ObjectivesThe aim of this study was: 1) to evaluate the acute and late outcomes of a transcatheter aortic valve implantation (TAVI) program including both the transfemoral (TF) and transapical (TA) approaches; and 2) to determine the results of TAVI in patients deemed inoperable because of either porcelain aorta or frailty.

Remodeling of the vessel wall after balloon angioplasty injury is incompletely understood, and in particular, the role of extracellular matrix synthesis in restenosis has received little attention. The objective of the present study was to determine the sequence of changes in collagen, elastin, and proteoglycan synthesis and content after balloon injury and to relate these changes to growth of the intimal lesions and extent of cell proliferation. In a double-injury non-cholesterol-fed model, right iliac arterial lesions in 43 rabbits were treated with balloon angioplasty, and the rabbits were killed at five time points ranging from immediate to 12 weeks. Vessel wall collagen and elastin content and synthesis were measured after incubation with '4C-proline and separation with a cyanogen bromide extraction procedure. assess cell proliferation. The intimal area significantly increased from 0.27±0.08 to 0.73±0.11 mm2 between 0 and 12 weeks. Intimal and medial cell proliferation were modest and peaked at 1 week (labeling indexes of 4.8% and 3.0%, respectively) and then markedly declined by 2 weeks. Significant increases in collagen, elastin, and proteoglycan synthesis, up to 4 to 10 times above control nondamaged contralateral iliac arteries, were noted at 1, 2, and 4 weeks. These increases in synthesis were accompanied by significant increases in collagen and elastin content (by "=35%) that coincided with the temporal increase in cross-sectional area. Our data suggest that extracellular matrix formation is a major factor in the development of the restenosis lesion. (Circ Res. 1994;75: 650-658.)

Transradial approach PCI can be performed by low-to-intermediate volume operators with standard equipment with a low failure rate. Age >75 years, prior coronary artery bypass graft surgery, and short stature are independent predictors of TR-PCI failure. Appropriate patient selection and careful risk assessment are needed to maximize benefits offered by TR-PCI.