Venous Coronary Artery Bypass Graft Research Articles

Investigating the peri-saphenous vein graft fat attenuation index on computed tomography angiography: relationship with progression of venous coronary artery bypass graft disease and temporal trends

BackgroundTo clarify the fat attenuation index (FAI) change trend of peri-saphenous vein graft (SVG) and determine the association between FAI and graft disease progression based on CCTA images.MethodsPatients with venous coronary artery bypass grafts (CABGs) were consecutively enrolled in this retrospective study. In study 1, 72 patients who had undergone 1, 3, and 5 years of CCTA examinations without graft occlusion were recruited, and generalized estimation equation was used to analyze the peri-SVG FAI change trend over time. In study 2, 42 patients with graft disease progression and 84 patients as controls were propensity score-matched. Generalized linear mixed model and continuous net reclassification improvement (NRI) were used for assessing the associations with graft disease progression. Multivariable Cox regression analysis was used for assessing risk factors predicting cardiac events.ResultsIn study 1, both the FAI of proximal right coronary artery and SVG decreased over time. In study 2, the 1-year CTA-derived FAI of grafts and graft anastomosis were independent indicators of graft disease progression at the 3-year CCTA follow-up (graft: odds ratio [OR] = 1.106; 95% confidence interval [CI] = 1.030–1.188, P = 0.006; graft anastomosis: OR = 1.170, 95% CI = 1.091–1.254, P < 0.001). Inclusion of the graft anastomosis FAI significantly improved reclassification compared with graft FAI (continuous NRI = 0.638, 95% CI: 0.345–0.931, P < 0.001). Moreover, The graft anastomosis FAI was found to be a risk factor for cardiac events after CABG and no statistically significant difference was found in the graft FAI (graft anastomosis: HR = 1.158, 95% CI = 1.034–1.297, P = 0.011; graft: HR = 1.116, 95% CI = 0.995–1.251, P = 0.061).ConclusionsA synchronism was found in the FAI change trend between native coronary artery and venous graft, which both decreased over time. The CCTA-derived FAI of venous grafts showed the potential of demonstrating SVG disease progression and graft anastomosis served as the optimal measured location.

Endothelial damage inhibitor preserves the integrity of venous endothelial cells from patients undergoing coronary bypass surgery.

Despite the success of coronary artery bypass graft (CABG) surgery using autologous saphenous vein grafts (SVGs), nearly 50% of patients experience vein graft disease within 10 years of surgery. One contributing factor to early vein graft disease is endothelial damage during short-term storage of SVGs in inappropriate solutions. Our aim was to evaluate the effects of a novel endothelial damage inhibitor (EDI) on SVGs from patients undergoing elective CABG surgery and on venous endothelial cells (VECs) derived from these SVGs. SVGs from 11 patients participating in an ongoing clinical registry (NCT02922088) were included in this study, and incubated with both full electrolyte solution (FES) or EDI for 1 h and then examined histologically. In 8 of 11 patients, VECs were isolated from untreated grafts, incubated with both FES and EDI for 2 h under hypothermic stress conditions and then analysed for activation of an inflammatory phenotype, cell damage and cytotoxicity, as well as endothelial integrity and barrier function. The EDI was superior to FES in protecting the endothelium in SVGs (74 ± 8% versus 56 ± 8%, P < 0.001). Besides confirming that the EDI prevents apoptosis in SVG-derived VECs, we also showed that the EDI temporarily reduces adherens junctions in VECs while protecting focal adhesions compared to FES. The EDI protects the connectivity and function of the SVG endothelium. Our data suggest that the EDI can preserve focal adhesions in VECs during short-term storage after graft harvesting. This might explain the superiority of the EDI in maintaining most of the endothelium in venous CABG surgery conduits.

Wall Shear Stress Differences Between Arterial and Venous Coronary Artery Bypass Grafts One Month After Surgery.

