Effectiveness and safety of drug-eluting stents in vein grafts: a meta-analysis

Drug-eluting versus bare metal stents in saphenous vein grafts compared to native coronary vessels. The NORSTENT study

BACKGROUND

Drug-eluting stents (DES) reduce target lesion revascularization (TLR) with no effect on mortality or myocardial infarction (MI) compared to bare metal stents (BMS) in native vessels. Randomized stent studies in saphenous vein grafts (SVG) are few and the reported effects are ambiguous. The NORSTENT study is the first to randomize lesions to percutaneous coronary intervention (PCI) in native vessels and SVG.

AIMS

To compare rate of mortality, MI and TLR across stent and vessel types.

METHODS

In this substudy 6087 patients with a single lesion in native vessels and 164 in SVG, were followed for 5 years.

RESULTS

MI was more frequent in SVG (subdistributional hazard ratio (SHR) 4.95 (3.75 - 6.54, p<0.001), but not affected by stent type. In the first 500 days DES reduced TLR in native vessels (SHR 0.21 ( 0.15 - 0.30)p<0.001) and SVG (SHR 0.18 (0.04 - 0.80) p=0.02). Thereafter DES and BMS were equivalent in native vessels, but DES had a higher TLR rate than BMS in SVG (SHR 3.31 (1.23 - 8.94) p=0.02). After 5 years the TLR rate was still significantly lower for DES in native vessels (3.2 % versus 7.8 %, p<0.001) but not in SVG (21.4 % vs 18. 4%).

CONCLUSION

In SVG no difference in TLR between DES and BMS was observed after 5 years in contrast to persistent benefit in native vessels. The high rate of TLR and myocardial infarction in SVG makes treatment of native vessels a preference whenever feasible and better treatment options for SVG are warranted.  .

Percutaneous coronary intervention in saphenous vein grafts after coronary artery bypass grafting: a systematic review and meta-analysis

To investigate the results of percutaneous coronary intervention (PCI) in saphenous vein grafts after coronary artery bypass grafting (CABG). Design. MEDLINE, Embase, and the Cochrane library were searched for relevant articles published between 1 January 2000 and 29 February 2020. The PICO (population, intervention, comparison, outcome) model was applied in constructing the clinical question. Two independent researchers performed the literature search. Thirty-six articles were identified and subjected to a quality assessment. The primary outcomes of the meta-analysis were long-term in-stent restenosis and long-term major adverse cardiac events (MACE). Results. In-stent restenosis was 9.4% (95% CI: 4.2-14.7%) and MACE was 35.3% (95% CI: 27-43.7%) at mean time 2.7 ± 1.0 years. The secondary outcomes were the unsuccessful PCI rate (7.7%; 95% CI: 2.9-12.5%), 30-day MACE (4.3%; 95% CI: 2.5-6.1%), and 1-year MACE (15.5%; 95% CI: 11.7-19.3%). The use of drug-eluting stents resulted in better outcomes at least in term of in-stent restenosis, while the benefit of using embolic protection devices was questionable. Conclusions. PCI of a stenosed or occluded saphenous vein graft is a challenge for interventional cardiologists, and is still associated with relatively high rates of restenosis, MACE, and procedural failure. All efforts to enhance the results are warranted, including improved quality of the venous grafts used during CABG.

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.

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.

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.

Clinical presentation and predictors of target vessel revascularization after drug-eluting stent implantation

BACKGROUND

Drug eluting stent (DES) failure including restenosis and stent thrombosis, or disease progression may result in target vessel revascularization (TVR) but the relative contribution of these mechanisms in the DES era is not well described. We sought to examine the predictors and presentations of patients with clinically driven TVR after DES.

METHODS

Patients with all lesions treated with a DES in the Dynamic Registry from 2004 to 2006 were analyzed. Included were 2691 patients with 3401 lesions. Patients with and without incident clinically driven TVR at 2years were compared according to baseline clinical, procedural, and angiographic characteristics and independent predictors of TVR and target lesion revascularization (TLR) were determined by multivariate analysis.

