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Background: Contradictory 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., Methods: The writing group selected 4 recent trials with apparently contradictory results (2 on revascularization for left main coronary stenosis and 2 on treatment of secondary mitral regurgitation). Detailed methodologic analysis was performed to elucidate the difference in findings., Results: Differences in the definition of the primary outcome are the most likely explanation for the contradictory findings of NOBLE versus EXCEL. Differences in study design (leading to substantially different patient populations) and in outcome definition might explain the discrepant findings of MITRA-FR versus COAPT., Conclusions: As shown by the comparative analysis of NOBLE and EXCEL and MITRA-FR and COAPT, changes in study design, outcome definitions, and patient population can markedly affect the outcome of randomized clinical trials., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: We used a large patient-level data set including 6 angiographic randomized controlled trials (RCTs) on coronary artery bypass conduits to explore incidence and determinants of coronary graft failure., Methods: Patient-level angiographic data of 6 RCTs comparing long-term outcomes of the radial artery and other conduits were joined. Primary outcome was graft occlusion at maximum follow-up. The analysis was divided as (1) left anterior descending coronary (LAD) distribution and (2) non-LAD distribution (circumflex and right coronary artery). Mixed-model multivariable Cox regression including all baseline characteristics with stratification by individual trials was used to identify predictors of graft occlusion., Results: Included were 1091 patients and 2281 grafts, consisting of 921 left internal mammary arteries, 74 right internal mammary arteries, 710 radial arteries, and 576 saphenous veins. All left internal mammary arteries were used on the LAD, the other conduits were used on the non-LAD distribution. Mean angiographic follow up was 65 ± 29 months. Occlusion rates were 2.3% for the left internal mammary arteries, 13.5% for the left internal mammary arteries, 9.4% for the right internal mammary arteries, and 17.5% for the saphenous veins. At multivariable analysis, type of conduit used, age, female sex, left ventricular ejection fraction of less than 0.50, and use of the Y graft were significantly associated with graft occlusion in the non-LAD distribution., Conclusions: Our analyses showed that failure of the left internal mammary arteries-to-LAD bypass is a very uncommon event. For the non-LAD distribution, the nonuse of radial artery, age, female sex, left ventricular ejection fraction of less than 0.50, and use of the Y graft configuration were significantly associated with midterm graft failure., (Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to investigate the incidence and impact on mortality of repeat revascularization after index percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for left main coronary artery disease (LMCAD)., Background: The impact on mortality of the need of repeat revascularization following PCI or CABG in patients with unprotected LMCAD is unknown., Methods: All patients with LMCAD and site-assessed low or intermediate SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) scores randomized to PCI (n = 948) or CABG (n = 957) in the EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial were included. Repeat revascularization events were adjudicated by an independent clinical events committee. The effect of repeat revascularization on mortality through 3-year follow-up was examined in time-varying Cox regression models., Results: During 3-year follow-up, there were 346 repeat revascularization procedures among 185 patients. PCI was associated with higher rates of any repeat revascularization (12.9% vs. 7.6%; hazard ratio: 1.73; 95% confidence interval: 1.28 to 2.33; p = 0.0003). Need for repeat revascularization was independently associated with increased risk for 3-year all-cause mortality (adjusted hazard ratio: 2.05; 95% confidence interval: 1.13 to 3.70; p = 0.02) and cardiovascular mortality (adjusted hazard ratio: 4.22; 95% confidence interval: 2.10 to 8.48; p < 0.0001) consistently after both PCI and CABG (p int  = 0.85 for both endpoints). Although target vessel revascularization and target lesion revascularization were both associated with an increased risk for mortality, target vessel non-target lesion revascularization and non-target vessel revascularization were not., Conclusions: In the EXCEL trial, repeat revascularization during follow-up was performed less frequently after CABG than PCI and was associated with increased mortality after both procedures. Reducing the need for repeat revascularization may further improve long-term survival after percutaneous or surgical treatment of LMCAD. (EXCEL Clinical Trial; NCT01205776)., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Despite the progressive expansion of clinical indications for percutaneous coronary intervention and the increasingly high risk profile of referred patients, coronary artery bypass grafting (CABG) remains the mainstay in multivessel disease, providing good long-term outcomes with low complication rates. Multiple arterial grafting, especially if associated with anaortic techniques, might provide the best longer-term outcomes. A surgical approach individualized to the patients' clinical and anatomic characteristics, and surgeon and team experience, are key to excellent outcomes. Current evidence regarding patient selection, indications, graft selection, and potential strategies to optimize outcomes in patients treated with CABG is summarized., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to determine whether high-risk patients with left main coronary artery disease (LMCAD) and prior cerebrovascular disease (CEVD) preferentially benefit from revascularization by percutaneous coronary intervention (PCI) compared with coronary artery bypass grafting (CABG)., Background: Patients with known CEVD requiring revascularization are often referred to PCI rather than CABG. There is a paucity of data regarding the impact of CEVD in patients with LMCAD undergoing revascularization., Methods: In the EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial, patients with LMCAD and low or intermediate SYNTAX (Synergy Between PCI with Taxus and Cardiac Surgery) scores were randomized to PCI with everolimus-eluting stents versus CABG. The effects of prior CEVD, defined as prior stroke, transient ischemic attack, or carotid artery disease, on 30-day and 3-year event rates were assessed., Results: Prior CEVD was present in 233 of 1,898 patients (12.3%). These patients were older and had higher rates of comorbidities, including hypertension, diabetes, peripheral vascular disease, anemia, chronic kidney disease, and prior PCI, compared with those without prior CEVD. Patients with prior CEVD had higher rates of stroke at 30 days (2.2% vs. 0.8%; p = 0.05) and 3 years (6.4% vs. 2.2%; p = 0.0003) and higher 3-year rates of the primary endpoint of all-cause death, stroke, or myocardial infarction (25.0% vs. 13.6%; p < 0.0001). The relative effects of PCI versus CABG on the 30-day and 3-year rates of stroke (p interaction  = 0.65 and 0.16, respectively) and the 3-year rates of the primary composite endpoint (p interaction  = 0.14) were consistent in patients with and those without prior CEVD., Conclusions: Patients with LMCAD and prior CEVD compared with those without CEVD have higher rates of stroke and reduced event-free survival after revascularization. Data from the EXCEL trial do not a priori support a preferential role of PCI over CABG in patients with known CEVD., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Guidelines advocate transit time flowmetry (TTFM) for intraoperative graft patency verification during coronary artery bypass graft surgery (CABG), but studies on accuracy and precision of the TTFM technique are few. In an