Drug eluting stents versus bare metal stents in the treatment of saphenous vein graft disease: a systematic review and meta-analysis

Repeat Coronary Bypass Surgery or Percutaneous Coronary Intervention After Previous Surgical Revascularization

OBJECTIVE

To assess long-term survival with repeat coronary artery bypass grafting (RCABG) or percutaneous coronary intervention (PCI) in patients with previous CABG.

METHODS

From January 1, 2000, through December 31, 2013, 1612 Mayo Clinic patients underwent RCABG (n=215) or PCI (n=1397) after previous CABG. The RCABG cohort was grouped by use of saphenous vein grafts only (n=75), or with additional arterial grafts (n=140); the PCI cohort by, bare metal stents (BMS; n=628), or drug-eluting stents (DES; n=769), and by the treated target into native coronary artery (n=943), bypass grafts only (n=338), or both (n=116). Multivariable regression and propensity score analysis (n=280 matched patients) were used.

RESULTS

In multivariable analysis, the 30-day mortality was increased in RCABG versus PCI patients (hazard ratio [HR], 5.32; 95%CI, 2.34-12.08; P<.001), but overall survival after 30 days improved with RCABG (HR, 0.72; 95% CI, 0.55-0.94; P=.01). Internal mammary arteries were used in 61% (129 of 215) of previous CABG patients and improved survival (HR, 0.82; 95% CI, 0.69-0.98; P=.03). Patients treated with drug-eluting stent had better 10-year survival (HR, 0.74; 95% CI, 0.59-0.91; P=.001) than those with bare metal stent alone. In matched patients, RCABG had improved late survival over PCI: 48% vs 33% (HR, 0.57; 95% CI, 0.35-0.91; P=.02). Compared with RCABG, patients with PCI involving bypass grafts (n=60) had increased late mortality (HR, 1.62; 95% CI, 1.10-2.37; P=.01), whereas those having PCI of native coronary arteries (n=80) did not (HR, 1.09; 95% CI, 0.75-1.59; P=.65).

CONCLUSION

RCABG is associated with improved long-term survival after previous CABG, especially compared with PCI involving bypass grafts.

Drug-eluting Stents Versus Bare-metal Stents for Saphenous Vein Graft Interventions: A Systematic Review and Meta-analysis of Studies With Longer Follow-up

Randomized controlled trials comparing drug eluting stents (DES) with bare-metal stents (BMS) for saphenous vein graft (SVG) interventions have shown conflicting results. We conducted this meta-analysis to evaluate the cumulative evidence for long-term efficacy and safety of DES vs BMS in SVG lesions. A systematic search was conducted of Randomized controlled trials comparing DES vs BMS in patients undergoing percutaneous interventions for SVG lesions. End-points of interest were all-cause death, cardiac death, myocardial infarction, target lesion revascularization and target vessel revascularization at longest available follow-up. Random effects meta-analysis was conducted to estimate risk ratio with 95% confidence intervals for individual end-points. Seven studies with 1639 patients were included in the final analysis. Mean follow-up period was 32 months. Compared with BMS, DES was associated with similar risks of all-cause death (risk ratio 1.06; 95% confidence intervals 0.76-1.48) and cardiac death (0.95; 0.59-1.54). Similarly, there were no differences between DES and BMS in terms of myocardial infarction (0.81; 0.50-1.29), target vessel revascularization (0.73; 0.48-1.110 or target lesion revascularization (1.05; 0.76-1.43). Current analysis suggests no strong evidence for routine DES use in patients undergoing SVG intervention. Future studies should evaluate if SVG lesion characteristics could influence these results.

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.

Management and Prevention of Saphenous Vein Graft Failure: A Review

Coronary artery bypass grafting (CABG) remains a vital treatment for patients with multivessel coronary artery disease (CAD), especially diabetics. The long-term benefit of the internal thoracic artery graft is well established and remains the gold standard for revascularization of severe CAD. It is not always possible to achieve complete revascularization through arterial grafts, necessitating the use of saphenous vein grafts (SVG). Unfortunately, SVGs do not have the same longevity, and their failure is associated with significant adverse cardiac outcomes and mortality. This paper reviews the pathogenesis of SVG failure, highlighting the difference between early, intermediate, and late failure. It also addresses the different surgical techniques that affect the incidence of SVG failure, as well as the medical and percutaneous prevention and treatment options in contemporary practice.

Choice of Stent for Percutaneous Coronary Intervention of Saphenous Vein Grafts

Background—

There are limited data on comparison of contemporary drug-eluting stent (DES) platforms, previous generation DES, and bare-metal stents (BMS) for percutaneous coronary intervention in saphenous vein grafts (SVG). We aimed to assess clinical outcomes following percutaneous coronary intervention to SVG in patients receiving bare-metal stents (BMS), first-generation DES, and newer generation DES in a large unselected national data set from the BCIS (British Cardiovascular Intervention Society).

