Bilateral Internal Thoracic Artery Research Articles

Bilateral internal thoracic artery grafting in children under 5 years of age with Kawasaki disease: a case series.

BackgroundAlthough persistent coronary artery aneurysm of Kawasaki disease (KD) is rare, some patients develop a life-threatening myocardial infarction. In paediatric coronary artery bypass surgery (PCABS), the internal thoracic artery (ITA) graft is a reliable graft with favourable coronary outcomes. However, few studies have reported the outcomes and technical considerations of PCABS using bilateral ITAs in small children who have multivessel disease.Case summaryWe present the cases of three children under 5 years of age who underwent PCABS utilizing bilateral ITAs. All three patients had known bilateral giant coronary aneurysms associated with KD. Paediatric coronary artery bypass surgery was indicated after confirming multiple coronary lesions with myocardial ischaemia. One child underwent emergency PCABS because of circulatory collapse. The arterial anastomoses were performed under cardioplegic arrest. The left ITA was anastomosed to the left anterior descending artery (LAD) or the circumflex artery. The right ITA was anastomosed to the right coronary artery or the LAD. Post-operative coronary angiography revealed patent bilateral ITA grafts with an excellent run-off in all patients, and none of them have suffered any subsequent coronary event.DiscussionBilateral ITA grafting is a feasible procedure with favourable coronary outcomes for treating small children with multivessel disease, even in the setting of circulatory collapse.

Abstract 14915: Incidence, Predictors and Clinical Impact of Left Ventricular Functional Recovery Following Coronary Artery Bypass Grafting in Patients With Ischemic Cardiomyopathy

Introduction: CABG is considered the standard treatment for patients with ischemic cardiomyopathy (ICM). However, it remains unknown who would achieve postoperative LV function recovery after CABG. Furthermore, the relationship of postoperative LV function recovery with long-term outcomes remains unclear. Hypothesis: In patients with ICM who undergo CABG, postoperative LV function recovery, which would be influenced by degree of LV remodeling at baseline, is associated with improved outcomes. Methods: This multicenter retrospective study comprised 490 cases with LVEF of ≤40% who underwent CABG between 1993 and 2015. Clinical follow-up was completed in 467 cases (95%), with a mean follow-up of 65±46 months (range, 0-266). A total of postoperative echocardiographic assessments were carried with an average number of 3.7±2.4. LV function recovery was defined as LVEF ≥35% at more than one exam. Association of LV function recovery with mortality after adjustments for clinically relevant covariates was estimated using Cox proportional hazard model. Pre- and intraoperative associates of LV function recovery were identified using logistic regression model. Results: During follow-up, there were 203 mortalities (41%) and overall 10-year survival was 45%. LV function recovery was found in 368 cases (75%), while not in 122 (25%). Overall 10-year survival was significantly higher in patients who achieved LV function recovery as compared with those who did not achieve it (52% vs. 23%). Multivariate analysis identified LV function recovery was independently associated with decreased overall mortality (adjusted HR 0.40, p<0.0001). Preoperative LVDs (adjusted OR 0.92, p<0.0001), eGFR (adjusted OR 1.12, p=0.016) and revascularization using bilateral internal thoracic arteries (BITA) (adjusted OR 2.81, p=0.018) are the independent predictors of LV function recovery. Conclusions: Among patients with ICM who underwent CABG, 75% achieved substantial postoperative LV function recovery, in association with better long-term survival, as compared with the remaining 25% of patients who did not achieve it. Preoperative less LV remodeling and preserved renal function as well as revascularization with use of BITA might be associated with LV function recovery.

