Grafting In Coronary Artery Bypass Grafting Research Articles

Choice of conduit for coronary artery bypass grafting: technical, anatomic, and pharmacologic considerations

The choice of graft used to bypass stenoses in the coronary circulation is crucial to coronary artery bypass grafting (CABG) surgery and its success. Herein is a review of the existing literature on CABG grafts, including the discussion of utilization of different CABG grafts, patency of different grafts, and technical and other considerations pertinent to the use of each graft. Lastly, we present special considerations for graft selection in women.

Effects of Fractional Flow Reserve on Coronary Artery Bypass Graft Flow to Left Anterior Descending Artery.

The relationships between preoperative fractional flow reserve (FFR) values of the left anterior descending artery (LAD), FFRLAD, and intraoperative transit time flow measurement (TTFM) variables in coronary artery bypass grafting (CABG) remain unclear.Methods and Results: We retrospectively collected data for 74 in situ left internal thoracic artery (LITA) grafts and 27 saphenous vein grafts (SVGs) to the LAD that were shown to be patent on postoperative angiography. Spearman correlation coefficients were determined between FFRLADand TTFM parameters of the LITA graft, as follows: maximum flow (Qmax), -0.22 (P=0.077); minimum flow (Qmin), -0.40 (P=0.014); mean flow (Qm), -0.35 (P=0.039); pulsatility index (PI), 0.33 (P=0.008); diastolic filling (DF): 0.01 (P=0.83); and systolic reverse flow (SRF), 0.37 (P=0.002). Spearman correlation coefficients between FFRLADand TTFM parameters of the SVG to LAD were: Qmax, -0.65 (P=0.004); Qmin, -0.43 (P=0.044); Qm, -0.75 (P=0.001); PI, 0.53 (P=0.033); DF, 0.14 (P=0.48); and SRF, 0.61 (P=0.009). Both LITA grafts and SVGs to the LAD show negative correlations for FFRLADwith Qminand Qm, but positive correlations for FFRLADwith PI and SFR. These relationships between FFRLADand TTFM variables of CABG grafts to the LAD should be recognized.

Integrated biophysical matching of bacterial nanocellulose coronary artery bypass grafts towards bioinspired artery typical functions

Revascularization via coronary artery bypass grafting (CABG) to treat cardiovascular disease is established as one of the most important lifesaving surgical techniques worldwide. But the shortage in functionally self-adaptive autologous arteries leads to circumstances where the clinical reality must deal with fighting pathologies coming from the mismatching biophysical functionality of more available venous grafts. Synthetic biomaterial-based CABG grafts did not make it to the market yet, what is mostly due to technical hurdles in matching biophysical properties to the complex demands of the CABG niche. But bacterial Nanocellulose (BNC) Hydrogels derived by growing biofilms hold a naturally integrative character in function-giving properties by its freedom in designing form and intrinsic fiber architecture. In this study we use this integral to combine impacts on the luminal fiber matrix, biomechanical properties and the reciprocal stimulation of microtopography and induced flow patterns, to investigate biomimetic and artificial designs on their bio-functional effects. Therefore, we produced tubular BNC-hydrogels at distinctive designs, characterized the structural and biomechanical properties and subjected them to in vitro endothelial colonization in bioreactor assisted perfusion cultivation. Results showed clearly improved functional properties and gave an indication of successfully realized stimulation by artery-typical helical flow patterns.

Graft Failure After Coronary Artery Bypass Grafting and Its Association With Patient Characteristics and Clinical Events: A Pooled Individual Patient Data Analysis of Clinical Trials With Imaging Follow-Up.

