Lack of clinical long-term benefit with the use of a drug eluting stent compared to use of a bare metal stent in saphenous vein 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.

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.

Pathology of drug-eluting versus bare-metal stents in saphenous vein bypass graft lesions

OBJECTIVES

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).

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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 strategies in saphenous vein graft lesions: long-term results

AIMS

Although half of saphenous vein grafts (SVGs) present obstructive atherosclerotic disease 10 years after implantation, controversy remains concerning the ideal treatment. Our aim was to compare percutaneous revascularization (PCI) options in SVG lesions, according to intervention strategy and type of stent.

METHODS

A retrospective single-center analysis selected 618 consecutive patients with previous bypass surgery who underwent PCI between 2003 and 2008. Clinical and angiographic parameters were analyzed according to intervention strategy - PCI in SVG vs. native vessel vs. combined approach - and type of stent implanted - drug-eluting (DES) vs. bare-metal (BMS) vs. both. A Cox regressive analysis of event-free survival was performed with regard to the primary outcomes of death, myocardial infarction (MI) and target vessel failure (TVF).

RESULTS

During a mean follow-up of 796±548 days the rates of death, MI and TVF were 10.9%, 10.5% and 29.5%, respectively. With regard to intervention strategy (74.4% of PCI performed in native vessels, 17.2% in SVGs and 8.4% combined), no significant differences were seen between groups (death p=0.22, MI p=0.20, TVF p=0.80). The type of stents implanted (DES 83.2%, BMS 10.2%, both 3.2%) also did not influence long-term prognosis (death p=0.09, MI p=0.11, TVF p=0.64). The implantation of DES had a favorable impact on survival (p<0.001) in the subgroup of patients treated in native vessels but not in SVG.

CONCLUSIONS

Among patients with SVG lesions, long-term mortality, MI and TVF were not affected by intervention options, except for the favorable impact on survival of DES in patients treated in native vessels.

Late outcomes of drug eluting and bare metal stents in saphenous vein graft percutaneous coronary intervention

AIMS

PCI with drug eluting stents (DES) has been shown to reduce restenosis and major adverse cardiac event (MACE) rates compared to bare metal stents (BMS) in native coronary vessels, although outcomes in saphenous vein graft (SVG) lesions are less clear. We retrospectively studied 388 consecutive patients admitted to our centre for SVG PCI to assess mortality and MACE outcomes (defined as composite endpoint of all-death, stroke, myocardial infarction, stent thrombosis and target lesion (TLR)/vessel (TVR) revascularisation) associated with BMS and DES use.

METHODS AND RESULTS

Two hundred and nineteen (219) patients had BMS and 169 had DES (total 388 patients). Mean follow up was 41.9±23.5 months. No significant differences were observed in mortality (14.2% vs. 11.8%) or MACE (37.6% vs. 35.8%) between the BMS and DES groups at four years follow-up or at other intervening time points studied. Similarly, no differences in TVR/TLR rates were observed over a similar time period (19.8% vs. 21.6%).

CONCLUSIONS

We have observed that DES and BMS use in SVG PCI have comparable mortality and MACE rates, and that in contrast to PCI in native coronary arteries, DES do not reduce revascularisation rates in our study cohort.

Drug-eluting or bare metal stents for the treatment of saphenous vein graft disease: a Bayesian meta-analysis

BACKGROUND

Observational studies and randomized, controlled trials have yielded uncertain results regarding the benefits of drug-eluting stents (DES) for the treatment of saphenous vein graft (SVG) disease. The objective of this meta-analysis was to assess the cumulative evidence regarding the efficacy and effectiveness of DES to treat SVG compared with bare metal stent (BMS).

METHODS AND RESULTS

We conducted a bayesian hierarchical meta-analysis of all randomized, controlled trials and observational studies that compared clinical outcomes after DES or BMS placement in SVG disease. Our search resulted in 25 studies, cumulating 5755 patients. DES implantation was not associated with an increased risk of death (odds ratio [OR], 0.85; 95% credible intervals (CrI) [CrI], 0.62 to 1.21) or myocardial infarction (OR, 0.83; 95% CrI, 0.56 to 1.32), but wide CrIs preclude definitive conclusions. Target vessel revascularization (OR, 0.55; 95% CrI, 0.39 to 0.76) and target lesion revascularization (OR, 0.58; 95% CrI, 0.37 to 0.87) were both reduced by approximately 45% with DES. When combining these outcomes, the OR for major adverse cardiac events was reduced in patients treated with DES (OR, 0.62; 95% CrI, 0.46 to 0.81). Finally, the relative risk of stent thrombosis appeared lower with DES, although again the CrIs were very wide (OR, 0.54; 95% CrI, 0.13 to 1.39).