Although coronary artery bypass graft (CABG) surgery is a well-established intervention, graft failure can occur, and the underlying mechanisms remain incompletely understood. The purpose of this prospective study is to utilize computational fluid dynamics (CFD) to investigate how graft hemodynamics one month post surgery may vary among graft types, which have different long-term patency rates. Twenty-four grafts from 10 participants (64.6 ± 8.5years, 9 men) were scanned with coronary CT angiography and 4D flow MRI one month after CABG surgery. Grafts included 10 left internal mammary arteries (LIMA), 3 radial arteries (RA), and 11 saphenous vein grafts (SVG). Image-guided CFD was used to quantify blood flow rate and wall area exposed to abnormal wall shear stress (WSS). Arterial grafts had a lower abnormal WSS area than venous grafts (17.9% vs. 70.1%; p = 0.001), and a similar trend was observed for LIMA vs. SVG (13.8% vs. 70.1%; p = 0.001). Abnormal WSS area correlated positively to lumen diameter (p < 0.001) and negatively to flow rate (p = 0.001). This CFD study is the first of its kind to prospectively reveal differences in abnormal WSS area 1month post surgery among CABG types, suggesting that WSS may influence the differential long-term graft failure rates observed among these groups.

Surgical myocardial revascularization outcomes in Kawasaki disease: systematic review and meta-analysis.

BackgroundKawasaki disease (KD) is a systemic inflammatory condition occurring predominantly in children. Coronary artery bypass grafting (CABG) is performed in the presence of inflammation and aneurysms of the coronary arteries. The objectives of our study were to assess which CABG strategy provides better graft patency and early and long-term outcomes.MethodsA systematic review using Medline, Cochrane, and Scopus databases was performed in February 2020, incorporating a network meta-analysis, performed by random-effect model within a Bayesian framework, and pooled prevalence of adverse outcomes. Hazard ratios (HR) and corresponding 95% credible intervals (CI) were calculated by Markov chain Monte Carlo methods.ResultsAmong 581 published reports, 32 studies were selected, including 1,191 patients undergoing CABG for KD. Graft patency of internal thoracic arteries (ITAs), saphenous veins (SV), and other arteries (gastroepiploic artery and radial artery) was compared. ITAs demonstrated the best patency rates at long-term follow-up (HR 0.33, 95% CI: 0.17–0.66). Pooled prevalence of early mortality after CABG was 0.28% (95% CI: 0.00–0.73%, I 2 = 0%, tau2 = 0), with 63/1,108 and 56/1,108 patients, undergoing interventional procedures and surgical re-interventions during follow-up, respectively. Pooled prevalence was 3.97% (95% CI: 1.91–6.02%, I 2 = 60%, tau2 = 0.0008) for interventional procedures and 3.47% (95% CI: 2.26–4.68%, I 2 = 5%, tau2 <0.0001) for surgical re-interventions. Patients treated with arterial, venous, and mixed (arterial plus second venous graft) CABG were compared to assess long-term mortality. Mixed CABG (HR 0.03, 95% CI: 0.00–0.30) and arterial CABG (HR 0.13, 95% CI: 0.00–1.78) showed reduced long-term mortality compared with venous CABG.ConclusionsCABG in KD is a safe procedure. The use of arterial conduits provides better patency rates and lower mortality at long-term follow-up.

MiRMap: Profiling 14q32 microRNA Expression and DNA Methylation Throughout the Human Vasculature.

Aims: MicroRNAs are regulators of (patho)physiological functions with tissue-specific expression patterns. However, little is known about inter-vascular differences in microRNA expression between blood vessel types or vascular beds. Differences in microRNA expression could influence cardiovascular pathophysiology at specific sites in the vasculature. Therefore, we aimed to map expression profiles of vasoactive 14q32 microRNAs throughout the human vasculature, as well as expression of vasoactive target genes of the 14q32 microRNAs. Furthermore, we aimed to map the DNA methylation status of the 14q32 locus, which has been linked to cardiovascular disease.Methods and Results: We collected 109 samples from different blood vessels, dissected during general surgery. Expression of a representative set of 17 14q32 microRNAs was measured in each sample. All 17 microRNAs showed a unique expression pattern throughout the vasculature. 14q32 microRNA expression was highest in lower limb vessels and lowest in head and neck vessels. All 17 microRNAs were expressed more abundantly in arteries than in veins. Throughout the human vasculature, we observed trends toward an inverse correlation between expression levels of the 14q32 microRNAs and their vasoactive target genes. DNA methylation of the 3 Differentially Methylated Regions (DMRs) along the 14q32 locus did not associate with primary or mature microRNA expression. However, hyper-methylation in venous coronary artery bypass grafts compared to arterial bypass grafts was observed in the Intergenic-DMR and MEG3-DMR. In patients with end-stage peripheral arterial disease we found differential DNA methylation throughout all DMRs in their lower limb veins. These findings were confirmed in a mouse model for vein-graft disease in which we found regulated 14q32 DNA methylation during the active phase of vascular remodeling. In ischemic tissues of a murine hind limb ischemia model we observed an increase in DNA methylation associated with increased ischemia over time.Conclusions: We show that 14q32 microRNAs are abundantly expressed in the human vasculature and that expression differs significantly between different blood vessels. 14q32 DNA methylation also varies throughout the vasculature and is associated with vascular health, independently of microRNA levels. These findings could have important implications for future research and for future site-specific targeting of epigenetics-based therapeutics.