observational study of CABG patients, we analyzed covariation of left internal mammary artery (LIMA) blood flow with TTFM and free flow measurements., Methods: Covariation of TTFM and free blood flows was evaluated in 60 patients undergoing CABG using the LIMA as one of the conduits. With LIMA flow measurements routinely performed before and after vasodilation, results are based on 120 paired intraoperative measurements., Results: As demonstrated by a combined approach of regression and Bland-Altman analysis for the two flow situations, TTFM was higher than free flow in 64% of measurements, with an overestimation by TTFM of 7.1% ± 16.3% in the overall cohort (prevasodilation), statistically carried by measurements with 4-mm probes (overestimation by 13.3% ± 15.4%, both p < 0.01). In a multiregression analysis, oversizing of the TTFM probe (odds ratio 9.56, 95% confidence interval: 2.03 to 45.10, p = 0.004) and high flows (odds ratio 1.02, 95% confidence interval: 1.01 to 1.04, p < 0.001) were independent determinants of flow overestimation by TTFM, although in the Bland-Altman analysis no systematic overestimation was seen in the postvasodilation situation. In a receiver-operating characteristics analysis, optimal cutoff value as determined from Youden's index for assuming flow overestimation was 68 mL/min., Conclusions: Overall, with slight overall overestimation of 7.1%, TTFM is an accurate indicator of LIMA blood flow during CABG, with a clinically acceptable precision. Overestimation may be expected with flows greater than 68 mL/min, but most importantly, in situations with oversized TTFM probes., (Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objectives: The authors sought to determine the extent to which the site of the left main coronary artery (LM) lesion (distal bifurcation versus ostial/shaft) influences the outcomes of revascularization with percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG)., Background: Among 1,905 patients with LM disease and site-assessed SYNTAX scores of <32 randomized in the EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial, revascularization with PCI and CABG resulted in similar rates of the composite primary endpoint of death, myocardial infarction (MI), or stroke at 3 years., Methods: Outcomes from the randomized EXCEL trial were analyzed according to the presence of angiographic core laboratory-determined diameter stenosis ≥50% involving the distal LM bifurcation (n = 1,559; 84.2%) versus disease isolated to the LM ostium or shaft (n = 293; 15.8%)., Results: At 3 years, there were no significant differences between PCI and CABG for the primary composite endpoint of death, MI, or stroke for treatment of both distal LM bifurcation disease (15.6% vs. 14.9%, odds ratio [OR]: 1.08, 95% confidence interval [CI]: 0.81 to 1.42; p = 0.61) and isolated LM ostial/shaft disease (12.4% vs. 13.5%, OR: 0.90, 95% CI: 0.45 to 1.81; p = 0.77) (p interaction  = 0.65). However, at 3 years, ischemia-driven revascularization occurred more frequently after PCI than CABG in patients with LM distal bifurcation disease (13.0% vs. 7.2%, OR: 2.00, 95% CI: 1.41 to 2.85; p = 0.0001), but were not significantly different in patients with disease only at the LM ostium or shaft (9.7% vs. 8.4%, OR: 1.18, 95% CI: 0.52 to 2.69; p = 0.68) (p interaction  = 0.25)., Conclusions: In the EXCEL trial, PCI and CABG resulted in comparable rates of death, MI, or stroke at 3 years for treatment of LM disease, including those with distal LM bifurcation disease. Repeat revascularization rates during follow-up after PCI compared with CABG were greater for lesions in the distal LM bifurcation but were similar for disease isolated to the LM ostium or shaft., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of the present study was to assess outcomes after coronary artery bypass grafting surgery (CABG) and percutaneous coronary intervention (PCI) according to sex in a large randomized trial of patients with unprotected left main disease., Background: In the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) trial, sex had a significant interaction effect with revascularization strategy, and women had an overall higher mortality when treated with PCI than CABG., Methods: The EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial was a multinational randomized trial that compared PCI with everolimus-eluting stents and CABG in patients with unprotected left main disease. The primary endpoint was the composite of all-cause death, myocardial infarction, or stroke at 3 years., Results: Of 1,905 patients randomized, 1,464 (76.9%) were men and 441 (23.1%) were women. Compared with men, women were older; had higher prevalence rates of hypertension, hyperlipidemia, and diabetes; and were less commonly smokers but had lower coronary anatomic burden and complexity (mean SYNTAX score 24.2 vs. 27.2, p < 0.001). By multivariate analysis, sex was not independently associated with either the primary endpoint (hazard ratio [HR]: 1.10; 95% confidence interval [CI]: 0.82 to 1.48; p = 0.53) or all-cause death (HR: 1.39; 95% CI: 0.92 to 2.10; p = 0.12) at 3 years. At 30 days, all-cause death, myocardial infarction, or stroke had occurred in 8.9% of woman treated with PCI, 6.2% of women treated with CABG, 3.6% of men treated with PCI, and 8.4% of men treated with CABG (p for interaction = 0.003). The 3-year rate of the composite primary endpoint was 19.7% in women treated with PCI, 14.6% in women treated with CABG, 13.8% in men treated with PCI, and 14.7% in men treated with CABG (p for interaction = 0.06). These differences were driven by higher periprocedural rates of myocardial infarction in women after PCI and in men after CABG., Conclusions: In patients with unprotected left main disease in the EXCEL trial, sex was not an independent predictor of adverse outcomes after revascularization. However, women undergoing PCI had a trend toward worse outcomes, a finding related to associated comorbidities and increased periprocedural complications. Further studies are required to determine the optimal revascularization modality in women with complex coronary artery disease., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Totally endoscopic coronary artery bypass (TECAB) has emerged as an alternative to other minimally invasive techniques. However, limited TECAB results are available to date. The purpose of this systematic review is to examine the existing literature to give an objective estimate of the outcomes of TECAB using a meta-analytical approach., Methods: A comprehensive online review was performed in Ovid MEDLINE®, Ovid EMBASE and The Cochrane Library from 2000 to July 2017. Eligible studies included single arm TECAB studies as well as comparative studies (TECAB vs minimally invasive direct coronary artery bypass (MIDCAB)). Pooled event rates and odds ratios (ORs) for operative mortality, perioperative myocardial infarction (MI), perioperative stroke, graft patency and repeat revascularization were estimated. Single arm and pairwise comparisons were performed., Results: Seventeen single arm TECAB articles (3721 patients, weighted mean follow-up 3.3years) were included. The pooled event rate was 0.80% (95%CI: 0.60-1.2%) for operative mortality, 2.28% (95%CI: 1.7-3%) for perioperative MI, 1.50% (95%CI: 1.1-2.0%) for perioperative stroke, 2.99% (95%CI: 1.6-5.4%) for repeat revascularization and 94.8% (95%CI: 89.3-97.5%) for early graft patency (weighted mean follow-up 10.1months). On pairwise meta-analysis 376 patients (263 TECAB and 113 MIDCAB) were included. No difference in operative mortality (OR=0.25, 95%CI: 0.02-2.83), perioperative MI (OR=3.09, 95%CI: 0.37-26.12) or perioperative stroke (OR=1.33, 95%CI: 0.17-10.26) was found between the two techniques., Conclusions: TECAB has an acceptably low operative risk and a good early patency rate. The incidence of perioperative MI requires further investigation. The dearth of data comparing TECAB to open approaches compels the need for future comparative trials., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

