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Background Although stent-to-vessel (S/V) diameter ratio has been described as a restenotic factor after superficial femoral artery (SFA) stenting, the reference vessel diameter is commonly measured distally at a healthy site. It remains unclear whether S/V ratio assessed at the lesion site would be more predictive than that assessed distally at a healthy site.Methods and Results:A total of 117 patients (mean age, 73±7 years; 74% male) who underwent successful nitinol stent implantation in SFA lesions (mean lesion length, 172±104 mm) on intravascular ultrasound (IVUS) were retrospectively analyzed. S/V ratio at the proximal and distal healthy site, and at the smallest lesion site, was evaluated on IVUS. One-year restenosis predictors were evaluated on multivariate analysis. Mean S/V diameter ratio on IVUS at proximal and distal healthy sites, and at the lesion site, was 0.98±0.11, 1.02±0.11 and 1.15±0.16, respectively. One-year primary patency was 77%. On multivariate analysis, lesion length (OR, 1.06 per 10-mm increment; P=0.046) and S/V ratio measured at the lesion site (OR, 1.34 per 0.1 increment; P=0.032), but not that at the distal healthy site (OR, 1.05 per 0.1 increment; P=0.705), were significantly associated with 1-year restenosis. Conclusions S/V ratio assessed on IVUS at the lesion site, but not at the distal healthy site, was independently associated with 1-year restenosis after SFA stenting.

BACKGROUND Several non-invasive methods for measuring pulmonary vascular resistance (PVR) have been proposed to date, but they remain empirical, lacking sufficient accuracy to be used in clinical practice. The aims of this study were to propose a novel echocardiographic measurement of PVR based on a theoretical formula and investigate the feasibilty and accuracy of this method in patients with heart failure. METHODS AND RESULTS Echocardiography was performed in 27 patients before right heart catheterization. Peak tricuspid regurgitation pressure gradient (TRPG), pulmonary regurgitation pressure gradient in end-diastole (PRPGed), and cardiac output derived from the time-velocity integral and the diameter in the left ventricular outflow tract (COLVOT) were measured. PVR based on a theoretical formula (PVRtheo) was calculated as (TRPG-PRPGed)/3COLVOTin Wood units (WU). The results were compared with PVR obtained by right heart catheterization (PVRcath) using linear regression and Bland-Altman analysis. Mean PVRcathwas 2.4±1.4 WU. PVRtheocorrelated well with PVRcath(r=0.83, P