Life-long clinical outcome after the first myocardial revascularization procedures: 40-year follow-up after coronary artery bypass grafting and percutaneous coronary intervention in Rotterdam.

Our goal was to evaluate the outcomes of the first patients treated by venous coronary artery bypass grafting (CABG) or percutaneous coronary interventions (PCIs) with balloon angioplasty at a single centre who have reached up to 40 years of life-long follow-up. We analysed the outcomes of the first consecutive patients who underwent (venous) CABG (n = 1041) from 1971 to 1980 and PCI (n = 856) with balloon angioplasty between 1980 and 1985. Follow-up was successfully achieved in 98% of patients (median 39 years, range 36-46) who underwent CABG and in 97% (median 33 years, range 32-36) of patients who had PCI. The median age was 53 years in the CABG cohort and 57 years in the PCI cohort. A total of 82% of patients in the CABG group and 37% of those in the PCI group had multivessel coronary artery disease. The cumulative survival rates at 10, 20, 30 and 40 years were 77%, 39%, 14% and 4% after CABG, respectively, and at 10, 20, 30 and 35 years after PCI were 78%, 47%, 21% and 12%, respectively. The estimated life expectancy after CABG was 18 and 17 years after the PCI procedures. Repeat revascularization was performed in 36% and 57% of the patients in the CABG and PCI cohorts, respectively. This unique life-long follow-up analysis demonstrates that both CABG and PCI were excellent treatment options immediately after their introduction as the standard of care. These procedures were lifesaving, thereby indirectly enabling patients to be treated with newly developed methods and medical therapies during the follow-up years.

Advantages and disadvantages of total arterial coronary artery bypass graft as compared to venous coronary artery bypass graft

Advantages and disadvantages of total arterial coronary artery bypass graft as compared to venous coronary artery bypass graft

Role of smooth muscle cells in coronary artery bypass grafting failure.

Atherosclerosis is the underlying pathology of many cardiovascular diseases. The formation and rupture of atherosclerotic plaques in the coronary arteries results in angina and myocardial infarction. Venous coronary artery bypass grafts are designed to reduce the consequences of atherosclerosis in the coronary arteries by diverting blood flow around the atherosclerotic plaques. However, vein grafts suffer a high failure rate due to intimal thickening that occurs as a result of vascular cell injury and activation and can act as 'a soil' for subsequent atherosclerotic plaque formation. A clinically-proven method for the reduction of vein graft intimal thickening and subsequent major adverse clinical events is currently not available. Consequently, a greater understanding of the underlying mechanisms of intimal thickening may be beneficial for the design of future therapies for vein graft failure. Vein grafting induces inflammation and endothelial cell damage and dysfunction, that promotes vascular smooth muscle cell (VSMC) migration, and proliferation. Injury to the wall of the vein as a result of grafting leads to the production of chemoattractants, remodelling of the extracellular matrix and cell-cell contacts; which all contribute to the induction of VSMC migration and proliferation. This review focuses on the role of altered behaviour of VSMCs in the vein graft and some of the factors which critically lead to intimal thickening that pre-disposes the vein graft to further atherosclerosis and re-occurrence of symptoms in the patient.

D-dimer is associated with arterial and venous coronary artery bypass graft occlusion

