Repeat Bypass Surgery Research Articles

Percutaneous coronary intervention of totally occluded coronary venous bypass grafts: An exercise in futility?

BACKGROUNDPercutaneous coronary intervention (PCI) of diseased saphenous vein grafts (SVG) continues to pose a clinical challenge. Current PCI guidelines give a class III recommendation against performing PCI on chronically occluded SVG. However, contemporary outcomes after SVG intervention have incrementally improved with distal protection devices, intracoronary vasodilators, drug-eluting stents, and prolonged dual antiplatelet therapy. AIMTo reassess the procedural and long-term outcomes of PCI for totally occluded SVG with contemporary techniques.METHODSThis was a retrospective observational study conducted at a single university hospital. The study population consisted of 35 consecutive patients undergoing PCI of totally occluded SVG. Post-procedure dual antiplatelet therapy was continued for a minimum of one year and aspirin was continued indefinitely. Clinical outcomes were assessed at a mean follow-up of 1221 ± 1038 d. The primary outcome was freedom from a major adverse cardiac event (MACE) defined as the occurrence of any of the following: death, myocardial infarction, stroke, repeat bypass surgery, repeat PCI, or graft reocclusion. RESULTSThe study group included 29 men and 6 women with a mean age of 69 ± 12 years. Diabetes was present in 14 (40%) patients. All patients had Canadian Heart Classification class III or IV angina. Clinical presentation was an acute coronary syndrome in 34 (97%) patients. Mean SVG age was 12 ± 5 years. Estimated duration of occlusion was acute (< 24 h) in 34% of patients, subacute (> 24 h to 30 d) in 26%, and late (> 30 d) in 40%. PCI was initially successful in 29/35 SVG occlusions (83%). Total stent length was 52 ± 35 mm. Intraprocedural complications of distal embolization or no-reflow occurred in 6 (17%) patients. During longer term follow-up, MACE-free survival was only 30% at 3 years and 17% at 5 years.CONCLUSIONPCI of totally occluded SVG can be performed with a high procedural success rate. However, its clinical utility remains limited by poor follow-up outcomes.

Successful Rescue Intervention of Internal Mammary Artery Anastomotic Site Acute Graft Failure With Direct New Generation Covered Stenting

Acute, perioperative myocardial infarction (MI) from acute left internal mammary artery (LIMA) to left anterior descending (LAD) graft failure immediately following coronary artery bypass grafting (CABG) surgery is associated with significantly increased in-hospital mortality. The leading etiology of such acute graft failure is acute thrombosis, dissection, spasm, anastomosis failure or no-reflow phenomenon. Repeat bypass surgery carries incremental risk and may not be feasible in hemodynamically unstable patients. Traditional percutaneous coronary intervention (PCI), with or without stent placement is sometimes used in such cases; however, graft anatomy and lesion location increase procedural complexity and challenge technical feasibility. This is particularly true of the LIMA to LAD graft anastomosis, where PCI carries the risk of anastomotic site perforation or avulsion. Therefore, the best revascularization strategy for such a lesion involving the LIMA to LAD graft anastomosis in the immediate perioperative period remains unknown. We present a case of 75-year-old male who suffered an acute MI complicated by cardiogenic shock less than 24 h after two-vessel CABG. Selective angiography revealed acute LIMA to LAD anastomotic site closure, posing a risk for perforation if treated with traditional angioplasty or stenting. We successfully performed rescue PCI, by directly deploying a PK Papyrus covered stent (Biotronik, Berlin, Germany) across the anastomosis. Our case report describes the upfront (rather than a bail out) use of the new covered stent as a novel revascularization strategy to treat “perforation prone” LIMA to LAD anastomotic site acute graft failure. J Med Cases. 2021;12(7):271-274 doi: https://doi.org/10.14740/jmc3695

Late (5-20 years) outcomes after STA-MCA anastomosis and encephalo-duro-myo-arterio-pericranial synangiosis in patients with moyamoya disease.

