A randomized comparison of the Endeavor zotarolimus-eluting stent versus the TAXUS paclitaxel-eluting stent in de novo native coronary lesions 12-month outcomes from the ENDEAVOR IV trial

Rationale and design of the clinical evaluation of the Resolute Zotarolimus-Eluting Coronary Stent System in the treatment of de novo lesions in native coronary arteries (the RESOLUTE US clinical trial)

BACKGROUND

Drug-eluting stents (DES) are commonly used to treat obstructive coronary disease and avoid restenosis. Newer DES have been developed to improve effectiveness and safety. We describe a clinical trial to evaluate a DES with a novel polymer that may improve the antirestenosis effectiveness while maintaining the safety standards of currently Food and Drug Administration-approved DES.

METHODS

The RESOLUTE US Trial is a multicenter, nonrandomized trial prospectively designed to compare the Resolute zotarolimus-eluting stent (R-ZES) to the Food and Drug Administration-approved Endeavor ZES using patient-level historical control data, adjusting for baseline covariates through propensity score. The stents differ primarily in the polymer, which, in the R-ZES, is designed to elute zotarolimus over a longer period. The study will enroll up to 1,574 patients with ischemic heart disease due to de novo native coronary lesions suitable for 1- or 2-vessel treatment with stents from 2.25 to 4.0 mm in diameter. The primary end point is target lesion failure at 12 months postprocedure, defined as the composite of cardiac death, target-vessel myocardial infarction (MI), and clinically driven target lesion revascularization by percutaneous or surgical methods. Secondary end points include device, lesion and procedural success, death, MI, cardiac death and MI, composites of these clinical events, and stent thrombosis at each follow-up assessment up to 5 years postprocedure.

CONCLUSIONS

The RESOLUTE US Trial (ClinicalTrials.gov #NCT00726453) is a prospective, multicenter, observational study with a patient-level historical control designed to assess the safety and efficacy of the R-ZES for the treatment of de novo lesions in native coronary arteries.

Which DES is the most appropriate for very small target vessels? Experimental study of stent expandable performance with SES, PES, ZES and EES

The restenosis rate of coronary stent has significantly decreased by implantation of the drug-eluting stent (DES). We often experienced the DES implantation for very small target vessels. The minimum size of DES in Japan and USA is 2.5 mm-diameter, but there were no reports of the expandability of DESs for the very small target vessels with reference diameter <2.2 mm. We clarify the expandable performance of 2.5 mm-DESs for very small target vessels with reference diameter <2.2 mm in vitro and vivo study. We studied 3 pieces in each kind of DES (Sirolimus-eluting stent; SES, Paclitaxel-eluting stent; PES, Zotarolimus-eluting stent; ZES and Everolimus-eluting stent; EES) in vitro and vivo study of the porcine coronary artery with reference diameter <2.2 mm. By using the delivery balloon, each stent was initially dilated with 3.5 atm. And the pressure of 0.5 atm. was applied until it reached the maximum pressure of 12 atm. The minimum pressure of the full expanded stent balloon was estimated as the minimum expandable pressure. The stent-inner diameter and area on each pressure were measured by IVUS. The average minimum expandable pressure (atm.) in vitro/vivo was 4.7/4.5 in SES, 7.2/6.8 in PES, 4.3/4.5 in ZES and 3.8/3.8 in EES. The inner diameter (mm) in vitro/vivo at minimum expandable pressure was 1.81 ± 0.07/1.84 ± 0.05 in SES, 2.31 ± 0.10/2.13 ± 0.13 in PES, 2.41 ± 0.13/1.98 ± 0.31 in ZES and 2.13 ± 0.11/1.88 ± 0.22 in EES. The stent inner-diameter (mm) of DESs at 8 atm. in vivo was 2.16/2.21/2.45/2.25 in SES/PES/ZES/EES. All kinds of DES could be delivered to very small target vessels with reference diameter <2.2 mm at the minimum expandable pressure in vivo study, but the stent which presented adequate stent inner-diameter at 8 atm. was only SES. We have to implant the 2.5 mm-DESs for very small target vessels according to the data based on this expandability of DESs to bail out threatening occlusion due to coronary dissection or elastic recoil.

Improved late clinical safety with zotarolimus-eluting stents compared with paclitaxel-eluting stents in patients with de novo coronary lesions: 3-year follow-up from the ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial

OBJECTIVES

The increased frequency of very late (>1 year) stent thrombosis (VLST) has raised concerns with regard to the safety of sirolimus-eluting stents and paclitaxel-eluting stents (PES).