Graft patency is the postulated mechanism for the benefits of coronary artery bypass grafting (CABG). However, systematic graft imaging assessment after CABG is rare, and there is a lack of contemporary data on the factors associated with graft failure and on the association between graft failure and clinical events after CABG. We pooled individual patient data from randomized clinical trials with systematic CABG graft imaging to assess the incidence of graft failure and its association with clinical risk factors. The primary outcome was the composite of myocardial infarction or repeat revascularization occurring after CABG and before imaging. A 2-stage meta-analytic approach was used to evaluate the association between graft failure and the primary outcome. We also assessed the association between graft failure and myocardial infarction, repeat revascularization, or all-cause death occurring after imaging. Seven trials were included comprising 4413 patients (mean age, 64.4±9.1 years; 777 [17.6%] women; 3636 [82.4%] men) and 13 163 grafts (8740 saphenous vein grafts and 4423 arterial grafts). The median time to imaging was 1.02 years (Q1;Q3: 1.00;1.03). Graft failure occurred in 1487 (33.7%) patients and in 2190 (16.6%) grafts. Age (adjusted odds ratio [aOR], 1.08 [per 10-year increment] [95% CI, 1.01-1.15]; P=0.03), female sex (aOR, 1.27 [95% CI, 1.08-1.50]; P=0.004), and smoking (aOR, 1.20 [95% CI, 1.04-1.38]; P=0.01) were independently associated with graft failure, whereas statins were associated with a protective effect (aOR, 0.74 [95% CI, 0.63-0.88]; P<0.001). Graft failure was associated with an increased risk of myocardial infarction or repeat revascularization occurring between CABG and imaging assessment (8.0% in patients with graft failure versus 1.7% in patients without graft failure; aOR, 3.98 [95% CI, 3.54-4.47]; P<0.001). Graft failure was also associated with an increased risk of myocardial infarction or repeat revascularization occurring after imaging (7.8% versus 2.0%; aOR, 2.59 [95% CI, 1.86-3.62]; P<0.001). All-cause death after imaging occurred more frequently in patients with graft failure compared with patients without graft failure (11.0% versus 2.1%; aOR, 2.79 [95% CI, 2.01-3.89]; P<0.001). In contemporary practice, graft failure remains common among patients undergoing CABG and is strongly associated with adverse cardiac events.

Graft Patency of No-Touch Saphenous Veins Used as Aortocoronary Bypass Grafts.

This study evaluated the early, 1-year, and 3-year graft patency rates and mid-term clinical outcomes after no-touch saphenous veins (NT-SVs) were used as aortocoronary grafts in coronary artery bypass grafting (CABG). In total, 101 patients who underwent CABG using NT-SVs as aortocoronary grafts were included. The 2 most common indications for performing aortocoronary grafting with NT-SVs were unavailability of the left internal thoracic artery (n=36) and moderate lesions where flow competition was expected (n=27). Early (median, 1 day; interquartile range [IQR], 1-2 days), 1-year (median, 13 months; IQR, 11-16 months), and 3-year (median, 34 months; IQR, 27-41 months) graft angiography was performed in 98 (97.0%), 84 (83.2%), and 40 patients (39.6%), respectively. The median follow-up duration was 43 months (IQR, 13-76 months). Overall survival rates and the cumulative incidence of major adverse cardiac events were evaluated. The operative mortality rate was 2% (2 of 101 patients). Early postoperative patency rates for overall and aortocoronary NT-SV grafts were 98.2% (223 of 227 distal anastomoses) and 98.2% (164 of 167), respectively. The 1- and 3-year patency rates for aortocoronary SV grafts were 94.9% (131 of 138) and 90.6% (58 of 64), respectively. The overall survival rates at 5 and 10 years were 81.7% and 59%, respectively. The cumulative incidence of major adverse cardiac events at 5 and 10 postoperative years was 20.7% and 39%, respectively. The feasibility of using NT-SVs as aortocoronary grafts in CABG was shown in this study, based on the graft patency rates up to 3 years and the mid-term clinical outcomes.

Systematic review and meta-analysis of &lt;i&gt;in situ&lt;/i&gt; versus composite bimammary coronary artery bypass grafting: immediate outcomes and 30-day mortality

