Isolation of pulmonary veins using a thermoreactive implantable device with external energy transfer: Evaluation in a porcine model.

Background: Pulmonary vein isolation (PVI) is a well-established method for the treatment of symptomatic paroxysmal atrial fibrillation, but is only partly successful with a high rate of electrical reconnection. We introduce a novel technique in which PVI is accomplished by noninvasive heating of a dedicated thermoresponse implant inserted into the pulmonary veins (PV), demonstrated in a porcine model.

Methods: A self-expanding nitinol-based implant was positioned in the common inferior PV of 11 pigs, using a fluoroscopy-guided transatrial appendage approach.

A preliminary study of pulmonary vein implant applicability and safety as a potential ablation platform in a follow-up study in pigs.

Background: Recurrence of atrial fibrillation after an ablation procedure remains a major problem which emphasizes the need for improved pulmonary vein isolation techniques.

Aims: The aim of this study was to describe an implantation procedure of a pulmonary vein-stent which may possibly serve as an ablation technique in the future and to examine stent safety in a follow-up study in pigs.

Methods And Results: Eight pigs were catheterized and nine self-expanding nitinol stents were implanted through a transfemoral or transatrial approach into the antra of the pulmonary veins.

A Preclinical Study of an Implanted Device in the Pulmonary Veins, Intended for the Treatment of Atrial Fibrillation in an Ovine Model.

Background: Atrial fibrillation is the most frequent arrhythmia in adults of which the interventional cure is hampered by high recurrence rates. Recurrence after ablation is due to an incomplete isolation of the pulmonary veins. A new ablation technique was performed, in the antra of ovine pulmonary veins, by device implantation, which was heated through a wireless heat-generating system.

Incidence and potential mechanism of resolved, persistent and newly acquired malapposition three days after implantation of self-expanding or balloon-expandable stents in a STEMI population: insights from optical coherence tomography in the APPOSITION II study.

Aims: The aim of the current study was to investigate the frequency and mechanisms of sequential incomplete stent apposition (ISA) changes such as persistent, resolved or newly acquired ISA during the first three days after primary PCI (pPCI) in a matched segment-level analysis, with the comparison between self-expanding and balloon-expandable stents assessed by optical coherence tomography (OCT).

Methods And Results: The current analysis is a substudy of the APPOSITION II study that included 69 patients (self-expanding: 35, balloon-expandable: 34) using serial optical coherence tomography (OCT) post procedure and three days after pPCI. In order to evaluate a temporal change in ISA, stented regions were segmented using fiduciary landmarks.

Iatrogenic left main coronary artery dissection and intramural hematoma caused by diagnostic transradial cardiac catheterization.

The growing use of the transradial approach for percutaneous coronary interventions has been shown to decrease the risk of major vascular complications. However, in this case report we describe a iatrogenic left main dissection during diagnostic coronary catheterization, which remains a rare, but still life-threatening condition. The adjunctive use of intravascular ultrasound may assist in the accurate diagnosis and treatment process.

Self-expanding versus balloon-expandable stents in acute myocardial infarction: results from the APPOSITION II study: self-expanding stents in ST-segment elevation myocardial infarction.

Objectives: This study sought to investigate whether self-expanding stents are more effective than balloon-expandable stents for reducing stent malapposition at 3 days after implantation in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Background: Acute myocardial infarction is associated with vasoconstriction and large thrombus burden. Resolution of vasoconstriction and thrombus load during the first hours to days after primary percutaneous coronary intervention may lead to stent undersizing and malapposition, which may subsequently lead to stent thrombosis or restenosis.

Compositional volumetry of non-calcified coronary plaques by multislice computed tomography: an ex vivo feasibility study.

Aims: Non-invasive quantitative compositional analysis of coronary plaque would be a major advantage to study coronary artery disease. This study explores the application to use the Hounsfield units (HU) distribution of coronary plaques imaged by multislice computed tomography-coronary angiography (MSCT-CA).

Methods And Results: A dedicated computer-assisted method was developed to measure the HU distribution within a coronary plaque by MSCT-CA.

The ProLimus trial: a prospective, non-randomised, multicentre trial to evaluate the safety and clinical performance of the pimecrolimus eluting stent system (ProGenic).