Surgical revascularization is known to reduce the incidence of further ischemic and hemorrhagic events in patients with moyamoya disease, but the majority of previous studies report only short-term (< 5 years) outcomes. Therefore, in this study the authors aimed to evaluate late (5-20 years) outcomes of moyamoya patients after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis and indirect bypass (encephalo-duro-myo-arterio-pericranial synangiosis [EDMAPS]). Cumulative incidences of late morbidity/mortality and disease progression were evaluated among 93 patients who underwent STA-MCA anastomosis and EDMAPS. All of the patients were prospectively followed up for longer than 5 years postsurgery (10.5 ± 4.4 years). There were 35 pediatric and 58 adult patients. Initial presentation included transient ischemic attack/ischemic stroke in 80 patients and hemorrhagic stroke in 10 patients, and 3 patients were asymptomatic. Surgery was performed in a total of 141 hemispheres. Follow-up MRI/MRA was performed within a 6- or 12-month interval during the follow-up periods. During the follow-up periods, 92/93 patients were free from any stroke or death, but 1 patient had a recurrence of hemorrhagic stroke (0.10% per patient-year). Disease progression occurred in the territory of the contralateral carotid or posterior cerebral artery (PCA) in 19 hemispheres of 15 patients (1.5% per patient-year). The interval between initial surgery and disease progression varied widely, from 0.5 to 15 years. Repeat bypass surgery for the anterior and posterior circulation resolved ischemic attacks in all 10 patients. The study results indicate that STA-MCA anastomosis and EDMAPS would be the best choice to prevent further ischemic and hemorrhagic stroke for longer than 10 years on the basis of the demonstrated widespread improvement in cerebral hemodynamics in both the MCA and ACA territories in the study patients. However, after 10 years postsurgery regular follow-up is essential to detect disease progression in the territory of the contralateral carotid artery and PCA and prevent late cerebrovascular events.

Abstract 84: Late (5-20 Years) Outcome After STA-MCA Anastomosis and Ultimate Indirect Bypass in Patients With Moyamoya Disease

Background and Purpose: Surgical revascularization is now known to improve the outcome in patients with moyamoya disease. However, majority of previous studies reported their short-term (&lt;5 years) outcome. Therefore, this study was aimed to evaluate long-term (5 to 20 years) outcome after STA-MCA anastomosis and ultimate indirect bypass, encephalo-duro-myo- arterio-pericranial synangiosis (EDMAPS). Methods: Cumulative incidence of late morbidity/mortality and disease progression were evaluated among 93 patients who underwent STA-MCA anastomosis and EDMAPS. All of them were prospectively followed up for longer than 5 years post-surgery (mean, 10.5±4.4 years). There were 35 pediatric and 58 adult patients. Clinical diagnosis included TIA or ischemic stroke in 80 patients, hemorrhagic stroke in 10, and asymptomatic in 3. STA-MCA anastomosis and EDMAPS were performed onto their 141 hemispheres. MRI and MRA were performed every 6 or 12 years during follow-up periods. Results: During follow-up periods, 92/93 patients were free from any stroke or death, but one recurred hemorrhagic stroke (0.10% per patient-year). Disease progression occurred in the territory of the contralateral carotid or posterior cerebral artery (PCA) in 19 hemispheres of 15 patients (1.5% per patient-year). The interval between initial surgery and disease progression varied from 0.5 to 15 years. Repeat bypass surgery for anterior and posterior circulations resolved ischemic attacks in all 10 patients. Conclusion: STA-MCA anastomosis and EDMAPS would be the best choice to prevent further cerebrovascular events for longer than 10 years by widely providing surgical collaterals to both the MCA and ACA territories. However, regular follow-up would be essential for longer than 10 years post-surgery to identify the disease progression in the territory of contralateral carotid artery and PCA and prevent late cerebrovascular events.

Strategy and effect of repeat bypass surgery for anterior/posterior circulation in refractory moyamoya disease.

