Scanning electron microscopic assessment of the biodegradable coating on expanded biolimus-eluting stents

AIMS: Biodegradable coatings on drug-eluting stents (DES) may help to avoid adverse long-term effects of DES such as late/very late stent thrombosis which is partly attributed to durable polymers. As the post-expansion morphology of biodegradable coatings is greatly unknown, we investigated the polylactic acid coating on biolimus-eluting BioMatrix stents. METHODS AND RESULTS: Scanning electron microscopy (SEM) was used to carefully examine five 3.5mm stents following expansion at 6-14atm (maximum 7% overstretch). SEM examination demonstrated only mild cracks of the coating after stent expansion at 6 atm. An increase in expansion pressure, associated with mild stent overstretch, resulted in more severe cracks. Lifting of the coating together with few sites of partial detachment of fragments was noticed after stent expansion in water at 14atm; these irregularities further increased after aggressive oversized partial postdilatation with a 5.0mm non-compliant balloon with additional secondary cracks. CONCLUSIONS: SEM assessment suggests a relatively low elasticity of the biodegradable coating on BioMatrix stents. At nominal pressure, stents showed predominantly mild cracks of the coating, while cracks increased after slight overstretch. Aggressive overexpansion of the stent, such as sometimes required in left main bifurcation stenting, worsened cracks and led to some detachment of fragments of the coating in vitro

Micro-computed tomographic assessment following extremely oversized partial postdilatation of drug-eluting stents

AIMS: To assess the spatial geometry of drug-eluting stents (DES) following extremely oversized proximal postdilatation. Interventions of distal left main (LM) disease generally require stenting across the LM bifurcation with inherent vessel tapering along this segment and a high likelihood of stent malapposition, which can be avoided by such postdilations. METHODS AND RESULTS: Sixteen DES (four 3.5 mm-samples of Cypher Select Plus, Taxus Liberté, Endeavor Resolute, Xience V) were deployed in water; 12 samples were then proximally postdilated with noncompliant 5.0 mm balloons at 18 atm. All samples were examined by micro-computed tomography. Taxus Liberté, Endeavor Resolute, and Xience V, showed increased cell areas in the transitional region (just distal to postdilated region), while Cypher Select showed its largest cells inside the postdilated region. Overall, the largest maximum cell area was observed in Endeavor Resolute, while Cypher Select showed the smallest (p<0.001, for both). In addition, the size of the very proximal postdilated cells was relatively small in most DES except Xience V. CONCLUSIONS: Extremely oversized partial stent postdilatation demonstrated significant between-DES differences in final spatial stent configuration and maximum cell size. These data could be of practical interest with regard to coronary interventions in LM stems with stenting across the LM bifurcation

Incidental congenital coronary artery vascular fistulas in adults:Evaluation with adenosine-N-13-ammonia PET-CT

AIM To assess the functionality of congenital coronary artery fistulas (CAFs) using adenosine stress N-13-ammonia positron emission tomography computed tomography (PET-CT). METHODS Congenital CAFs were incidentally detected during coronary angiography (CAG) procedures in 11 adult patients (six males and five females) with a mean age of 64.3 years (range 41-81). Patients were collected from three institutes in the Netherlands. The characteristics of the fistulas (origin, pathway and termination), multiplicity of the origins and pathways of the fistulous vessels were assessed by CAG. Five patients underwent adenosine pharmacologic stress N-13-ammonia PET-CT to assess myocardial perfusion and the functional behavior of the fistula. RESULTS Eleven patients with 12 CAFs, 10 unilateral and one bilateral, originating from the left anterior descending coronary artery (n = 8), right coronary artery (n = 2) and circumflex (n = 2). All fistulas were of the vascular type, terminating into either the pulmonary artery (n = 11) or coronary sinus (n = 1). The CAG delineated the characteristics of the fistula (origin, pathway and termination). Multiplicity of the origins and pathways of the fistulous vessels were common in most fistulas (8/12, 67% and 9/12, 75%, respectively). Multiplicity was common among the different fistula components (23/36, 64%). Adenosine pharmacologic stress N-13-ammonia PET-CT revealed normal myocardial perfusion and ejection fraction in all but one patient, who showed a reduced ejection fraction. CONCLUSION PET-CT may be helpful for assessing the functional status of congenital CAFs in selected patients regarding clinical decision-making. Studies with a larger patient series are warranted

