Polymer‐free drug‐eluting stents for coronary artery disease

Polymer‐free drug‐eluting stents (PF‐DES) were designed with the expectation of avoiding late restenosis and thrombosis related to the polymer used in traditional DES platforms. Furthermore, due to similarities with bare metal stents after drug elution, PF‐DES has been considered as particularly suitable for patients at high bleeding risk. A variety of PF‐DES platforms have been clinically tested. Despite their theoretical advantages, PF platforms showed comparable clinical outcomes with modern permanent‐ or biodegradable polymer‐based DES up to 5 years after implantation. Use of more biocompatible polymers on the modern DES platforms is one of the reasons therefore. Their improved safety profile allows already less intensive antithrombotic regimes after DES. Hence, nowadays PF‐DES platforms can be considered as one of many DES options for percutaneous treatment of coronary artery disease.

     

Five‐year clinical follow‐up after implantation of the endeavor zotarolimus‐eluting stent: ENDEAVOR I,first‐in‐human study

Objective : To evaluate the 5‐year clinical outcomes of patients treated with the Endeavor zotarolimus‐eluting stent (ZES) in the ENDEAVOR I first‐in‐human study. Background : ENDEAVOR I was a prospective, nonrandomized, multicenter study of the Endeavor ZES in 100 consecutive patients with symptomatic coronary artery disease (CAD) due to de novo, stenotic lesions in native coronary arteries. Methods : Patients with single or multivessel CAD were eligible to participate, but only one lesion per patient was treated. The lesion had to have ≥50% stenosis, be ≤15 mm in length, and located in a vessel with a reference diameter of 3.0–3.5 mm. Major adverse cardiac events (MACE), target lesion revascularization (TLR), target vessel failure (TVF), and stent thrombosis were evaluated 5 years after stent implantation. Results : The cumulative incidence of MACE was 2.0% at 1 year, 3.0% at 2 years, 6.1% at 3 years, 7.2% at 4 years, and 7.2% at 5 years. At 5 years, there were seven patients who had eight events; four noncardiac (cancer) deaths, three cases of TLR, of which one presented as a non‐Q‐wave MI because of a stent thrombosis at 10 days after the index procedure. There were no late or very late stent thromboses by any definition. TVF at 5 years was 5.2%. Conclusions : Use of the Endeavor ZES to treat symptomatic CAD due to de novo lesions in native coronary arteries resulted in sustained clinical benefits to 5 years, with low rates of MACE, TLR, TVF, and stent thrombosis. © 2009 Wiley‐Liss, Inc.     

Clinical outcomes of drug‐eluting versus bare‐metal in‐stent restenosis

In‐stent restenosis (ISR) is a challenging syndrome that affects drug‐eluting stents and bare‐metal stents. However, data comparing the outcomes of drug‐eluting versus bare‐metal ISR are limited. Our objective was to evaluate the long‐term clinical outcomes of drug‐eluting versus bare‐metal ISR. Patients who underwent percutaneous coronary intervention at Cleveland Clinic for ISR from 05/1999 to 06/2007 were included. Unadjusted outcomes were tested using Kaplan‐Meier curves followed by multivariable adjusted Cox proportional hazards analyses. Twenty seven variables, including type of stent used to treat ISR and procedural date, were included. The primary end point was a composite of death, myocardial infarction (MI), or target lesion revascularization (TLR). The secondary endpoints were components of the primary endpoint. Of 931 patients identified, 225 had drug‐eluting ISR and 706 had bare‐metal ISR. There were 279 cumulative events for a median follow‐up of 3.2 years. The primary endpoint was not different between drug eluting and bare‐metal ISR (22% versus 33%, adjusted hazard ratio [HR] 1.14; 95% confidence interval [CI], 0.79–1.66; P = 0.49). The secondary endpoints of death (8% versus 16%, adjusted HR 1.05; 95% CI, 0.56–1.98; P = 0.88), MI (4% versus 5%, adjusted HR 1.48; 95% CI, 0.54–4.04; P = 0.45), and TLR (15% versus 16%, adjusted HR 1.30; 95% CI, 0.81–2.11; P = 0.28) were also not different. This study represents the largest analysis comparing drug‐eluting to bare‐metal ISR. On multivariable Cox proportional hazard analyses, drug‐eluting and bare‐metal ISR have similar long term outcomes. © 2009 Wiley‐Liss, Inc.     