RESULTS

By 2-years, TVR occurred in 7.2% of patients and TLR in 3.8%, with 71.6% and 82.5% of repeat revascularization events occurring in the first year, respectively. The indication for first TVR was myocardial infarction in 18.6% (n=34), unstable angina in 42.6% (n=78), stable coronary disease in 25.7% (n=47) and other/unknown in 13.1% (n=24). Disease progression was responsible for 47% of TVR. Among patients with TLR, restenosis was the mechanism in 86.6% and stent thrombosis in 13.4%. Independent predictors of TVR included younger age, diabetes, attempted graft lesion, lesion length >30mm and prior lesion intervention. Independent predictors of TVR and TLR were similar.

CONCLUSION

The incidence of clinically driven TVR is low in patients treated with DES and nearly half is attributable to disease progression, which along with the low rate of in-stent restenosis explains why the mode of presentation is often an acute coronary syndrome.

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.

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.

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.

Long-term effectiveness and safety of sirolimus drug-eluting stents

The root cause of coronary artery disease is atherosclerosis, ie, intraluminal narrowing (stenosis) of the arteries that supply blood to tissues of the heart. The introduction of the drug-eluting stent over the past decade has revolutionized the field of interventional cardiology. It is used extensively in clinical practice for the treatment of coronary artery disease. The first drug-eluting stent to receive US Food and Drug Administration approval was the sirolimus-eluting stent. Recently, two other stent analogs of sirolimus were approved, ie, the zotarolimus-eluting stent and the everolimus-eluting stent. However, concern has arisen in recent years about the long-term safety and efficacy of drug-eluting stents, due to the occurrence of late adverse clinical events, such as stent thrombosis. This review focuses on clinical studies that have been performed with the sirolimus-eluting stent or its analogs. We discuss the pharmacology, safety, and various therapeutic options that exist when choosing stents for coronary artery disease. Our aim is to provide a thorough review of the long-term efficacy and safety of sirolimus drug-eluting stents, and also to discuss currently approved and promising investigational drug-eluting stents, in an effort to provide insight into how these stents are currently evolving and generate further investigation in this area.

Comparison of drug-eluting and bare metal stents for saphenous vein graft lesions (from the National Heart, Lung, and Blood Institute Dynamic Registry)

The effectiveness and safety of drug-eluting stents (DES) compared with bare-metal stents (BMS) in saphenous vein graft (SVG) disease remains unclear. In particular, there is a paucity of data on long-term outcomes. In this study, 395 patients enrolled in the National Heart, Lung, and Blood Institute Dynamic Registry who underwent stenting of SVG lesions with BMS (n = 192) from 1999 to 2006 or DES (n = 203) from 2004 to 2006 were analyzed. Patients were followed prospectively for the occurrence of cardiovascular events and death at 3 years. Patients treated with DES were more likely to have diabetes mellitus and other co-morbidities and previous percutaneous coronary intervention. Treated lesions in DES patients were more complex than those in BMS patients. At 3 years of follow-up, the adjusted risk for target vessel revascularization (hazard ratio 1.03, 95% confidence interval 0.65 to 1.62, p = 0.91) and death or myocardial infarction (hazard ratio 0.72, 95% confidence interval 0.49 to 1.04, p = 0.08) was similar in patients treated with DES and those treated with BMS. The combined outcome of death, myocardial infarction, or target vessel revascularization excluding periprocedural myocardial infarction was also similar (adjusted hazard ratio 0.82, 95% confidence interval 0.62 to 1.09, p = 0.16). In conclusion, this multicenter nonrandomized study of unselected patients showed no benefit of DES in SVG lesions, including no reduction in target vessel revascularization, compared with BMS at 3 years. An adequately powered randomized controlled trial is needed to determine the optimal stent type for SVG percutaneous coronary intervention.