ObjectiveIn this observational prospective study, we assessed the role of clinical variables and circulating biomarkers in graft occlusion at 18 months to identify a signature for graft occlusion. MethodsA total of 330 patients undergoing primary elective coronary artery bypass grafting were enrolled. Blood collection for biomarker assessment was performed before surgery and discharge. Patients were then scheduled to undergo coronary computed tomography angiography at 18 months follow-up, and 179 patients underwent coronary computed tomography angiography 18 ± 2 months postoperatively. ResultsThere were 46 of 503 (9.1%) occluded grafts; of these, 29 (63%) were venous and 17 (37%) were arterial grafts; overall, 43 of 179 patients (24%) had at least 1 occluded graft. Logistic mixed effects model assessing independent factors associated with graft occlusion identified that lower D-dimer levels at baseline (odds ratio [OR], 2.58; 95% confidence interval [CI], 1.36-4.89; P = .00) and total protein content at discharge (OR, 1.09; 95% CI, 1.01-1.19; P = .028) were related to overall graft occlusion at follow-up, along with an arterial graft other than the left internal thoracic artery (OR, 2.92; 95% CI, 1.24-6.9; P = .078); moreover, a venous graft emerged was possibly associated with graft occlusion (OR, 1.51; 95% CI, 0.95-2.39; P = .078). By separately analyzing saphenous vein and arterial grafts, D-dimer levels (OR, 2.67; 95% CI, 1.15-6.2; P = .022 and OR, 2.5; 95% CI, 1.01-7.0; P = .05 for venous and arterial graft, respectively) were still associated with arterial and venous graft occlusion at follow-up. ConclusionsWe identified D-dimer as a biomarker associated with arterial and venous grafts occlusion. This may help stratify patients at risk of graft failure and identify new molecular targets to prevent this complication.

The Unplanned Postoperative Coronary Angiogram after CABG: Identifying the Patients at Risk

Objectives Coronary artery bypass grafting (CABG) is the "gold standard" for patients with multiple vessel coronary artery disease (CAD). However, there is no "gold standard" to control bypass patency immediately postoperatively. "Post-completion" control angiogram (CA) is not routinely performed. We retrospectively analyzed the data of all patients undergoing urgent coronary angiogram post-CABG at our center. Methods Between January 2005 and June 2011, a total of 6,025 patients underwent CABG (isolated or combined) for CAD in our hospital. In patients who underwent urgent postoperative CA, high serum cardiac enzymes (>100 CK-MB), severe new ECG changes, or unexpected low left ventricular function were present. Results A total of 106 patients (1.8%) underwent post-CABG urgent coronary angiogram. Overall 30-day mortality in this cohort was 8.5%. The average time between the cardiac operation and the coronary angiogram in these patients was 3.41 ± 5.68 days. The rates for an urgent coronary angiogram were 1.3% (n = 25), 2% (n = 65), and 1.8% (n = 16) for total arterial, combined arterial, and venous and solely venous CABG, respectively. Twenty-four percent of patients underwent CABG bypass revision, while 32% of the patients underwent PTCA, stenting, or both. Younger patients, female patients, smaller patients, and patients receiving a combined arterial and venous revascularization were at a higher risk for an unplanned postoperative CA in the multivariate risk analysis. Conclusion This study shows that the necessity for urgent post-CABG coronary angiogram is low (1.8%). However, more than half of the patients undergoing postoperative coronary angiogram needed reintervention, and, in spite of it, had high mortality. "Completion" control angiogram is not always feasible, patients at higher risk (e.g., female patients) should be identified and post-CABG coronary angiogram performed as soon as possible without undue delay, or a primary hybrid approach with an intraoperative CA should be applied.

0025 : Myocardial revascularization modalities in 200 patients with venous coronary artery bypass graft failure

The therapeutic management of bypass failure has been little studied. Compare prognosis and the occurrence of cardiovascular events at 2 years in patients with venous bypass graft failure by differentiating between three patient groups: medical therapy, percutaneous coronary intervention (PCI) in native vessels (native PCI), and PCI in coronary artery bypass grafts (PCI-CABG). Retrospective observational study in patients with bypass graft failure diagnosed between February 2009 and September 2013 at Poitiers University Hospital, France. Follow-up data at 1 year and at 2 years regarding major adverse cardiac events (MACEs), defined as death, acute coronary syndrome (ACS) or revascularization, were collected during patient visits to the department. From a series of 320 CABG patients examined using coronary angiography, all patients with bypass graft failure were included in the study (200 patients). Mean age was 69 years (+/- 11). Coronary angiography was performed a mean of 117 months after bypass surgery. Medical therapy alone was chosen in 88 patients, 75 patients underwent native PCI, and 37 patients underwent PCI-CABG. Patients in the PCI-CABG group were older (73.6 years; p = 0.027) and had significantly older bypass grafts (22% for a period of more than 10 years; p = 0.018), and their typical clinical presentation was one of ACS without ST-segment elevation (41%; p = 0.006). The groups were comparable in terms of hospital complications, except for vascular complications, which were more common in the PCI-CABG group (8%; p =0.01). At 1 year, no significant difference in terms of MACEs was found, but there was a trend towards an increase in ACS without ST-segment elevation (11%; p =0.06) in the PCI-CABG group, and towards an increase in ACS with STsegment elevation (7%; p = 0.06) in the medical therapy group. At 2 years, the medical therapy group stood out by virtue of a significant increase in MACEs compared with the other two groups (63%; p = 0.02). The native PCI group presented both fewer MACEs and fewer vascular complications. MACEs were common and more severe in the medical therapy group. When coronary lesions are amenable to PCI, PCI in native vessels should be proposed as first-line treatment. PCI of CABG is performed in a riskier setting and has poorer prognosis.