A comparative analysis of major clinical outcomes using drug‐eluting stents versus bare‐metal stents in a large consecutive patient cohort

Objectives : To ascertain the long‐term safety, efficacy, and pattern of use of drug‐eluting stents (DES) in routine clinical practice. Methods : We analyzed a registry of 6,583 consecutive patients undergoing percutaneous coronary intervention (PCI), of whom 2,633 were treated using DES (DES group) and 3,950 were treated using bare‐metal stents (BMS group). Propensity score was used for stratified analysis of outcomes and for matching. Outcomes were total mortality, myocardial infarction (MI), repeat target vessel revascularization (TVR) rates, and risk‐adjusted event‐free survival. Results : Follow‐up time was 6 months to 5.18 years (mean: 3 years). Patients in the DES group were more likely to be diabetic and had use of longer or more stents, treatment of more lesions and of more proximal main vessels. After propensity score matching, the cumulative mortality was 12.85% in the DES group versus 14.14% in the BMS group (P = 0.001). Use of DES reduced the occurrence of MI (5.17% vs.5.83%, P = 0.046), of clinically driven TVR (9.76% vs. 12.28%, P < 0.001) and of the composite endpoint of death/MI/TVR (23.38% vs. 26.07%; P < 0.001). Conclusions : Our risk‐adjusted event‐free survival analysis indicates a prognostic benefit for DES utilization that sustains up to 5 years following PCI. © 2010 Wiley‐Liss, Inc.     

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. © 2010 Wiley‐Liss, Inc.     

Use of drug‐eluting stents for chronic total occlusions: A systematic review and meta‐analysis

Aim: To perform a systematic review and meta‐analysis of studies reporting outcomes after drug‐eluting stent (DES) implantation in chronic total occlusions (CTOs). Methods: A review of publications and online databases in January 2010 retrieved 17 published studies that reported outcomes after DES implantation in CTOs: eight uncontrolled studies, seven nonrandomized comparative studies with bare‐metal stents (BMS), one post‐hoc analysis of a randomized trial, and one randomized trial. Data were pooled using random‐effects meta‐analysis models. Results: All published studies evaluated sirolimus‐ or paclitaxel‐eluting stents. All studies reporting comparative angiographic outcomes revealed less binary angiographic restenosis with DES implantation compared to BMS (odds ratio: 0.15, 95% CI: 0.08, 0.26). Over a mean follow‐up period of 18.9 ± 16.5 months, the cumulative incidence of death, myocardial infarction, or stent thrombosis was similar between DES and BMS in all studies. Target lesion revascularization (odds ratio: 0.13, 95% CI: 0.06, 0.26) and target vessel revascularization (odds ratio 0.18, 95% CI: 0.11, 0.31) at 6–12 months were consistently lower among DES‐treated patients. Similar patterns of safety and efficacy event rates were also observed in studies reporting >12 month outcomes. Conclusions: Compared with BMS, treatment of chronic total coronary occlusions with DES is associated with significant reductions in angiographic and clinical restenosis with similar safety. The consistency and magnitude of treatment effect across both individual trials and the pooled analysis establish DES as the preferred therapy for percutaneous revascularization of CTOs. © 2010 Wiley‐Liss, Inc.     