BACKGROUND

Experimental and preliminary clinical findings with the zotarolimus-eluting stent (ZES) have suggested a favorable safety profile.

METHODS

The ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial is a single-blind randomized ZES versus PES clinical trial in 1,548 patients with de novo native coronary lesions; the primary end point-9-month target vessel failure-was previously reported, annual clinical follow-up is planned for 5 years, and this report describes the 3-year outcomes.

RESULTS

The ZES compared with PES reduced target vessel failure (12.3% vs. 15.9%, hazard ratio [HR]: 0.76, 95% confidence interval [CI]: 0.58 to 1.00, p = 0.049), myocardial infarctions (MI) (2.1% vs. 4.9%, HR: 0.44, 95% CI: 0.25 to 0.80, p = 0.005), and cardiac death plus MI (3.6% vs. 7.1%, HR: 0.52, 95% CI 0.32 to 0.82, p = 0.004). Although the overall 3-year rate of Academic Research Consortium definite/probable stent thrombosis did not differ significantly (1.1% vs. 1.7%, HR: 0.67, 95% CI 0.28 to 1.64, p = 0.380), VLST (between 1 and 3 years) was significantly reduced in ZES patients (1 event vs. 11 events; 0.1% vs. 1.6%, HR: 0.09, 95% CI: 0.01 to 0.71, p = 0.004). Ischemia-driven target lesion revascularization at 3 years was similar with ZES versus PES (6.5% vs. 6.1%, HR: 1.10, 95% CI: 0.73 to 1.65, p = 0.662).

CONCLUSIONS

Three-year follow-up results from the ENDEAVOR IV trial indicate similar antirestenosis efficacy but improved clinical safety associated with ZES compared with PES, due to significantly fewer peri-procedural and remote MIs associated with fewer VLST events. (A Randomized, Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Taxus Paclitaxel-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions; NCT00217269).

[Update in interventional cardiology]

This article contains a detailed review of the most important studies on interventional cardiology reported in either publications or presentations. With regard to coronary interventions, ST-elevation myocardial infarction is highlighted because of the ongoing substantial expansion in primary angioplasty programs. Drug-eluting stents, especially new-generation stents, continue to be the focus of numerous studies. Clinical outcomes in diabetic patients with left main coronary artery or multivessel disease are also dealt with by much research. In addition, intracoronary diagnostic techniques, particularly optical coherence tomography, is reviewed. Finally, there is increasing interest in the percutaneous treatment of structural heart disease, particularly percutaneous aortic valve implantation.

Drug-eluting versus bare-metal stents in large coronary arteries

BACKGROUND

Recent data have suggested that patients with coronary disease in large arteries are at increased risk for late cardiac events after percutaneous intervention with first-generation drug-eluting stents, as compared with bare-metal stents. We sought to confirm this observation and to assess whether this increase in risk was also seen with second-generation drug-eluting stents.

METHODS

We randomly assigned 2314 patients needing stents that were 3.0 mm or more in diameter to receive sirolimus-eluting, everolimus-eluting, or bare-metal stents. The primary end point was the composite of death from cardiac causes or nonfatal myocardial infarction at 2 years. Late events (occurring during months 7 to 24) and target-vessel revascularization were the main secondary end points.

RESULTS

The rates of the primary end point were 2.6% among patients receiving sirolimus-eluting stents, 3.2% among those receiving everolimus-eluting stents, and 4.8% among those receiving bare-metal stents, with no significant differences between patients receiving either drug-eluting stent and those receiving bare-metal stents. There were also no significant between-group differences in the rate of late events or in the rate of death, myocardial infarction, or stent thrombosis. Rates of target-vessel revascularization for reasons unrelated to myocardial infarction were 3.7% among patients receiving sirolimus-eluting stents, 3.1% among those receiving everolimus-eluting stents, and 8.9% among those receiving bare-metal stents. The rate of target-vessel revascularization was significantly reduced among patients receiving either drug-eluting stent, as compared with a bare-metal stent, with no significant difference between the two types of drug-eluting stents.

CONCLUSIONS

In patients requiring stenting of large coronary arteries, no significant differences were found among sirolimus-eluting, everolimus-eluting, and bare-metal stents with respect to the rate of death or myocardial infarction. With the two drug-eluting stents, similar reductions in rates of target-vessel revascularization were seen. (Funded by the Basel Cardiovascular Research Foundation and the Swiss National Foundation for Research; Current Controlled Trials number, ISRCTN72444640.).

