Effect of direct stenting on clinical outcome in patients treated with percutaneous coronary intervention on saphenous vein graft

The stress hyperglycemic ratio can predict the no-reflow phenomenon following saphenous vein graft intervention in patients with acute coronary syndrome

AIMS

The no-reflow phenomenon (NRP) is a common complication of saphenous vein graft (SVG) interventions. The aim of this study was to investigate the effect of the stress hyperglycemia ratio (SHR) on the development of NRP in patients with acute coronary syndrome (ACS) undergoing percutaneous SVG intervention.

METHODS

The study included 223 patients who presented at our center with ACS, had a history of coronary artery bypass graft and underwent a saphenous graft procedure. The relationship between SHR calculated at the time of presentation from glucose and HbA1c values, and the development of NRP evaluated after the procedure with angiography was determined with univariate and multivariate binary regression analysis.

RESULT

The study population was separated into two groups as those who developed and did not develop NRP. Mean age was determined to be significantly higher in the group that did not develop NRP compared to the group with NRP (p: 0.004). Angiographically, the thrombus burden was determined to be significantly higher in the group that developed NRP (p < 0.001). Patients were separated into 3 tertiles according to the SHR level (T1, T2, T3), and the rate of NRP development was determined at a significantly higher rate in the T3 group (p < 0.001).

CONCLUSIONS

This study showed that SHR, a parameter that can be easily calculated noninvasively, is an independent predictor of NRP development in ACS patients undergoing saphenous interventions. In addition, high thrombus burden and predilatation before stenting were also found to be factors that increase the likelihood of developing NRP.

Self-Expanding Versus Balloon Expanding Coronary Stents in Intervention of the Degenerated Saphenous Vein Graft: Memmingen Coronary Artery Bypass Stenosis Trial (MECAST)

Objectives. The aim of this retrospective analysis was to compare the patient outcome after interventional therapy of saphenous vein graft (SVG) stenoses in an all-comers population receiving either self-expanding drug-eluting stents (SExS) or balloon expanding drug-eluting stents (BExS). Background. The interventional therapy of degenerated SVGs remains challenging. Diameter variations of stenotic segments and friable plaques can lead to malapposition and distal embolization with increased major adverse cardiac event (MACE) rates. Methods. 107 patients with a total of 130 SVG interventions were separated into two groups according to either SExS (n = 51) or BExS (n = 56) treatment. Primary endpoint was the MACE rate, which is defined as the composite of cardiac death, myocardial infarction (MI), target vessel (TVR), and target lesion revascularization (TLR) at 30 days and at one-year follow-up. Results. Both patient groups did not differ significantly regarding patient characteristics. The patient outcome was significantly better in the SExS patient group: the MACE rate at 30 days was 1/51 (2.0%) in group SExS vs. 7/56 (12.5%) in group BExS; $p<0.05$ . At one-year follow-up, the MACE rate remained significantly lower in the SExS group 8/51(15.7%) vs. 20/56 (35.7%) in the BExS group, $p<0.02$ . Additionally, cardiac death occurred significantly later within the SExS patient group compared to the BExS group ( $p<0.05$ ). A better overall outcome of patients with de novo SVG-stenosis compared to patients with previous CABG (coronary artery bypass graft) intervention was noted in both groups. Conclusion. Our findings demonstrate that SVG treatment with SExS is safe and provides clinical benefits by comparatively improving short and especially long-term patient outcomes.

Saphenous Vein Graft Intervention

Even though saphenous vein grafts (SVGs) are the most commonly used surgical conduits, their long-term patency is limited by accelerated atherosclerosis often resulting in acute coronary syndrome or asymptomatic occlusion. SVG intervention is associated with 2 significant challenges: a significant risk of distal embolization with resultant periprocedural myocardial infarction in the short-term and restenosis in the long-term. Several individual trials have compared bare metal stents with drug-eluting stents for SVG intervention. This review article discusses the pathophysiology of SVG lesions, indications for SVG intervention, and the challenges encountered, and also technical considerations for SVG intervention and the supporting evidence.

Chronic Total Occlusion Percutaneous Coronary Intervention in Patients With Prior Coronary Artery Bypass Graft: Current Evidence and Future Perspectives

Coronary chronic total occlusion (CTO), which occurs in 18. 4-52% of all patients referred for coronary angiography, represents one of the last barriers in coronary intervention. Approximately half of all patients with prior coronary artery bypass graft (CABG), who undergo coronary angiography, are diagnosed with coronary CTO. In fact, these patients often develop recurrent symptoms and events, necessitating revascularization. Currently, there is neither a consensus nor developed guidelines for the treatment of CTO patients with prior CABG, and the prognosis of these patients remains unknown. In this review, we discuss current evidence and future perspectives on CTO revascularization in patients with prior CABG, with special emphasis on clinical and lesion characteristics, procedural success rates, periprocedural complications, and long-term outcomes.