Quality Improvement: Arterial Grafting Redux, 2010:2019

The evidence base favoring utilization of multiple arterial conduits in coronary artery bypass grafting has strengthened in recent years. Nevertheless, utilization of arterial conduits in the US lags behind that of many European peers. We describe a statewide collaborative based approach to improving utilization. Four metrics of arterial revascularization were devised. These were displayed and discussed at quarterly statewide quality collaborative meetings from January 2016 onwards, integrated with an educational program regarding attendant benefits. We undertook retrospective review of isolated coronary artery bypass grafting statewide from 2012-2019 to assess impact. A total of 38,523 cases met inclusion/exclusion criteria. Statewide incidence of multiple arterial grafting increased from 7.4% at baseline to 21.7% in 2019 (P < .001), implementation across hospitals varied widely, ranging from 67.6% to 0.0%. Utilization of total arterial revascularization increased 1.9% to 4.4% (P < .001) between time frames. Utilization of both radial artery and bilateral internal thoracic artery conduit increased significantly from 5.3% to 13.2% (P < .001) and 2.1% to 8.5% (P < .001), respectively; radial artery utilization was significantly higher than bilateral internal thoracic artery for each year (P < .001 for all comparisons). Our statewide quality improvement initiative improved rates of utilization of multiple arterial grafting by all metrics. Barriers to current utilization were identified to guide future quality improvement efforts. This reproducible approach is readily transferable to improve quality of care in other domains and geographical areas.

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&amp;lt;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.

Open-Repair Surgery for Pectus Excavatum to Preserve Internal Thoracic Artery (ITA)

Pectus excavatum has been performed using techniques such as sternum elevation and sternum reversal; however, the Nuss method is now widely used. The Nuss method is considered less invasive, but it requires a plate. We have performed open-repair surgery that can be completed at once without using a plate as a standard procedure. Conversely, the usefulness of the internal thoracic artery (ITA) in coronary artery bypass surgery and breast reconstruction has increased in recent years. Therefore, since 2017, we changed the surgical procedure to preserve the ITA; here, we mainly report on the surgical procedure. Five patients, four boys and one girl, were examined for in Haller index, operation time, blood loss, postoperative complications, and postoperative hospital stay. Among the five cases, before the change of surgical procedure, the operation time, blood loss, and hospitalization period postoperatively were not significantly different from those before the change. Bilateral ITA could be preserved except in one patient in whom one side was damaged and ligated during the operation. No postoperative complications were observed in all cases. It is possible to preserve the ITA, and we intend to perform additional studies to evaluate its long-term effectiveness.

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.

Primary isolated CABG restrictive blood transfusion protocol reduces transfusions and length of stay.

Cardiac surgery accounts for 10-15% of blood transfusions in the US, despite benefits and calls of limiting its use. We sought to evaluate the impact of a restrictive transfusion protocol on blood use and clinical outcomes in patients undergoing isolated primary coronary artery bypass grafting (CABG). Blood conservation measures, instituted in 2012, include preoperative optimization, intraoperative anesthesia, and pump fluid restriction with retrograde autologous priming and vacuum-assisted drainage, use of aminocaproic acid and cell saver, intra- and postoperative permissive anemia, and administration of iron and low-dose vasopressors if needed. Medical records of patients who underwent isolated primary CABG from 2009 to 2012 (group A; n = 375) and 2013 to 2016 (group B; n = 322) were compared. CABG with grafting to three or four coronary arteries was performed in 262 (70%) and 222 (69%) patients and bilateral internal thoracic artery grafting in 202 (54%) and 196 (61%) patients in groups A and B, respectively. Mean preoperative and intraoperative hematocrit was 40.3% and 40.7%, 28.9% and 29.4% in groups A and B, respectively. Total blood transfusion was 24% and 6.5%, intraoperative transfusion 11% and 1.2%, and postoperative transfusion 20% and 5.6% (P < .0001 for all) in groups A and B, respectively. Median postoperative length of stay was 5.0 days in group A and 4.5 days in group B (P = .02), with no significant differences in mortality or morbidity. A restrictive transfusion protocol reduced blood transfusions and postoperative length of stay without adversely affecting outcomes following isolated primary CABG.