Saphenous vein graft (SVG) disease and subsequent vein graft failure remain a major problem after coronary artery bypass graft operations. In an effort to mitigate loss of endothelial viability, the vein is stored, intraoperatively, in a preservation solution. However, human SVG samples demonstrate endothelial denudation and dysfunction after such storage, the severity of which varies, depending on the medium. The paucity of clinical data evaluating preservation solutions is illustrated by the absence of optimal procedural protocol. This review evaluates the potential efficacy of different storage solutions in preserving vein grafts, in relation to a mechanistic understanding of SVG pathophysiology., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Arterial grafts have long-term patency superior to vein grafts but have a tendency to develop spasm that can lead to potentially life-threatening complications. A perfect antispastic protocol should include advanced surgical technique and adequate pharmacologic methods. All pharmacologic vasodilator drugs relax the vessel through specific mechanisms, and therefore, there is no perfect, single best vasodilator to prevent or treat spasm of the arterial graft against all mechanisms of contraction. One of the choices is to use a combination of pharmacologic vasodilators targeting different mechanisms of spasm to obtain the reliable and best effect., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: Current randomized controlled trials (RCTs) comparing percutaneous coronary intervention with drug eluting stent (DES-PCI) with coronary artery bypass grafting (CABG) in multivessel disease are underpowered to detect a difference in hard clinical end-points such as mortality, myocardial infarction and stroke. We aimed to overcome this limitation by conducting a meta-analysis of contemporary RCTs., Methods: A systematic literature search was conducted for all RCTs comparing DES-PCI versus CABG in multivessel disease published through May 2015. Inverse variance weighting was used to pool data from individual studies (<1 favouring DES-PCI and >1 CABG favouring surgery)., Results: A total of five randomized trials including 4563 subjects were analysed. After an average follow-up of 3.4 years, DES-PCI was associated with a significantly increased risk of overall mortality (HR 1.51; 95%CI 1.23-1.84; P<0.001), MI (HR 2.02; 95%CI 1.57-2.58; P<0.001) and repeat revascularization (HR 2.54; 95%CI 2.07-3.11; P=<0.001). CABG marginally increased the risk of stroke (HR 0.70; 95%CI 0.50-0.98; P=0.04). The absolute risk reduction for all-cause mortality (3.3%) and myocardial infarction (4.3%) with CABG was larger than the absolute risk reduction for stroke (0.9%) with DES-PCI., Conclusion: In patients with multivessel coronary disease, CABG was found to be superior to DES-PCI by reducing the risk of mortality and subsequent myocardial infarction at the expense of a marginally increased risk of stroke., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Early and late graft occlusion remains a significant complication of coronary artery bypass grafting. Transit time flowmetry is the most commonly used imaging technique to assess graft patency intraoperatively. Although the value of transit time flowmetry for intraoperative quality control of coronary anastomosis is well established, its standard variables for predicting eventual graft failure remain controversial. This review readdresses the issue of intraoperative transit time flowmetry, with a particular emphasis on defining cutoff values for standard variables and correlating them with the ability to predict midterm and long-term graft patency for arterial and venous conduits. Further research is warranted to support clinically useful recommendations on the intraoperative application and interpretation of transit time flowmetry., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Spasm of arterial grafts in coronary artery bypass grafting surgery is still a clinical problem, and refractory spasm can occasionally be lethal. Perioperative spasm in bypass grafts and coronary arteries has been reported in 0.43% of all coronary artery bypass grafting surgery, but this may be an underestimate. Spasm can develop not only in the internal mammary artery but more frequently in the right gastroepiploic and radial artery. The mechanism of spasm can involve many pathways, particularly those involving regulation of the intracellular calcium concentration. Endothelial dysfunction also plays a role in spasm. Depending on the clinical scenario, the possibility of spasm during and after coronary artery bypass grafting should be confirmed by angiography. If present, immediate intraluminal injection of vasodilators is often effective, although other procedures such as an intraaortic balloon pump or extracorporeal membrane oxygenation may also become necessary to salvage the patient. Prevention of spasm involves many considerations, and the principles are discussed in this review article., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Diabetes mellitus is a significant risk modifier for stable coronary artery disease, causing patients to have more extensive and diffuse lesions. Opposing treatment strategies remain a matter of debate. A multiple database search was conducted and outcomes, lesion, and patient characteristics were compared. Overall mortality, cardiac death, major adverse cardiovascular and cerebrovascular events, and need for revascularization were higher with percutaneous coronary intervention than with coronary artery bypass graft surgery. Multivessel disease and high Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) scores were associated with better outcomes for coronary artery bypass graft surgery., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

