Intravascular ultrasound comparison of sirolimus-eluting stent versus bare metal stent implantation in diseased saphenous vein grafts (from the RRISC [Reduction of Restenosis In Saphenous Vein Grafts With Cypher Sirolimus-Eluting Stent] trial)

Long-Term Outcome of Consecutive Patients With Previous Coronary Bypass Surgery, Treated With Newer-Generation Drug-Eluting Stents

Background

Percutaneous coronary intervention (PCI) in patients with previous coronary artery bypass grafting (CABG) is associated with adverse clinical events. Although newer generation drug‐eluting stents showed favorable short‐term safety profiles, there is a lack of long‐term outcome data. We evaluated the impact of previous CABG on 5‐year clinical outcomes of patients treated with PCI using newer‐generation drug‐eluting stents.

Methods and Results

In this patient‐level pooled analysis of the prospective TWENTE (The Real‐World Endeavor Resolute versus Xience V Drug‐Eluting Stent Study in Twente) trial and nonenrolled TWENTE registry, we assessed a consecutive series of patients who underwent PCI with newer‐generation drug‐eluting stents for non–ST‐segment–elevation acute coronary syndromes or stable angina. Of all 1709 patients, 202 (11.8%) had a history of CABG. Patients with previous CABG had significantly higher 5‐year rates of cardiac death (10.4% versus 4.3%; P<0.001) and target vessel revascularization (25.0% versus 8.1%; P<0.001). These differences remained statistically significant after adjustment for differences in baseline characteristics. Landmark analysis revealed that from 1‐ to 5‐year follow‐up, the rates of cardiac death (8.1% versus 3.2%; P<0.001) and target vessel revascularization (17.1% versus 5.9%; P<0.001) were significantly higher in patients with previous CABG. Among patients with a history of CABG, PCI of an obstructed vein graft was associated with a higher rate of 5‐year target vessel revascularization (P=0.003).

Conclusions

At 5‐year follow‐up after PCI with newer‐generation drug‐eluting stents, the risk of cardiac death and target vessel revascularization was significantly higher in patients with previous CABG. The target vessel revascularization rate was highest in patients who underwent PCI of obstructed vein grafts.

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.

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.

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.

Re-examining minimal luminal diameter relocation and quantitative coronary angiography--intravascular ultrasound correlations in stented saphenous vein grafts: methodological insights from the randomised RRISC trial

AIMS

Angiographic parameters (such as late luminal loss) are common endpoints in drug-eluting stent trials, but their correlation with the neointimal process and their reliability in predicting restenosis are debated.

METHODS AND RESULTS

Using quantitative coronary angiography (QCA) data (49 bare metal stent and 44 sirolimus-eluting stent lesions) and intravascular ultrasound (IVUS) data (39 bare metal stent and 34 sirolimus-eluting stent lesions) from the randomised Reduction of Restenosis In Saphenous vein grafts with Cypher stent (RRISC) trial, we analysed the "relocation phenomenon" of QCA-based in-stent minimal luminal diameter (MLD) between post-procedure and follow-up and we correlated QCA-based and IVUS-based restenotic parameters in stented saphenous vein grafts. We expected the presence of MLD relocation for low late loss values, as MLD can "migrate" along the stent if minimal re-narrowing occurs, while we anticipated follow-up MLD to be located close to post-procedural MLD position for higher late loss. QCA-based MLD relocation occurred frequently: the site of MLD shifted from post-procedure to follow-up an "absolute" distance of 5.8 mm [2.5-10.2] and a "relative" value of 29% [10-46]. MLD relocation failed to correlate with in-stent late loss (rho = 0.14 for "absolute" MLD relocation [p = 0.17], and rho=0.03 for "relative" relocation [p = 0.811). Follow-up QCA-based and IVUS-based MLD values well correlated in the overall population (rho = 0.76, p < 0.001), but QCA underestimated MLD on average 0.55 +/- 0.49 mm, and this was mainly evident for lower MLD values. Conversely, the location of QCA-based MLD failed to correlate with the location of IVUS-based MLD (rho = 0.01 for "absolute" values--in mm [p = 0.911, rho = 0.19 for "relative" values--in % [p = 0.111). Overall, the ability of late loss to "predict" IVUS parameters of restenosis (maximum neointimal hyperplasia diameter, neointimal hyperplasia index and maximum neointimal hyperplasia area) was moderate (rho between 0.46 and 0.54 for the 3 IVUS parameters).

CONCLUSIONS

These findings suggest the need for a critical re-evaluation of angiographic parameters (such as late loss) as endpoints for drug-eluting stent trials and the use of more precise techniques to describe accurately and properly the restenotic process.

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.