Vein Graft Occlusion Research Articles

THE CASE FILES

THE CASE FILES

Intensive versus moderate atorvastatin therapy and one-year graft patency after CABG: Rationale and design of the ACTIVE (Aggressive Cholesterol Therapy to Inhibit Vein Graft Events) randomized controlled trial (NCT01528709)

RationaleSaphenous vein graft disease remains a major limitation of coronary artery bypass graft surgery (CABG). Statin therapy inhibits the development of vein graft disease and improves outcomes after CABG. However, it is unclear whether treatment with high-dose statins will further slow the process of vein graft disease and improve graft patency, as compared to conventional moderate doses. Therefore, the goal of this study will be to evaluate the efficacy of high-dose statin therapy versus moderate-dose statin therapy for the prevention of saphenous vein graft occlusion following CABG. Study designThe Aggressive Cholesterol Therapy to Inhibit Vein Graft Events (ACTIVE) trial is a multi-center double-blind randomized controlled trial enrolling patients who have undergone multi-vessel CABG with at least one saphenous vein graft. Patients will be randomized to receive either atorvastatin 80mg daily or atorvastatin 10mg daily for one year starting within 5days after surgery. The target enrollment is 100 patients in each arm (200 patients total). Lipid levels will be assessed every 3months. After one year, patients will undergo computed tomography (CT) coronary angiography to assess the incidence of vein graft occlusion and stenosis. ConclusionThis trial is the first prospective study to evaluate the impact of early postoperative high-dose statin therapy on graft patency after CABG. Should high-dose statin therapy reduce the incidence of postoperative graft occlusion, the results will add to the growing evidence supporting the role of high-intensity statins for modern lipid management after coronary surgical revascularization (ClinicalTrials.govNCT01528709).

Association of lipoprotein(a) level with short- and long-term outcomes after CABG: The role of lipoprotein apheresis

ObjectiveTo evaluate the association of lipoprotein(a) [Lp(a)] level with short- and long-term outcomes after coronary artery bypass grafting (CABG) and to assess the effect of a 12 month course of weekly lipoprotein apheresis on vein graft patency and coronary atherosclerosis course in post-CABG patients with hyperlipidemia. MethodsThis study was performed in patients after successful CABG and consisted of three parts: a) a retrospective part with computed tomography assessment of vein graft patency in patients with first-year recurrence of chest pain after CABG (n = 102); b) a prospective trial with evaluation of cardiovascular outcomes during follow up time up to 15 years in relation to baseline Lp(a) levels (n = 356); c) an 12-months interventional controlled study in 50 patients with low-density lipoprotein cholesterol (LDL-C) levels >2.6 mmol/L prior to the operation despite statin treatment that allocated into 2 groups: active (n = 25, weekly apheresis by cascade plasma filtration (CPF) plus atorvastatin), and control (n = 25, atorvastatin alone). ResultsPatients subjected to computed tomography were divided in two groups: 66 (65%) with at least one vein graft occlusion and 36 (35%) without occlusions. Lp(a) levels were significantly higher in patients with occluded grafts with a median (95% confidence intervals (CI)) of 24 (17–42) mg/dL vs. 12 (6–24) mg/dL in patients with patent grafts, p < 0.01.Over a mean of 8.5 ± 3.5 years (range 0.9–15.0 years), the primary and secondary endpoints were registered in 46 (13%) and 107 (30%) patients, respectively. Patients with Lp(a) ≥30 mg/dL were at significantly greater risk for the primary endpoint (hazard ratio (HR) 2.98, 95% confidence interval (CI) 1.76–5.03, p < 0.001) and secondary endpoint (HR 3.47, 95%CI 2.48–4.85, p < 0.001) than patients with Lp(a) values <30 mg/dL.During the CPF procedure LDL-C levels decreased by 59 ± 14%, Lp(a) levels by 49 ± 15. The frequency of vein graft occlusions at study end was 14.3% (11 of 77) in the apheresis group and 27.4% (23 of 84) in the control group, p < 0.05. Progression of atherosclerosis was obtained in 26 (14.2%) segments of native coronary arteries in the apheresis group and in 50 (25.0%) segments of the control group. Regression signs were found in 30 (16.4%) and 19 (9.5%) segments, stabilization in 127 (69.4%) and 131 (65.5%) segments, respectively (χ2 = 9.37, p < 0.01). A Lp(a) level higher than 30 mg/dL was associated with a three-fold increased risk of vein grafts occlusion during first year after CABG, p < 0.001. ConclusionOur data suggest that elevated Lp(a) is associated with a significantly increasing rate of one-year vein graft occlusions and adverse long-term cardiovascular outcomes whereas the use of lipoprotein apheresis improves vein graft patency during the first year after CABG.