Aim. To compare the immediate outcomes and 30-day mortality of in situ bimammary coronary artery bypass grafting (CABG) using two internal thoracic arteries (ITAs) versus a composite grafting.Material and methods. We searched PubMed, Google Scholar, and Web of Science databases for a period from 1990 to 2020 for studies comparing in situ bimammary CABG versus composite grafts. The PICO search model was used as follows: patient, intervention, comparison, outcomes. The data were derived by two independent researchers and subjected to a meta-analysis using a random effect.Results. A total of 10 studies were selected for this meta-analysis. Of these, there were 2 randomized controlled trials (n=705), 4 observational propensity score matching studies (n=4267) and 4 unadjusted observational studies (n=3517). With both ITA in situ surgery, fewer distal anastomoses are applied (MD=0,23; 95% confidence interval (CI), 0,15-0,32; p&lt;0,001). But there was no significant difference n myocardial ischemia between groups (3 min with 95% CI, -3,23-9,79; p=0,32). There was no significant difference between groups in the incidence of perioperative stroke (hazard ratio (HR)=0,5; 95% CI; 0,63-1,74; p=0,85 ), myocardial infarction (HR=1,1; 95% CI 0,66-1,85; p=0,71), mediastinitis (HR=0,86; 95% CI; 0,62-1,20; p=0,38), resternotomy due to bleeding (HR=1,29; 95% CI, 0,75-2,21; p=0,36), acute renal injury (HR=1,24; 95% CI, 0, 84-1,84; p=0,29), inhospital mortality (HR=1,08; 95% CI, 0,67-1,75; p=0,75) and 30-day mortality (HR=1,19; 95% CI, 0,81-1,75; p=0,38), but the incidence of postoperative atrial fibrillation was significantly lower in the group with both ITA in situ surgery (RR=1,23 with 95% CI 1,04-1,44; p=0,01).Conclusion. With composite bimammary CABG, more distal anastomoses with ITA were applied, while the time of myocardial ischemia did not differ between the groups. We found no significant difference in the incidence of perioperative myocardial infarction, stroke, mediastinitis, acute renal injury, resternotomy due to bleeding, inhospital mortality, and 30-day mortality. But at the same time, the HR for postoperative atrial fibrillation was significantly lower in the group with both ITA in situ surgery.

The impact of percutaneous coronary intervention versus coronary artery bypass grafting surgery in left main coronary disease

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Although coronary artery bypass grafting (CABG) has been considered the gold-standard method for the treatment for left main stable ischemic coronary disease (s-LMCAD), percutaneous coronary intervention (PCI) has shown good results. Objective To evaluate patients with s-LMCAD who performed CABG or PCI and compare their outcomes. Study design Single center, retrospective study that included all s-LMCAD patients who performed LM PCI or CABG between January 2015 and November 2018 (n = 35 in the PCI group and 35 in the CABG group after propensity score and matches in a ratio of 1:1). Clinical and imaging information of patients was collected, relating to the pre- and post-procedure and with 3 years of follow-up (FUP). Results Overall, baseline clinical and angiographic characteristics were balanced between the groups. The PCI group had higher prevalence of previous coronary disease (54.3%% vs 28.6%, p = 0.029) and chronic obstructive pulmonary disease (22.9% vs 5.7%, p = 0.04). The anatomical complexity estimated through the calculation of the SYNTAX score showed no significant differences between groups (16 vs 19, p = 0.151). 50% of PCI group performed IVUS, 2.8% OCT and 2.8% FFR. All CABG grafts used were arterial. There were no registries of events during hospitalization. At 30 days, cardiovascular-mortality was higher in the PCI group than in CABG group (n = 2 (5.56%) vs 0, respectively), representing all cases of cardiovascular death in PCI group through the 3-years follow-up. In CABG group, cardiovascular-related death was more substantial at 3 years. At 3 years of FUP, no significant differences were found between the PCI and CABG groups in MACCE (hazard ratio (HR) of the PCI group, 2,786; confidence interval (CI) of 95%, 0.873 to 8,889; p = 0.084). However, patients submitted to PCI with a SYNTAX score≥23 had worse MACCE results (HR 9.022, 95% CI, 1,054 to 77.210; p = 0,045), though a large confidence interval was also registered. Though not significantly different, cardiac-related hospital admissions were more frequent in the CABG group (18 (25.00%) vs 6 (16.67%) in the PCI group), but occurred more acutely in the PCI group (&amp;lt; 30 days). Stroke events happened more frequently in the CABG group, with a total of 4 cases reported (5.56%) whereas in the PCI group none happened. Myocardial infarction rate was also higher in the PCI group (2, 5.71%) and 1 happened in the first 30 days which was related to a target lesion failure. Revascularization through PCI due to restenosis had only 1 (2.78%) case registered. Graft failure happened in only 1 patient. Conclusion In conclusion, for the treatment of patients with stable s-LMCAD and low anatomical complexity, PCI was noninferior to CABG. Our results suggest that PCI is an acceptable alternative to CABG for patients with stable left main coronary artery disease, except for the ones with high anatomical complexity.