Comparison between sirolimus‐ and paclitaxel‐eluting stents in complex patient and lesions subsets

Background : Sirolimus‐eluting stents (SES) and paclitaxel‐eluting stents (PES) both significantly reduce the need for repeat intervention compared to bare metal stents. Studies comparing the clinical outcomes of these stents in noncomplex subsets of patients and lesions demonstrate a similar safety and efficacy profile. The data for more complex subsets of patients and lesions remains conflicting. This study aimed to compare SES with PES in a selected population with a broad range of complex features. Methods and Results : The patient population consisted of 1,591 consecutive patients with complex features undergoing drug‐eluting stent (DES) implantation. In the SES group there were 1,095 patients (1,653 lesions) and in the PES group 496 patients (802 lesions). In‐hospital, 30‐day, and 12‐month clinical outcomes were compared between groups. No discernable difference in major adverse cardiac events (MACE) between SES and PES was detected at intermediate and longer‐term follow‐up (SES 22.4% vs. PES 20.5% at 12 months; P = 0.407). A trend toward increased angiographically documented stent thrombosis was observed in the SES group at both 3 and 12 months (SES 2.2% vs. PES 0.8% at 12 months; P = 0.051). When adopting the more inclusive definition of probable stent thrombosis, this trend was no longer seen. After adjusting for baseline differences between the two groups, there still remained no difference in MACE between SES and PES (HR 1.051 [CI 0.826–1.339] P = 0.685). The trend toward increased angiographically documented stent thrombosis in the SES group remained after adjustment for baseline differences (HR 2.836 [CI 0.968–8.311] P = 0.057). Conclusions : In a selected population with complex disease the rate of MACE was comparable between SES and PES, with higher overall rates of thrombosis and MACE compared to a noncomplex population. Thus, the focus should be directed to prevent late complications in this complex subset regardless of stent type selection. © 2007 Wiley‐Liss, Inc.     

Decreased risk of stent fracture‐related restenosis between paclitaxel‐eluting stents and sirolimus eluting stents: Results of long‐term follow‐up

Objective: To compare the outcomes between paclitaxel‐eluting stents (PES) and sirolimus‐eluting stents (SES) for the treatment of drug‐eluting stent (DES) fracture. Background: DES fracture is considered as an important predictor of in‐stent restenosis (ISR). However, little data are available evaluating the optimal treatment for this complication of coronary stenting. Methods: From January 1, 2004 to December 31, 2008, patients with DES ISR treated with a second DES were identified and evaluated for stent fracture. Stent fracture was defined by the presence of strut separation in multiple angiographic projections, assessed by two independent reviewers. Target lesion revascularization (TLR) at 6 and 12 months were the primary end points. Results: Of 131 lesions with DES ISR treated with a second DES, we found 24 patients (24 lesions, 18.2%) with angiographically confirmed stent fracture. Of these, 20 patients (20 lesions) treated with either PES (n = 11/55%) or SES (n = 9/45%) were included in the study. TLR at 6 months occurred in 9% of patients treated with PES and 22% of those treated with SES (P = 0.41). After 12 months, TLR was 9% and 55.5%, respectively (P = 0.024). Conclusions: This study demonstrates a high incidence of stent fracture in patients presenting with DES ISR in need of further treatment with another DES. The suggested association between treatment of stent fracture‐associated DES ISR with PES as compared with SES, and better long‐term outcomes, is in need of confirmation by larger prospective registries and randomized trials. © 2011 Wiley Periodicals, Inc.     

IMPACT Trial: angiographic and intravascular ultrasound observations of the first human experience with mycophenolic acid-eluting polymer stent system.

The purpose of the study was to examine the safety and efficacy of two different formulations of mycophenolic acid (MPA)-eluting Duraflex stents on coronary de novo lesions. Recent data indicate that local delivery of MPA in the porcine overstretch coronary model significantly reduces neointimal hyperplasia (NIH). Patients were divided into three consecutive groups. The first (n=50) and second (n=55) groups received moderate- and slow-release MPA-eluting Duraflex stent, respectively. The last group (n=50) received the bare metal Duraflex stent. Clinical, angiographic, and intravascular ultrasound analysis were performed at 6-month follow-up. All stents were successfully deployed and patients were discharged home without clinical events. Compared to controls, 6-month in-lesion and in-stent minimum luminal diameter as well as late lumen loss were not significantly different in the moderate- and slow-release treatment groups. At follow-up, percentage obstruction and NIH volume were also similar between the three groups. At 30 days and 6 and 12 months, there were no differences noted between the three groups with respect to major adverse cardiac events as well as the individual rates of mortality, myocardial infarction, or repeat revascularization. There were no cases of subacute or late thrombosis. In this feasibility trial, the MPA-eluting Duraflex stents in either slow- or moderate-release formulations were well tolerated, but showed no benefit for treatment of coronary lesions when compared to controls. Further testing with different drug dosing or delivery rate might improve these results.     