In this study the authors aimed to describe clinical features, surgical techniques, and long-term outcomes of repeat bypass surgery required for a certain subset of patients with moyamoya disease. The authors retrospectively reviewed a total of 22 repeat bypass surgeries for 20 patients (age range 1-69 years) performed during the last 20 years at their institutions. The patients were classified into 2 groups. Group A included 10 patients who underwent repeat bypass surgery for anterior circulation due to insufficient revascularization on the ipsilateral side. Group B included 10 patients who underwent repeat bypass surgery for posterior circulation due to the involvement of the posterior cerebral artery (PCA) after successful initial surgery for anterior circulation. Preoperative symptoms included headache in 3 patients, transient ischemic attack in 10, cerebral infarction in 3, and intracranial hemorrhage in 4 patients. Intervals between the initial bypass surgery and repeat bypass surgery were 0.3-30 years (median 3 years). In group A, superficial temporal artery to middle cerebral artery (MCA) anastomosis and indirect bypass were performed on 7 hemispheres. Only indirect bypass was performed on 3 hemispheres because of the lack of suitable donor or recipient arteries. In group B, occipital artery (OA) to PCA anastomosis and indirect bypass were conducted on 4 hemispheres, and OA-MCA anastomosis and indirect bypass on 1 hemisphere. Only indirect bypass was conducted on 7 hemispheres because of the lack of suitable recipient arteries. All 22 repeat bypass surgeries were successfully conducted. During follow-up periods (median 4 years), none of the patients suffered repeat stroke except 1 patient who died of recurrent intracerebral hemorrhage 3 years after repeat bypass surgery for anterior circulation. Repeat bypass surgery was feasible and effective to reduce further incidence of headache attack, transient ischemic attack, and ischemic/hemorrhagic stroke in moyamoya disease patients. Through precise radiological analysis, surgical procedures should be planned to yield maximal therapeutic effects.

Off- vs. On-Pump Coronary Artery Bypass Grafting Long-Term Survival is Driven by Incompleteness of Revascularisation

Off-pump coronary artery bypass grafting (CABG) negates the requirement for extracorporeal circulation used with the traditional on-pump approach. However, off-pump CABG is technically more challenging and may theoretically lead to less complete revascularisation. Recent data suggests a prognostic benefit for traditional on-pump CABG, but the mechanism for this remains unclear. We hypothesised that the inferior outcomes with off-pump CABG could be driven by the need for repeat revascularisation, with this benefit only becoming clear at long-term follow-up. We therefore evaluated short, medium and long-term outcomes of patients undergoing revascularisation with on vs. off-pump CABG. Electronic databases were searched to identify suitable randomised controlled trials enrolling ≥100 patients in each arm. Clinical outcomes were extracted at 30-days, 12-months or >4years. The primary outcome was long-term all-cause death, while secondary outcomes included 30-day, 12-month and >4-year cardiac death, stroke, myocardial infarction or revascularisation. Thirteen (13) studies comprising 13,234 patients were included. Off-pump CABG was associated with an increased risk of all-cause death (Odds Ratio [OR] 1.18, 95% confidence interval [CI] 1.02-1.32, p=0.01) and repeat bypass surgery (OR 2.57, 95%CI 1.23-5.39, p=0.01) at long-term follow-up. A significant, increased requirement for revascularisation in off-pump was seen at 12-month follow-up (OR 1.59, 95%CI 1.09-2.33, p=0.02). No differences were noted between groups at 30-days, 12-months and >4years for myocardial infarction or stroke. Off-pump CABG is associated with significantly higher rates of all-cause mortality rate at long-term follow-up. These outcomes demonstrate a temporal relationship that may be driven by a greater requirement for repeat revascularisation at 1- and 5-year follow-up. CRD42018102019 (PROSPERO).

Abstract WP131: Repeat Bypass Surgery for Moyamoya Disease Refractory to Previous Surgery

Background and Purpose: Surgical revascularization is known to reduce subsequent incidence of ischemic and hemorrhagic stroke with low morbidity in moyamoya disease. However, repeat bypass surgery is required for a certain subgroup of patients, although the information on indication, surgical technique, and outcome is limited. Therefore, this study was aimed to precisely analyze clinical features, surgical technique, and long-term outcome of repeat bypass surgery for refractory moyamoya disease. Methods: This study included totally 20 surgeries for18 patients who underwent repeat bypass surgery because previous surgery was inadequate in 10 surgeries (Group A) or because the posterior cerebral artery was further involved after surgery in 10 (Group B). There were 7 males and 11 females. Their age ranged from one to 69 years. Precise radiological examinations were performed before surgery, using MRI, cerebral angiography, and SPECT. In Group A, all patients who previously underwent inadequate surgery repeated headache attack, TIA, or hemorrhagic stroke, and underwent repeat bypass surgery targeted to the non-revascularized area, using STA-MCA anastomosis and/or indirect synangiosis as appropriate. On the other hands, occipital artery to posterior cerebral artery (OA-PCA) anastomosis and/or indirect bypass was required in Group B who developed disease progression in the PCA. Results: All 18 patients successfully underwent repeat bypass surgery. Postoperative course was uneventful. Postoperative examinations revealed good revascularization in the operated hemispheres and the improvement of cerebral hemodynamics. Headache attack and TIA disappeared within 6 months at the latest after surgery. During follow-up periods, one (5.6% per person) of 18 patients died of recurrent hemorrhagic stroke two years after repeat bypass surgery. Conclusion: Repeat bypass surgery is feasible and effective to reduce further incidence of headache attack, TIA, and ischemic and hemorrhagic stroke. Through precise radiological analysis, surgical procedures should be planned to yield maximal therapeutic effects.