Short-term assessment of radial artery grafts with multidetector computed tomography

BackgroundThe clinical use of the radial artery (RA) in coronary artery bypass grafting (CABG) is still limited worldwide, although it has been recommended by several guidelines. Multidetector computed tomography (MDCT) is widely used to evaluate graft patency, as invasive coronary angiography could cause potentially serious risks including bleeding, dissection and stroke. This study aims to report the short-term results of the RA in CABG with MDCT.MethodsThe study population consists of 41 consecutive patients undergoing elective CABG with the RA graft between 2017 to 2018, with MDCT performed to evaluate graft patency during follow-up, and target vessels for the RA were non-left anterior descending coronary arteries with > 70% stenosis.ResultsA total of 150 grafts were assessed by MDCT during follow-up (mean, 8.9 ± 5.1 months). MDCT could clearly show the structure and patency of grafts, even for complex coronary artery revascularization. Graft patency of the left internal mammary artery was 92.9% (39/42), with the RA patency of 84.4% (38/45) and the patency of the saphenous vein graft of 81.1% (30/37). And the RA anastomosed to the left coronary artery system might have better patency than the RA anastomosed to the right coronary artery system (25/29, 86.2% vs 13/16, 81.3%, p = 0.686).ConclusionsThe short-term patency rate of RA grafts is good, and the RA might be associated with better patency when anastomosed to the left but not the right coronary artery. MDCT could provide excellent visualization of grafts in CABG.

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

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

How decisive is the number of distal arterial anastomoses in coronary bypass surgery?

BackgroundThe benefit of arterial revascularization in coronary surgery remains controversial. The incremental value of additional grafts to the left internal thoracic artery (ITA) has been mainly assessed according to the number of arterial grafts, possibly limiting the detection of its actual impact. We analyzed the influence of the number of distal arterial anastomoses (DAA) performed on late mortality in patients having received from one to three arterial grafts.MethodsRetrospective review of 3685 primary isolated coronary artery bypass grafting (CABG) performed from 1989 to 2014 was conducted with a 13-year mean follow-up. One arterial graft (SITA) was used in 969 patients, two arterial grafts, ITA or gastroepiploic artery (GEA), in 1883 patients (BITA: 1644; SITA+GEA: 239), and three arterial grafts in 833 patients (BITA+GEA). Totally, 795 patients (22%) received one DAA, 1142 patients (31%) two, 1337 patients (36%) three, and 411 patients (11%) four or more. A sub-group analysis was done in the 2104 patients with 3-vessel disease who received at least 2 arterial grafts.ResultsIn this series the early mortality was 1.6% and it was not influenced by the surgical technique. Late mortality was significantly influenced by age, gender, heart failure, LV ejection fraction, diabetes status, complete revascularization, number of arterial grafts, number of DAA, both ITA, sequential ITA graft, GEA graft. In multivariable analysis with Cox regression model, the number of DAA was the only technical significant independent prognosis factor of late survival (p < 0.0001), predominant over both ITA, complete revascularization and number of arterial grafts. The impact of the number of DAA on survival was found discriminant from 1 to 3; after 3 there was no more additional effect. In 3-vessel disease patients who received at least 2 arterial grafts, the number of DAA remained a significant independent prognosis factor of late survival (p < 0.0001).ConclusionsThe number of distal arterial anastomoses is an independent predictor of long-term survival, predominant over the number of arterial grafts and the completeness of the revascularization; higher the number, better the late survival. It is a strong support of the extensive use of arterial grafting in CABG.