Histological evaluation of age-related variations in saphenous vein grafts used for coronary artery bypass grafting

IntroductionVenous coronary artery bypass grafts (CABG) might undergo a process of arterialization resulting in neointimal formation and medial hypertrophy. It is often followed by critical occlusion of the graft lumen. The aim of the study was to assess histological representative features of saphenous vein reconstruction in aging as well as to establish optimal patients’ age limits applicable for optimal selection of grafts.Material and methodsOne hundred and ten patients undergoing venous CABG were divided into 4 age subgroups: (A) 50 years and less, (B) 51-60 years, (C) 61-70 years and (D) > 70 year-old subjects. Distal venous graft segments were saved for an adequate morphometric assay which was followed by suitable statistical analysis.ResultsThe entire venous wall thickness as well as its tunica media were found to become significantly thinner between subgroups A and D. The number of smooth muscle cell (SMC) nuclei within the tunica media did not differ between study subgroups. The majority of these nuclei in subgroup D were found, however, to be more elongated than in subgroup A (SMC length/width index in subgroup D was found to be significantly higher than in subgroup A).ConclusionsProgressive, age-related thinning of the venous wall and tunica media as well as SMC nucleus elongation might suggest impairment of SMCs’ migration and proliferation rate. Consequently, individuals aged 70 years and over may benefit clinically more from venous CABG than younger patients due to the lower risk of arterialization and occlusion of the graft lumen in the future.

Rupture of a Saphenous Graft Into the Right Ventricle

![Figure][1] [![Graphic][3] ][3][![Graphic][4] ][4] A 90-year-old male patient with a 28-year history of saphenous venous coronary artery bypass graft on the left anterior descending was admitted for acute chest pain followed by shortness of breath after rushing to catch a train

EComment: External nitinol meshing of venous coronary artery bypass grafts: is safety of application really in doubt?

eComment: External nitinol meshing of venous coronary artery bypass grafts: is safety of application really in doubt?

Evaluation of contrast wash-in and peak enhancement in adenosine first pass perfusion CMR in patients post bypass surgery.

BackgroundAdenosine first pass perfusion cardiovascular magnetic resonance (CMR) yields excellent results for the detection of significant coronary artery disease (CAD). In patients with coronary artery bypass grafts (CABG) the kinetics of a contrast bolus may by altered only due to different distances through the bypass grafts compared to native vessels, thereby possibly imitating a perfusion defect. The aim of the study was to evaluate semiquantitative perfusion parameters in order to assess possible differences in epicardial contrast kinetics in areas supplied by native coronaries and CABG, both without significant stenosis.MethodsTwenty patients with invasive exclusion of significant CAD (control group) and 38 patients with CABG without angiographically significant (≥50%) stenosis in unbypassed coronaries or grafts were retrospectively included in the study. They underwent adenosine first pass (0.05 mmol/kg Gd-DTPA) perfusion (3 short axis views/heart beat) and late gadolinium enhancement (LGE) imaging 1 day before invasive coronary angiography. Areas perfused by native coronaries and/or the different bypasses were identified in X-ray angiography using the 16 segment model. In each of these areas upslope and maximal signal intensity (SImax) relative to the left ventricular parameters, time to 50% maximal signal intensity (TSI50%max) and time to maximal signal intensity (TSImax) were calculated.ResultsIn areas perfused by coronary arteries with bypasses compared to native coronaries relative upslope and relative SImax did not show a significant difference. TSI50%max and TSImax in native coronaries and bypasses were 7.2s ± 1.9s vs. 7.5s ± 1.9s (p < 0.05) and 12.6s ± 3.0s vs. 13.1s ± 3.0s (p < 0.05), respectively. The delay in Tmax resulted in a significant (p < 0.05) delay of 0.5 ± 1.1 heart beats (=images) when adjusted to the heart rate. Differences in time were most pronounced in areas perfused by left internal mammary artery grafts rather than by venous CABG, but were also present between native vessel territories in patients without CAD, albeit with smaller variability.ConclusionAdenosine perfusion CMR in patients post CABG may be associated with a short delay in contrast arrival. However, once the contrast is in the myocardium there is similar wash-in kinetics and peak enhancement. Therefore, since the delay is only short, the possibly differing contrast kinetics through grafts and native vessels does not seem to be a limiting factor for the accuracy of first pass adenosine perfusion in patients post CABG.