Preoperative factors predicting saphenous vein graft occlusion in coronary artery bypass grafting: a multivariate analysis

Saphenous vein segments are frequently used as aortocoronary bypass grafts, particularly in patients over 65 years of age. In the majority of patients, venous grafts maintain their patency for 5–6 years; however, some become occluded within 12 months after surgery. There are some defined predictive biological factors used to assess saphenous vein graft long-term patency rates, but little is known about molecular parameters for estimating the risk of early vein occlusion. The pathogenesis of this process involves the proliferation of stem cells, as well as progenitor cells, in the graft wall. Histologically, this is reflected by CD34 and CD133 expression in endothelial and smooth muscle cells. Thus, the aim of present work was to perform a multivariate analysis of stem cell and progenitor cell markers in saphenous vein graft walls before transplantation to arterial circulation and correlate these results with early graft occlusion. A total of 718 patients, who underwent coronary artery bypass grafting using a saphenous vein graft, were enrolled in this prospective study. CD34, CD133 and von Willebrand factor expression was evaluated via immunohistochemistry. A multivariate analysis revealed that strong CD133 expression in smooth muscle cells can be considered a risk factor for early graft failure. Our findings suggest that CD133 expression in smooth muscle cells of the tunica media in saphenous vein grafts obtained from coronary artery bypass graft patients before graft transplantation to coronary circulation might predict the possibility of early graft occlusion.

Recombinant soluble apyrase APT102 inhibits thrombosis and intimal hyperplasia in vein grafts without adversely affecting hemostasis or re‐endothelialization

Background Occlusion of vein grafts (VGs) after bypass surgery, owing to thrombosis and intimal hyperplasia (IH), is a major clinical problem. Apyrases are enzymes that scavenge extracellular ATP and ADP, and promote adenosine formation at sites of vascular injury, and hence have the potential to inhibit VG pathology. Objectives To examine the effects of recombinant soluble human apyrase, APT102, on platelets, smooth muscle cells (SMCs) and endothelial cells (ECs) in vitro, and on thrombosis and IH in murine VGs. Methods SMC and EC proliferation and migration were studied in vitro. Inferior vena cava segments from donor mice were grafted into carotid arteries of recipient mice. Results APT102 potently inhibited ADP-induced platelet aggregation and VG thrombosis, but it did not impair surgical hemostasis. APT102 did not directly inhibit SMC or EC proliferation, but significantly attenuated the effects of ATP on SMC and EC proliferation. APT102 significantly inhibited SMC migration, but did not inhibit EC migration, which may be mediated, at least in part, by inhibition of SMC, but not EC, migration by adenosine. At 4 weeks after surgery, there was significantly less IH in VGs of APT102-treated mice than in control VGs. APT102 significantly inhibited cell proliferation in VGs, but did not inhibit re-endothelialization. Conclusions Systemic administration of a recombinant human apyrase inhibits thrombosis and IH in VGs without increasing bleeding or compromising re-endothelialization. These results suggest that APT102 has the potential to become a novel, single-drug treatment strategy to prevent multiple pathologic processes that drive early adverse remodeling and occlusion of VGs.