The use of internal mammary artery (IMA) grafts for coronary artery bypass may devascularize the sternum. We performed a literature review by searching the PubMed database for studies that assessed sternal perfusion after IMA harvesting. The majority of papers describe various techniques and compared (1) IMA harvest versus no IMA harvest, (2) single versus bilateral, and (3) skeletonized versus pedicled. Evidence is inconclusive as to whether single harvesting causes significant devascularisation and whether this is increased with bilateral harvesting. Sternal ischemia may also be a transient phenomenon. However, skeletonization may preserve perfusion more than pedicled harvesting, particularly in diabetic patients., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: External stents inhibit saphenous vein graft (SVG) intimal hyperplasia in animal studies. We investigated whether external stenting inhibits SVG diffuse intimal hyperplasia 1 year after coronary artery bypass graft surgery., Methods: Thirty patients with multivessel disease undergoing coronary artery bypass graft surgery were enrolled. In addition to an internal mammary artery graft, each patient received one external stent to a single SVG randomly allocated to either the right or left coronary territories; and one or more nonstented SVG served as the control. Graft patency was confirmed at the end of surgery in all patients. The primary endpoint was SVG intimal hyperplasia (mean area) assessed by intravascular ultrasonography at 1 year. Secondary endpoints were SVG failure, ectasia (>50% initial diameter), and overall uniformity as judged by Fitzgibbon classification., Results: One-year follow-up angiography was completed in 29 patients (96.6%). All internal mammary artery grafts were patent. Overall SVG failure rates did not differ significantly between the two groups (30% stented versus 28.2% nonstented SVG, p = 0.55). The SVG mean intimal hyperplasia area, assessed in 43 SVGs, was significantly reduced in the stented group (4.37 ± 1.40 mm(2)) versus nonstented group (5.12 ± 1.35 mm(2), p = 0.04). In addition, stented SVGs demonstrated marginally significant improvement in lumen uniformity (p = 0.08) and less ectasia (6.7% versus 28.2%, p = 0.05). There was some evidence that ligation of side branches with metallic clips increased SVG failure in the stented group., Conclusions: External stenting has the potential to improve SVG lumen uniformity and reduce diffuse intimal hyperplasia 1 year after coronary artery bypass graft surgery., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