Association of hypoxia and mitochondrial damage associated molecular patterns in the pathogenesis of vein graft failure: a pilot study

Coronary artery bypass grafting (CABG) is the standard treatment modality in revascularization of the myocardium. However, the graft failure remains the major complication following CABG procedure. Involvement of mitochondrial damage-associated molecular patterns (mt-DAMPs) in the pathogenesis of vein-graft failure is largely unknown. Here, we investigated the expression of major protein-mt-DAMPs, cytochrome-C (Cyt-C), heat shock protein-60 (Hsp-60), mitochondrial transcription factor A (mtTFA), in the occluded graft and associated tissues, including distal left anterior descending (LAD), LAD adjacent to anastomosis, and left internal mammary artery (LIMA) in the microswine CABG model. The protein expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) was significantly decreased in the graft and LIMA, whereas the protein expression of hypoxia inducible factor-1 alpha (HIF-1α) and Cyt-C was decreased and that of mtTFA and Hsp60 was increased in all tissues compared to controls. There was no significant difference in the protein expression of citrate synthase, complex-1, and mitochondrial pyruvate dehydrogenase in the graft and associated tissues compared to control. Hypoxia in cultured smooth muscle cells (SMCs) significantly upregulated all mitochondrial biomarkers and mt-DAMPs compared to normoxia. The increased reactive oxygen species (ROS) content and compromised membrane integrity in the hypoxic SMCs correlated well with increased mt-DAMPs in the graft and associated tissues, suggesting a possible role of mt-DAMPs in the pathogenesis of graft failure. These findings suggest that the pathological signals elicited by mt-DAMPs could reveal targets for better therapeutic approaches and diagnostic strategies in the management of CABG graft failure.

Assessing the Long-term Patency and Clinical Outcomes of Venous and Arterial Grafts Used in Coronary Artery Bypass Grafting: A Meta-analysis.

IntroductionThe long-term patency of the grafts used during the coronary artery bypass grafting (CABG) is one of the most significant predictors of the clinical outcomes. The gold standard graft used during CABG with the best long-term patency rate and the better clinical outcomes is left internal thoracic artery (LITA) grafted to the left coronary artery (LCA). The controversy lies in choosing the second-best conduit for the non-left coronary artery (NLCA) with similar patency rate as LITA. This meta-analysis examines the long-term patency and clinical outcomes of all arterial grafts versus all venous grafts used during the CABG.MethodsA comprehensive literature search of all published randomized control trials (RCTs) assessing long-term patency and clinical outcomes of grafts used in CABG was conducted using PubMed, Cochrane Central Registry of Controlled Trials, and Google Scholar (1966-2018). Keywords searched included combinations of “CABG”, “venous grafts in CABG”, “arterial grafts in CABG”, “radial artery grafts in CABG”, “gastroepiploic artery grafts in CABG”, “patency and clinical outcomes”. Inclusion criteria included: RCTs comparing the long-term patency, and clinical outcomes of radial artery, right internal thoracic artery, gastroduodenal artery, and saphenous vein grafts used in CABG. Long-term patency of the grafts and clinical outcomes were analyzed.ResultsEight RCTs involving 2,091 patients with 1,164 patients receiving arterial grafts and 927 patients receiving venous grafts were included. There was no difference between the long-term patency rate (relative risk (RR) = 1.050, 95% confidence interval (CI) = 0.949 to 1.162, and p = 0.344), overall mortality rate (RR = 1.095, 95% CI = 0.561 to 2.136, and p = 0.790), rate of myocardial infarction (MI) (RR = 0.860, 95% CI = 0.409 to 1.812, and P = 0.692), and re-intervention rate (RR = 0.0768, 95% CI = 0.419 to 1.406, and P = 0.392) between arterial and venous grafts.ConclusionThe use of arterial conduits over the venous conduits has no significant superiority regarding the long-term graft patency, the rate of MI, overall mortality, and the rate of revascularization following CABG. Additional adequately powered studies are needed to further evaluate the long-term outcomes of arterial and venous grafts following the CABG.

Graft Strategy for Coronary Artery Bypass Grafting in Patients with Severe Left Ventricular Dysfunction.