Bilateral internal thoracic artery grafting in coronary surgery: 10-year outcomes

Abstract Background The advantages to use the bilateral internal thoracic artery grafting (BITA) technique for coronary artery bypass grafting (CABG) have been recently questioned, but data on long-term follow-up is limited. Using data from the PRIORITY project, this study aims to assess the outcome with the use of BITA grafting and its implications for public health. Methods The PRIORITY project was planned to evaluate the long-term outcomes of two prospective multicenter studies on CABG conducted between 2002-2004 and 2007-2008. Data on isolated CABG were linked to administrative data in order to retrieve patients' late outcome. Time-to-event distributions were analyzed accordingly to primary event-type (death, major adverse cardiac events (MACEs)) using the Kaplan-Meier and the Cox proportional hazards methods. Results The study population consisted of 11021 patients who underwent isolated CABG. BITA grafting was employed in 24.6% of patients. The median follow-up time was 8.0 years (interquartile range 7.6-10.0 years). After adjustment for potential confounding factors, BITA grafting was significantly associated with better survival (HR 0.85, 95%CI 0.76-0.95, p = 0.003). Moreover, using BITA grafting reduced the incidence of MACE (HR 0.87, 95%CI 0.80-0.94, p = 0.001), showing to be a protective factor for recurrent acute myocardial infarction (HR 0.84, 95%CI 0.71-0.99, p = 0.05) and for rehospitalization for percutaneous cardiac intervention (HR 0.82, 95%CI 0.70-0.96, p = 0.013). Conclusions BITA grafting during isolated CABG is associated with survival advantage at 10-year with a significantly reduced incidence of MACE. Being the choice to perform isolated CABG with or without BITA based mainly on operator personal preferences, these findings may have important implications from a public health perspective. Key messages The choice to perform CABG with or without BITA grafting is associated to different outcomes. The choice to perform CABG with or without BITA grafting is mainly based on operator preferences and may have important implications in terms of healthcare expenditures.

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.

Feasibility of bilateral internal thoracic artery harvesting using the da Vinci SP system.

We conducted this study to investigate the feasibility of mobilizing the bilateral internal thoracic arteries (ITAs) using the da Vinci SP through a single intercostal incision and to compare the amount of rib spreading with that required for mini-thoracotomy procedures. We also evaluated the construction of an intrathoracic T-graft anastomosis using existing instrumentation of the SP system. We harvested bilateral ITAs from two male cadavers via a single incision made in the fifth intercostal space using the da Vinci SP. A T-graft end-to-side anastomosis was created in one cadaver. The bilateral ITAs were harvested in less than 60min and a T-graft was completed. No additional rib spreading was required. Intraoperative adjustments of the da Vinci SP were necessary to maintain alignment with the surgical targets. Bilateral ITA harvest using the da Vinci SP through a single intercostal incision was feasible, with less rib spreading than in mini-thoracotomy procedures. Thus, creating an intrathoracic T-graft with the existing da Vinci SP instruments is possible.

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.

Effect of Skeletonization of Bilateral Internal Thoracic Arteries on Deep Sternal Wound Infections

Bilateral internal thoracic arteries (BITA) coronary bypass grafting may improve long-term outcomes but is associated with increased deep sternal wound infections (DSWIs). We analyzed whether BITA skeletonization impacts DSWIs and operative mortality (OM) using The Society of Thoracic Surgeons Adult Cardiac Surgery Database. Primary, isolated, nonemergent/nonsalvage BITA patients (July 2017 to December 2018) in The Society of Thoracic Surgeons Adult Cardiac Surgery Database were divided into groups based on BITA harvesting technique: both skeletonized (ssBITA) and ≥1 nonskeletonized (Non-ssBITA). DSWI and OM observed-to-expected (O/E) ratios were compared using The Society of Thoracic Surgeons Perioperative Risk Models. ssBITA versus Non-ssBITA DSWI and OM adjusted odds ratios were calculated by multivariable logistic regression and corroborated by propensity score matching. We analyzed 11,269 patients (42.8% ssBITA, 57.2% Non-ssBITA, 770 hospitals, 1448 surgeons). The ssBITA group had a higher incidence of comorbidities and off-pump surgery. Overall incidences of DSWIs and OM were 0.98% (O/E ratio, 5.1) and 1.72% (O/E ratio, 1.4), respectively, and were 28% (P= .129) and 23% (P= .096) lower in ssBITA. The DSWI O/E ratio was highest (5.9) in Non-ssBITA and lowest in ss-BITA (4.1). After multivariable adjustment, ssBITA was associated with a decreased risk of DSWIs (adjusted odds ratio, 0.66; 95% confidence interval, 0.44-1.00; P= .05), with no difference in OM. These results were confirmed among 3884 propensity score-matched pairs. DSWIs increased sharply with increasing number of risk factors for DSWIs regardless of harvesting technique, with a trend for higher DSWIs among Non-ssBITA for all risk categories. The observed high O/E ratio indicates that BITA grafting is associated with increased risk of DSWIs. Risk-adjusted DSWI rate and a lower O/E ratio in ssBITA support the protective role of skeletonization.