The radial artery (RA) can be used as part of an arterial revascularization strategy in coronary artery bypass grafting (CABG). It is easy to harvest and several randomized controlled trials and meta-analyses have reported superior long-term patency over saphenous vein grafts. However, the RA is not used as frequently as the saphenous vein and questions remain regarding its optimum use as a conduit. This article comprehensively appraises current evidence surrounding outcomes, patient selection, harvesting technique, intraoperative strategy, and graft spasm prophylaxis to provide a contemporary review of the use of the RA as a conduit in CABG., (Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Graft patency verification is increasingly recognized as an important component of coronary artery bypass grafting. Intuitively, eliminating intraoperative graft failure should reduce cardiac mortality and morbidity in the short term and improve clinical outcome in the long term. Although conventional angiography remains the gold standard technique for assessing graft patency, it is rarely available in the operating room and consequently several other less invasive approaches have been advocated. This article reviews the two currently most commonly used modalities for graft patency assessment, intraoperative fluorescence imaging and transit-time flowmetry, and discusses their value and limitations. Both techniques can reliably detect otherwise unsuspected occluded grafts and this is crucial for internal thoracic arteries because of their prognostic significance. Although neither technology can consistently identify more minor, non-occlusive abnormalities, the intraoperative fluorescence imaging technique seems to be more sensitive and less susceptible to "false positive" images.