Abstract 12889: Drug-Eluting Stents in the Treatment of Saphenous Vein Graft Disease: Disappointing Outcome During Long-term Follow-up

Introduction: Drug-eluting stents (DES) have been shown to have superior short term outcomes in the treatment of saphenous vein graft (SVG) disease compared to bare metal stents. Hypothesis: The goal of this study was to assess the long term clinical outcome of all patients with SVG disease treated with DES. Methods: 183 consecutive patients undergoing SVG intervention with DES were evaluated. Post-procedure, antiplatelet therapy included aspirin indefinitely and dual antiplatelet therapy for a minimum of 1 year. Major adverse cardiac events (MACE) were assessed at a mean follow-up of 5 years. MACE was defined as any of the following: death, stroke, myocardial infarction, repeat bypass surgery, repeat target vessel revascularization, or stent thrombosis. Results: The study population consisted of 149 men and 34 women with a mean age of 69 ± 10 years. Diabetes was present in 83 (45%) and acute coronary syndromes were present in 116 (63%). Mean SVG age was 12 ± 6 years. Diffuse disease (≥ 30 mm of treated disease and/or 3 or more lesions in a single vessel) was present in 37%. A total of 243 lesions were treated with 395 DES. Procedural techniques during DES deployment included direct stenting in 50%, pretreatment with intracoronary nicardipine in 49%, and use of a distal protection device in 38%. Kaplan Meier analysis of long-term MACE free survival is shown in the Figure. Although only 18% of patients had a MACE at one year, continued events were common after the first year. At 49 months, 50% of the patients had one or more MACE. Event free survival which was 82% at 1 year was only 41% at 5 years. MACE free survival after first and second generation DES were similar. Conclusions: The long-term outcome after percutaneous intervention of aortocoronary bypass vein grafts continues to present a clinical challenge. Within 5 years after DES placement for SVG disease, fewer than half of the patients remain event free.

Abstract 101: Repeat Bypass Surgery for Moyamoya Disease Refractory to Previous Surgery

Purpose: Surgical revascularization is known to reduce subsequent incidence of ischemic and hemorrhagic stroke with low morbidity in moyamoya disease. However, repeat bypass surgery is required for a certain subgroup of patients, although the information on indication, surgical technique, and outcome is limited. Therefore, this study was aimed to precisely analyze clinical features, surgical technique, and long-term outcome of repeat bypass surgery for refractory moyamoya disease. Methods: This study included 16 patients who underwent repeat bypass surgery because previous surgery was inadequate in 10 patients or because the posterior cerebral artery was further involved after surgery in 6. There were 7 males and 9 females. Their age ranged from one to 69 years. Precise radiological examinations were performed before surgery, using MRI, cerebral angiography, and SPECT. All 10 patients who previously underwent inadequate surgery repeated headache attack, TIA, or hemorrhagic stroke, and underwent repeat bypass surgery targeted to the non-revascularized area, using STA-MCA anastomosis and/or indirect synangiosis as appropriate. OA-PCA anastomosis and/or indirect bypass was required in 6 patients who developed disease progression in the PCA. Results: All 16 patients successfully underwent repeat bypass surgery. Postoperative course was uneventful. Postoperative examinations revealed good revascularization in the operated hemispheres and the improvement of cerebral hemodynamics. Headache attack and TIA disappeared within 6 months at the latest after surgery. During follow-up periods, one of 16 patients died of recurrent hemorrhagic stroke two years after repeat bypass surgery. Conclusion: Repeat bypass surgery is feasible and effective to reduce further incidence of headache attack, TIA, and ischemic and hemorrhagic stroke. Through precise radiological analysis, surgical procedures should be planned to yield maximal therapeutic effects.