Advances in the treatment of ST Elevation Myocardial Infarction in the UK

The treatment of acute coronary occlusion with Primary PCI has been a major factor in improving outcomes of patients suffering STEMI in the last 15 years, and is the standard treatment for patients suffering STEMI in the UK. Treatment is beneficial for patients presenting within 12 hours of the onset of symptoms, with the goal being opening of the occluded artery within 150 min of the call for help. Opening of the occluded artery is typically completed with a drug-eluting stent followed by administration of antiplatelet medications for 12 months. Procedures are performed using the radial artery which is associated with improved outcomes compared to vascular access via the femoral artery. Evidence is growing to support full revascularisation including the treatment of severe narrowing in other blood vessels as well as the culprit vessel.

Saphenous Vein Graft Failure: From Pathophysiology to Prevention and Treatment Strategies

Saphenous vein grafts (SVGs) remain the most frequently used conduits in coronary artery bypass graft surgery (CABG). Despite advances in surgical techniques and pharmacotherapy, SVG failure rates remain high, often leading to repeat coronary revascularization. The no-touch SVG harvesting technique (minimal graft manipulation with preservation of vasa vasorum and nerves) reduces the risk of SVG failure, whereas the effect of the off-pump technique on SVG patency remains unclear. Use of buffered storage solutions, intraoperative graft flow measurement, careful selection of the target vessels, and physiological assessment of the native coronary circulation before CABG may also reduce the incidence of SVG failure. Perioperative aspirin and high-intensity statin administration are the cornerstones of secondary prevention after CABG. Dual antiplatelet therapy is recommended for off-pump CABG and in patients with a recent acute coronary syndrome. Intermediate (30%-60%) SVG stenoses often progress rapidly. Stenting of intermediate SVG stenoses failed to improve outcomes; hence, treatment focuses on strict control of coronary artery disease risk factors. Redo CABG is associated with higher perioperative mortality compared with percutaneous coronary intervention (PCI); hence, the latter is preferred for most patients requiring repeat revascularization after CABG. SVG PCI is limited by high rates of no-reflow and a high incidence of restenosis during follow-up. Drug-eluting and bare metal stents provide similar long-term outcomes in SVG PCI. Embolic protection devices reduce no-reflow and should be used when feasible. PCI of the corresponding native coronary artery is associated with better short- and long-term outcomes and is preferred over SVG PCI, if technically feasible.

Percutaneous coronary interventions on vein graft bifurcation lesions presenting as an acute coronary syndrome

Interventions on graft bifurcation lesions are uncommon, especially in the setting of acute coronary syndromes (ACS). We described three cases of graft bifurcation intervention where we tailored our approach based on lesion characteristics, anatomy, and angulation to achieve excellent angiographic and clinical outcomes. In case 1, shared ostia of saphenous vein graft (SVG) to Diagonal (D) and Radial graft to Obtuse Marginal (OM) was severely stenosed. We prioritized the radial arterial graft as it is known to have a longer patency rate over a totally occluded SVG of an undetermined period. We performed provisional stenting of the ostium of the radial artery and balloon angioplasty of the SVG ostium, while stenting the body of the SVG. In case 2 (bifurcation lesion at the anastomosis of SVG to D1 and sequential jump graft to OM), we utilized a V stenting strategy after an embolization protection device (EPD) was deployed in the branch with a suitable landing zone. Kissing balloon dilatation of both the branches was performed both pre- and poststenting. In case 3 (bifurcation lesion at SVG to OM and Sequential "T" graft to diagonal), there was >90% angulation between both the grafts. We used "T" stenting strategy in this case. At 2-year follow-up, patients had no major adverse cardiovascular events since and remained symptom free.

Long-term outcomes of percutaneous coronary interventions within coronary artery bypass grafts

INTRODUCTION

The long-term outcomes of percutaneous coronary interventions (PCIs) within coronary artery bypasses are still poor as compared to those within native coronary arteries. Thus, we aimed to assess predictors of long-term clinical outcomes after PCIs of coronary bypasses.

MATERIAL AND METHODS

We enrolled 194 patients after PCIs of coronary artery bypasses at the mean age of 69.5 ±8.3 years (73.2% male). The primary study endpoint was a combination of target-vessel revascularization (TVR), target-lesion revascularization (TLR), myocardial infarction (MI), stroke, coronary artery bypass grafting (CABG) and death. The mean follow-up was 964 ±799.1 days and was completed among 156 patients. Multivariate analysis was used to assess determinants of study endpoints during follow-up. Moreover, we compared survival curves according to the type of PCI and presence of anti-embolic protection.

RESULTS

The primary endpoint of the study occurred in 59.7% of patients after the mean time of 669.6 ±598.7 days. The TVR occurred in 37.9% of individuals, TLR in 24.2%, MI in 26.3%, stroke in 4.2%, CABG in 2.1% and death in 30.5% of patients. In Cox multivariate analysis, PCI of two or more bypasses (p < 0.01), post-dilatation (p < 0.05) and no-reflow (p < 0.05) were the independent determinants of the primary study endpoint. No significant impact of anti-embolic protection devices on long-term outcomes was observed.

CONCLUSIONS

Percutaneous coronary interventions of two or more bypasses, post-dilatation and no-reflow are predictors of worse outcome in patients undergoing PCI within coronary artery bypass grafts.