Platelet function one and three months after coronary bypass surgery in relation to once or twice daily dosing of acetylsalicylic acid

IntroductionCurrent guidelines recommend acetylsalicylic acid (ASA) treatment after coronary artery bypass grafting (CABG) to reduce thrombotic vein graft occlusion. The optimal dosage of ASA is not known. Materials and methodsForty-two patients undergoing elective CABG were randomized to receive either ASA 75mg or 160mg once daily (OD) or 75mg twice daily (BID) after the operation. Platelet function testing was performed before, and one and three months after the operation. ResultsWhite blood cell counts increased during the initial postoperative days whereas platelet counts were initially slightly reduced after the operation but increased after one month without any major changes of mean platelet volumes. Serum thromboxane B2 was more effectively suppressed at one and three months after the operation with ASA 75mg BID or 160mg OD than with 75mg OD (p<0.001). ASA 75mg BID and 160mg OD were equally effective. Adenosine diphosphate stimulated platelet aggregation in whole blood (Multiplate®) was increased one and three months after the operation, and this was counteracted by ASA 75mg BID but not by 75 or 160mg OD. Arachidonic acid-induced aggregation was more effectively inhibited by 75mg BID or 160mg OD compared to 75mg OD at three months. ConclusionsLess effective inhibition of platelet activation was obtained with ASA 75mg OD than with ASA 160mg OD or 75mg BID up to three months after CABG. Especially the latter dose is of interest for further studies of efficacy and clinical outcomes after CABG.

Patterns in the Management of Acute Limb Ischemia: A VESS Survey

Treatment strategies for acute limb ischemia (ALI) are abundant with few established guidelines. We sought to determine nationwide ALI treatment patterns in the modernera. Anonymous electronic surveys examining the management of ALI involving native vessel and bypass occlusion were sent to all members of the Vascular and Endovascular Surgery Society (n=738). Treatment options included catheter-directed lysis (CDL) or pharmacomechanical (PMT) thrombolysis and open surgery. CDL management strategies were evaluated for lytic and heparin dosing, fibrinogen monitoring, and treatment duration. Influence of Rutherford category (RC), time from training, practice type, hospital size, region, and protocol use was assessed. Data were analyzed by univariate contingency tables and multinomial regression analysis. A total of 117 (response rate of 16%) surveys were completed. The most common management strategy RC 2a ischemia in all conduit occlusions was endovascular (prosthetic graft, 96 [82%] respondents; vein graft 96 [82%] respondents; native artery occlusion 79 [68%] respondents), while those with RC 3 ischemia were more commonly treated with open techniques (prosthetic graft, 96 [83%]; vein graft 94 [81%]; native artery occlusion 94 [80%]). Of those respondents using endovascular therapy, CDL was most commonly used in RC 2a patients, while PMT was most commonly used in RC 3 patients. Multivariate analysis identified prosthetic and vein graft occlusion were more likely to be treated via endovascular approach (odds ratio, 2.45 and 2.78, respectively; P<0.001), while those with RC 2b (odds ratio, 0.19; P<0.001), RC 3 (odds ratio, 0.01; P<0.001), or in centers without a hybrid operating room (odds ratio, 0.49; P=0.017) were more likely to be treated by openapproach. Tissue plasminogen activator (TPA) dosing during catheter directed therapywas usually 1mg/hr (77%) with variable concentrations and duration of the initial treatment of 8-24 hr (78%). Most respondents indicated having developed their own protocols and patterns of treatment varied but were influenced by training and practice environment variables. Management strategies vary widely in ALI. Some effects of provider training and individual protocol development were observed, and TPA protocols were influenced by increased institutional responsibility for thrombolysis. Further efforts are needed to develop consensus guidelines for ALI management.

Lipoprotein(a) is a predictor of one-year vein graft occlusions in stable angina patients received lipoprotein apheresis for refractory hypercholesterolemia after coronary artery bypass grafting

Lipoprotein(a) is a predictor of one-year vein graft occlusions in stable angina patients received lipoprotein apheresis for refractory hypercholesterolemia after coronary artery bypass grafting

Is It Worthwhile Treating Occluded Cold Stored Venous Allografts by Thrombolysis?

