Cytomegalovirus, Chlamydia pneumoniae, and Helicobacter pylori IgG antibodies and restenosis after stent implantation: an angiographic and intravascular ultrasound study

OBJECTIVE—To determine the impact of previous infection with cytomegalovirus, Chlamydia pneumoniae, and Helicobacter pylori on neointimal proliferation after coronary angioplasty with stent implantation.
DESIGN—The study population was made up of 180 patients who had stent implantation in a native coronary artery with systematic angiographic and intravascular ultrasound (IVUS) follow up at six months. Quantitative coronary angiography was used to assess the late lumen loss. The mean area of neointimal tissue within the stent and the ratio of neointimal tissue to stent area were assessed from IVUS images. Previous cytomegalovirus, C pneumoniae, and H pylori infection was identified by IgG antibody determination.
RESULTS—Previous cytomegalovirus infection was detected in 50% of the population, previous C pneumoniae in 18%, and previous H pylori in 33%. Mean (SD) reference diameter was 2.94 (0.48) mm and mean minimum lumen diameter after stent implantation was 2.45 (0.42) mm. At six months, the mean late loss was 0.74 (0.50) mm, the mean neointimal tissue area was 3.8 (1.7) mm(2), and the average ratio of neointimal tissue area to stent area was 45 (18)%. None of these variables of restenosis was linked to any of the three infectious agents. By multivariate analysis, lesion length was the variable best correlated with mean neointimal tissue area, the ratio of neointimal tissue to stent area, and late loss, explaining respectively 31%, 39%, and 8% of their variability.
CONCLUSIONS—Previous infection with cytomegalovirus, C pneumoniae, or H pylori was not a contributing factor in the process of restenosis after stent implantation.


Keywords: restenosis; stent; ultrasonics; angiography; infectio

Single-crystal based composite wafers for high quality passive RF microdevices

International audienceNew guiding principles and concepts are currently investigated for developing high frequency devices capable to answer the RF manufacturer demand for telecommunication an remote transmission modern components. Beside the use of physically or chemically deposited piezoelectric overlays, the use of composite wafers composed by single crystal layers and wafers obtained by wafer bonding and lapping/polishing techniques offers attractive opportunities for overpassing the known limitations of acoustics-based radio-frequency devices. In this paper, we present different approaches for manufacturing such composite wafers and we describe different applications taking advantage of their unique characteristics. Lithium niobate is particularly considered for the piezoelectric layers because of its exceptional piezoelectric properties and its very high acoustic quality, and various substrate such as silicon, sapphire and lithium niobate again are used to guide and trap the excited waves. State-of-the-art Surface Acoustic Wave (SAW) devices, Harmonic Bulk Acoustic Resonators (HBARS) and Periodically Poled Transducers developed on such wafers are presented to illustrate the potential of this technological approach