Aims: The aim of this multicentre, non-randomised trial was to evaluate the safety and efficacy at 180+/-14 days of a pimecrolimus eluting coronary stent based on a cobalt-chromium platform and a poly-L-lactic acid (PLLA) bioresorbable polymer.

Methods And Results: Sixty-one patients, with single de novo coronary lesions <14 mm in length and a reference vessel diameter of 3.0 to 3.

Re-examining minimal luminal diameter relocation and quantitative coronary angiography--intravascular ultrasound correlations in stented saphenous vein grafts: methodological insights from the randomised RRISC trial.

Aims: Angiographic parameters (such as late luminal loss) are common endpoints in drug-eluting stent trials, but their correlation with the neointimal process and their reliability in predicting restenosis are debated.

Methods And Results: Using quantitative coronary angiography (QCA) data (49 bare metal stent and 44 sirolimus-eluting stent lesions) and intravascular ultrasound (IVUS) data (39 bare metal stent and 34 sirolimus-eluting stent lesions) from the randomised Reduction of Restenosis In Saphenous vein grafts with Cypher stent (RRISC) trial, we analysed the "relocation phenomenon" of QCA-based in-stent minimal luminal diameter (MLD) between post-procedure and follow-up and we correlated QCA-based and IVUS-based restenotic parameters in stented saphenous vein grafts. We expected the presence of MLD relocation for low late loss values, as MLD can "migrate" along the stent if minimal re-narrowing occurs, while we anticipated follow-up MLD to be located close to post-procedural MLD position for higher late loss.

Rotational vs. standard coronary angiography: an image content analysis.

Objective: To evaluate the clinical utility of images acquired from rotational coronary angiographic (RA) acquisitions compared to standard "fixed" coronary angiography (SA).

Background: RA is a novel angiographic modality that has been enabled by new gantry systems that allow calibrated automatic angiographic rotations and has been shown to reduce radiation and contrast exposure compared to SA. RA provides a dynamic multiple-angle perspective of the coronaries during a single contrast injection.

Comparison of assessment of native coronary arteries by standard versus three-dimensional coronary angiography.

Vessel foreshortening is a major limitation of standard coronary angiography due to the 2-dimensional representation of 3-dimensional structures. Three-dimensional models may overcome it. The aim of this study was to compare measurements of coronary segments from quantitative coronary angiography (QCA) in an operator-selected "working view" of standard 2-dimensional coronary angiography with those from 3-dimensional coronary angiography (3D-CA) reconstruction models, which are automatically generated from software applied to rotational coronary angiographic acquisitions.

"Virtual" in-vivo bench test for bifurcation stenting with "StentBoost".

"StentBoost" is a new angiographic technique that allows improved angiographic visualization of stents deployed in coronary arteries, by enhancing the X-ray focus of the region where the stent is placed. Using this technique we were able to assess the deformation and the expansion of a stent deployed to treat a bifurcation lesion between the mid-left anterior descending (LAD) artery and a big second diagonal branch, during sequential inflations of: (1) the stent per se in the LAD, (2) the ostium of the diagonal branch through the stent struts, (3) the stent again with a non compliant balloon, and (4) both branches with the kissing balloon technique. "StentBoost" guided our clinical and angiographic decision-making process and allowed us to create a "virtual" bench test of the stent deployed at the level of the bifurcation treated.

Three-dimensional and quantitative analysis of atherosclerotic plaque composition by automated differential echogenicity.

Objective: To validate automated and quantitative three-dimensional analysis of coronary plaque composition using intracoronary ultrasound (ICUS).

Background: ICUS displays different tissue components based on their acoustic properties in 256 grey-levels. We hypothesised that computer-assisted image analysis (differential echogenicity) would permit automated quantification of several tissue components in atherosclerotic plaques.

Mitochondrial uncoupling protein 2 mediates temperature heterogeneity in atherosclerotic plaques.

Aims: Rupture-prone atherosclerotic plaques show an elevated temperature, but a molecular explanation for this phenomenon is unknown. Here, we investigated whether mitochondrial uncoupling protein 2 (UCP2) could be involved because this protein is a macrophage homologue of thermogenin in brown fat tissue.

Methods And Results: Immunohistochemistry, western blotting, and real-time quantitative polymerase chain reaction were used to detect UCP2 expression in human and rabbit atherosclerotic plaques.