Thrombolysis has been reported to be suboptimal in occluded vein grafts and cryopreserved allografts, and there are no data on the efficacy of thrombolysis in occluded cold stored venous allografts. The aim was to evaluate early outcomes, secondary patency and limb salvage rates of thrombolysed cold stored venous allograft bypasses and to compare the outcomes with thrombolysis of autologous bypasses. This was a single center study of consecutive patients with acute and non-acute limb ischemia between September 1, 2000, and January 1, 2014, with occlusion of cold stored venous allografts, and between January 1, 2012, and January 1, 2014, with occlusion of autologous bypass who received intra-arterial thrombolytic therapy. Sixty-one patients with occlusion of an infrainguinal bypass using a cold stored venous allograft (n=35) or an autologous bypass (n=26) underwent percutaneous intra-arterial thrombolytic therapy. The median duration of thrombolysis was 20h (IQR 18-24) with no difference between the groups (p=.14). The median follow up was 18.5 months (IQR 11.0-52.0). Secondary patency rates of thrombolysed bypass at 6 and 12 months were 44±9% and 32±9% in patients with a venous allograft bypass and 46±10% and 22±8% with an autologous bypass, with no difference between groups (p=.40). Limb salvage rates at 1, 6, and 12 months after thrombolysis in the venous allograft group were 83±7%, 72±8% and 63±9%, and in the autologous group 91±6%, 76±9%, and 65±13%, with no difference between groups (p=.69). Long-term results of thrombolysis of venous allograft bypasses are similar to those of autologous bypasses. Occluded cold stored venous allograft can be successfully re-opened in most cases with a favorable effect on limb salvage.

Secondary prevention for CABG patients: take two arterial grafts at the time of your coronary operation.

Due to its platelets-inhibitory effect, aspirin is one of the cornerstones in the field of prevention of ischemic events, having been widely shown to improve survival in patients with ischemic heart disease (1-4). The main reason explaining the antiplatelet activity of this drug consists in its ability to irreversibly act on thromboxane-A2 (TXA2), by reducing its production. As part of the wide spectrum of patients with ischemic heart disease, aspirin plays a key role also in the cohort of those undergoing coronary artery bypass grafting (CABG) surgery. Vein graft patency has in fact been demonstrated to be strongly influenced by aspirin, with angiographically detected vein graft occlusion occurring up to five times more frequently in patients receiving placebo than in those receiving acetylsalicylic acid (5). Aspirin administration shortly after CABG has been proved to improve survival by reducing the burden of ischemic events (6) and, accordingly, international guidelines recommend aspirin to be initiated within 6–12 hours postoperatively, if not administered preoperatively (7,8).

Risk Factors for Nonplatelet Thromboxane Generation After Coronary Artery Bypass Graft Surgery.

BackgroundPersistent thromboxane (TX) generation while receiving aspirin therapy is associated with an increased risk of cardiovascular events. The Reduction in Graft Occlusion Rates (RIGOR) study found that aspirin‐insensitive TXA 2 generation, indicated by elevated urine 11‐dehydro‐TXB 2 (UTXB 2) 6 months after coronary artery bypass graft surgery, was a potent risk factor for vein graft thrombosis and originated predominantly from nonplatelet sources. Our goal was to identify risks factors for nonplatelet TXA 2 generation.Methods and ResultsMultivariable modeling was performed by using clinical and laboratory variables obtained from 260 RIGOR subjects with verified aspirin‐mediated inhibition of platelet TXA 2 generation. The strongest variable associated with UTXB 2 6 months after surgery, accounting for 47.2% of the modeled effect, was urine 8‐iso‐prostaglandin (PG)F 2α, an arachidonic acid metabolite generated nonenzymatically by oxidative stress (standardized coefficient 0.442, P<0.001). Age, sex, race, lipid therapy, creatinine, left ventricular ejection fraction, and aspirin dose were also significantly associated with UTXB 2 (P<0.03), although they accounted for only 4.8% to 10.2% of the modeled effect. Urine 8‐iso‐PGF 2α correlated with risk of vein graft occlusion (odds ratio 1.67, P=0.001) but was not independent of UTXB 2. In vitro studies revealed that endothelial cells generate TXA 2 in response to oxidative stress and direct exposure to 8‐iso‐PGF 2α.ConclusionsOxidative stress–induced formation of 8‐iso‐PGF 2α is strongly associated with nonplatelet thromboxane formation and early vein graft thrombosis after coronary artery bypass graft surgery. The endothelium is potentially an important source of oxidative stress–induced thromboxane generation. These findings suggest therapies that reduce oxidative stress could be useful in reducing cardiovascular risks associated with aspirin‐insensitive thromboxane generation.