CONCLUSIONS

In this study-level meta-analysis, the largest ever reported and the first using bayesian methods, the use of DES for the treatment of SVG disease reduces target vessel revascularization and target lesion revascularization procedures compared with BMS. Although there is no evidence to date to suggest increased rates of mortality, myocardial infarction, or stent thrombosis, further data are needed to address this safety issue.

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.

Drug-eluting versus bare-metal stent for treatment of saphenous vein grafts: a meta-analysis

BACKGROUND

Saphenous vein grafts develop an aggressive atherosclerotic process and the efficacy of drug eluting stents (DES) in treating saphenous vein graft (SVG) lesions has not been convincingly demonstrated. The aim of this study was to review and analyze the current literature for controlled studies comparing DES versus bare metal stents (BMS) for treatment of SVG stenoses.

METHODOLOGY/PRINCIPAL FINDINGS

We searched several scientific databases and conference proceedings up to March 15, 2010 for controlled studies comparing target vessel revascularization (TVR) between DES and BMS. Summary odds ratios (OR) for the primary endpoint TVR and secondary endpoints infarction, stent thrombosis and death were calculated using random-effect models. A total of 29 studies (3 randomized controlled trials RCT) involving 7549 (202 in RCT) patients were included. The need for target vessel revascularization in the DES group tended to be lower compared to BMS for the 3 RCT (OR 0.50 [0.24-1.00]; p = 0.051) and for observational studies (0.62 [0.49-0.79]; p<0.001). There was no significant difference in the risk for myocardial infarction in the RCT (OR 1.25 [0.22-6.99]; p = 0.250) but a lower risk for DES based on the observational studies 0.68 [0.49-0.95]; p = 0.023. The risk for stent thrombosis was found to be non-different in the RCT (OR 0.78 [0.03-21.73], p = 0.885) while it was in favor of DES in the observational studies (0.58 [0.38 - 0.84]; p<0.001). The mortality was not significantly different between DES and BMS in the RCT's (OR 2.22 [0.17 - 29.50]; p = 0.546) while the observation studies showed a decreased mortality in the DES group (0.69 [0.55-0.85]; p<0.001).

CONCLUSION

DES may decrease TVR rate in treatment of SVG stenoses. No differences in reinfarction rate, stent thrombosis or mortality was found between the DES and BMS groups in the RCT's while the observational data showed lower risk for myocardial infarction, stent thrombosis and death in the DES group. This may be a result of patient selection bias in the observational studies or represent a true finding that was not the detected in the RCT analysis due to limited statistical power.

Comparison of the Long-Term Safety and Efficacy of Drug-Eluting and Bare-Metal Stent Implantation in Saphenous Vein Grafts

Background—

Concerns about the long-term safety of drug-eluting stents (DES) in saphenous vein grafts has become an area of controversy and uncertainty.

Methods and Results—

In this retrospective registry, we compared the outcomes in 127 patients (143 lesions) treated with DES from April 2002 to June 2006 (DES group) with 131 patients (160 lesions) treated with bare-metal stents in the preceding 36 months (bare-metal stent group). End points analyzed were cumulative death, myocardial infarction, and target vessel revascularization at 2 years after stent implantation. The DES group was significantly ( P <0.05) more complex with a greater frequency of diabetes (33.1%versus 15.3%), older grafts (11.6±5.3 years versus 9.6±5.2 years), restenotic lesions (23.8% versus 4.4%), total occlusions (7.7% versus 1.2%), and smaller grafts (3.16±0.66 mm versus 3.44±0.76 mm) treated with longer stents (34.1±25.1 mm versus 22.7±11.6 mm). At 2 years, there was no statistical difference in death (8.7% versus 7.8%), myocardial infarction (6.3% versus 9.4%), or target vessel revascularization (19.7% versus 24.2%) between DES and bare-metal stents, respectively. A propensity analysis to adjust for baseline differences suggested that there was no observed association between DES and increased mortality (hazard ratio, 0.72; 95% CI, 0.21 to 2.44; P =0.60) but possibly an association with a reduction in target vessel revascularization (hazard ratio, 0.31; 95% CI, 0.14 to 0.66; P =0.002).