Improvements in techniques in coronary revascularization over the past decade have led to a revival of interest in off-pump coronary artery surgery. A fifth of coronary revascularization procedures are now performed off-pump. Randomized trials comparing off-pump surgery with conventional coronary artery bypass grafting using cardiopulmonary bypass (CPB) mainly included low-risk patients and were therefore underpowered to detect a difference in mortality. Current evidence, however, suggests a significant reduction in morbidity with off-pump surgery. The avoidance of CPB and the elimination of any aortic manipulation may significantly reduce the risk of stroke. Those benefits are likely to be most marked in older, sicker patients, who represent an increasing proportion of the surgical population.

Background: The Allen test is commonly used to assess collateral hand circulation before radial artery harvest for coronary artery bypass grafting. However there is no consensus as to whether an abnormal Allen test is an absolute or relative contraindication to radial artery harvesting. We assessed the safety of harvesting the radial artery using arterial duplex ultrasonography in patients with an abnormal Allen test., Methods: Two hundred and eighty-seven consecutive patients scheduled for total arterial coronary revascularisation underwent preoperative Allen tests over a 34-month period. Patients with an abnormal Allen test underwent duplex ultrasonography preoperatively to assess the adequacy of the ulnar collateral supply and the suitability of the radial artery for harvesting., Results: Two hundred and forty-four patients (85%) had a normal left Allen test and proceeded directly to radial artery harvest. Forty-three patients (15%) with an abnormal left Allen test underwent duplex ultrasonography scans and of those, 5 patients had an abnormal scan. These patients underwent scanning of the contralateral forearm. Three patients had a normal right forearm arterial duplex scan and the right radial artery was harvested. The mean diameter of the radial and ulnar arteries was not significantly different between the patients with normal and abnormal duplex ultrasonograms. There were no ischemic hand complications in this series., Conclusions: The Allen test is a quick, easy, and reliable screening test before radial artery harvesting in the majority of patients. Duplex ultrasonography predicts safe radial artery harvest in the majority of patients with an abnormal Allen test.

Background: Early graft failure is a common cause of cardiac morbidity and mortality after coronary artery bypass grafting (CABG), and there is particular concern about graft patency in off-pump CABG. We describe our preliminary experience with a novel imaging technique (the SPY system), based on fluorescence of Indocyanine Green when exposed to near infrared light, for the intraoperative assessment of coronary graft patency., Methods: Graft patency was assessed in patients undergoing off-pump and on-pump total arterial revascularization. The imaging technique requires injection of a 1-mL bolus of Indocyanine Green into the central venous line, followed by imaging with the SPY system., Results: We assessed intraoperative graft patency in 213 conduits in 84 patients (mean, 2.54 grafts per patient), of which, 65 (77%) were done off-pump. It took approximately 3 minutes to image each graft. Skeletonized conduits provided better visualization than pedicled ones. Fluorescence, confirming graft patency, was observed in all but four (1.9%) conduits in 4 (5%) patients. In these latter cases, graft revision was necessitated., Conclusions: Fluorescence imaging of coronary grafts using the SPY is a uniquely simple, safe, noninvasive, and reproducible technique for intraoperative confirmation of graft patency. In 4 patients, it necessitated revision of the initial intraoperative procedure. Quantification of graft flow would enhance the value of the system.