Intercorrências clínicas no membro submetido à exérese de veia safena magna para revascularização do miocárdio

The aim of this study was to assess clinical complications of limbs undergone harvesting of the great saphenous vein for venous coronary artery bypass graft surgery using bridge technique. Fourty-four patients who had undergone CABG using the great saphenous vein harvested by the bridge technique over more than 3 months ago were randomly selected. The exclusion criteria were the harvesting of both saphenous veins, prior saphenectomy of the contralateral limb, edema caused by a systemic etiology, such as heart, renal, thyroid or hepatic diseases and venous insufficiency of the lower limbs as characterized by swollen varicose veins both with and without trophic changes. The age, gender, diabetes, time of surgery and occurrence of complications, such as edema, paresthesia, infection, lymphorrhea, erysipelas and deep venous thrombosis, were assessed. The assessment was clinic and diagnosis of the diabetes was performed by the preoperative exams. The chi-square, Fisher and Student's t tests were used for statistical analysis with an alpha error of 5%. The time between surgery and assessment ranged between 3 and 187 months with a mean of 47.3+/-42.5 months. Infections of the saphenous harvest site were detected in 25% of the cases, edema in 52.3%, paresthesia in 29.5%, erysipelas in 9.1%, lymphorrhea in 4.5% and deep venous thrombosis in 2.3%. There was no association between diabetes and complications. The saphenous vein harvesting using bridge technique for coronary artery bypass grafting does not eliminate clinical complications, such as paresthesia, infection and edema of the saphenous vein harvesting site.

The clinical outcome after coronary bypass surgery: a 30-year follow-up study

To investigate the long-term clinical outcome (up to 30 years) after coronary artery bypass graft (CABG) surgery and to assess the life expectancy (LE) among subgroups of patients. We analysed the 30-year outcome of the first 1041 consecutive patients in our institution (age at operation 53 years, 88% male) who underwent venous CABG between 1971 and 1980. During follow-up, every 5-7 years follow-up status was obtained by reviewing the hospital records and from general practitioners and civil registries. Data were collected on death and repeat coronary revascularization procedures. Follow-up was complete in 98%. Median follow-up was 29 years (26-36 years). The cumulative 10-, 20-, and 30-year survival rates were 77%, 40%, and 15%, respectively. Overall, 623 coronary re-interventions were performed in 373 patients (36%). The cumulative 10-, 20-, and 30-year freedom from death and coronary re-intervention rates were 60%, 20%, and 6%, respectively. Age [hazard ratio (HR) 1.04/year], extent of vessel disease (VD) (two-VD HR 1.4; three-VD HR 1.9), left main disease (HR 1.6) and impaired left ventricular ejection fraction (LVEF) (HR 1.8) were independent predictors of mortality. We were able to assess the exact LE by calculating the area under the Kaplan-Meier curves. Overall LE after first CABG was 17.6 years. LE in patients with one-, two-, and three-VD was 21.4, 18.8, and 15.4 years, respectively (P < 0.0001). Patients with impaired LVEF had a significant shorter LE than patients with normal LVEF (13.9% vs. 19.3%; P < 0.0001). This 30-year follow-up study comprises the almost complete life cycle after CABG surgery. Overall median LE was 17.6 years. As the majority of the patients (94%) needed a repeat intervention, we conclude that the classic venous bypass technique is a useful but palliative treatment of a progressive disease.

