Impact of Polymer Formulations on Neointimal Proliferation After Zotarolimus-Eluting Stent With Different Polymers

Abstract

Background— Polymer formulation may affect the efficacy of drug-eluting stents. Resolute, Endeavor, and ZoMaxx are zotarolimus-eluting stents with different stent platforms and different polymer coatings and have been tested in clinical trials. The aim of this analysis was to compare the efficacy of zotarolimus-eluting stents with different polymers. Methods and Results— Data were obtained from the first-in man trial or first randomized trials of each stent, The Clinical RESpOnse EvaLUation of the MedTronic Endeavor CR ABT-578 Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions (RESOLUTE), Randomized Controlled Trial to Evaluate the Safety and Efficacy of the Medtronic AVE ABT-578 Eluting Driver Coronary Stent in De Novo Native Coronary Artery Lesions (ENDEAVOR II), and ZoMaxx I trials. Follow-up intravascular ultrasound analyses (8 to 9 months of follow-up) were possible in 353 patients (Resolute: 88, Endeavor: 98, ZoMaxx: 82, Driver: 85). Volume index (volume/stent length) was obtained for vessel, stent, lumen, peristent plaque, and neointima. Cross-sectional narrowing was defined as neointimal area divided by stent area (%). Neointima-free frame ratio was calculated as the number of frames without intravascular ultrasound–detectable neointima divided by the total number of frames within the stent. At baseline, vessel, lumen, and peristent plaque volume index were not significantly different among the 4 stent groups. At follow-up, percent neointimal obstruction was significantly lower in Resolute compared with Endeavor, ZoMaxx, and Driver (Resolute: 3.7±4.0, Endeavor: 17.5±10.1, ZoMaxx: 14.6±8.1, Driver: 29.4±17.2%; P <0.001). Greater maximum cross-sectional narrowing and higher neointima-free frame ratio, suggesting less neointimal coverage, were observed in Resolute compared with other stent groups. Multiple regression analysis confirmed that the biodurable polymer used in Resolute independently correlated with neointimal suppression among 3 zotarolimus-eluting stents. Conclusions— The different polymer formulations significantly affect the relative amount of neointima for zotarolimus-eluting stents. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00248079.

One‐year outcomes of consecutive patients treated by endeavor zotarolimus and resolute zotarolimus stents: The impact of polymer coating in drug‐eluting stent technology

“…Taken together with the recent observation from the Resolute‐US trial investigators , this study suggest that the adoption of the novel R‐ZES in the clinical practice may translate into improved clinical outcomes compared to that associated with the E‐ZES. Such findings fit with the lower neointimal growth in R‐ZES compared to E‐ZES documented by intravascular ultrasound thus reinforcing the perception that polymer‐coating is key modulator of the DES clinical performance.…”

“…Then, a novel zotarolimus‐eluting stent (Resolute Zotarolimus‐eluting stent, R‐ZES) (Medtronic, Santa Rosa, California), differing from E‐ZES in the polymer coating only, became available . Experimental studies have shown that the new polymer system is associated to better biocompatibility, less inflammation, and extended drug‐elution kinetics .…”

Comparison of Resolute zotarolimus-eluting stents versus everolimus-eluting stents in patients with metabolic syndrome and acute myocardial infarction

“…Moreover, endothelial dysfunction as well as pro-inflammatory characteristics of MetS could be factors governing local pharmacokinetics, and thus these characteristics of MetS might differently affect the clinical outcomes between EES and R-ZES, which have different drug-release kinetics and stent structures [19][20][21][22][23].…”

Resolute zotarolimus‐eluting stent in ST‐elevation myocardial infarction (resolute‐STEMI): A prespecified prospective register from the DAPT‐STEMI trial

“…Indeed, thinner stent struts favor a better and homogeneous endothelial strut coverage as compared to the thicker stainless steel struts of the first‐generation DES, and DES with thin struts have shown a low risk of adverse cardiovascular events in patients with a variety of clinical syndromes . The R‐ZES uses a biocompatible durable polymer that enables longer drug elution and has shown to significantly affect the amount of neointima compared with the previous zotarolimus‐eluting platform . Moreover, OCT studies have demonstrated essentially complete endothelial coverage at 3 months with this device …”