Methods and Results—

Patients undergoing percutaneous coronary intervention to SVG in the United Kingdom from January 2006 to December 2013 were divided into 3 groups according to stent use: BMS, first-generation DES, and newer generation DES group. Study outcomes included in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality. Patients (n=15 003) underwent percutaneous coronary intervention to SVG in England and Wales during the study period. Of these, 38% received BMS, 15% received first-generation DES, and 47% received second-generation DES. The rates of in-hospital major adverse cardiovascular events were significantly lower in patients treated with second-generation DES (odds ratio, 0.51; 95% confidence interval, 0.38–0.68; P <0.001), but not with first-generation DES, compared with BMS-treated patients. Similarly, 30-day mortality (odds ratio, 0.43; 95% confidence interval, 0.32–0.59; P <0.001) and 1-year mortality (odds ratio, 0.60; 95% confidence interval, 0.51–0.71; P <0.001) were lower in patients treated with second-generation DES, but not with first-generation DES, compared with the patients treated with BMS.

Conclusions—

Patients receiving second-generation DES for the treatment SVG disease have lower rates of in-hospital major adverse cardiovascular events, 30-day mortality, and 1-year mortality, compared with those receiving BMS.

Drug-eluting versus bare metal stent in treatment of patients with saphenous vein graft disease: A meta-analysis of randomized controlled trials

Drug-eluting stent (DES) and bare metal stent (BMS) are effective treatments for preventing vascular disease, but whether using DES is associated with positive clinical outcomes compared with BMS in patients with saphenous vein graft disease (SVGD) has not been established. Three electronic databases including PubMed, EmBase, and the Cochrane Central Register of Controlled Trials were searched to identify potentially includible studies. We did a random-effects meta-analysis of randomized controlled trials (RCTs) to obtain summary effect estimates for the clinical outcomes with the use of relative risk calculated from the raw data of individual trial. Among 812 patients from 4 RCTs, DES was associated with lower risk of short-term major cardiovascular events (MACEs) when compared with BMS, whereas no significant effect on the risk of long-term MACEs. Furthermore, there was no significant difference between DES and BMS for short-term myocardial infarction (MI) and long-term MI. Similarly, DES was not associated with risk of short- and long-term mortality risk as compared with BMS. In addition, DES has no significant effect on the risk of cardiac death and stent thrombosis. Finally, DES therapy significantly reduced the risk of TLR, TVF, and TVR. SVGD patients received DES can minimize the risk of short-term MACEs, TLR, TVF, and TVR when compared with BMS. However, it does not effect on the incidence of long-term MACEs, MI, mortality, cardiac death, and stent thrombosis.

The evidence base for revascularisation of chronic total occlusions

When patients with ischaemic heart disease are considered for revascularisation the Heart Team's aim is to choose a therapy that will provide complete relief of angina for an acceptable procedural risk. Complete functional revascularisation of ischaemic myocardium is thus the goal and for this reason the presence of a chronic total occlusion (CTO) - which remain the most technically challenging lesions to revascularise percutaneously - is the most common reason for selecting coronary artery bypass surgery. From the behaviour of Heart Teams it is clear that physicians believe that CTOs are important. Yet when faced with patients with CTOs for whom surgery appears excessive (e.g. nonproximal LAD) or too high risk, there remains a reluctance to undertake CTO PCI, despite significant recent advances in procedural success and safety and a considerable body of evidence supporting a survival benefit following successful CTO PCI. This article reviews the relationship between CTOs, symptoms of angina, ischaemia and left ventricular dysfunction and further explores the evidence relating their treatment to improved quality of life and prognosis in patients with these features.

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.

Saphenous vein graft failure after coronary artery bypass surgery: pathophysiology, management, and future directions

OBJECTIVE

To review our current understanding of the epidemiology and pathogenesis of vein graft failure (VGF), give an overview of current preventive and interventional measures, and explore strategies that may improve vein graft patency.

BACKGROUND

VGF and progression of native coronary artery disease limit the long-term efficacy of coronary artery bypass graft surgery.

METHODS

We reviewed the published literature on the pathophysiology, prevention, and/or treatment of VGF by searching the MEDLINE (January 1, 1966-January 1, 2012), EMBASE (January 1, 1980-January 1, 2012), and Cochrane (January 1, 1995-January 1, 2012) databases. In addition, we reviewed references from the selected articles for studies not identified in the initial search. Basic science and clinical studies were included; non-English language publications were excluded.

RESULTS

Acute thrombosis, neointimal hyperplasia, and accelerated atherosclerosis are the 3 mechanisms that lead to VGF. Preventive measures include matching and quality assessment of conduit and target vessel, lipid-lowering drugs, antithrombotic therapy, and cessation of smoking. Treatment of VGF includes medical therapy, percutaneous intervention, and redo coronary artery bypass graft surgery. In patients undergoing graft intervention, the use of drug-eluting stents, antiplatelet agents, and embolic protection devices may improve clinical outcomes.