Extended follow-up safety and effectiveness of the Endeavor zotarolimus-eluting stent in real-world clinical practice: two-year follow-up from the E-Five Registry

OBJECTIVES

To present data from the cohort of patients in the all-comers Endeavor zotarolimus-eluting stent (ZES) registry (E-Five) who underwent 2-year follow-up.

BACKGROUND

The Endeavor ZES has been shown to be safe and efficacious for treatment of single, de novo lesions in patients with stable coronary artery disease. E-Five evaluated the ZES in over 8,000 real-world patients, at 188 sites followed to 1 year. A subset of sites continued follow-up through 2 years to evaluate late-term safety and effectiveness of the ZES in this population with diverse clinical and lesion characteristics.

METHODS

E-Five, a prospective, multicenter, nonrandomized global registry, collected 2-year outcomes for 2,116 patients from 26 centers. Sites were selected for participation based on patient accrual rates and the ability to continue follow-up activities for an additional year. Complete data was available for 2,054 patients. To observe whether or not a sustained benefit was achieved, data for all patients from the selected sites were included in the analysis.

RESULTS

The outcomes in the 2-year cohort tracked with the results of randomized controlled trials using the Endeavor ZES. One year results were MACE 7.5%, TLR 4.5%, and ARC definite/probable stent thrombosis 0.6%. Outcomes at 2 years for MACE, TLR, and ARC definite/probable stent thrombosis were 8.5, 5.1, and 0.7%, respectively.

CONCLUSIONS

Long-term efficacy and safety outcomes were maintained between 1 and 2 years for the 2-year patient cohort, with only a small number of additional MACE, TLR, and very late stent thrombosis events.

Small coronary vessel angioplasty: outcomes and technical considerations

Small vessel (<3 mm) coronary artery disease is common and has been identified as independent predictor of restenosis after percutaneous coronary intervention. It remains controversial whether bare-metal stent (BMS) implantation in small vessels has an advantage over balloon angioplasty in terms of angiographic and clinical outcomes. Introduction of drug-eluting stent (DES) has resulted in significant reduction in restenosis and the need for repeat revascularization. Several DESs have been introduced resulting in varying reduction in outcomes as compared with BMS. However, their impact on outcomes in small vessels is not clearly known. It is expected that DES could substantially reduce restenosis in smaller vessels. Large, randomized studies are warranted to assess the impact of different DESs on outcomes in patients with small coronary arteries.

Usefulness of intravascular low-power laser illumination in preventing restenosis after percutaneous coronary intervention

Despite the several years of studies, no factor that could reduce the restenosis rate without significant limitations has been introduced. The aim of the present study was to evaluate the influence of low-power 808-nm laser illumination of coronary vessels after percutaneous angioplasty in preventing restenosis. The procedure of laser intravascular illumination was performed on 52 patients (laser group), and another 49 patients formed the control group. All patients were monitored for major adverse cardiac events (MACE) at the 6- and 12-month follow-up points. The MACE rate after 6 and 12 months was 7.7% in the laser group at both points. The MACE rate was 14.3% and 18.5% at 6 and 12 months of follow-up in the control group, respectively (p = NS). Follow-up coronary angiography was performed after 6 months. The difference in the restenosis rate was insignificant (15.0% vs 32.4%); however, significant differences were observed in the minimal lumen diameter (2.18 ± 0.70 vs 1.76 ± 0.74 mm; p < 0.05), late lumen loss (0.53 ± 0.68 vs 0.76 ± 0.76 mm; p < 0.01), and the late lumen loss index (0.28 ± 0.39 vs 0.46 ± 0.43; p < 0.005) in favor of the laser group. In conclusion, the new therapy seemed effective and safe. Marked differences between late loss, late loss index, and minimal lumen diameter were observed. The late lumen loss in the laser group was only slightly greater than that in studies of drug-eluting stents, and MACE rate remained within very comparable ranges. This suggests that intravascular laser illumination could bring advantages comparable to those of drug-eluting stents without the risk of late thrombosis.

Twelve-month outcomes in patients with diabetes implanted with a zotarolimus-eluting stent: results from the E-Five Registry

Objective

To retrospectively evaluate the 12-month effectiveness of the Endeavor zotarolimus-eluting stent (ZES) in diabetic versus non-diabetic patients enrolled in the E-Five Registry.

