Publications by authors named "Augusto C Lopes"

Background: Transcatheter aortic valve implantation (TAVI) has established itself as the preferential strategy to approach severe aortic stenosis. Information on procedural improvements and nationwide results obtained with the technique throughout the past decade are unknown.

Objectives: To assess the temporal variation of the demographic profile, procedural characteristics, and in-hospital outcomes of patients undergoing TAVI procedures at the Rede D'Or São Luiz.

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We present a novel and time-efficient method for intracoronary lumen detection, which produces three-dimensional (3-D) coronary arteries using optical coherence tomographic (OCT) images. OCT images are acquired for multiple patients and longitudinal cross-section (LOCS) images are reconstructed using different acquisition angles. The lumen contours for each LOCS image are extracted and translated to 2-D cross-sectional images.

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Stent thrombosis is a major complication of coronary stent and scaffold intervention. While often unanticipated and lethal, its incidence is low making mechanistic examination difficult through clinical investigation alone. Thus, throughout the technological advancement of these devices, experimental models have been indispensable in furthering our understanding of device safety and efficacy.

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Purpose: Three-dimensional reconstruction of a vessel centerline from paired planar coronary angiographic images is critical to reconstruct the complex three-dimensional structure of the coronary artery lumen and the relative positioning of implanted devices. In this study, a new vessel centerline reconstruction method that can utilize non-isocentric and non-orthogonal pairs of angiographic images was developed and tested.

Methods: Our new method was developed in in vitro phantom models of bifurcated coronary artery with and without stent, and then tested in in vivo swine models (twelve coronary arteries).

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Background: Stacking cross-sectional intravascular images permits three-dimensional rendering of endovascular implants, yet introduces between-frame uncertainties that limit characterization of device placement and the hemodynamic microenvironment. In a porcine coronary stent model, we demonstrate enhanced OCT reconstruction with preservation of between-frame features through fusion with angiography and a priori knowledge of stent design.

Methods And Results: Strut positions were extracted from sequential OCT frames.

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Up to 80% of all endovascular stents have malapposed struts, and while some impose catastrophic events others are inconsequential. Thirteen stents were implanted in coronary arteries of seven healthy Yorkshire pigs, using specially-designed cuffed balloons inducing controlled stent malapposition and under-expansion. Optical coherence tomography (OCT) imaging confirmed that 25% of struts were malapposed (strut-wall distance View Article and Find Full Text PDF

Background: Vascular remodeling, the dynamic dimensional change in face of stress, can assume different directions as well as magnitudes in atherosclerotic disease. Classical measurements rely on reference to segments at a distance, risking inappropriate comparison between dislike vessel portions.

Objective: to explore a new method for quantifying vessel remodeling, based on the comparison between a given target segment and its inferred normal dimensions.

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Background: The Inspiron™ sirolimus-eluting stent (SES) is a low-dose, ultra-thin-strut cobalt-chromium stent abluminally coated with biodegradable polymers (BP). Previous results from the INSPIRON-I trial, a first-in-man study, have proven the efficacy of the novel stent in reducing neointimal proliferation. The present report aims at evaluating the long-term clinical outcomes of patients enrolled into the INSPIRON-I trial (Clinical Trials Gov.

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Endovascular stent deployment is a mechanical procedure used to rehabilitate a diseased arterial segment by restoring blood flow in occluded regions. The success or failure of the stent implantation depends on the stent device and the deployment technique. The optimal stent deployment can be predicted by investigating the factors that influence this minimally invasive procedure.

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Objectives: The aim of this study was to evaluate the impact of intravascular ultrasound (IVUS) guidance on the final volume of contrast agent used in patients undergoing percutaneous coronary intervention (PCI).

Background: To date, few approaches have been described to reduce the final dose of contrast agent in PCIs. We hypothesized that IVUS might serve as an alternative imaging tool to angiography in many steps during PCI, thereby reducing the use of iodine contrast.

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Aims: The INSPIRON-I trial is a first-in-man evaluation of the safety and efficacy of the Inspiron drug-eluting stent, a sirolimus-eluting stent with abluminal biodegradable polymer coating and thin cobalt-chromium alloy.

Methods And Results: This is a randomised, multicentre comparison between Inspiron and a stent with the same metallic structure but without polymer coating or drug elution (Cronus). The primary objective was to evaluate the in-segment late loss (LLL) at six months.

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Introduction: The safety and effectiveness of drug-eluting stent (DES) compared with bare metal stents (BMS) for the treatment of saphenous vein graft (SVG) disease is controversial, especially because of the lack of long-term follow-up. The aim of this study was to address the late outcome of DES versus BMS for the treatment of SVG lesions.

Methods: A matched, case-control study included 82 patients in each group.

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