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

Right or Left Internal Thoracic Artery to the Left Anterior Descending Artery: Informed Choice or Flip a Coin

Neither of the two seminal coronary artery bypass grafting studies from the Cleveland Clinic that established the superiority of the internal thoracic artery (ITA) grafts over saphenous veins specified which ITA was used to bypass the left anterior descending artery (LAD).1,2 However, the in situ left ITA (LITA) to the LAD was the most popular configuration based on comments made by the authors and their direct feedback. The Society of Thoracic Surgeons guidelines encourage the use of bilateral ITA (BITA) grafting and leaves the options open when it comes to choosing which ITA to use for bypassing the LAD.

Optimal Configuration for Bypass of the Left Anterior Descending Artery During Bilateral Internal Thoracic Artery Grafting

The left internal thoracic artery (LITA) to left anterior descending (LAD) artery bypass remains the reference standard for coronary artery bypass graft surgery. With the advent of bilateral internal thoracic artery (BITA) grafting, optimal bypass configuration to the LAD is unclear. The objective of this study was to compare clinical outcomes between LITA-LAD and right internal thoracic artery (RITA)-LAD configurations in BITA grafting. The primary outcome was the need for percutaneous or surgical reintervention of the LAD. Secondary outcomes included all-cause mortality and cardiac mortality. Cox proportional hazard and competing risk models were used with entropy weighting. Among BITA patients, 1527 had LITA-LAD grafts, and 523 RITA-LAD. Before entropy weighting, RITA-LAD patients were older with more diabetes, peripheral vascular disease, and left ventricular dysfunction, more urgent status (P < .05), and more frequently performed off-pump (P < .001). Need for repeat revascularization of the LAD territory at 10 years was 2.8% in the LITA-LAD group and 1.8% in the RITA-LAD group (subhazard ratio= 0.686; 95% confidence interval [CI], 0.296-1.589; P= .38). Adjusted survival at 10 years was 97.2% in the LITA-LAD group and 98.2% in the RITA-LAD group (hazard ratio= 1.056; 95% CI, 0.677-1.647; P= .81). There was no difference in cardiac mortality (subhazard ratio= 1.063; 95% CI, 0.502-2.251; P= .87). Use of either LITA or RITA for LAD grafting during BITA revascularization has no effect on long-term all-cause or cardiac mortality or need for repeat revascularization of the LAD. Cardiac surgeons should be confident in using a RITA-LAD bypass during BITA grafting.