BackgroundOptimal graft selection for coronary artery bypass grafting (CABG) in patients with severe left ventricular (LV) dysfunction remains debatable. We report an analysis of our experiences of isolated CABG in patients with severe LV dysfunction and the impact of graft strategy on long-term outcomes.MethodsWe analyzed 209 patients with severe LV dysfunction (ejection fraction [EF] <30%) who underwent primary isolated CABG. Of these, 169 were revascularized with a bilateral internal thoracic arterial (ITA) graft (BITA group) and 40 were revascularized with a single ITA graft (SITA group). The mean follow-up duration was 22±32 months.ResultsThere were 18 early deaths (8.6%). Overall survival at 5 years was 66.7%. The rate of freedom from cardiac-related death at 5 years was 74.1%, and was significantly higher in patients who underwent off-pump CABG (p=0.005) and in the BITA group (p=0.023). Multivariate analysis demonstrated that old age (hazard ratio [HR], 2.548; 95% confidence interval [CI], 1.134–5.762; p=0.024), off-pump CABG (HR, 0.245; 95% CI, 0.090–0.661; p=0.006), and BITA grafts (HR, 0.333; 95% CI, 0.146–0.757; p=0.009) were correlated with cardiac mortality.ConclusionCABG in patients with severe LV dysfunction (EF <30%) showed reasonable long-term outcomes. The rate of freedom from cardiac-related death was significantly higher in patients who underwent off-pump CABG and in the BITA group. Off-pump BITA grafting strategies can be accepted as a viable primary option in patients with severe LV dysfunction if performed by an experienced surgeon.

The comparative effects of esmolol and amiodarone on isolated coronary artery bypass grafts

Background/aim: Esmolol and amiodarone are two most commonly used antiarrhythmic drugs in coronary artery bypass grafting (CABG) surgery. Nevertheless, blockade of beta-2 receptors by increasing doses raise concerns about possible vasospasms. We studied the vasoactive effects of amiodarone and esmolol on left internal mammary artery (LIMA), radial artery (RA), and saphenous vein (SV) grafts. Materials and methods: After determining the presence of functional smooth muscle and endothelial layers, the responses of submaximally preconstricted graft samples were recorded in a tissue bath system. A total of 96 graft samples from 40 patients were used: 16 LIMA, 16 RA, and 16 SV grafts for each drug. Esmolol and amiodarone were added to reservoirs separately, starting from a concentration of 10-8 M until a concentration of 10-4 M. Results: Although both drugs caused vasodilatation, amiodarone exhibited a more potent vasodilatory effect than esmolol (P < 0.0001 for LIMA, P = 0.0128 for RA, and P < 0.0001 for SV). The vasodilatation rates with esmolol were 48.99 ± 2.28% in LIMA, 49.77 ± 3.03% in RA, and 41.90 ± 4.05% in SV grafts and with amiodarone they were 71.65 ± 5.18% in LIMA, 58.61 ± 5.87% in RA, and 65.07 ± 4.09% in SV grafts. Conclusion: This in vitro study revealed that even increasing doses of both drugs induce vasodilatation of CABG grafts, with amiodarone having a more potent vasodilatory effect than esmolol.

Network meta-analysis of antiplatelet therapy following coronary artery bypass grafting (CABG): none versus one versus two antiplatelet agents.

Numerous agents have been trialed following coronary artery bypass grafting (CABG) to maintain long-term graft patency. While clear evidence exists for the use of aspirin in maintaining graft patency, the role of dual-antiplatelet therapy in CABG patients is not as well established. This network meta-analysis aimed to compare the short-term post-CABG graft patency outcomes for patients with none, one or two antiplatelet agents. Electronic databases were queried for randomized controlled trials comparing CABG graft patency rates at three months and beyond using various antiplatelet agents or placebo. Drug and graft patency data were compared using a mixed treatment comparison under a Bayesian hierarchical framework. A random-effects consistency model was applied. Direct and indirect comparisons were made between drugs and used to determine the relative efficacy for graft patency. The literature search identified 16 papers fulfilling the inclusion criteria, including a total of 3,133 patients with an average of 2.43 [95% confidence interval (CI): 2.20-2.66] grafts per patient. Graft types were incompletely reported, however, saphenous vein grafts (SVGs) were predominantly used [where specifically reported: 4,490 SVG, 1,226 internal mammary artery (IMA) grafts]. In all, five different agents and placebo in various regimens were compared by results of angiographic follow-up conducted at a mean of 10.4 months (95% CI: 9.28-11.5 months). Compared to placebo, aspirin alone [odds ratio (OR) 1.9; 95% credible interval (CrI): 1.3-2.8], aspirin + dipyridamole (OR 1.9; 95% CrI: 1.3-2.6), aspirin + clopidogrel (OR 2.9; 95% CrI: 1.5-5.7) and aspirin + ticagrelor (OR 3.8; 95% CrI: 1.2-13.0) significantly improved graft patency. When compared to aspirin monotherapy, aspirin + clopidogrel (OR 1.6; 95% CrI: 0.86-2.7) and aspirin + ticagrelor (OR 2.0; 95% CrI: 0.69-6.3) had OR that suggested a trend favoring patency compared to aspirin monotherapy, however, these results did not reach significance. Sub-group analysis of SVG graft patency was unable to reach significance (only eight studies with six treatment comparisons were evaluated). Secondary endpoints of death, bleeding, myocardial infarction and cerebrovascular accident were incompletely reported and were pooled but not compared between drug treatment arms. Aspirin monotherapy and dual antiplatelet therapy (DAPT) provided significant all-graft patency benefit compared to placebo at three months and beyond. A trend existed for DAPT to improve graft patency compared to aspirin, although this did not reach statistical significance. Further randomized controlled studies comparing aspirin monotherapy to DAPT are required to determine the utility of DAPT in CABG patients for maintaining graft patency.