Abstract 12032: Chronic Kidney Disease Augments Vein Graft Disease Through Interleukin-9-dependent Mechanisms

Chronic kidney disease (CKD, glomerular filtration rate (GFR) &lt;60 ml/min/1.73 m 2 ) is a powerful independent predictor of cardiovascular events, and CKD increases the risk of vein graft occlusion in CABG patients by 62%. Because CKD impairs clearance of small proteins, we tested the hypothesis that CKD exacerbates vein graft disease by elevating serum levels of critical cytokines that promote neointimal hyperplasia. We modeled CKD in C57BL/6 mice with 5/6ths nephrectomy and modeled vein grafting with IVC-to-carotid interposition grafting. Two wk after 5/6 th s nephrectomy, GFR was 60±10% less than in sham-operated (control) mice, as determined by FITC-inulin clearance ( p &lt;0.05); parallel mouse cohorts were used for either blood collection or vein grafting. Of 23 serum cytokines measured by a Luminex-based assay, the following were elevated in CKD (n=12) compared with control mice (n=9): IL-9 (5-fold), IL-12 (1.8-fold), MCP-1 (1.3-fold), TNF (1.3-fold), and RANTES (1.8-fold) ( p &lt; 0.0003 for each). Four wk after grafting, CKD (n=7) and control mouse (n=7) vein graft neointimas comprised predominantly smooth muscle cells (SMCs), of equivalent prevalence. However, vein graft neointimal area was 4±0.5-fold fold greater in CKD mice: 0.23±0.2 vs. 0.052±0.004 mm 2 ( p &lt;0.01). By quantitative immunofluorescence, vein grafts from CKD mice showed equivalent neointimal expression of NFκB p65 but ~2-fold greater neointimal activation of NFκB, as judged by phosphorylation of p65 on Ser536 and by expression of VCAM-1 ( p &lt;0.01). Vein graft protein levels of IL-9 and IL-9 receptor-α were 3.0±0.6- and 1.7±0.3-fold higher in CKD than control mice ( p &lt;0.01). We then treated CKD mice with IL-9-neutralizing (n=7) or isotype control IgG (n=7) for 4 wk after vein grafting. Control IgG did not affect vein graft neointimal area (0.19±0.02 mm 2 ). However, anti-IL-9 IgG treatment reduced vein graft neointimal area 4-fold (to 0.044±0.004 mm 2 , p &lt; 0.01), and reduced neointimal levels of phospho-p65, IL-9, and IL-9Rα by 40-50% ( p &lt;0.05). Of the 5 serum cytokines elevated by CKD, only IL-9 and IL-6 were reduced by anti-IL-9 IgG treatment: 26±3% and 70±20%, respectively ( p &lt;0.001). We conclude that CKD aggravates vein graft disease dramatically, in large part by elevating plasma levels of IL-9.

Dobutamine stress echocardiography related sustained ventricular tachycardia in a patient with ischemic cardiomyopathy