Conclusions—

Despite being implanted in patients and lesions more complex than the bare-metal stent group, there was no observed association between DES implantation in saphenous vein grafts and an increase in late mortality. DES may maintain their efficacy in reducing revascularization rates in diseased saphenous vein grafts over a 2-year follow-up period.

Comparison by meta-analysis of drug-eluting stents and bare metal stents for saphenous vein graft intervention

This meta-analysis was undertaken to assess the efficacy and safety of drug-eluting stents (DESs) compared to bare metal stents (BMSs) in saphenous vein graft (SVG) interventions. DESs decrease the risk of target vessel revascularization in native coronary arteries compared to BMSs. The ideal treatment strategy in patients with SVG disease is unknown. A search of the published reports was conducted to identify studies that compared DESs and BMSs in SVG intervention with a minimum follow-up of 6 months. A total of 19 studies (2 randomized trials and 17 registries), including 3,420 patients who had undergone SVG intervention (DESs, n = 1,489 and BMS, n = 1,931), met the selection criteria. The mean length of follow-up was 20 + or - 12 months. Using the fixed effect model, target vessel revascularization was less frequently performed in patients who had undergone SVG intervention with a DES than with a BMS (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.49 to 0.72). The incidence of myocardial infarction was lower in patients with a DES than in those with a BMS (OR 0.69, 95% CI 0.49 to 0.99). No differences were found in the risk of death (OR 0.78, 95% CI 0.59 to 1.02) or stent thrombosis (OR 0.41, 95% CI 0.15 to 1.11) between the 2 groups. In conclusion, these findings support the use of DESs in SVG lesions.

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

BACKGROUND

The use of drug-eluting stents (DES) in degenerative vein grafts is currently an off-label indication. Recent studies have had conflicting results regarding the effectiveness and safety of this practice. The objective of this meta-analysis was to compare DES to bare-metal stents for the treatment of vein graft stenosis.

METHODS

PubMed and the Cochrane clinical trials database were systematically searched to identify all randomized controlled trials (RCTs) and observational studies examining DES for vein graft stenosis published in English between 2003 and 2009. Inclusion criteria included follow-up duration > or =6 months. Data were stratified by study design and pooled using random effects models.

RESULTS

Twenty studies were found to meet our inclusion criteria. Eighteen studies were observational and 2 were RCTs. In observational studies, DES were associated with a reduction in major adverse cardiac events (MACE) (odds ratio [OR] 0.50, 95% CI 0.35-0.72), death (OR 0.69, 95% CI 0.53-0.91), target vessel revascularization (TVR) (OR 0.54, 95% CI 0.37-0.79), and target lesion revascularization (TLR) (OR 0.54, 95% CI 0.37-0.78). The incidence of myocardial infarction was similar between groups. In the RCTs, pooled results were inconclusive because of small sample sizes.

CONCLUSIONS

Although data from observational studies suggest that the use of DES for vein graft stenosis has favorable effects on MACE, death, TVR, and TLR, these data should be interpreted with caution due to their observational nature. Corresponding RCT data are inconclusive. There remains a need for large multicenter RCTs to address the effectiveness and safety of DES for vein graft stenosis.

Outcomes with drug-eluting versus bare-metal stents in saphenous vein graft intervention results from the STENT (strategic transcatheter evaluation of new therapies) group

OBJECTIVES

This study compares outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) in patients undergoing saphenous vein graft (SVG) intervention.

BACKGROUND

The safety and efficacy of DES in patients undergoing SVG intervention is controversial.

METHODS

The STENT (Strategic Transcatheter Evaluation of New Therapies) registry is a multicenter U.S. registry evaluating outcomes with DES. Our study population includes patients undergoing PCI of SVG lesions with DES (n = 785) or BMS (n = 343) who completed 9-month or 2-year follow-up. Outcomes were adjusted with propensity analyses.