Why Don’t We Kill 2 Birds with 1 Stone?

Article, see p 1698 In this issue of Circulation , Goldstone and colleagues1 report the early and midterm outcomes of more than 59 000 patients who underwent primary isolated multivessel coronary artery bypass grafting (CABG) at 126 nonfederal hospitals in California from 2006 to 2011. They found that after propensity matching, receipt of a second arterial conduit was associated with significantly lower all-cause mortality, myocardial infarction, and coronary reintervention at a median follow-up of more than 5 years. It is interesting to note that compared with radial artery (RA) grafting, right internal thoracic artery (RITA) grafting did not confer a survival or cardiovascular advantage, but was associated with increased risk of sternal wound infection. During the study period, use of a second arterial conduit decreased from 10.7% to 9.1%, mirroring a national trend reported by the Society of Thoracic Surgeons Adult Cardiac Surgery Database (11.6% in 2000–2009 versus 6.7% in 2010–2013).2 Notably, 30% of cardiac surgeons in California did not use a second arterial graft for the duration of the study. So why is there a reluctance to use multiple arterial grafts in multivessel CABG despite the potential benefit? As for the 70% of California’s surgeons who use 2 arteries, why do they do so only in a small percentage of patients? The answers to those questions are complex but not elusive. Barriers to multiarterial grafting are diverse, ranging from perceptions about available scientific evidence, to surgical expertise, to health economics and more (Table). View this table: Table. Barriers to Multiarterial Grafting, Proposed Solutions, and Responsible Parties Starting with the scientific evidence, the California study is the largest study to date and an important addition to other large …

Roles of Transit-Time Flow Measurement for Coronary Artery Bypass Surgery.

Transit-time flow measurement (TTFM) has been increasingly applied to detect graft failure during coronary artery bypass grafting (CABG), because TTFM is less invasive, more reproducible, and less time consuming. Many authors have attempted to validate TTFM and to gain the clear cutoff values and algorithm in TTFM to predict graft failure. The TTFM technology has also been shown to be a useful tool to investigate CABG graft flow characteristics and coronary circulation physiology. It is important to recognize the practical roles of TTFM in the cardiac operating room by review and summarize the literatures.

Unstable angina due to spontaneous left internal mammary artery dissection seventeen years after coronary artery bypass graft surgery: A case report and literature review