A 66 year-old Asian man; with a complex history of ischaemic heart disease presented with cardiac and troponin negative chest pain. His ECG showed sinus bradycardia with old left bundle branch block. The transthoracic echocardiography showed severely impaired left ventricular systolic function (EF 30-35%). The patient had had coronary artery bypass grafting at age of 42 years and remained asymptomatic until age of 56 years when he presented with incessant ventricular tachycardia requiring amiodarone, lidocaine and electrical cardioversion. Coronary angiography at that time showed occluded vein grafts to the circumflex and diagonal arteries. The right coronary artery (RCA) was small and received collaterals from the left system. A myocardial perfusion scan showed extensive inferolateral infarction but no evidence for reversible ischaemia. An implantable cardiac defibrillator (ICD) was thus inserted. Over the following years, the patient underwent multiple PCI procedures with rotational atherectomy to the native LAD and associated vein graft, but subsequently developed in-stent restenosis. He also had PCI to the native RCA. He declined a minimally invasive grafting of the left internal mammary artery (LIMA) to the LAD and re-implantation of a new ICD after ex-plantation of the original one due to sepsis. His coronary artery disease remained stable following a recent admission with Troponin positive event which was confirmed by a repeat angiogram, therefore, had up-titrated anti-anginal medications. A low dose beta-blockade was discontinued due to documented sinus pauses up to 3 seconds. Following the recent admission, a joint cardiology-cardiothoracic meeting discussion recommended a stress echocardiogram with highdose dobutamine to guide towards considering re-do bypass grafting. A dobutamine stress echocardiogram (DSE) was performed (40 mcg/kg/min + 300 mcg atropine) by an experienced operator and the patient achieved 84% of target heart rate. At peak stress, he experienced hot sensation in the chest for which he was given GTN spray. Study analysis confirmed no evidence of inducible ischaemia (Figure 1), but three minutes into recovery, he developed sustained ventricular tachycardia at a rate of 218 bpm (Figure 2), but without obvious haemodynamic compromise. Intravenous metoprolol and amiodarone were administered and sinus rhythm was restored after approximately twenty minutes. The patient was observed overnight in CCU, and discharged few days later with a plan to refractory angina clinic referral in a tertiary centre, and to be assessed by an electrophysiologist for potential device therapy.

Symptomatic ischemia resulting from late upper extremity venous graft occlusion

Summary Reconstruction of traumatic or occluded vessels with vein grafts to treat ischemia of the hand is common in current upper-extremity surgery. Late symptomatic occlusion of the venous graft, however, has seldom been reported. We report two cases involving patients who developed acute symptomatic ischemia in their hands from occlusion of their vein grafts > 15 years after their initial surgery. Our management strategy was additional arterial reconstruction. An extensive review of the literature on late vein graft occlusion in the upper extremity was performed to compare presentations, management strategies, and outcomes for this disease. In both cases, computed tomography angiogram results confirmed clinical suspicions of late venous graft occlusions. Conservative management was attempted first with no resolution of symptoms. Repeated arterial or venous grafting was performed to bypass the diseased segments. PubMed searches with the separate key phrases “late graft occlusion”, “late vein graft occlusion”, and “late vein graft occlusion hand” were entered. Titles and abstracts were filtered and relevant full texts were reviewed. Limited studies have been reported on symptomatic late vein graft occlusions of the upper extremity. Experimental studies have shown that intra-arterial microvenous grafts undergo the same vessel remodeling as macrovenous grafts in animal models. The same mechanism of neointima proliferation and subsequent atherosclerotic events were considered the main causes of graft occlusions in these cases. After regrafting, their symptoms subsided during follow-ups at 1 year and 6 years, respectively. We present two rare clinical case reports of patients who suffered ischemic symptoms in their hands from late (> 15 years) occlusion of vein grafts. Both patients were assessed with preoperative computed tomography angiograms and successfully treated with regrafting. In cases of late occlusion with ischemic symptoms, a repeat arterial reconstruction with venous or arterial grafting is recommended.

Benefit and Safety of Dual Antiplatelet Therapy after Coronary Artery Bypass Grafting for Off-pump CABG: A Systematic Review and Meta-analysis