Long-Term Clinical Outcomes of Percutaneous Coronary Intervention in Saphenous Vein Grafts in a Low to Middle-Income Country

Background Revascularization of saphenous vein grafts (SVGs) is challenging and debated for the last few decades. The percutaneous revascularization of SVGs was reported to have poorer long-term outcomes than native coronary artery revascularization. Purpose We aim to study the peri-procedural complications and long-term outcomes of the percutaneous revascularization of SVGs in a low-middle-income country. Methods In this retrospective study, we included 110 patients who underwent percutaneous revascularization from January 2011 to March 2020 and followed them retrospectively for long-term outcomes and major adverse cardiovascular events. Results The mean age was 71 ±9, and 81% were male. The most common reason for the presentation was non-ST segment elevation myocardial infarction (NSTEMI) (46%). The mean follow-up period of the study was 48±27 months. The most common comorbidity was hypertension (86%). A drug-eluting stent (80%) was placed in most of the patients, followed by a bare-metal stent (BMS) (14%) and percutaneous balloon angioplasty (POBA) (6%). We did not find any significant difference in major adverse cardiac events (MACE) (P=0.48), target vessel revascularization (TVR) (p=0.69), and target lesion revascularization (TLR) (p=0.54) with drug-eluting stent (DES) as compared to either BMS or POBA. The mean period from coronary artery bypass grafting (CABG) to SVG percutaneous coronary intervention (PCI) was 15± 5.5 years. Multivariate Cox regression analysis showed that an acute coronary syndrome (ACS) event, stroke, and female sex were independently associated with MACE. Conclusion The long-term outcomes of SVG PCI are not affected by the types of stents. Female gender, ACS, and stroke are the independent predictors of MACE after SVG PCI, and statin therapy has a positive impact on the long-term outcomes of SVG PCI.

Stent-Only Versus Adjunctive Balloon Angioplasty Approach for Saphenous Vein Graft Percutaneous Coronary Intervention: Insights From DIVA Trial

BACKGROUND

Direct stenting without pre-dilation or post-dilation has been advocated for saphenous vein graft percutaneous coronary intervention to decrease the incidence of distal embolization, periprocedural myocardial infarction, and target lesion revascularization.

METHODS

We performed a post hoc analysis of patients enrolled in the DIVA (Drug-Eluting Stents Versus Bare Metal Stents in Saphenous Vein Graft Angioplasty; NCT01121224) prospective, double-blind, randomized controlled trial. Patients were stratified into stent-only and balloon-stent groups. Primary end point was 12-month incidence of target vessel failure (defined as the composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization). Secondary end points included all-cause death, stent thrombosis, myocardial infarction, and target lesion revascularization during follow-up.

RESULTS

Of the 575 patients included in this substudy, 185 (32%) patients underwent stent-only percutaneous coronary intervention. Patients in the stent-only versus balloon-stent group had similar baseline characteristics and similar incidence of target vessel failure at 12-months (15% versus 19%; hazard ratio, 1.34 [95% CI, 0.86-2.08]; P=0.19). During long-term follow-up (median of 2.7 years), the incidence of definite stent thrombosis (1% versus 5%; hazard ratio, 9.20 [95% CI, 1.23-68.92]; P=0.0085), the composite of definite or probable stent thrombosis (5% versus 11%; hazard ratio, 2.52 [95% CI, 1.23-5.18]; P=0.009), and target vessel myocardial infarction (8% versus 14%; hazard ratio, 1.92 [95% CI, 1.08-3.40]; P=0.023) was lower in the stent-only group. Multivariable analysis showed that a higher number of years since coronary artery bypass grafting and >1 target saphenous vein graft lesions were associated with increased target vessel failure during entire follow-up, while preintervention Thrombolysis in Myocardial Infarction-3 flow was protective.

CONCLUSIONS

In patients undergoing percutaneous coronary intervention of de novo saphenous vein graft lesions, there was no difference in target vessel failure at 12 months and long-term follow-up in the stent-only versus the balloon-stent group; however, the incidence of stent thrombosis was lower in the stent-only group, as was target vessel myocardial infarction. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01121224.

Current State of the Art in Approaches to Saphenous Vein Graft Interventions

Saphenous vein grafts (SVGs), used during coronary artery bypass graft surgery for severe coronary artery disease, are prone to degeneration and occlusion, leading to poor long-term patency compared with arterial grafts. Interventions used to treat SVG disease are susceptible to high rates of periprocedural MI and no-reflow. To minimise complications seen with these interventions, proper stents, embolic protection devices (EPDs) and pharmacological selection are crucial. Regarding stent selection, evidence has demonstrated superiority of drug-eluting stents over bare-metal stents in SVG intervention. The ACCF/AHA/SCA American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Society for Cardiovascular Angiography and Interventions guidelines recommend the use of EPDs during SVG intervention to decrease the risk of periprocedural MI, distal embolisation and no-reflow. The optimal pharmacological treatment for slow or no-reflow remains unclear, but various vasodilators show promise.