The Role of Transesophageal Echocardiography During Surgery for Patients With Tetralogy of Fallot

Routine use of intraoperative transesophageal echocardiography (TEE) is a safe monitoring and diagnostic method during pediatric congenital cardiac surgery. However, the question of whether intraoperative TEE is accurate and cost effective for patients with tetralogy of Fallot (TOF) has not been raised. This study aimed to analyze the cost-benefit of routine TEE during the repair of TOF. The medical records, including TEE results, for patients who underwent correction of TOF between January 1997 and June 2007 were reviewed and retrospectively analyzed. Intraoperative TEE was performed for 340 patients (85 %). Residual problems were detected in 17.9 % (61/340), and a return to bypass was needed for 10 % (34/340) of the patients. The degree of agreement between the intraoperative TEE and early postoperative transthoracic echocardiography (TTE) was relatively high. Surgeons with less surgical experience more frequently used intraoperative TEE (p = 0.007) and performed repeat bypass surgery at a higher rate (p = 0.00). Even relatively unskilled surgeons might be able to achieve surgical outcomes similar to those of experienced surgeons using intraoperative TEE. By avoiding late surgical revision, the possible cost savings were estimated to be 1,726,000 Korean won (US$1,489) per TEE examination. Intraoperative TEE can be used as a tool for surgeons in making decisions in the operating room. In addition, intraoperative TEE decreased the frequency of reoperations and postoperative interventions. The results of this study demonstrate that routine intraoperative TEE during repair of TOF was both clinically beneficial and cost effective.

Pathology of Drug-Eluting Versus Bare-Metal Stents in Saphenous Vein Bypass Graft Lesions

The purpose of this study was to assess the pathological responses of atherosclerotic saphenous vein bypass grafts (SVBGs) to drug-eluting stents (DES) versus bare-metal stents (BMS). Repeat bypass surgery is typically associated with a high rate of morbidity and mortality. Percutaneous coronary interventions have emerged as the preferred treatment; however, only limited data are available on SVBGs pathological responses to DES and BMS. Formalin-fixed SVBG of >2 years duration (n = 31) were collected to histologically characterize advanced atherosclerotic lesions in native SVBG. In a separate group, SVBGs treated with DES (n = 9) and BMS (n = 9) for >30 days duration were assessed for morphological and morphometric changes. Necrotic core lesions were identified in 25% of SVBG sections, and plaque rupture with luminal thrombosis was observed in 6.3% of histological sections (32% [10 of 31] vein grafts examined). Morphometry of DES demonstrated reduction in neointimal thickening versus BMS (0.13 mm [interquartile range: 0.06 to 0.16 mm] vs. 0.30 mm [interquartile range: 0.20 to 0.48 mm], p = 0.004). DES lesions also showed greater delayed healing characterized by increased peristrut fibrin deposition, higher percentage of uncovered struts, and less endothelialization compared with BMS. Stent fractures (DES 56% vs. BMS 11%, p = 0.045) and late stent thrombosis (DES 44% vs. BMS 0%, p = 0.023) were more common in DES versus BMS. Advanced SVBG atherosclerotic lesions are characterized by large hemorrhagic necrotic cores. Stenting of such lesions is associated with delayed vascular healing and late thrombosis particularly following DES implantation, which may help explain the higher rates of cardiovascular events observed in SVBG stenting as compared with native coronary arteries.

Percutaneous Revascularization Is the Preferred Strategy for Patients With Significant Left Main Coronary Stenosis

