Impact of postdilatation on performance of bioresorbable vascular scaffolds in patients with acute coronary syndrome compared with everolimus-eluting stents: A propensity score-matched analysis from a multicenter “real-world” registry

Background: Safety and efficacy of bioresorbable vascular scaffolds (BRS) and the role of postdilatation on outcome in acute coronary syndrome (ACS) patients compared with those of everolimus-eluting stents (EES) remain unknown. The aim of the study is to compare the safety and efficacy of BRS with EES in ACS and to investigate the role of BRS postdilatation. Methods: Consecutive ACS patients undergoing BRS implantation in 8 centers were com­pared with those with EES before and after propensity score matching. Major adverse cardiac event (MACE), myocardial infarction, and target lesion revascularization (TLR) were the primary endpoint. Sensitivity analysis was performed according to postdilatation after BRS implantation. We enrolled 303 BRS and 748 EES patients; 215 from each group were com­pared after matching, and 117 (55.2%) BRS patients were treated with postdilatation. Results: After a median follow-up of 24.0 months, MACE rates were higher in BRS patients than in EES patients (9.3% vs. 4.7%, p < 0.001), mainly driven by TLR (6.1% vs. 1.9%, p < 0.001). Stent thrombosis increased in the BRS group (2.8% vs. 0.9%, p = 0.01). How­ever, after sensitivity analysis, MACE rates in BRS patients with postdilatation were signifi­cantly lower than in those without, comparable to EES patients (6.0% vs. 12.6% vs. 4.7%, p < 0.001). The same trend was observed for TLR (3.4% vs. 8.4% vs. 1.9%, p < 0.001). Stent thrombosis rates were higher in both the BRS groups than in EES patients (2.6% vs. 3.2% vs. 0.9%, p = 0.045). Conclusions: Postdilatation appears effective when using BRS in ACS patients. MACE rates are comparable to those of EES, although scaffold thrombosis is not negligible. Randomized prospective studies are required for further investigation

Precise Measurement of Cosmic-Ray Proton and Helium Spectra with the BESS Spectrometer

We report cosmic-ray proton and helium spectra in energy ranges of 1 to 120 GeV and 1 to 54 GeV/nucleon, respectively, measured by a balloon flight of the BESS spectrometer in 1998. The magnetic-rigidity of the cosmic-rays was reliably determined by highly precise measurement of the circular track in a uniform solenoidal magnetic field of 1 Tesla. Those spectra were determined within overall uncertainties of +-5 % for protons and +- 10 % for helium nuclei including statistical and systematic errors.Comment: 12 pages, 4 figure

Impact of structural features of very thin stents implanted in unprotected left main or coronary bifurcations on clinical outcomes

Objectives: To evaluate the independent clinical impact of stent structural features in a large cohort of patients undergoing unprotected left main (ULM) or coronary bifurcation percutaneous coronary intervention (PCI) with a range of very thin strut stents. Background: Clinical impact of structural features of contemporary stents remains to be defined. Methods: All consecutive patients enrolled in the veRy thin stents for patients with left mAIn or bifurcatioN in real life (RAIN) registry were included. The following stent structural features were studied: antiproliferative drugs (everolimus vs. sirolimus vs. zotarolimus), strut material (platinum-chromium vs. cobalt-chromium), polymer (bioresorbable vs. durable), number of crowns (<8 vs. ≥8) and number of connectors (<3 vs. ≥3). For small diameter stents (≤2.5 mm), struct thickness (74 vs. 80/81 μm) was also tested. Target lesion failure (TLF), a composite of target lesion revascularization and stent thrombosis, was the primary endpoint. Multivariate analysis was performed with Cox regression models. Results: Out of 2,707 patients, 110 (4.1%) experienced a TLF event after 16 months (12–18). After adjustment for confounders, an increased number of connectors (adjusted hazard ratio [adj-HR] 0.62, 95% confidence interval (CI) 0.39–0.99, p =.04) reduced risk of TLF, driven by stents with ≥2.5 mm diameter (HR 0.54, 95% CI 0.32–0.93, p =.02). This independent relationship was lost for stents with diameter <2.5 mm, where only strut thickness appeared to impact. Conversely, no independent relationship of polymer type, number of crowns, and the specific limus-family eluted drug with outcomes was observed. Conclusions: Among a range of contemporary very thin stent models, an increased number of connectors improved device-related outcomes in this investigated high-risk procedural setting

Daily risk of adverse outcomes in patients undergoing complex lesions revascularization: a subgroup analysis from the RAIN-CARDIOGROUP VII study (veRy thin stents for patients with left mAIn or bifurcatioN in real life)

Introduction: Percutaneous coronary intervention (PCI) for complex lesions, including unprotected left main (ULM) and bifurcations, is gaining a relevant role in treating coronary artery disease with good outcomes, also thanks to new generation stents. The daily risk of adverse cardiovascular events and their temporal distribution after these procedures is not known.Methods: All consecutive patients presenting with a critical lesion of ULM or bifurcation treated with very thin struts stents, enrolled in the RAIN-Cardiogroup VII study, were analyzed. The daily risk of major acute cardiovascular events (MACE), target lesion revascularization (TLR) and stent thrombosis (ST) and their temporal distribution in the first year of follow-up was the primary endpoint. Differences among subgroups (ULM, patient presentation, kind of stent polymer) were the secondary endpoint.Results: 2745 patients were included, mean age 68 ± 11 years, 33.3% diabetics, 54.5% had an acute coronary syndrome (ACS); 88.5% of treated lesions were bifurcations, 27.2% ULM. Average daily risk was 0.022% for MACE, 0.005% for TLR and 0.004% for ST, in the first year. Bimodal distribution of adverse events, especially TLR, with an early peak in the first 50 days and a late one after 150 days, was observed. Patients with ULM presented a significantly higher daily risk of events, and ACS patients presented higher MACE risk. No difference emerged according to the type of stent polymer.Conclusions: The daily risk of adverse events in the first year after complex PCI in our study is acceptably low. PCI on ULM carries a higher risk of complications

Measurements of atmospheric muon spectra at mountain altitude

We report new measurements of the atmospheric muons at mountain altitude. The measurement was carried out with the BESS detector at the top of Mt. Norikura, Japan. The altitude is 2,770 m above sea level. Comparing our results and predictions given by some interaction models, a further appropriate model has been investigated. These studies would improve accuracy of atmospheric neutrino calculations.Comment: Mean momentum in Table 1 was correcte

Measurements of Cosmic-ray Low-energy Antiproton and Proton Spectra in a Transient Period of the Solar Field Reversal

The energy spectra of cosmic-ray low-energy antiprotons and protons have been measured by BESS in 1999 and 2000, during a period covering the solar magnetic field reversal. Based on these measurements, a sudden increase of the antiproton to proton flux ratio following the solar magnetic field reversal was observed, and it generally agrees with a drift model of the solar modulation.Comment: 4 pages, 4 figures, revised version accepted for publication in Phys. Rev. Let