Aspirate from human stented saphenous vein grafts induces epicardial coronary vasoconstriction and impairs perfusion and left ventricular function in rat bioassay hearts with pharmacologically induced endothelial dysfunction

Stent implantation into aortocoronary saphenous vein grafts (SVG) releases particulate debris and soluble vasoactive mediators, for example, serotonin. We now analyzed effects of the soluble mediators released into the coronary arterial blood during stent implantation on vasomotion of isolated rat epicardial coronary artery segments and on coronary flow and left ventricular developed pressure in isolated perfused rat hearts. Coronary blood was retrieved during percutaneous SVG intervention using a distal occlusion/aspiration protection device in nine symptomatic patients with stable angina pectoris and a flow‐limiting SVG stenosis. The blood was separated into particulate debris and plasma. Responses to coronary plasma were determined in isolated rat epicardial coronary arteries and in isolated, constant pressure‐perfused rat hearts (±nitric oxide synthase [NOS] inhibition and ±serotonin receptor blockade, respectively). Coronary aspirate plasma taken after stent implantation induced a stronger vasoconstriction of rat epicardial coronary arteries (52 ± 8% of maximal potassium chloride induced vasoconstriction [% KCl_max = 100%]) than plasma taken before stent implantation (12 ± 8% of KCl_max); NOS inhibition augmented this vasoconstrictor response (to 110 ± 15% and 24 ± 9% of KCl_max). Coronary aspirate plasma taken after stent implantation reduced in isolated perfused rat hearts only under NOS inhibition coronary flow by 17 ± 3% and left ventricular developed pressure by 25 ± 4%. Blockade of serotonin receptors abrogated these effects. Coronary aspirate plasma taken after stent implantation induces vasoconstriction in isolated rat epicardial coronary arteries and reduces coronary flow and left ventricular developed pressure in isolated perfused rat hearts with pharmacologically induced endothelial dysfunction.

Saphenous Vein Graft Interventions

Saphenous vein graft interventions compose a small but important subset of percutaneous coronary revascularization. Because of their unique biology, percutaneous angioplasty and stenting require tailored patient and lesion selection and modification of intervention technique to optimize outcomes. The use of embolic protection and appropriate adjunctive pharmacology can help minimize periprocedural complications, such as the no-reflow phenomenon. Recommendations for best practice in saphenous vein graft interventions continue to evolve with emerging research and therapy.

Release of Intracoronary Microparticles during Stent Implantation into Stable Atherosclerotic Lesions under Protection with an Aspiration Device

OBJECTIVE

Stent implantation into atherosclerotic coronary vessels impacts on downstream microvascular function and induces the release of particulate debris and soluble substances, which differs qualitatively and quantitatively between native right coronary arteries (RCAs) and saphenous vein grafts on right coronary arteries (SVG-RCAs). We have now quantified the release of microparticles (MPs) during stent implantation into stable atherosclerotic lesions and compared the release between RCAs and SVG-RCAs.

METHODS

In symptomatic, male patients with stable angina and a stenosis in their RCA or SVG-RCA, respectively (n = 14/14), plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation with a distal occlusion/aspiration device and divided into particulate debris and plasma. Particulate debris was weighed. Platelet-derived MPs (PMPs) were distinguished by flow cytometry as CD41+, endothelium-derived MPs (EMPs) as CD144+, CD62E+ and CD31+/CD41-, leukocyte-derived MPs as CD45+, and erythrocyte-derived MPs as CD235+.

RESULTS

In patients with comparable plaque volume and composition in RCAs and SVG-RCAs, intracoronary PMPs and EMPs were increased after stent implantation into their RCAs and SVG-RCAs (CD41+: 2729.6 ± 645.6 vs. 4208.7 ± 679.4 and 2355.9 ± 503.9 vs. 3285.8 ± 733.2 nr/µL; CD144+: 451.5 ± 87.9 vs. 861.7 ± 147.0 and 444.6 ± 74.8 vs. 726.5 ± 136.4 nr/µL; CD62E+: 1404.1 ± 247.7 vs. 1844.3 ± 378.6 and 1084.6 ± 211.0 vs. 1783.8 ± 384.3 nr/µL, P < 0.05), but not different between RCAs and SVG-RCAs.

CONCLUSION

Stenting in stable atherosclerotic lesions is associated with a substantial release not only of PMPs, but also of EMPs in RCAs and SVG-RCAs. Their release does not differ between RCAs and SVG-RCAs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01430884.

An update on coronary bypass graft intervention

Coronary artery bypass grafting (CABG) remains one of the most common surgical procedures. In spite of great advancements like arterial grafts and off-pump bypass procedure, recurrent ischaemia may ensue with the lesions of the graft. Early postoperative ischaemia (<30 days) is due to graft occlusion or stenosis, and percutaneous coronary intervention (PCI) is frequently feasible. Late postoperative ischaemia (>3 years) is most often due to a saphenous vein graft (SVG) lesion. Multiple diseased grafts, reduced left ventricular function, and available arterial conduits favour repeat CABG, whereas, a patent left internal mammary artery to left anterior descending favours PCI. Embolic protection reduces atheroembolic myocardial infarction during PCI of SVG and should be routinely used in treatment of SVG lesions. A variety of vasodilators may reduce the risk of or mitigate the consequences of no-reflow. Drug-eluting stents reduce restenosis in SVG grafts, and have become the default strategy for many interventionalists.