Aims: This study aims to evaluate benefit and safety compared dual antiplatelet therapy with single aspirin therapy after coronary artery bypass grafting. Study Design: A systematic review and Meta-analysis. Place and Duration of Study: Medline, Embase, ScienceDirect and Cochrane Library databases were searched for randomized controlled trials or observational studies focusing on anticoagulant therapy after coronary artery bypass grafting until December 2014. Methodology: Endpoints included postoperative mortality, bleeding events, myocardial infraction, stroke, repeat revascularization and graft occlusion. All these endpoints were compared between dual antiplatelet therapy and single aspirin therapy. Newcastle-Ottawa and Jadal scale were used to assess the quality of observational studies and randomized controlled trials respectively. Software R2.15.2 was utilized for Meta-analysis. Results: 15 studies composed of 31,365 patients were included. Compared with single aspirin Original Research Article Wang et al.; BJMMR, 9(11): 1-15, 2015; Article no.BJMMR.19433 2 therapy, dual antiplatelet therapy resulted in reducing risk of vein graft occlusion (OR=0.53, 95%CI 0.36-0.81, P=0.001), but no significant difference for artery graft occlusion (OR=0.91, 95%CI 0.392.12, P=0.882), Risk of postoperative mortality (OR=0.57, 95%CI 0.38-0.85, P=0.006) and repeat revascularization (OR=0.15, 95%CI 0.05-0.45, P=0.001) was also reduced. There were no significant difference for MI (OR=0.77, 95%CI 0.55-1.09, P=0.137), Stroke (OR=0.85, 95%CI 0.601.19, P=0.330) and bleeding (OR=0.95, 95%CI 0.82-1.09, P=0.465). In subgroup analysis of offpump CABG, dual antiplatelet therapy reduced risk of graft occlusion (OR=0.49, 95%CI 0.30-0.82, P=0.006), MI (OR=0.28, 95%CI 0.11-0.72, P=0.009), mortality (OR=0.39, 95%CI 0.25-0.60, P<0.001), and did not increase risk of bleeding (OR=0.75, 95%CI 0.55-1.02, P=0.066). Conclusions: Dual antiplatelet therapy reduced risk of postoperative graft occlusion and mortality in the early and late postoperative phase after CABG. It appeared to be more beneficial for offpump CABG.

Abstract 20606: Comparison of Saphenous Vein Graft Occlusion and Stent Thrombosis: Discrepancies in Clinical Presentation, Procedural Characteristics and Clinical Outcomes

Background: Difference in technical complexity and clinical outcomes between percutaneous coronary intervention (PCI) for stent thrombosis (ST) and PCI for occluded saphenous vein graft (SVG) have not been systematically examined. The aim of this study was to compare clinical presentation, procedural characteristics and clinical outcomes of acute coronary syndrome (ACS) patients who underwent PCI motivated by ST with those whom PCI was motivated by SVG total occlusion. Methods: We retrospectively included all the patients admitted for ACS due to ST (ST group; n=136) or SVG occlusion (SVG group; n=279) in our institution. The SVG group was divided into the following two subgroups; patients who underwent PCI in the SVG (SVG-PCI; n=75) and those who underwent PCI in native coronary arteries (native-PCI; n=204). Clinical presentation, procedural characteristics and short-term mortality were compared between the 3 groups (ST vs SVG-PCI vs native-PCI). Results: Compared with the SVG-PCI and native-PCI groups, acute myocardial infarction (76.5% vs 58.7% vs 30.4%, p &lt;0.001; respectively) and cardiogenic shock (24.3% vs 6.8% vs 3.5%, p &lt;0.001; respectively) were more frequent in the ST group. Concerning procedural characteristics, SVG-PCI group had the highest number of guiding catheter, procedural time, fluoroscopic time and contrast amount, as well as the lowest angiographical success rate (Table). Patients of the ST group had the highest in-hospital mortality and a trend toward higher 30-day mortality (Table). Conclusions: The present study suggests that ST when compared to SVG occlusion although easier to treat is associated with a worse outcome especially with respect to the clinical presentation at the time of the event.

Adropin: a new marker for predicting late saphenous vein graft disease after coronary artery bypass grafting.

Saphenous vein graft disease (SVGD), defined as an occlusion of 50% or more of the SVG excluding distal anastomotic occlusion, is an important predictor of morbidity after coronary artery bypass grafting (CABG). Late graft occlusion is a serious complication that often limits the use of the saphenous vein as a coronary bypass graft. Late graft occlusion is particularly common in old, degenerated venous grafts with advanced atherosclerotic plaques. Adropin has been implicated in the homeostatic control of metabolism. The purpose of this study was to investigate whether serum adropin levels are associated with late SVGD following CABG. Thirty-eight patients with SVGD involving at least one graft (occluded group; 14 females, 24 males) and 42 patients with a patent saphenous vein graft (patent group; 15 females, 27 males) were enrolled in this study. Venous blood samples were taken from all of the participants to measure plasma adropin levels using an enzyme-linked immunsorbent assay kit. The mean adropin level was significantly lower in the occluded group than in the patent group (3.2 ± 0.71 vs. 4.9 ± 1.51 ng/mL, p < 0.001). Multivariate regression analysis showed that the adropin level was the independent predictor of late saphenous vein graft occlusion. Adropin levels are lower in patients with late saphenous vein graft occlusion and these reduced adropin levels, together with other factors, may lead to saphenous vein graft occlusion. Larger and prospective studies are needed to determine if adropin plays a role in the pathogenesis of SVGD.