Surgical strategies and long-term outcomes of total arterial coronary artery bypass grafting: a series of 208 patients

Objective: To examine the short and long-term clinical outcomes of total arterial coronary artery bypass grafting. Methods: Clinic data of 208 patients with left main and multiple vessel coronary artery disease and undertaken total arterial coronary artery bypass grafting from February 2009 to December 2019 in Department of Cardiac Surgery, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine were analyzed retrospectively. There were 188 males and 20 females with an age of (54.7±10.7) years (range: 32 to 79 years). The harvest of arterial conduits and grafting strategies were depended upon the individual patient characteristics and surgeon's experience. Left internal thoracic artery (LITA) was applied in 207 cases, right internal thoracic artery (RITA) in 38 cases (bilateral internal thoracic artery (BITA) in 37 cases), and radial artery (RA) in 187 cases (188 grafts). The graft number per case was 2.6±0.7 (range: 2 to 4). Surgical procedures was completed with off-pump technique in 98.1% patients (204/208). Subgroup analysis was carried out between subgroup BITA (n=37) and subgroup SITA (single ITA+RA) (n=171). The t test, χ(2) test or Fisher exact test were used to compare the clinic characteristics between the two subgroups. The Kaplan-Meier curve was used to estimate the rate of late mortality, major adverse cardiac cerebrovascular event (MACCE), and target vessel revascularization (TVR). A Cox proportional hazards model was used to identify the independent prognosis factors of late mortality. Results: The overall mortality within 30 days postoperatively was 1.4%(3/208). The incidences of perioperative MACCE, re-operation for bleeding and deep sternal wound infection (DSWI) were 1.9%(4/208), 0.5%(1/208) and 1.4%(3/208), respectively. Perioperative myocardial infarction and TVR were not observed. There was no significant difference of 30-day mortality, MACCE, bleeding and DSWI between subgroup BITA and SITA+RA (all P>0.05). In a follow-up period of (5.4±2.8)years (range: 0.2 to 10.9 years), the incidence of all-cause mortality at 1-, 5- and 10-year was 2.3%, 3.4% and 6.9%, respectively. The incidence of MACCE was 3.9%,11.2% and 28.5%, respectively. The rate of TVR was 0.4%, 3.7% and 11.9%, respectively. Age>65 was an independent prognosis factor of late mortality (HR=1.125, 95% CI:1.050 to 1.205, P<0.01). Conclusions: Total arterial coronary bypass grafting is safe and achievable with proper patient selection and surgical strategies. It significantly decreases the risks of late mortality and repeated revascularization.

Minimally invasive coronary bypass surgery with bilateral internal thoracic arteries: Early outcomes and angiographic patency

ObjectiveMultivessel minimally invasive coronary artery bypass grafting, performed chiefly with left internal thoracic artery and saphenous vein grafts through a left anterolateral thoracotomy, has recently emerged as an alternative to conventional coronary artery bypass grafting. The present study involves our initial experience with respect to early postoperative and angiographic outcomes after total arterial multivessel off-pump minimally invasive coronary artery bypass grafting with bilateral internal thoracic arteries. MethodsA total of 88 consecutive patients undergoing total arterial off-pump minimally invasive coronary artery bypass grafting with bilateral internal thoracic arteries without ascending aortic manipulation were included in this study. Bilateral internal thoracic arteries were harvested under direct vision through a left anterolateral thoracotomy and used as Y or in situ grafts. Multivessel grafting was performed off pump. Postoperative graft assessment was performed in 51 patients. ResultsThe mean age of patients was 67.1 ± 7.2 years, and 79 patients (89.8%) were male. The mean body mass index and ejection fraction were 26.7 ± 2.7 kg/m2 and 57.6% ± 6.6%, respectively, and 40 patients (45.5%) had left main disease. No intraoperative conversions to cardiopulmonary bypass or sternotomy occurred. A total of 209 distal anastomoses (mean 2.4 ± 0.5) were performed, with 57 patients undergoing double, 29 patients undergoing triple, and 2 patients undergoing quadruple coronary artery bypass grafting. There was no in-hospital mortality, and 5 patients underwent reexploration for bleeding. No patient had stroke or chest wound infections. Predischarge coronary angiography revealed an overall graft patency rate of 96.8%. ConclusionsOff-pump minimally invasive coronary artery bypass grafting using total arterial revascularization with bilateral internal thoracic arteries is a feasible and safe operation that is associated with excellent short-term outcomes and early graft patency. Future studies should focus on improving the generalizability and reproducibility of this technique.