Aspirate from human stented native coronary arteries vs. saphenous vein grafts: more endothelin but less particulate debris

Stent implantation into atherosclerotic coronary arteries releases particulate debris and soluble substances that contribute to impaired microvascular perfusion. Here we addressed the potential for microvascular obstruction in patients with stenotic native right coronary arteries (nRCA) compared with saphenous vein grafts on right coronary arteries (SVG-RCA). We enrolled symptomatic, male patients with stable angina pectoris and a flow-limiting stenosis in their nRCA or SVG-RCA ( n = 18/18). Plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Coronary aspirate was retrieved during stent implantation under protection with a distal occlusion/aspiration device and divided into particulate debris and plasma. The release of catecholamines, endothelin, serotonin, thromboxane B2, and tumor necrosis factor-α was measured. The response of rat mesenteric arteries with intact (+E) and denuded (−E) endothelium to aspirate plasma (without and with selective endothelin receptor blockade) was normalized to that by potassium chloride (KClmax = 100%). Plaque volume and composition were not different between nRCA and SVG-RCA. There was less particulate debris (65 ± 8 vs. 146 ± 23 mg; P < 0.05) and more endothelin release (5.8 ± 0.8 vs. 1.3 ± 0.7 pg/ml; P < 0.05) in nRCA than in SVG-RCA, whereas the release of the other mediators was not different. Aspirate from nRCA induced stronger vasoconstriction than that from SVG-RCA [nRCA, 78 ± 6% (+E)/84 ± 5% (−E); SVG-RCA, 59 ± 6% (+E)/68 ± 3% (−E); P < 0.05 nRCA vs. SVG-RCA], which was attenuated by a nonspecific endothelin and a specific endothelin receptor A antagonist. Thus coronary aspirate from stented nRCA is characterized by less debris but more endothelin and stronger vasoconstrictor response than that from SVG-RCA.

Current percutaneous treatment strategies for saphenous vein graft disease

Coronary artery bypass graft surgery remains one of the most widely performed surgical procedures in North America and aortocoronary saphenous vein grafts (SVG) are the most frequently used surgical conduits. SVG disease (SVGD) remains the leading cause of symptomatic coronary artery disease postcoronary artery bypass graft. When optimal medical therapy is ineffective, repeat surgery is associated with higher mortality combined with less favorable clinical and angiographic results, thus percutaneous revascularization on SVG is currently the standard of care for the revascularization of SVGD. Balloon angioplasty, bare metal stents, polytetrafluoroethylene-covered stents, and drug-eluting stents have been extensively investigated for SVG interventions. Multiple recent randomized trials and meta-analyses have confirmed the pathophysiologic and clinical differences between SVGD and coronary artery disease. Decisions such as patient selection, premedication, stent, and protection device characteristics should be carefully considered to achieve optimal procedural and clinical results. Acute coronary syndromes due to SVG involvement, chronic total occlusions, retrograde approaches, and SVG perforation management are newer fields requesting additional research.

Degenerated Saphenous Vein Graft Intervention: Should We Target the Native Vessel instead?

Coronary interventions of degenerated saphenous vein grafts (SVGs) continue to present a management challenge. Although repeat coronary artery bypass grafting (CABG) remains a significant risk factor for operative mortality, percutaneous coronary intervention (PCI) is still associated with a high risk for periprocedural events. There is a lack of consensus on the optimal treatment strategy for patients with severe stenosis of SVGs. It is imperative to review the characteristics of native versus SVG disease, risk factors for complications after SVG intervention, procedural treatment strategies important to the decision on which therapeutic strategy to follow, and measures to mitigate the risks of periprocedural complications.

Management of Complications During Saphenous Vein Graft Interventions

Because of greater patient comorbidities, more diffusely diseased vessels, and the greater possibility of mechanical complications, saphenous vein graft interventions are fraught with complications. The greatest risk is a higher risk of periprocedural myocardial infarction due to distal embolization of microemboli. The risk for noreflow in a patient with concomitant native critical vessel disease can have grave consequences. Minimizing the risk of periprocedural myocardial infarction with the use of distal embolic protection, understanding the role of adjunctive pharmacotherapy, and learning how to manage less common but serious mechanical complications during saphenous vein graft interventions are important to ensure optimal patient outcomes.

Optimal Stenting in Saphenous Vein Graft Intervention

Percutaneous interventions of (usually degenerated) saphenous vein grafts (SVG) are associated with higher risk of distal embolization and worse clinical outcomes, including target vessel revascularization, myocardial infarction, and death, as compared with percutaneous coronary intervention of native coronary arteries. Embolic protection devices have demonstrated value in reducing the risk of embolization and postprocedural enzyme elevation after SVG interventions. Frequently, however, such devices are not used or cannot be used. As a result, novel stenting strategies intended to decrease the risk of periprocedural myocardial infarction seem to play a major role in enhancing the results following SVG interventions.

PERIPROCEDURAL MYOCARDIAL DAMAGE

Percutaneous coronary intervention (PCI), as a method of myocardial revascularisation, is widely and effectively used for the treatment of coronary heart disease (CHD), with immediate success rates of >90%. Depending on the diagnostic criteria, 5–30% of these patients could develop the signs of periprocedural myocardial damage (PMD) or periprocedural myocardial infarction (PMI). PMD predictors, mechanisms of PMD development, and its specific clinical features play an important role in the PMI prevention. At present, there is no universal agreement on the definition and diagnostics of periprocedural myocardial necrosis and PMI, or on their impact on the clinical outcomes. According to the results of the recent studies, which are presented in this review, the current criteria of PMI might need to be modified, due to the increasingly high sensitivity of the modern threshold levels of troponin. 