Angiography for management of perioperative myocardial ischemia: does it have any role?

Perioperative myocardial ischemia (PMI) is a relatively rare but potentially fatal complication after coronary artery bypass grafting and is due to graft-related problems in a significant proportion of cases. The usual indicators of MI in the postoperative setting are unreliable and therefore have uncertain diagnostic value. Angiography, the criterion standard for preoperative angina, remains underused for evaluation of PMI. The aim of this study was to evaluate the role of angiography in the management of PMI. Between January 2011 and September 2012, a total of 2312 isolated primary consecutive coronary artery bypass graft surgeries were performed, of which 2057 (89%) were carried out on the beating heart. Twenty-six (1.12%) of these patients needed perioperative angiography. The patients needing angiography were selected on the basis of a number of clinical, biochemical, and other diagnostic parameters Twenty-six patients with PMI required angiography, of which 18 (69 %) were found to have graft-related issues. The mean (SD) time between operation and angiography was 24.58 (6.71) hours. Of the 18 patients, 17 (94.44%) required surgical intervention and 1 patient was treated with angioplasty. There were 2 deaths (11.1%) in the group undergoing intervention. Angiographic findings included occluded vein graft (n = 7), narrowing of the left internal mammary artery (n = 3), and kinking or stretching of grafts (n = 8). Angiography is useful in diagnosing graft-related problems in the perioperative period. In presence of signs of graft compromise, we suggest that having a low threshold for angiographic graft evaluation may be beneficial in a carefully selected subset of patients after coronary artery bypass.

The long-term impact of diabetes on graft patency after coronary artery bypass grafting surgery: A substudy of the multicenter Radial Artery Patency Study

The study objective was to determine the impact of diabetes on radial artery and saphenous vein graft occlusion and clinical outcomes more than 5 years after coronary artery bypass surgery in the multicenter Radial Artery Patency Study (NCT00187356). A total of 529 patients aged less than 80 years with triple-vessel disease undergoing coronary bypass surgery participated in this study. Angiographic follow-up occurred more than 5 years after surgery with annual clinical follow-up. The primary objective was to compare the proportion of complete graft occlusion between radial artery and saphenous vein grafts among diabetic and nondiabetic persons. Additional objectives included determining predictors of complete graft occlusion and comparison of major adverse cardiac events defined by cardiac death, late myocardial infarction, and reintervention. There were 148 of 529 patients (27.8%) with diabetes; 269 patients (83/269 [30.9%] diabetic) underwent late angiography at mean of 7.7±1.5 years after surgery. In diabetic patients, the proportion of complete graft occlusion was significantly lower in the radial grafts (4/83 [4.8%]) than in the saphenous grafts (21/83 [25.3%]) (P=.0004), and this was similar in nondiabetic patients (P=.19). Multivariate modeling showed that the use of the radial artery and high-grade target vessel stenosis were protective against late graft occlusion, whereas female gender, smoking history, and elevated creatinine were associated with an increased risk; interaction between diabetic status and conduit type also was significant (P=.02). Major adverse cardiac events were higher in diabetic patients (23/148 [15.5%] vs 35/381 [9.2%], P=.04). The use of the radial artery should be strongly considered in diabetic patients undergoing coronary bypass surgery, especially with high-grade target vessel stenosis.

Lipoprotein(a) and cell adhesion molecules as predictors of vein graft occlusion in post-cabg patients receiving lipoprotein apheresis

Lipoprotein(a) and cell adhesion molecules as predictors of vein graft occlusion in post-cabg patients receiving lipoprotein apheresis