In the early 1970s, coronary artery bypass graft (CABG) was found to improve late survival in comparison to medical therapy in patients with significant left main stenosis.1–3 Once CABG became the standard of care for left main disease, a distinction between “protected”—by at least 1 patent bypass graft to the left coronary artery—and “unprotected left main (UPLM)”— no patent bypass graft to the left coronary artery—was made. In the 1980s, early attempts at balloon angioplasty of UPLM stenoses were associated with poor early outcomes because of coronary dissection, abrupt closure, and restenosis. Mortality rates as high as 30% at 1 year were reported.4–6 In the 1990s, bare metal stents were introduced and soon used to treat UPLM disease. Several small registries found a low rate of procedural complications, but repeat revascularization rates of 20% to 30% because of restenosis were considered unacceptable.7–12 Early bare metal stent registries for UPLM also found high mortality rates, particularly in high-risk patients, such as patients with acute coronary syndromes and poor left ventricular function. Importantly, high-risk subgroups often presented with late sudden death after stenting.11,13 In the early 2000s, the introduction of drug-eluting stents (DES), with the promise of vastly reduced rates of restenosis,14–17 raised the possibility of improved late outcomes in this challenging patient group. Response by Smith p 1033 Clinical outcomes after treatment of UPLM disease with either the sirolimus-eluting stent or the paclitaxel-eluting stent from >20 small registries have been published. Results reported in these registries vary widely.18–40 As depicted in Table 1, cardiac mortality between 6 and 12 months after the procedure ranges from 0% to 11%. Target lesion revascularization (TLR) or target vessel revascularization (TVR) rates range from 2% to 38%. This wide variation in clinical outcome appears largely because of variation …

Current Management Of Saphenous Vein Graft Disease

The percutaneous management of saphenous vein graft disease is rapidly changing and continues to be an ongoing challenge for the interventional cardiologist. As compared to percutaneous coronary intervention in native vessels, graft vessel interventions are associated with sub-optimal results, increased major adverse cardiac events and less favorable long-term results. The arrival of stents, better antithrombotic medication, distal protection and thrombectomy devices have made it possible to attempt interventions in larger number of patients and obtain favorable results. The results vary according to age of the graft, clinical presentation and thrombus load. Chronically occluded vein grafts still pose the biggest challenge. While treating a patient with saphenous vein graft disease, a choice should be made between treatment of native vessels, repeat bypass surgery and a vein graft intervention. The first choice should be an intervention of the native vessel if feasible. Repeat coronary artery bypass surgery should be seriously considered particularly if arterial grafts can be implanted. The last choice should be intervention on saphenous venous grafts and should include implantation of a stent along with use of a distal protection device. Drug coated stents may change the scenario and future data in this field is eagerly awaited. Aggressive atherosclerosis modification and intensive medication should continue in all these patients to improve the long -term survival.

Percutaneous coronary intervention versus repeat bypass surgery for patients with medically refractory myocardial ischemia: AWESOME randomized trial and registry experience with post-CABG patients

ObjectivesThis report compares long-term percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) survival among post-CABG patients included in the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) randomized trial and prospective registry. BackgroundRepeat CABG surgery is associated with a higher risk of mortality than first-time CABG. The AWESOME is the first randomized trial comparing CABG with PCI to include post-CABG patients. MethodsOver a five-year period (1995 to 2000), patients at 16 hospitals were screened to identify a cohort of 2,431 individuals who had medically refractory myocardial ischemia and at least one of five high-risk factors. There were 454 patients in the randomized trial, of whom 142 had prior CABG. In the physician-directed registry of 1,650 patients, 719 had prior CABG. Of the 327 patient-choice registry patients, 119 had at least one prior CABG. The CABG and PCI survivals for the three groups were compared using Kaplan-Meier curves and log-rank tests. ResultsThe CABG and PCI three-year survival rates were 73% and 76% respectively for the 142 randomized patients (75 and 67 patients) (log-rank = NS). In the physician-directed registry, 155 patients were assigned to reoperation and 357 to PCI (207 received medical therapy); 36-month survivals were 71% and 77% respectively (log-rank = NS). In the patient-choice registry, 32 patients chose reoperation and 74 chose PCI (13 received medical therapy); 36-month survivals were 65% and 86% respectively (log-rank test p = 0.01). ConclusionPercutaneous coronary intervention is preferable to CABG for many post-CABG patients.