Background: Coronary artery bypass grafting (CABG) is the commonest major operation in most developed countries. A single internal mammary artery (IMA) graft has proven survival benefits, but the additional survival advantage of a second graft is unknown. We systematically reviewed published studies of bilateral versus single IMA grafts in CABG to assess any differences in survival., Methods: We identified from Medline all studies in which single and bilateral IMA grafts were compared. We included studies in which at least 100 patients in each group had been followed up for at least 4 years. We assessed study quality on the basis of patient selection, comparability of intervention groups (especially for age, sex, ventricular function, and diabetes status), outcome assessment, and completeness of follow-up. Our primary outcome was survival. Estimates of treatment effect (single versus bilateral) expressed as hazard ratios were pooled across studies., Findings: None of the studies was a randomised trial, but nine cohort studies met our inclusion criteria. Seven studies yielded survival data for meta-analysis, and included 15962 patients: 11269 single and 4693 bilateral IMA grafts. The bilateral group had significantly better survival than the single group (hazard ratio for death 0.81; 95% CI 0.70-0.94). Exclusion of methodologically weak studies improved survival rates with bilateral IMA grafts., Interpretation: Because no study was a randomised trial, our results are more uncertain than is indicated by the 95% CI. Nevertheless, bilateral IMA grafts seem to give better survival rates than single grafts.

The radial artery is usually harvested as a pedicle with surrounding veins, perivascular fat, and areolar tissue. We describe an alternative technique of skeletonization of the radial artery and its potential advantages over the pedicled technique.

Background: Platelet-activating factor is a mediator of lung injury during cardiac operation. Platelet-activating factor antagonists reduce lung injury in animal models of cardiopulmonary bypass but there is no confirmatory evidence in clinical practice., Methods: The effect of a low or high dose of a platelet-activating factor antagonist (Lexipafant) was assessed in a single center, double-blind, placebo-controlled, parallel group study. One hundred fifty patients undergoing coronary artery bypass grafting were randomized by minimization into three groups to receive placebo infusion, 10 or 100 mg of lexipafant for over 24 hours. Serial arterial oxygen and carbon dioxide tension, alveolar arterial oxygen gradient, and percent saturation were measured before operation and at 1, 6, 24, 48 hours, and 5 days after operation., Results: Patient groups were similar with respect to age, sex, body surface area, and urgency of operation. Likewise, the groups were similar with respect to duration of cardiopulmonary bypass and the number and type of grafts. Maximum lung injury occurred at 48 hours when the arterial oxygen tension and percent saturation reached a nadir (both p < 0.001) accompanied by the maximum increase in the alveolar arterial gradient (p < 0.001). All measurements demonstrated partial recovery by 5 days but remained significantly (p < 0.001) impaired in comparison to baseline values. Duration of ventilation was similar in all groups. Lexipafant, at low or high dose, did not moderate lung injury after cardiopulmonary bypass and did not influence the duration of postoperative ventilation., Conclusions: Despite experimental and clinical evidence implicating platelet-activating factor in the pathophysiology of lung injury after cardiopulmonary bypass, no beneficial effect of a platelet-activating factor antagonist on lung function or ventilation could be demonstrated in this clinical trial.

Background: Cerebral injury is the most important complication of cardiac operations with cardiopulmonary bypass. Prolonged total circulatory arrest (TCA) can expose patients to an even greater risk of cerebral injury. We sought to detect the degree of cerebral injury in adults who had thoracic aortic operations with TCA by measuring S100B protein, which is released into the circulation after cerebral injury., Methods: Serial measurements of S100B protein, a highly specific serum marker of astroglial damage, were performed in 26 patients who had complex aortic operations, of whom 13 required cardiopulmonary bypass alone (for aortic root replacement), and in 13 patients who required an additional period of TCA (for type A aortic dissections and arch aneurysms). Blood samples were taken preoperatively, at skin closure, and 5 and 24 hours postoperatively., Results: There were significant increases in serum S100B concentrations in all patients, and peak levels occurred at skin closure. The magnitude of the increase in S100B was significantly greater at all postoperative time points and persisted longer in the TCA group. There was a significant correlation between the duration of the TCA and S100B concentration at 5 hours (r = 0.66, p = 0.01) and 24 hours (r = 0.63, p = 0.02) postoperatively., Conclusions: S100B levels were higher in all patients who had complex aortic operations and were significantly greater in patients requiring a period of TCA. The duration of the TCA period correlated with S100B levels 5 hours and at 24 hours postoperatively. Circumstantial evidence, in accordance with other studies, suggests that S100B protein is a marker for cerebral injury during cardiac operations.

