Six-month follow-up evaluation for everolimus-eluting stents by intracoronary optical coherence tomography: Comparison with paclitaxel-eluting stents

Abstract

BackgroundAlthough several clinical trials have shown the superior efficacy and safety of second-generation everolimus-eluting stents (EES) in comparison with first-generation paclitaxel-eluting stents (PES), the differences in the vascular healing process between EES and PES in a human coronary artery during an early stage are unknown. MethodsA prospective optical coherence tomography (OCT) observation was performed for 25 EES in 21 patients and 27 PES in 21 patients at 6months after implantation. Cross-sections within single-stent segments were analyzed at intervals of 1mm. The neointimal (NI) thickness on each strut was measured. Uncovered struts (NI thickness=0μm), malapposed struts, NI area (%), uncovered strut ratio >0.3 (UCSR; number of uncovered struts/number of total struts) per cross-section, and in-stent thrombus were evaluated. ResultsA total of 5198 EES struts in 514 cross-sections and 4243 PES struts in 469 cross-sections were identified. NI thickness and its area were smaller for EES than PES (80.0±84.8μm vs. 117.9±140.0μm and 19.1±8.9% vs. 23.7±11.5%, respectively; P<0.001). The frequencies of uncovered struts and malapposed struts were lower in EES compared to PES (2.3% vs. 5.2% and 2.1% vs. 5.7%, respectively; P<0.001). Patients who had cross-sections of UCSR >0.3 and thrombi were identified less frequently in EES than in PES group (5% vs. 57%; P<0.001, and 19% vs. 48%; P=0.05, respectively). ConclusionsSix-month OCT examination showed a favorable vessel healing response after the implantation of EES, demonstrating less in-stent late loss as well as fewer uncovered struts and better stent apposition to the vessel wall in comparison with PES.