Flow and wall shear stress in end-to-side and side-to-side anastomosis of venous coronary artery bypass grafts

PurposeCoronary artery bypass graft (CABG) surgery represents the standard treatment of advanced coronary artery disease. Two major types of anastomosis exist to connect the graft to the coronary artery, i.e., by using an end-to-side or a side-to-side anastomosis. There is still controversy because of the differences in the patency rates of the two types of anastomosis. The purpose of this paper is to non-invasively quantify hemodynamic parameters, such as mass flow and wall shear stress (WSS), in end-to-side and side-to-side anastomoses of patients with CABG using computational fluid dynamics (CFD).MethodsOne patient with saphenous CABG and end-to-side anastomosis and one patient with saphenous CABG and side-to-side anastomosis underwent 16-detector row computed tomography (CT). Geometric models of coronary arteries and bypasses were reconstructed for CFD analysis. Blood flow was considered pulsatile, laminar, incompressible and Newtonian. Peri-anastomotic mass flow and WSS were quantified and flow patterns visualized.ResultsCFD analysis based on in-vivo CT coronary angiography data was feasible in both patients. For both types of CABG, flow patterns were characterized by a retrograde flow into the native coronary artery. WSS variations were found in both anastomoses types, with highest WSS values at the heel and lowest WSS values at the floor of the end-to-side anastomosis. In contrast, the highest WSS values of the side-to-side anastomosis configuration were found in stenotic vessel segments and not in the close vicinity of the anastomosis. Flow stagnation zones were found in end-to-side but not in side-to-side anastomosis, the latter also demonstrating a smoother stream division throughout the cardiac cycle.ConclusionCFD analysis of venous CABG based on in-vivo CT datasets in patients was feasible producing qualitative and quantitative information on mass flow and WSS. Differences were found between the two types of anastomosis warranting further systematic application of the presented methodology on multiple patient datasets.

Venous coronary artery bypass grafting: late results of a 15-year actuarial follow-up in 486 patients.

The aim of this study was to clarify the long-term results of venous coronary artery bypass grafting in Japanese patients. The study population included 492 patients who underwent venous coronary artery bypass procedures at the Department of Cardiothoracic Surgery of Juntendo University from January 1984 to December 1989. The great majority of patients, 420 of 492 (85.4%), were males, and the mean patient age was 61.1 years (range: 32-82 years). The disease conditions included single-vessel disease in 32 patients (6.5%), double-vessel disease in 111 patients (22.6%), triple-vessel disease in 251 patients (51.2%), and 50% or more stenosis of the left main coronary artery in 98 patients (19.9%). A mean of 2.4 grafts was used per patient. The 15-year survival rate was 57.7%. The 15-year actuarial cardiac survival and cardiac event-free survival were 81.3% and 51.3%, respectively. The 15-year actuarial freedom from reoperation and myocardial infarction were 87.5% and 92.1%, respectively. Of 192 patients who died during the follow-up period, 62 deaths were due to cardiac causes (32.3%), 43 were due to malignant neoplasms (22.4%), and 25 were due to cerebral vascular accidents (13.0%). The prognosis of Japanese patients undergoing coronary artery bypass grafting may therefore be more favorable than that of Western patients. In addition, diabetes mellitus was an independent risk factor for both cardiac death and cardiac events.

Local generation of C-reactive protein in diseased coronary artery venous bypass grafts and normal vascular tissue.

Venous coronary artery bypass grafts (CABGs) are prone to accelerated atherosclerosis. In atherosclerotic diseases, serum C-reactive protein (CRP) levels have become an important diagnostic and prognostic marker. The origin of CRP in this setting remains to be elucidated. Monoclonal anti-CRP identified CRP expression in medial and intimal alpha-actin-positive smooth muscle cells (SMCs) of diseased CABGs with type V and VI lesions and also of native saphenous veins of atherosclerotic individuals. In addition, patent coronary arteries with type IV and V but not with type I through III lesions exhibited intense SMC staining for CRP. Calcified desobliterates of occluded coronary arteries with end-stage disease did not show SMC staining for CRP and were consistently negative for CRP mRNA, as detected by means of real-time polymerase chain reaction. However, CRP mRNA was expressed in 11 of 15 diseased CABGs and also in 10 of 15 native veins. By contrast, only 3 of 18 internal mammary and 4 of 12 radial arteries with virtually no atherosclerosis were positive for CRP mRNA. CRP is produced by SMCs of atherosclerotic lesions with active disease but not in end-stage plaques. The role of CRP constitutively expressed by normal vascular tissue in vein graft disease has yet to be elucidated.