Design and Setting

The E-Five Registry is a prospective, multicentre registry of 8314 patients presenting with symptomatic coronary artery disease treated with the Endeavor (ZES). Patients were treated at 188 centres located in 37 countries across Europe, Latin America and Asia Pacific.

Patients

There were 2721 (32.7%) patients with diabetes (DM) and among these patients 682 were insulin-treated (ITDM) and 2039 were non-insulin-treated diabetic patients (NITDM).

Interventions

All enrolled patients received an Endeavor ZES and were followed for 12 months.

Main outcome measurements

The primary outcome measure was major adverse cardiac event (MACE) at 12 months. Secondary endpoints included target lesion revascularisation (TLR), target vessel revascularisation (TVR), target vessel failure (TVF) and stent thrombosis.

Results

Compared with non-DM patients, DM patients had higher rates of MACE (9.7% vs 6.4%, p<0.001), TLR (5.3% vs 4.0%, p=0.028) and Academic Research Consortium (ARC) definite and probable stent thrombosis (1.5% vs 0.9%, p=0.041). Compared with non-DM patients, ITDM patients had higher rates of MACE (12.6% vs 6.4%, p<0.001). ITDM patients had higher rates of death (6.7% vs 1.7%, p<0.001), cardiac death (4.5% vs 1.2%, p<0.001) and TLR (6.5% vs 4.0%, p=0.011) than non-DM patients.

Conclusions

The Endeavor ZES performed well in DM patients; however, DM patients experienced higher rates of adverse clinical events compared with non-DM patients.

Trial Reg No

Clinical trial registration information: http://www.clinicaltrials.gov; Unique identifier: NTC00623441

Sex-specific outcomes following revascularization with zotarolimus-eluting stents: comparison of angiographic and late-term clinical results

OBJECTIVES

We examined angiographic and late-term clinical outcomes according to sex in recent percutaneous coronary intervention (PCI) trials involving zotarolimus-eluting stents (ZES).

BACKGROUND

Differences in outcome between men and women undergoing PCI have been inconsistently described with bare metal and first-generation drug-eluting stents.

METHODS

Clinical and angiographic outcomes among ZES-treated patients were evaluated by sex using propensity score modeling in a patient-level systematic overview of six trials and were also compared to patients receiving bare metal stents (BMS).

RESULTS

Among 2,132 patients, 608 were female (28.5%). Compared to men, women were older and more frequently had diabetes, hypertension, and a smaller reference vessel diameter (P < 0.05 for all). For both sexes, the relative reductions in 8-month angiographic binary restenosis and late lumen loss were statistically significant and of similar extent with ZES compared to BMS. By 2 years, treatment with ZES resulted in significantly lower target vessel revascularization (TVR) and target vessel failure (TVF; 10.0% vs. 21.5%, P = 0.0003) among women that paralleled risk reductions for men. However, among ZES-treated patients, 2-year rates of TVR (8.2% vs. 10.4%, P = 0.005) and TVF (9.9% vs. 12.8%, P = 0.004) were significantly lower among women, although rates of death and myocardial infarction were similar.

CONCLUSIONS

Despite greater baseline clinical and angiographic risk than men, women undergoing PCI with ZES compared to BMS experienced significant reductions in angiographic restenosis and repeat revascularization yet similar safety. Among all patients treated with ZES, late-term safety and efficacy outcomes are similar, if not lower, among women compared to men.

The molecular mechanisms of congenital hypofibrinogenaemia

Congenital hypofibrinogenaemia is characterized by abnormally low levels of fibrinogen and is usually caused by heterozygous mutations in the fibrinogen chain genes (alpha, beta and gamma). However, it does not usually result in a clinically significant condition unless inherited in a homozygous or compound heterozygous state, where it results in a severe bleeding disorder, afibrinogenaemia. Various protein and expression studies have improved our understanding of how mutations causing hypo- and afibrinogenaemia affect secretion of the mature fibrinogen molecule from the hepatocyte. Some mutations can perturb chain assembly as in the gamma153 Cys-->Arg case, while others such as the Bbeta Leu-->Arg and the Bbeta414 Gly-->Ser mutations allow intracellular hexamer assembly but inhibit protein secretion. An interesting group of mutations, such as gamma284 Gly-->Arg and gamma375 Arg-->Trp, not only cause hypofibrinogenaemia but are also associated with liver disease. The nonexpression of these variant chains in plasma fibrinogen is due to retention in the endoplasmic reticulum, which in turn leads to hypofibrinogenaemia.