Increased late mortality after sirolimus-eluting stents versus bare-metal stents in diseased saphenous vein grafts: results from the randomized DELAYED RRISC Trial.

Objectives: We sought to provide long-term follow-up data of sirolimus-eluting stents (SES) versus bare-metal stents (BMS) in saphenous vein grafts (SVG) from the RRISC (Reduction of Restenosis In Saphenous vein grafts with Cypher) trial.

Background: We have previously shown that, in SVG, the use of SES reduces 6-month restenosis and repeated revascularization procedures versus the use of BMS. These data are consistent with trials in native coronary arteries.

Intravascular ultrasound comparison of sirolimus-eluting stent versus bare metal stent implantation in diseased saphenous vein grafts (from the RRISC [Reduction of Restenosis In Saphenous Vein Grafts With Cypher Sirolimus-Eluting Stent] trial).

The randomized Reduction of Restenosis In Saphenous Vein Grafts with Cypher Sirolimus-Eluting Stent trial compared angiographic outcomes of sirolimus-eluting stents (SESs) versus bare metal stents (BMSs) in saphenous vein grafts (SVG). Using intravascular ultrasound (IVUS) performed during 6-month follow-up angiography, we compared the vascular effects of the 2 types of stent on SVGs. Of 75 patients (96 lesions) included, 59 patients underwent IVUS in 61 SVGs; 29 patients received 40 SESs for 34 lesions, and 30 patients received 42 BMSs for 39 lesions.

Acute and mid-term local vascular effects of compliant balloon inflation (GuardWire system) on saphenous vein bypass grafts: an angiographic analysis.

Background: The GuardWire distal protection device reduces the incidence of periprocedural complications during percutaneous stenting of diseased saphenous vein grafts. Its mechanism of action is based on the occlusion of the vessel distal to the lesion with an inflated compliant balloon before the intervention, and the aspiration of embolized material after stent implantation. Although no safety issues related to the compliant balloon have been reported in vein graft treatment, concerns related to the potential injury of the balloon on the vessel wall have been raised.

Randomized double-blind comparison of sirolimus-eluting stent versus bare-metal stent implantation in diseased saphenous vein grafts: six-month angiographic, intravascular ultrasound, and clinical follow-up of the RRISC Trial.

Objectives: We sought to compare, in a randomized fashion, sirolimus-eluting stents (SES) versus bare-metal stents (BMS) in saphenous vein grafts (SVGs).

Background: Sirolimus-eluting stents reduce restenosis and repeated revascularization in native coronary arteries compared with BMS. However, randomized data in SVG are absent.

Dissimilar relevance given to diseases by medical literature, and the potential to create biases in the clinical decision-making process: the case of late stent thrombosis.

We discuss two cases of non-occlusive sub-acute/late stent thrombosis, one correctly diagnosed (with the help of intravascular ultrasound) 12 days after implantation of a sirolimus eluting stent, the other erroneously non recognized 17 days after implantation of a bare metal stent and evolving 6 weeks later in total thrombotic occlusion of the stent itself. We believe that our clinical judgment, accurate in case of sirolimus eluting stent thrombosis, but wrong in case of bare metal stent thrombosis, was largely influenced by the recent literature giving overwhelming attention, in the drug-eluting stent era, to an issue (late stent thrombosis) that was already present but under-considered, also in the bare metal stent era.

Macroscopic assessment of porcine coronary vessel wall trauma after percutaneous cardiac catheterization and intervention.

A macroscopic pathological assessment of the coronary arteries of a pig's heart, in which stent implantation and intra-vascular ultrasound and thermography pullbacks were performed, shows that during percutaneous coronary catheterization and intervention, one of the major vessel traumas occurs in the very proximal part of the coronary arteries, where the guiding catheter tip is manipulated to adequately engage the vessels.

Comparison of the CardioShield filter with the guardwire balloon in the prevention of embolisation during vein graft intervention: results from the CAPTIVE randomised trial.

Aims: This study assessed safety and efficacy of a third-generation distal protection device, MedNova CardioShield Bare Wire Myocardial Protection System, for treating Saphenous Vein Graft (SVG) disease.Treatment of SVG disease remains difficult, with increased adverse cardiac events (MACE) primarily manifested as no reflow and periprocedural infarction. Even with approved embolic protection devices, 30-day MACE rates are approximately 10%.