Drug‐eluting stents versus bare‐metal stents for treatment of bare‐metal in‐stent restenosis

Objectives : We compared the long‐term outcomes of drug‐eluting stents (DES) versus bare‐metal stents (BMS) for treatment of bare‐metal in‐stent restenosis (ISR). Background : There are no randomized trials or observational studies directly comparing the safety and efficacy of DES versus BMS for treatment of bare‐metal ISR. Methods : We examined data on all patients who underwent percutaneous coronary intervention (PCI) for ISR at Cleveland Clinic between 05/1999 and 06/2007. We compared the efficacy and safety of DES to BMS for treating bare‐metal ISR. The primary end point was a composite of death, myocardial infarction (MI), or target lesion revascularization (TLR). The secondary endpoints were individual components of the primary endpoint. Results : Of the 931 patients identified over 8 years, 706 had bare‐metal ISR and met our study criteria. Of the 706 patients with bare‐metal ISR, 362 were treated with DES and 344 with BMS. There were 230 cumulative events for a median follow‐up of 3.2 years. After adjusting for 27 variables, DES were associated with lower primary endpoint compared to BMS for treatment of bare‐metal ISR (21% vs. 45%, adjusted hazard ratio [HR] 0.63; 95% confidence interval [CI], 0.42–0.95; P = 0.03). The individual secondary endpoint of death (8% vs. 24%, P = 0.005) favored DES, but MI (3% vs. 8%, P = 0.31), and TLR (13% vs. 20%, P = 0.23) failed to reach statistical significance. Conclusions : In our multivariate analysis of patients with bare‐metal ISR, DES use was associated with significantly lower death, MI, or TLR when compared to BMS. © 2010 Wiley‐Liss, Inc.     

Complete versus incomplete revascularization with drug‐eluting stents for multi‐vessel disease in stable,unstable angina or non‐ST‐segment elevation myocardial infarction: A meta‐analysis

Objectives

To determine whether drug‐eluting stent (DES) coronary complete revascularization (CR) confers clinical benefit over incomplete revascularization (IR) in patients with multivessel coronary artery disease (MVD).

Background

Clinical benefit of CR over IR in patients with MVD with angina (both stable and unstable) and non‐ST‐segment elevation myocardial infarction (NSTEMI) in DES has not been well studied.

Methods

We conducted a systematic online literature search of PUBMED and EMBASE. Literatures that compared the clinical outcomes between CR and IR with exclusively or majority (>80%) using DES in patients without or included only small portion (<20%) of ST‐segment elevation myocardial infarction or single‐vessel coronary artery disease were included. Hazards ratio (HR) with 95% confidence interval (CI) was calculated with random‐effects model.

Results

No randomized clinical trials were identified. A total of 14 observational studies with total of 41 687 patients (CR 39.6% and IR 60.4%) were included in this meta‐analysis. CR was associated with lower incident of all‐cause mortality (HR 0.71, P = 0.001), major adverse events (HR 0.75, P < 0.001), cardiovascular mortality (HR 0.39, P < 0.001). Meta‐regression analysis showed that CR significantly reduced the risk of all‐cause mortality in advanced age, triple vessel disease and male sub‐groups.

Conclusions

CR with DES conferred favorable outcomes compared to IR in MVD patients with stable, unstable angina or NTEMI. Further research to achieve higher CR in MVD patients may lead to improvement in prognosis in these cohorts.