Coronary aspirate TNFα reflects saphenous vein bypass graft restenosis risk in diabetic patients

BACKGROUND

Patients with diabetes mellitus (DM) have an increased risk for periprocedural complications and adverse cardiac events after percutaneous coronary intervention. We addressed the potential for coronary microvascular obstruction and restenosis in patients with and without DM undergoing stenting for saphenous vein bypass graft (SVG) stenosis under protection with a distal occlusion/aspiration device.

METHODS

SVG plaque volume and composition were analyzed using intravascular ultrasound before stent implantation. Percent diameter stenosis was determined from quantitative coronary angiography before, immediately after and 6 months after stent implantation. Coronary aspirate was retrieved during stent implantation and divided into particulate debris and plasma. Total calcium, several vasoconstrictors, and tumor necrosis factor (TNF)α in particulate debris and coronary aspirate plasma were determined.

RESULTS

Patients with and without DM had similar plaque volume, but larger necrotic core and greater particulate debris release in patients with than without DM (20.3±2.7 vs. 12.7±2.6% and 143.9±19.3 vs. 75.1±10.4 mg, P<0.05). The TNFα concentration in particulate debris and coronary aspirate plasma was higher in patients with than without DM (15.9±6.6 vs. 5.1±2.4 pmol/mg and 2.2±0.7 vs. 1.1±0.2 pmol/L, P<0.05), whereas total calcium and vasoconstrictors were not different. Patients with DM had a greater percent diameter stenosis 6 months after stent implantation than those without DM (22.17±5.22 vs. 6.34±1.11%, P<0.05). The increase in TNFα immediately after stent implantation correlated with restenosis 6 months later (r=0.69, P<0.05).

CONCLUSION

In diabetics, particulate debris and coronary aspirate plasma contained more TNFα, which might reflect the activity of the underlying atherosclerotic process.

TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov/ct2/results?term=NCT01430884; unique identifier: NCT01430884.

Saphenous vein aorto-coronary graft atherosclerosis in patients with chronic kidney disease: more plaque calcification and necrosis, but less vasoconstrictor potential

Atherosclerotic coronary arteries are more calcified in patients with than without chronic kidney disease (CKD). We addressed the potential for coronary microvascular obstruction in patients with and without CKD during stenting for saphenous vein aorto-coronary graft (SVG) stenosis under protection with a distal occlusion/aspiration device. In patients with and without CKD (n = 20/20), SVG plaque composition was analyzed from virtual histology using intravascular ultrasound analysis before stent implantation. There was more dense calcium and more necrotic core in patients with than without CKD (14 ± 3 vs. 3 ± 1 % and 21 ± 3 vs. 12 ± 2 % of plaque volume, respectively). Coronary aspirate was retrieved during stent implantation and divided into particulate debris and plasma. Patients with CKD had more particulate debris and calcium release than patients without CKD. In contrast, the release of serotonin was less in patients with than without CKD (0.4 ± 0.1 vs. 1.2 ± 0.3 μmol/L), whereas that of catecholamines, endothelin, tissue factor, thromboxane, tumor necrosis factor α, and C reactive protein was not significantly different. Confirming the biochemical results, aspirate plasma from patients with CKD induced less vasoconstriction of rat mesenteric arteries than that from patients without CKD (with endothelium (+E), 26 ± 7 %; without endothelium (-E): 28 ± 7 % vs. +E, 68 ± 12 %; -E: 95 ± 16 % of maximum KCl-induced vasoconstriction). Graft atherosclerosis of patients with CKD is more degenerated and releases more particulate debris and calcium, but the aspirate has surprisingly less serotonin and vasoconstrictor potential.

Saphenous vein graft intervention

Saphenous vein grafts are commonly used conduits for surgical revascularization of coronary arteries but are associated with poor long-term patency rates. Percutaneous revascularization of saphenous vein grafts is associated with worse clinical outcomes including higher rates of in-stent restenosis, target vessel revascularization, myocardial infarction, and death compared with percutaneous coronary intervention of native coronary arteries. Use of embolic protection devices is a Class I indication according to the American College of Cardiology/American Heart Association guidelines to decrease the risk of distal embolization, no-reflow, and periprocedural myocardial infarction. Nonetheless, these devices are underused in clinical practice. Various pharmacological agents are available that may also reduce the risk of or mitigate the consequences of no-reflow. Covered stents do not decrease the rates of periprocedural myocardial infarction and restenosis. Most available evidence supports treatment with drug-eluting stents in this high-risk lesion subset to reduce angiographic and clinical restenosis, although large, randomized trials comparing drug-eluting stents and bare-metal stents are needed.