Background: Variations in the morphology and vascular reactivity of the proximal and distal radial artery might influence its performance as a bypass conduit., Methods: The morphologic and functional characteristics of the proximal and distal RAs were compared with those of the left and right internal mammary arteries by using histologic and in vitro organ bath techniques., Results: Proximal RA had a significantly greater medial cross-sectional area compared with that of the distal RA (2.48+/-0.27 mm2 compared with 1.86+/-0.21 mm2, p< 0.05), which were both significantly greater than the left internal mammary artery (0.54+/-0.09 mm2) or the right internal mammary artery (0.67+/-0.03 mm2). Proximal RA had a significantly greater response to 90 mmol/L potassium chloride than that of distal RA (88.4+/-7.3 compared with 60.2+/-10.3 mN, p<0.05), and both contracted more than the left internal mammary artery (30.3+/-2.9 mN) and the right internal mammary artery (32.6+/-4.1 mN). There was no difference in the response to noradrenaline and adrenaline between proximal and distal RA, both of which contracted more than the left and right internal mammary arteries., Conclusions: When choosing a segment of RA for use as a bypass conduit, regional variations in biologic properties should be considered.

Background: Recent reports have documented left ventricular recovery in patients with dilated cardiomyopathy off-loaded long term with a left ventricular assist device. We sought to document the natural history of left ventricular recovery., Methods: We implanted the TCI left ventricular assist device without the intention to perform transplantation in 2 patients with dilated cardiomyopathy who had been rejected for transplantation. Both were in New York Heart Association functional class IV and had renal failure. One was a diabetic. We studied left ventricular function with detailed echocardiography at 4, 6, and 8 weeks postoperatively., Results: With the left ventricular assist device turned off, we observed a progressive increase in myocardial contractility beginning as early as 4 weeks after implantation and improving progressively. Histologic examination showed resolution of myocytolysis in both patients., Conclusions: Left ventricular recovery begins earlier than was previously suspected. Mechanical bridge to myocardial recovery is a potential approach to therapy for such patients.

The location of the gastroepiploic artery makes it strategically useful for isolated revascularization of the inferior surface of the heart. In comparison with the radial artery, however, the usefulness of the gastroepiploic artery is limited by its progressively smaller caliber with mobilization and its greater tendency for vasospasm. I describe a case of radial artery-to-proximal gastroepiploic artery anastomosis to revascularize the right coronary artery in a patient requiring redo coronary artery bypass grafting.

Background: The risk of overt and subtle cerebral injury may be higher in intracardiac operation (ICO) rather than coronary artery bypass grafting (CABG). S-100 protein is a specific astroglial protein whose serum level increases after cerebral injury. Elevated serum levels of S-100 have been detected after adult cardiac operations and correlated with neurologic injury., Methods: The level of S-100 protein was measured serially over 24 hours in 40 patients (27 undergoing aortic valve replacement, 9 mitral valve replacement, 4 closure of atrial septal defect) undergoing ICO and 20 patients undergoing CABG., Results: The groups were similar with respect to age and cardiopulmonary bypass times. The S-100 level was not elevated before operation in any patient. Peak S-100 levels were reached at skin closure, when 35 of the ICO patients (88%) and 13 of the CABG patients (65%) had elevated S-100 levels. At skin closure peak S-100 levels were significantly greater in the ICO group (median [interquartile range], 0.76 [0.44-1.16] versus 0.3 [0-0.55] microgram/L; p < 0.01). At 5 hours S-100 levels were still elevated in 22 patients in the ICO group compared with 1 patient in the CABG group (p < 0.01), and at 24 hours 17 ICO patients had persistently elevated S-100 levels in comparison with 2 in the CABG group (p < 0.01). One valve patient had a stroke 24 hours after operation accompanied by a secondary increase in the S-100 level. There was no significant difference in postoperative S-100 levels between 5 patients in the ICO group with a prior history of stroke and those without. The peak S-100 level correlated with patient age (r = 0.59; p < 0.001) but not with the duration of cardiopulmonary bypass or core temperature during the operation., Conclusions: Intracardiac operation results in a significantly greater elevation in S-100 levels than CABG. Elevated S-100 levels correlate with increasing patient age but not with the duration of cardiopulmonary bypass or intraoperative core temperature. These findings raise the possibility that ICO patients may be more vulnerable to even subtle levels of cerebral injury than CABG patients.

We report a patient with multiple brachiocephalic arterial occlusive disease who suffered failure of a bifurcated aorto-carotid artery graft. Profound hypothermic circulatory arrest provided adequate cerebral protection during redo aorto-brachiocephalic arterial grafting.