Comparison of eligible non-enrolled patients and the randomised TWENTE trial population treated with Resolute and XIENCE V drug-eluting stents

Aims: The TWENTE trial recently enrolled more than 80% of all eligible patients, who were randomised to zotarolimus-eluting Resolute or everolimus-eluting XIENCE V stents. In the present study, we investigated whether eligible, non-enrolled patients differed from the randomised TWENTE trial population in baseline characteristics and one-year outcome. Methods and results: Characteristics of 1,709 eligible patients were analysed. Independent external adjudication of clinical events was likewise performed for non-enrolled (n=318) and randomised patients (n=1,391). Non-enrolled and randomised patients did not differ in gender distribution, diabetes mellitus, and clinical presentation, but differed significantly in age and cardiovascular history. Nevertheless, clinical outcome after one year did not differ in the primary composite endpoint target-vessel failure (TVF; 9.8% vs. 8.1%; p=0.34), and its components cardiac death (1.6% vs. 1.2%; p=0.61), target vessel-related myocardial infarction (4.7% vs. 4.6%; p=0.92), and target-vessel revascularisation (3.8% vs. 3.0%; p=0.48). Previous bypass surgery predicted TVF in non-enrolled patients (p=0.001); removal of these patients resulted in identical TVF rates for non-enrolled and randomised patients (7.3% vs. 7.3%; p=0.99). Conclusions: Despite some differences in baseline characteristics, non-enrolled and randomised patients did not differ in one-year outcome, which was favourable for both populations and may be related to the drug-eluting stents used

A Randomized Controlled Trial in Second-Generation Zotarolimus-Eluting Resolute Stents Versus Everolimus-Eluting Xience V Stents in Real-World Patients : The TWENTE Trial

ObjectivesThe aim of this study was to compare the safety and efficacy of Resolute zotarolimus-eluting stents (ZES) (Medtronic Cardiovascular, Santa Rosa, California) with Xience V everolimus-eluting stents (EES) (Abbott Vascular Devices, Santa Clara, California) at 1-year follow-up.BackgroundOnly 1 randomized trial previously compared these stents.MethodsThis investigator-initiated, patient-blinded, randomized noninferiority study had limited exclusion criteria (acute ST-segment elevation myocardial infarctions not eligible). Patients (n = 1,391; 81.4% of eligible population) were randomly assigned to ZES (n = 697) or EES (n = 694). Liberal use of stent post-dilation was encouraged. Cardiac biomarkers were systematically assessed. The primary endpoint was target vessel failure (TVF), a composite of cardiac death, myocardial infarction not clearly attributable to non-target vessels, and clinically indicated target-vessel revascularization. An external independent research organization performed clinical event adjudication (100% follow-up data available). Analysis was by intention-to-treat.ResultsAcute coronary syndromes were present in 52% and “off-label” feature in 77% of patients. Of the lesions, 70% were type B2/C; the post-dilation rate was very high (82%). In ZES and EES, TVF occurred in 8.2% and 8.1%, respectively (absolute risk-difference 0.1%; 95% confidence interval: −2.8% to 3.0%, pnoninferiority = 0.001). There was no significant between-group difference in TVF components. The definite-or-probable stent thrombosis rates were relatively low and similar for ZES and EES (0.9% and 1.2%, respectively, p = 0.59). Definite stent thrombosis rates were also low (0.58% and 0%, respectively, p = 0.12). In EES, probable stent thrombosis beyond day 8 was observed only in patients not adhering to dual antiplatelet therapy.ConclusionsResolute ZES were noninferior to Xience V EES in treating “real-world” patients with a vast majority of complex lesions and “off-label” indications for drug-eluting stents, which were implanted with liberal use of post-dilation. (The Real-World Endeavor Resolute Versus XIENCE V Drug-Eluting SteNt Study: Head-to-head Comparison of Clinical Outcome After Implantation of Second Generation Drug-eluting Stents in a Real World Scenario; NCT01066650