Percutaneous intervention of a thrombotic-occluded saphenous vein graft successfully treated using the undersized stent approach to prevent distal embolization

Percutaneous intervention carries a higher risk of distal embolization and poorer outcome in saphenous vein grafts (SVG) than in native coronary vessels. Embolic protection devices (EPD) have demonstrated value in decreasing the risk of embolization and post-procedural enzymes elevation after SVG intervention. Although there is ample evidence to support the routine use of EPD for SVG interventions, frequently those devices are not utilized or cannot be used because of technical reasons. As we previously reported, the "undersized stenting" approach seems to be an attractive strategy when EPD cannot be used. We present a case with severe SVG degeneration that illustrates the feasibility of this strategy.

Endovascular stenting of an extracranial-intracranial saphenous vein high-flow bypass graft: Technical case report

Background:

The authors describe a case of endovascular stenting of an extracranial–intracranial saphenous vein high-flow bypass graft in the management of a complex bilateral carotid aneurysm case.

Case Description:

A 43-year-old woman was admitted with progressive visual field restriction and headache. Imaging studies revealed bilateral supraclinoid carotid aneurysms. The right carotid aneurysm was clipped and the left one was treated by an endovascular procedure, after performing an internal carotid artery–middle cerebral artery (ICA-MCA) saphenous vein bypass graft. A few months following the bypass procedure, a 70–80% stenosis of the graft was discovered and treated endovascularly with a stenting procedure. Follow-up at 36 months after the first operation showed the patency of the venous graft and no neurological deficits.

Conclusions:

Endovascular stenting of the extracranial–intracranial saphenous vein high-flow bypass graft is technically feasible when postoperative graft occlusion is discovered.

A comparison of the radial and the femoral approach in vein graft PCI. A retrospective study

BACKGROUND

Transradial PCI is a safe and effective method of percutaneous revascularization. However, there is limited data on the efficacy of the transradial approach for saphenous vein graft (SVG) PCI.

METHODS

We studied 334 patients who underwent SVG PCI between January 2000 and December 2003, and compared the radial (132 patients) and the femoral (202 patients) approach.

RESULTS

Mean EF (55.6+/-18.6% radial versus 58.1+/-16.8% femoral), lesion location (proximal, mid, distal: 22.6/50.6/26.7% versus 22.6/44.5/32.9% respectively) and lesion type (B1/B2/C: 3.4/4.1/92.5% versus 0.4/3.1/96.5%) were similar in both groups (P>0.05). Five patients had a failed radial attempt (3.8%) and were switched to the femoral approach. Mean fluoroscopy time (20.4+/-12.2 versus 18.4+/-10.2 min), procedural time (60.0+/-27.2 versus 61.6+/-24.9 min) and the use of contrast (223+/-91 versus 234+/-91 ml) IIB/IIIA inhibitors (27.2 versus 33.2%), and stenting (81.5 versus 81.3%) were similar in both groups, whereas 5 or 6 French sheaths were used more often in the radial group (83.4 versus 64.9%, P<0.01). Angiographic success (93.9 versus 92.9%), in hospital MACE (radial:5 MI (3.8%) versus femoral: 1 death (0.5%) and 7 MI (3.5%) and major vascular complications (0.7 versus 0.5%) were also similar.

CONCLUSIONS

The radial approach in SVG PCI is as fast and successful as the femoral.

[Saphenous graft angioplasty]

In our daily practice the rate of saphenous graft angioplasty is less than 5%. This kind of angioplasty is more complex with a higher rate of complications in known fragile patients. Some technical trips and tricks are necessary to easily perform these angioplasties. Main difficulties are the extension of saphenous graft lesions, the risk of distal embolism, coronary slow or no flow and the high rate of restenosis. Pharmacological treatment is disappointing with no efficacy of the Gp IIb-IIa blockers. Otherwhise the use of protection devices is clearly effective and must be used when it is technically possible. With the use of bare metal stents in saphenous graft angioplasty the rate of restenosis is very high. There are some encouraging results with drug eluting stents. But we are still now not allowed to use them in this indication in our daily practice.

Thrombus predicts ischemic complications during percutaneous coronary intervention in saphenous vein grafts: Results from TARGET (do tirofiban and reopro give similar efficacy trial?)

BACKGROUND

Saphenous vein graft (SVG) percutaneous coronary intervention (PCI) carries a high risk of ischemic complications. However, there are scant recent data to identify which SVG lesions carry particularly high risk in recent years. We studied demographic and angiographic factors associated with ischemic complications after SVG PCI without distal protection in the TARGET (do tirofiban and reopro give similar efficacy trial?) study.

METHODS

TARGET was a multicenter double-dummy, double-blinded study randomizing 4,809 PCI patients to tirofiban or abciximab. Of these, 254 patients underwent PCI involving an SVG lesion. The primary endpoint of this analysis was major adverse cardiac events (MACEs) at 30 days, including death, nonfatal myocardial infarction (MI), and urgent target vessel revascularization.