Predictors of long-term outcome after stent implantation in a saphenous vein graft

Stenting of saphenous vein graft (SVG) lesions is associated with significant clinical events at late follow-up. We sought to determine predictors of clinical outcome after this procedure. One hundred twenty-eight balloon-expandable stents were implanted in the SVGs of 106 patients. Baseline clinical and angiographic characteristics were analyzed. All grafts, including those not stented, were scored for extent of disease involving the luminal surface of the graft, and for the presence of low profile lesions (<50% graft stenosis) and/or high profile lesions (≥50% graft stenosis). The in-hospital success rate was 98.1%. Before discharge, no patient died, required bypass surgery, or had repeat angioplasty of the same graft. Follow-up was obtained on all the patients. At a median of 18 months, 15% had died, 17% had experienced myocardial infarction, 20% had required repeat bypass surgery, and 37% needed repeat angioplasty to either the same site or a different lesion. Event-free survival was recorded in only 44% of the patients. The cumulative Kaplan-Meier survival at 2.4 years was 78.7%. Using the Cox proportional hazards model, predictors of survival were the absence of a high profile lesion in any nonstented patent graft (p = 0.004), and the use of lipid-lowering agents at follow-up (p = 0.01). Stenting SVG lesions can be performed with a high degree of procedural success, but at long-term follow-up there is a high rate of cardiac events. The absence of a high profile lesion in any nonstented patent graft is the strongest predictor of survival.

Update on Interventions in Saphenous Vein Grafts

Interventions in saphenous vein grafts present some of the most challenging problems in preventing acute complications and limiting restenosis. Available options include repeat bypass surgery, balloon angioplasty, directional atherectomy, transluminal extraction atherectomy, rotational atherectomy, laser angioplasty, and stenting. Stenting appears to provide the best acute and long‐term results. Debulking with directional atherectomy prior to stenting may be helpful but its role is unproven. With any device, it is essential to attain the lowest possible residual stenosis with the least amount of manipulation. Complications with vein graft interventions are most commonly related to distal embolization, which occurs most frequently in older vein grafts with diffuse disease, large plaque volume or thrombus, or those with total occlusion. Use of thrombolytics, glycoprotein Ilb/IIIa receptor inhibitors, and thrombectomy devices may be helpful when thrombus is present. Calcium channel blockers may be beneficial when embolization of plaque debris results in slow flow or no‐flow during interventions.

Exercise technetium 99m sestamibi single-photon emission computed tomography late after coronary artery bypass surgery: long-term follow-up.

The prognostic value of exercise technetium 99m sestamibi single-photon emission computed tomography (SPECT) imaging in patients with previous bypass surgery is unknown. The aim of our study was to assess the prognostic information obtained with exercise scintigraphy performed for routine follow-up or reappearance of symptoms. We studied 75 patients referred to our Center at a mean of 38 +/- 53 months from the revascularization procedure and prospectively followed them for 38 +/- 24 months. Fifteen patients (20%) had events at follow-up: there were 4 cardiac deaths, 3 nonfatal acute myocardial infarctions, 8 late revascularization procedures (4 percutaneous transluminal angioplasty and 4 repeat bypass surgery). Univariate analysis identified a history of typical angina (p = 0.001), a clinically positive ergometric test (p = 0.009), peak exercise heart rate (p = 0.0003), percentage of maximal predicted heart rate (p = 0.0001), peak exercise double product (p = 0.048), therapy during exercise (p = 0.003), scintigraphic summed reversibility score (i.e., the summation of the segmental differences between stress and rest) (p = 0.014), as significant predictors of events. Three multivariate models were built, with clinical variables (Model 1, chi square 15.97), ergometric variables (Model 2, chi square 19.66), and with scintigraphic variables added to clinical/ergometric variables (Model 3, chi square 31.13). The scintigraphic variable selected in the model as significant predictor of events was the summed reversibility score (p = 0.008). Exercise sestamibi SPECT scintigraphy provides optimal prognostic information after clinical and ergometric parameters in patients with previous bypass surgery.

Influence of Procedural Success on Immediate and Long-Term Clinical Outcome of Patients Undergoing Percutaneous Revascularization of Occluded Coronary Artery Bypass Vein Grafts

