of complications in the early postoperative period did not have a statistically significant difference between the groups.CONCLUSION. Bilateral internal thoracic arteries coronary artery bypass grafting in CHD patients did not lead to a significant increase in the duration of the operation, an increase in mortality and infectious complications from the sternum, compared with single internal thoracic arteries grafting.

Has Arterial Revascularization Trial [ART] burst the BITA bubble?

The 10-year outcome of the Arterial Revascularization Trial (ART) has recently been published. The study is the largest randomized study comparing bilateral internal thoracic artery (BITA) with single internal thoracic artery (SITA) as a grafting strategy for coronary artery bypass. In this review, a critical appraisal of the study has been performed where the result of the trial has been discussed along with the risk of sternal wound infections, the presence of a learning curve, and the influence of volume on outcomes. The influence of BITA grafting on other aspects like influence on hospital stay and quality of life outcomes has also been discussed.

Are two internal thoracic grafts better than one? An analysis of 5301 cases.

Although bilateral internal thoracic artery (BITA) grafting is associated with improved survival, many surgeons are reluctant to use this technique due to its greater complexity and the potentially increased risk of sternal infection. This observational study examined if BITA grafting provides improved outcomes compared with single internal thoracic artery (SITA) grafting in patients with multivessel coronary disease. Patients in our institution who underwent BITA grafting during 1996-2011 were compared to those who underwent SITA grafting during the same period. To adjust for differences in demographic and clinical characteristics, patients were matched by propensity score. The Cox model was used to identify predictors of decreased survival and the Kaplan-Meier analysis was performed, both for the entire cohort and for the matched cohort. SITA patients were older than BITA patients, included more females, and were more likely to have chronic obstructive lung disease, an ejection fraction <30%, diabetes, renal insufficiency, peripheral vascular disease and emergency and repeat operations. Three-vessel and left main diseases were more common among BITA patients, and operative mortality was reduced (2.1% vs 3.6% for SITA, P = 0.002). Sternal infection and stroke rates were similar for the groups. Ten-year Kaplan-Meier survival of BITA patients was better (71.2% vs 56.8%, respectively, P < 0.001). BITA grafting was found to be a predictor of better survival in the analysis of the matched cohort (P < 0.001). Our results support the routine use of BITA grafting in patients who undergo myocardial revascularization.

Bilateral internal thoracic artery versus single internal thoracic artery: a meta-analysis of propensity score-matched observational studies.

The lack of benefit in terms of mid-term survival and the increase in the risk of sternal wound complications published in a recent randomized controlled trial have raised concerns about the use of bilateral internal thoracic artery (BITA) in myocardial revascularization surgery. For this reason, we decided to explore the current evidence available on the subject by carrying out a meta-analysis of propensity score-matched studies comparing BITA versus single internal thoracic artery (SITA). PubMed, EMBASE and Google Scholar were searched for propensity score-matched studies comparing BITA versus SITA. The generic inverse variance method was used to compute the combined hazard ratio (HR) of long-term mortality. The DerSimonian and Laird method was used to compute the combined risk ratio of 30-day mortality, deep sternal wound infection and reoperation for bleeding. Forty-five BITA versus SITA matched populations were included. Meta-analysis showed a significant benefit in terms of long-term survival in favour of the BITA group [HR 0.78; 95% confidence interval (CI) 0.71-0.86]. These results were consistent with those obtained by a pooled analysis of the matched populations comprising patients with diabetes (HR 0.65; 95% CI 0.43-0.99). When compared with the use of SITA plus radial artery, BITA did not show any significant benefit in terms of long-term survival (HR 0.86; 95% CI 0.69-1.07). No differences between BITA and SITA groups were detected in terms of 30-day mortality or in terms of reoperation for bleeding. Compared with the SITA group, patients in the BITA group had a significantly higher risk of deep sternal wound infection (risk ratio 1.66; 95% CI 1.41-1.95) even when the pooled analysis was limited to matched populations in which BITA was harvested according to the skeletonization technique (risk ratio 1.37; 95% CI 1.04-1.79). The use of BITA provided a long-term survival benefit compared with the use of SITA at the expense of a higher risk of sternal deep wound infection. The long-term survival advantage of BITA is undetectable when compared with SITA plus radial artery.