RESULTS

No demographic characteristic was associated with 30-day MACE. Lesion length > 20 mm (odds ratio [OR] = 2.7, P = 0.03), thrombus (OR = 3.9, P = 0.003), eccentricity (P = 0.001), thrombolysis in myocardial infarction flow < 3 post-procedure (OR = 5.6, P = 0.037), and >1 target lesion (OR = 2.5, P = 0.035) were univariate variables associated with 30-day MACE. Multivariate analysis associated only thrombus (OR = 3.8, P = 0.015) with 30-day MACE. No difference in outcomes was noted between patients receiving abciximab and tirofiban. SVG patients had lesser angiographic success (95.6% vs. 98%, P = 0.04) and increased 30-day Q-wave MI (2.5% vs. 0.9%, P = 0.039) compared with non-SVG patients, but a similar incidence of death (0% vs. 0.4%), non-Q-MI (5.9% vs. 4.5%), and target vessel revascularization (0.5% vs. 1%).

CONCLUSION

In the era of routine stenting and GpIIb/IIIa inhibitors, thrombus is the angiographic characteristic most closely associated with adverse outcomes of SVG PCI.

Peri-procedural myocardial injury: 2005 update

During the past three decades, percutaneous coronary intervention has become one of the cardinal treatment strategies for stenotic coronary artery disease. Technical advances, including the introduction of new devices such as stents, have expanded the interventional capabilities of balloon angioplasty. At the same time, there has been a decline in the rate of major adverse cardiac events, including Q-wave acute myocardial infarction, emergency coronary artery bypass grafting, and cardiac death. Despite these advances, the incidence of post-procedural cardiac marker elevation has not substantially decreased since the first serial assessment 20 years ago. As of now, these post-procedural cardiac marker elevations are considered to represent peri-procedural myocardial injury (PMI) with worse long-term outcome potential. Recent progress has been made for the identification of two main PMI patterns, one near the intervention site (proximal type, PMI type I) and one in the distal perfusion territory of the treated coronary artery (distal type, PMI type II) as well as for preventive strategies. Integrating these new developments into the wealth of clinical information on this topic, this review aims at giving a current perspective on the entity of PMI.

Provisional stenting for multivessel PCI

BACKGROUND

Bare stents reduce acute complications and repeat revascularization following percutaneous coronary intervention (PCI), but are costly and may lead to in-stent restenosis. It remains unclear whether stents should be universally implanted or whether provisional stenting mainly to suboptimal balloon dilatation results is an acceptable approach for multivessel PCI.

OBJECTIVE

To compare the long-term clinical restenosis and target lesion revascularization (TLR) of stented and non-stented coronary artery lesions in patients who had multivessel PCI.

METHODS

We performed retrospective analysis of matched data from 129 consecutive patients who underwent multivessel PCI (at least optimal balloon angioplasty to one coronary artery segment and balloon angioplasty plus stenting to another coronary artery in the same patient, all lesions are de novo native coronary artery lesions with vessel diameter >/=2.5 mm). The study endpoint was restenosis and repeat revascularization at one-year follow-up.

RESULTS

Baseline characteristics were similar in both groups. Low in-hospital MACE (3.1%). Acute myocardial infarction, emergency revascularization via either PCI or CABG was detected and angiographic success was achieved in 99.3% of lesions in both groups. The rate of clinically driven angiographic restenosis and TLR at one-year (follow-up 100%) was similar (17.1% versus 18.6%, P=0.871, and 13.9% versus 16.3%, P=0.728, for optimal balloon angioplasty versus provisional stenting.

CONCLUSIONS

The main findings from this study are that long-term angiographic restenosis and TLR was comparable for optimal balloon angioplasty and provisional stenting, suggesting that provisional stenting is an acceptable approach for multivessel PCI.

Cutting balloons versus conventional long balloons for PCI of long coronary lesions

BACKGROUND

PCI for long coronary lesions remains a challenge because of high incidence of early complications and late restenosis. Cutting balloon angioplasty may result in reduced procedural complications and late restenosis than angioplasty with conventional long balloons (LBA) due to minimized injury to the culprit arteries.

OBJECTIVE

To compare the immediate and one-year outcomes of CBA and LBA for long coronary lesions.

METHODS

169 consecutive patients were retrospectively identified who underwent CBA or LBA for de novo lesions 20 mm in length and 2.5 mm in diameter. The primary endpoint was immediate procedural outcomes and angiographic restenosis at one year.

RESULTS

CBA was performed in 54 patients (56 lesions) and LBA in 115 patients (151 lesions). Baseline characteristics were similar in both groups with a mean lesion length of 34.89+/-11.19 mm, and vessel diameter of 3.03+/-0.54 mm. CBA resulted in reduced incidence of side branch loss (23.2% versus 41.7%, P=0.022) which was associated with less peri-procedural infarction (OR: 11.39 (95% CI: 1.34-96.53), P=0.026). It also caused less dissection (23.2% versus 38.4%, P=0.048) leading to a trend of less provisional focal stenting (32.1% versus 41.1%, P=0.264). The rate of angiographic restenosis and clinically driven target lesion revascularization at one year (follow-up 91.1%) was similar (25% versus 21.2%, and 20.4% versus 20%, for CBA versus LBA, both P=NS). The mean event-free survival was also similar (10.15+/-0.45 months for CBA versus 9.50+/-0.39 months for LBA, P=NS).

CONCLUSION

CBA demonstrated better immediate results and equivalent late results than LBA, and therefore, it may be considered a reasonable firstline approach for PCI of long coronary lesions.