Abstract and Introduction
Abstract
Background While, theoretically, a drug-eluting stent (DES) with a biodegradable polymer should reduce the incidence of late in-stent thrombosis, this has not been experimentally tested.
Objectives This study compared long-term manifestations of the Excel DES, with a biodegradable polymer, to the Endeavor DES, with a biocompatible polymer, in the same individuals.
Methods Forty-eight patients underwent simultaneous implantation of 1 or more Endeavor stents and 1 or more Excel stents, during the same procedure, and were evaluated with coronary angiography and intravascular ultrasound (IVUS) at least 1 year postprocedure. Within-patient comparisons were made between the Excel- and Endeavor-stented segments for efficacy and safety.
Results A total of 131 stents (69 Endeavor stents and 62 Excel stents) were implanted in 98 lesions among 48 patients. Baseline characteristics of the lesions in the two stented-segments groups were comparable. Average follow-up duration was 14.3 ± 2.5 months. In-stent late luminal loss and luminal stenosis were higher in Endeavor-stented segments than in Excel-stented segments (P<.01). The binary restenosis rate was slightly higher in Endeavor-stented segments (4.3% vs 1.6%; P=.379). In-stent thrombosis, late incomplete stent apposition, and uncovered stent struts were higher in Excel-stented segments than in Endeavor-stented segments (P<.01). There was 1 case of an in-stent coronary aneurysm with an Excel-stented segment. Four segments, in 4 cases (2 in each stent group), required target lesion revascularization.
Conclusion. This study suggested that, compared to DESs with a biocompatible polymer, DESs with biodegradable polymer do not appear to present an advantage for long-term safety.
Introduction
The safety and efficacy of drug-eluting stents (DESs) employing a biocompatible polymer, such as the Endeavor stent (Medtronic Vascular), which uses a phosphorylcholine polymer on a cobalt alloy thin-strut stent, have been demonstrated in randomized clinical trials, as well as in real-world practice. Earlier studies indicated that the durable polymer may play a significant role in DES-related hypersensitivity and delayed vessel healing, which may further contribute to stent thrombosis. Theoretically, a DES employing a biodegradable polymer should reduce the late in-stent thrombosis rate. Therefore, biodegradable polymer coatings are now used in the newest generation of DESs. However, recent angioscopic and optical coherence tomography studies have not supported the advantages of biodegradable polymer over durable polymer. Therefore, it is necessary to obtain further clinical trial data to test the long-term implications of biodegradable-polymer coated stents.
Currently, randomized, controlled clinical trials and registries are used to evaluate the safety and efficacy of different DESs. However, in these studies, different DESs were compared using grouped patients, who had similar clinical features. Though the baseline differences between groups are counterpoised by statistical methods, the impact of individual variation on the results is unavoidable. Based on these considerations, we set out to investigate the angiographic and intravascular ultrasound (IVUS) manifestations of a DES with a biodegradable polymer (Excel stent; JW Medical System) to a DES with a biocompatible polymer (Endeavor stent) in the same individuals, who were simultaneously implanted with each DES.