ObjectivesThis study sought to determine whether successful recanalization of an occluded vein graft is associated with improvement in long-term clinical outcome. BackgroundCoronary angioplasty of occluded vein grafts is associated with a lower initial success rate and a higher complication rate than angioplasty of vein grafts with subtotal stenoses and native coronary arteries. Whether successful angioplasty improves clinical outcome is unknown. MethodsWe analyzed 77 consecutive patients who underwent angioplasty of an occluded saphenous vein coronary artery bypass graft between August 1983 and June 1994. Patients with a myocardial infarction in the previous 24 h were excluded from the study. ResultsThe mean age of the study cohort was 65 years; the mean (±SD) age of the treated grafts was 7.5 ± 3.9 years. As an adjunct to balloon angioplasty, stents were used in 9% of procedures, laser in 30%, and atherectomy in 16%, and thrombolytic therapy was administered in 23% of patients. The angioplasty success rate was 71%. Major complications within 30 days of the procedure included death in 5.2% of patients, Q wave myocardial infarction in 1.3% and repeat bypass surgery in 7.8%; these events occurred with similar frequency in patients in whom angiographic success was and was not achieved. Kaplan-Meier analysis comparing patients in whom angioplasty was successful (n = 55) and not successful (n = 22) revealed no differences in survival or occurrence of myocardial infarction or recurrent severe angina between the two groups in the 3 years after the procedure. Univariate analysis identified the age of the graft and use of newer interventional devices as predictors of death or myocardial infarction during this time period; procedural success was not associated with freedom from these adverse events after adjusting for these variables. ConclusionsAngioplasty of occluded vein grafts is associated with a low initial success rate and a high complication rate. Successful angioplasty does not appear to reduce the occurrence of adverse events in the 3 years after the procedure.

Percutaneous revascularization of ostial saphenous vein graft stenoses

This study sought to evaluate the short-term results and long-term outcome of percutaneous revascularization of ostial saphenous vein graft stenoses in a large patient series. Previous studies have demonstrated that the results of balloon angioplasty for native coronary ostial stenoses are significantly worse than those for nonostial lesions. However, it is controversial whether interventions in patients with ostial saphenous vein grafts carry a similar prognosis. We identified 68 consecutive patients with ostial (group I) and 72 consecutive patients with proximal, nonostial (group II) saphenous vein graft stenoses who underwent percutaneous angioplasty or directional atherectomy for a single new stenosis at the Cleveland Clinic between 1986 and 1992. Success was achieved in 61 patients (89.7%) in group I and 64 (88.9%) in group II (p = 0.88). There were no differences in major procedural complications (death, Q wave infarction and bypass surgery) between the two groups. At a mean (+/- SD) follow-up of 23 +/- 17 months, 36 patients (64%) in group I had one or more adverse events (death, infarction, repeat coronary revascularization or cardiac-related hospital admission) compared with 34 patients (58%) in group II (p = 0.87). Twenty-eight patients (50%) were angina free in group I compared with 33 (56%) in group II (p = 0.65). During the follow-up period in group I, 7 patients died (13%), 10 had a myocardial infarction (18%), 11 had repeat bypass surgery (20%), 8 had repeat percutaneous interventions (14%), and 30 had one or more cardiac-related hospital admissions (54%). The incidence of these events was similar in group II except for a slightly higher incidence of myocardial infarction: 6 patients died (10%), 3 had a myocardial infarction (5%), 12 had repeat bypass surgery (20%), 12 had repeat percutaneous interventions (20%), and 26 had one or more cardiac-related hospital admissions (44%). Unlike ostial native coronary disease, the clinical, procedural and follow-up profile of ostial saphenous vein graft revascularization is not significantly worse than proximal nonostial disease. This finding may be related to the overall suboptimal results of percutaneous revascularization in saphenous vein grafts compared with native coronary arteries or to the unfavorable intrinsic properties of ostial native coronary arteries compared with ostial vein grafts.

Percutaneous Interventions for Significant Narrowing in Saphenous Vein Aortocoronary Conduits

Coronary artery bypass surgery often is used to treat patients who have multivessel coronary artery disease requiring revascularization. Unfortunately, within a decade of surgery, significant atherosclerosis may develop in the vein grafts of these patients, requiring additional revascularization. Repeat coronary artery bypass surgery is necessary in selected patients. However, the risk of mortality is increased when compared with the first operation and may not be feasible in some patients. Percutaneous revascularization may provide an alternative treatment for patients who are not candidates for repeat surgery and for those who choose not to undergo repeat bypass surgery. Significant narrowings in saphenous vein conduits can be treated with careful use of balloon angioplasty and newer percutaneous techniques, such as stenting and atherectomy (directional and extraction). Successful percutaneous intervention may result in significant clinical improvement for these patients.