RESULTS

The DES patients had fewer emergent procedures but had smaller vessels and longer lesions. The DES patients had less death or myocardial infarction at 9 months (hazard ratio [HR]: 0.52, 95% confidence interval [CI]: 0.33 to 0.83, p = 0.006) and less death at 2 years (HR: 0.60, 95% CI: 0.36 to 0.98, p = 0.041). Target vessel revascularization (TVR) was less with DES at 9 months (7.2% vs. 10.0%, HR: 0.36, 95% CI: 0.22 to 0.61, p < 0.001) but was no different by 2 years (18.3% vs. 16.9%, p = 0.86), although adjusted TVR rates were lower (HR: 0.60, 95% CI: 0.40 to 0.90, p = 0.014). The DES reduced TVR at 9 months in SVG lesions with diameter <3.5 mm (8.0% vs. 17.2%, p = 0.013) but not >or=3.5 mm (6.0% vs. 6.6%, p = 0.74).

CONCLUSIONS

Treatment of SVG lesions with DES vs. BMS is effective in reducing TVR at 9 months, although most of this advantage is lost at 2 years. The DES seem safe with less death or myocardial infarction, although selection bias might have affected these results. Our data suggest that DES might have short-term advantages over BMS in SVG lesions with diameter <3.5 mm.

Drug-eluting versus bare-metal stents for treating saphenous vein grafts

BACKGROUND

Current data show conflicting results regarding safety and efficacy of drug-eluting stents (DES) versus bare-metal stents (BMS) for treating saphenous vein grafts (SVG). Our objective was to compare DES with BMS for SVG intervention.

METHODS

Patients undergoing stenting with DES or BMS to SVG from January 2000 to June 2007 were included. To eliminate any unobserved bias regarding stent selection, the BMS cohort was divided into pre- and post-2003 when DES became available. Adjusted Cox analysis compared DES with pre- and post-2003 BMS patients. The primary end point was a composite of all-cause mortality, myocardial infarction, or target lesion revascularization.

RESULTS

Of the total 566 patients, 217 (38%) received DES, 110 (20%) received BMS post-2003, and 239 (42%) received BMS pre-2003. Median follow-up was 2.9 years (interquartile range 1.4-4.9 years). There was a trend toward lower primary end point with DES compared to post-2003 BMS (91 events, adjusted hazard ratio 0.61, 95% CI 0.35-1.07, P = .08). However, despite 179 events, DES use was not associated with lower primary end point compared with pre-2003 BMS (adjusted hazard ratio 0.61, 95% CI 0.28-1.35, P = .23).

CONCLUSIONS

Although DES showed a trend toward a lower primary end point when compared with BMS post-2003, this association was no longer present when DES was compared to pre-2003 BMS. These results are consistent with the preponderance of available data and indicate that unobserved bias in observational registries may explain the reported benefit of DES over BMS for treating SVG.

Drug-eluting stents: a comprehensive appraisal

Cardiovascular medicine has evolved over the last few decades, with the advent of percutaneous interventional treatments. In particular, balloon angioplasty and, subsequently, coronary stenting has revolutionized our current perspective of stable and unstable coronary artery disease management. However, the long-term results of stent usage have been blighted by the dual problems of in-stent restenosis and stent thrombosis. Whilst stent thrombosis became much less frequent with the introduction of dual-antiplatelet therapy, restenosis remained a significant problem. Intense work on stent development has successfully led to the introduction of drug-eluting stents (DES) in an effort to address this problem. Randomized trials have consistently proven the superior efficacy of DES over bare metal stents, in elective patients, acute coronary syndromes and patients with diabetes mellitus. Nevertheless, the routine use of DES in by-pass venous graft disease remains debatable. The initial DES used sirolimus and paclitaxel are now being joined by newer stents releasing drugs, such as everolimus, zotarolimus and tacrolimus. Ongoing developments with the stent platform and the polymer coating are also gradually improving the performance of these stents in clinical practice. More recently, the idea of antibody-coated stents that would encourage epithelialization of stent struts by endothelial progenitor cells recruitment has gained attraction among interventionists, with a possible beneficial impact on reducing the incidence of restenosis.