CONCLUSIONS

Despite advances in management, VGF remains one of the leading causes of poor in-hospital and long-term outcomes after coronary artery bypass graft surgery. New developments in VGF prevention such as gene therapy, external graft support, fully tissue-engineered grafts, hybrid grafts, and synthetic conduits are promising but unproven. Future efforts to reduce VGF require a multidisciplinary approach with a primary focus on prevention.

Drug-Eluting Stents Versus Bare Metal Stents in Saphenous Vein Graft Intervention

Percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) is associated with higher adverse event rates, lower procedural success, and inferior longterm patency rates compared with native vessel PCI. The ability to comply with dual antiplatelet therapy, and whether the patient will need an interruption in dual antiplatelet therapy, should be considered when deciding whether to implant a drug-eluting stent (DES) or bare metal stent (BMS) in an SVG. DES should be used for SVG PCI because they seem to reduce target vessel revascularization. This article reviews the evolution and contemporary evidence regarding use of DES versus BMS in SVG PCI.

Clinical outcomes of percutaneous interventions in saphenous vein grafts using drug-eluting stents compared to bare-metal stents: a comprehensive meta-analysisof all randomized clinical trials

BACKGROUND

Clinical outcomes of percutaneous coronary intervention (PCI) in patients with saphenous vein grafts (SVGs) remain poor despite the use of drug-eluting stents (DES). There is a disparity in clinical outcomes in SVG PCI based on various registries, and randomized clinical data remain scant. We conducted a meta-analysis of all existing randomized controlled trials (RCTS) comparing bare-metal stents (BMS) and DES in SVGPCIs.

HYPOTHESIS

PCI in patients with SVG disease using DES may reduce need for repeat revascularization without an excess mortality when compared to BMS.

METHODS

An aggregate data meta-analysis of clinical outcomes in RCTs comparing PCI with DES vs BMS for SVGs reporting at least 12 months of follow-up was performed. A literature search between Janurary 1, 2003 and September 30, 2011 identified 4 RCTs (812 patients; DES = 416, BMS = 396). Summary odds ratio (OR) and 95% confidence interval (CI) were calculated using the random-effects model. The primary endpoint was all-cause mortality. Secondary outcomes included nonfatal myocardial infarction (MI), repeat revascularization, and major adverse cardiac events (MACE). These outcomes were assessed in a cumulative fashion at 30 days, 18 months, and 36 months.

RESULTS

There were no intergroup differences in baseline clinical and sociodemographic characteristics. At a median follow-up of 25 months, patients in the DES and BMS group had similar rates of death (OR: 1.63, 95% CI: 0.45-5.92), MI (OR; 0.83, 95% CI: 0.27-2.60), and MACE (OR: 0.58, 95% CI: 0.25-1.32). Patients treated with DES had lower rates of repeat revascularization (OR: 0.40, 95% CI: 0.22-0.75).

CONCLUSIONS

In this comprehensive meta-analysis of all RCTs comparing clinical outcomes of PCI using DES vs BMS in patients with SVG disease, use of DES was associated with a reduction in rate of repeat revascularization and no difference in rates of all-cause death and MI. Clin. Cardiol. 2012 DOI: 10.1002/clc.21984 Dr. Virani is supported by a Department of Veterans Affairs Health Services Research and Development Service (HSR&D) Career Development Award (CDA-09-028), and has research support from Merck and National Football League Charities (all grants to the institution and not individual). The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs. The authors have no other funding, financial relationships, or conflicts of interest to disclose.

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.

Paclitaxel-eluting stents reduce neointimal hyperplasia compared to bare metal stents in saphenous vein grafts: intravascular ultrasonography analysis of the SOS (Stenting of Saphenous Vein Grafts) trial

AIMS

To compare the intravascular ultrasonography (IVUS) findings between saphenous vein grafts (SVG) treated with paclitaxel-eluting stents (PES) vs. bare metal stents (BMS) in the Stenting Of Saphenous Vein Grafts (SOS) trial.

METHODS AND RESULTS

Of the 80 SOS trial patients, 38 had both baseline and follow-up IVUS examination and were included in this substudy: 17 patients received 28 BMS in 26 lesions and 21 patients received 30 PES in 28 lesions. Quantitative IVUS analysis was performed to determine the volume of in-stent neointimal hyperplasia (NIH) - defined as the difference between stent volume and lumen volume in the stented segments. Baseline characteristics were similar between patients who did and did not undergo baseline and follow-up IVUS. Patients receiving BMS and PES had similar stent and lumen volumes immediately after stenting. At 12-month follow-up, compared to BMS, PES-treated lesions had significantly less NIH volume (3.4 vs. 21.9 mm³, p<0.001) and neointima hyperplasia progression (1.6 vs. 17.1 mm³, p<0.001). No significant differences were seen in the 5 mm segment proximal and distal to the stent.

CONCLUSIONS

Compared to BMS, use of PES in SVG lesions is associated with significantly lower NIH formation, which may help explain the improved clinical outcomes with PES in these lesions.