Clinical Outcome Following Stringent Discontinuation of Dual Antiplatelet Therapy After 12 Months in Real-World Patients Treated With Second-Generation Zotarolimus-Eluting Resolute and Everolimus-Eluting Xience V Stents : 2-Year Follow-Up of the Randomized TWENTE Trial

Objectives The aim of this study was to assess the safety and efficacy of the implantation of Resolute zotarolimus-eluting stents (ZES) (Medtronic Inc., Santa Rosa, California) and Xience V everolimus-eluting stents (EES) (Abbott Vascular, Santa Clara, California) following strict discontinuation of dual antiplatelet therapy (DAPT) after 12 months. Background Only limited long-term follow-up data are available from head-to-head comparisons of second-generation drug-eluting stents. Methods The randomized TWENTE (The Real-World Endeavor Resolute Versus Xience V Drug-Eluting Stent Study in Twente) trial is an investigator-initiated study performed in a population with many complex patients and lesions and only limited exclusion criteria. Patients were randomly assigned 1:1 to ZES (n = 697) or EES (n = 694). Results Two-year follow-up information was available on all patients. The rate of continuation of DAPT beyond 12 months was very low (5.4%). The primary endpoint of target vessel failure, a composite of cardiac death, target vessel–related myocardial infarction, and target vessel revascularization, did not differ between ZES and EES (10.8% vs. 11.6, p = 0.65), despite fewer target lesion revascularizations in patients with EES (2.6% vs. 4.9%, p = 0.03). The patient-oriented composite endpoint was similar (16.4% vs. 17.1%, p = 0.75). Two-year rates of definite or probable stent thrombosis were 1.2% and 1.4%, respectively (p = 0.63). Very late definite or probable stent thrombosis occurred only in 2 patients in each study arm (0.3% vs. 0.3%, p = 1.00). Conclusions After 2 years of follow-up and stringent discontinuation of DAPT beyond 12 months, Resolute ZES and Xience V EES showed similar results in terms of safety and efficacy for treating patients with a majority of complex lesions and off-label indications for drug-eluting stents. (The Real-World Endeavor Resolute Versus Xience V Drug-Eluting Stent Study in Twent

TCT-47 Two-Year Clinical Outcome of the TWENTE Trial, a Randomized Controlled Trial Comparing Second-Generation Zotarolimus-Eluting Resolute Stents Versus Everolimus-Eluting Xience V Stents in Real-World Patients

Background: In the prospective, randomized TWENTE trial, the zotarolimus-eluting Resolute stent was at 1 year follow-up non-inferior to the everolimus-eluting Xience V stent for the primary endpoint target vessel failure. This composite endpoint consisted of cardiac death, clinically indicated target vessel revascularization, or target vessel-related myocardial infarction (MI). So far, few long-term data of prospective head-to-head comparisons between both DES have been reported. Methods: Patients requiring percutaneous coronary interventions (PCI) with DES implantation at Thoraxcentrum Twente in Enschede were randomization between Resolute (Medtronic Vascular, Santa Rosa, CA, USA) and Xience V (Abbott Vascular, Santa Clara, CA, USA) in a 1:1 fashion. Inclusion of all coronary or bypass graft lesions and all clinical settings was permitted except for primary PCI (i.e. acute ST-elevation myocardial infarction (STEMI) was an exclusion criterion). Both external monitoring and clinical event adjudication were performed by an independent external contract research organization (Cardialysis, Rotterdam, the Netherlands). Two year clinical follow-up was performed as indicated in the study protocol. Results: A total of 1,391 patients were enrolled in the TWENTE trial between June 2008 and August 2010. The study population comprised 21.6% diabetics with a vast majority of complex lesions and “off-label” indications for drug-eluting stents (77.4%). Patients presented with either stable angina (48.5%) or unstable angina/Non-STEMI (51.5%). Demographics, baseline angiographic and procedural data, and 2-year clinical follow-up data will be presented. This includes the primary endpoint of the study: Target vessel failure (TVF) at 2 year follow-up. Secondary endpoints include the individual components of the primary endpoint and the incidence of very late stent thrombosis. In addition, results of subgroup analyses will be reported. Conclusions: Results of pre-specified analyses of 2-year clinical outcome of the TWENTE trial will be presented at TCT 2012