A 64 year-old male was admitted to the emergency department for multiple episodes of chest pain at rest. His cardiac history began seventeen years before when a coronary artery bypass grafting (CABG) was performed. This included left internal mammary artery (LIMA) graft to left anterior descending artery (LAD) and saphenous vein graft (SVG) to the diagonal branch. Since then the patient was subjected to numerous percutaneous coronary angioplasties on LAD, circumflex artery and SVG. The last angiographic control showed LIMA graft patency. The coronary angiography showed LAD, circumflex and right coronary artery occlusion and LIMA graft critical stenosis with evidence of dissection. Then, the lesion was crossed and intravascular ultrasound (IVUS) evaluation was performed to investigate the extent of the dissection. IVUS demonstrated dissection with an intramural hematoma and presence of intimal tear. Therefore, a coronary angioplasty with multiple direct drug eluting stents implantation completed with post-dilatation was performed. Good angiographic and IVUS results were achieved. Spontaneous LIMA graft dissection is a rare condition. We reported the ninth case in literature and the one with the highest latency period between CABG and LIMA graft dissection. This situation may lead to an acute coronary syndrome, an unstable angina in our report, therefore prompt treatment, percutaneous or surgical, is decisive. Spontaneous arterial graft dissection is sometimes seen in women, especially in the post-partum period, it usually occurs during the fifth and sixth decade in patients affected by arterial hypertension, vasculitis, connective tissue disorders or atherosclerotic disease.

Potent Vasodilatory Effect of Fasudil on Radial Artery Graft in Coronary Artery Bypass Operations

The radial artery (RA) is a useful conduit for coronary artery bypass grafting (CABG) but is susceptible to vasospasm during harvesting. We evaluated the usefulness of fasudil, a Rho kinase inhibitor, in dilating the RA graft and increasing graft free flow (GFF) compared with the conventional graft-dilating agents papaverine and verapamil-nitroglycerin (VG). Between June 2012 and January 2013, 45 patients with ischemic heart disease who underwent isolated CABG using the RA were enrolled and randomly assigned to fasudil (n = 15), papaverine (n = 15), or VG (n = 15). Fasudil (2.67 mmol/L), papaverine (1.0 mmol/L) mixed with heparinized blood, or VG (30 μmol/L each of verapamil and nitroglycerin) was injected intraluminally into the RA graft after harvesting. Main outcome measures were RA GFF, hemodynamic changes, and histopathologic examination of the RA. In the fasudil group, GFF increased significantly (p < 0.001) from 36.8 ± 20.4 at baseline to 148.0 ± 88.3 mL/min after injection. GFF increased significantly (p < 0.001) from 36.0 ± 19.0 to 72.3 ± 36.7 mL/min in the papaverine group and increased significantly (p < 0.001) from 39.5 ± 23.3 to 64.3 ± 29.9 mL/min in the VG group. The GFF was significantly higher (p = 0.001) in fasudil-treated RA than in papaverine- or VG-treated RA. Histopathologically, RA graft diameter was markedly increased after fasudil injection, and the structure of the multiple elastic lamellae was intact. Blood pressure did not change significantly after drug injection in all groups. Fasudil exhibited a very potent vasodilatory effect on the RA compared with conventional papaverine or VG, resulting in increased GFF. This agent is useful for dilating RA grafts in CABG.

Long-Term Angiographic Follow-Up of Robotic-Assisted Coronary Artery Revascularization

Robotic-assisted coronary artery bypass grafting (CABG) has been shown in short-term studies to increase patient satisfaction and to reduce surgical morbidity and recovery times. However, the long-term patency rate of robotic-assisted CABG is unknown. Therefore, the objective of this study was to assess the long-term patency rate of robotic-assisted coronary artery bypass grafts. The study cohort included all patients who underwent robotic-assisted conduit dissection for CABG at London Health Sciences Centre between September 1999 and December 2003. These patients had selective graft patency assessment using cardiac catheterization or computed tomography angiography (CTA), or both, and stress myocardial perfusion scintigraphy (MPS) 5 to 10 years after surgery to evaluate graft patency and to give functional information on the hemodynamic significance of any graft stenosis. Patients also completed quality of life questionnaires. From a total of 160 patients who underwent robotic-assisted CABG, 82 eligible patients were followed with graft patency assessments for a mean period of 8 years±16.3 months. The patency rate of all robotic-assisted CABG grafts in this patient cohort was 92.7%. The patency rate of left internal thoracic artery grafts to the left anterior descending artery after robotic-assisted CABG in this patient cohort was 93.4%. Patients consistently attained high scores on quality of life questionnaires after surgery. The long-term patency rate of grafts after robotic-assisted CABG was 92.7% at a mean follow-up period of 95.8±16.3 months. Specifically, the patency rate of left internal thoracic artery grafts to the left anterior descending artery after robotic-assisted CABG was 93.4%.