Mizuki Miura

The University of Tokyo | Todai · Department of Cardiovascular Medicine

Background Various cardiovascular diseases cause acquired von Willebrand syndrome (AVWS), which is characterized by a decrease in high-molecular-weight (large) von Willebrand factor (VWF) multimers. Mitral regurgitation (MR) has been reported as a cause of AVWS. However, much remains unclear about AVWS associated with MR. Objectives To evaluate VW...

Background Severe aortic stenosis (AS) causes acquired von Willebrand syndrome by the excessive shear stress–dependent cleavage of high molecular weight multimers of von Willebrand factor (VWF). While the current standard diagnostic method is so-called VWF multimer analysis that is western blotting under nonreducing conditions, it remains unclear w...

Aims In patients with severe aortic stenosis, trans-prosthetic haemodynamics after transcatheter aortic valve implantation (TAVI) tend to be more favourable than after surgical aortic valve replacement, especially after self-expandable valve (SEV) implantation. The relative performance of TAVI according to leaflet position, that is supra-annular an...

Objectives The aim of this study was to define predictors of prosthesis-patient mismatch (PPM) and its impact on mortality after transcatheter aortic valve replacement (TAVR) with self-expandable valves (SEVs) in patients with small annuli. Background TAVR seems to reduce the risk for PPM compared with surgical aortic valve replacement, especially...

New transcatheter technologies for the treatment of severe tricuspid insufficiency, in patients at high surgical risk, are demonstrating promising efficacy and a high safety profile. In certain conditions of advanced right failure, with significant tethering of the leaflets, repair techniques are not the ideal solution, reporting a fair rate of res...

Objectives To evaluate outcome and its predictors of bioprosthetic valve fracture (BVF) in patients undergoing valve‐in‐valve transcatheter aortic valve replacement (VIV‐TAVR). Background BVF is feasible and reduces transvalvular gradients in VIV‐TAVR‐procedures, but follow‐up‐data and information on factors influencing the outcome are missing. M...

Objectives: To evaluate the use and outcomes of percutaneous mechanical circulatory support (pMCS) utilized during transcatheter aortic valve implantation (TAVI) from high-volume centers. Methods and results: Our international multicenter registry including 13 high-volume TAVI centers with 87 patients (76.5 ± 11.8 years, 63.2% men) who underwent...

Background: Tricuspid regurgitation (TR) has a poor prognosis and limited treatment options and is frequently accompanied by right ventricular (RV) dysfunction. Transcatheter tricuspid valve interventions (TTVI) to reduce TR have been shown to be safe and feasible with encouraging early results. Patient selection for TTVI remains challenging, with...

Background Scarce data exist on patients with right ventricular dysfunction (RVD) or pulmonary hypertension (PH) undergoing transcatheter tricuspid valve intervention. This study aimed to determine the early and midterm outcomes and the factors associated with mortality in this group of patients. Methods This subanalysis of the multicenter TriValv...

Background Scarce data exist on patients with previous left valve surgery (PLVS) undergoing transcatheter tricuspid valve intervention (TTVI). Objectives This study sought to investigate the procedural and early outcomes in patients with PLVS undergoing TTVI. Methods This was a sub-analysis of the multicenter TriValve registry including 462 patie...

Aims: Aim: To provide a step-by-step recommendation on how to align the Portico transcatheter heart valve, in a reproducible and reliable way, aiming to achieve proper neo-commissure alignment during transcatheter aortic valve implantation. Methods and results: Patient-specific 3D aortic models were developed and printed based on CT scan reconst...

[This corrects the article DOI: 10.15420/icr.2020.07.].

Background No data have been published to now about the outcomes of MitraClip in inoperable patients with Barlow's Mitral Valve Disease. Despite the technical advantages of the new generation of MitraClips, the length and the thickness of the mitral leaflets and presence of flails with complete eversion and pseudo-cleft are challenging MitraClip pr...

Introduction Since the first transcatheter aortic valve implantation (TAVI), remarkable changes in procedure features and patients' profile have been reported, making it a widespread treatment for severe aortic stenosis in all risk-class patients. Purpose To evaluate TAVI contemporary trends and outcomes in the last 8 years in a high-volume TAVI c...

In the current era of transcatheter edge-to-edge repair, deciding clip size in each case is still a challenge. We demonstrate that the XTR clip can achieve a better outcome than the NTR clip in a calcified leaflet.

Objectives: The aim of this study was to assess the clinical outcome of baseline massive or torrential tricuspid regurgitation (TR) after transcatheter tricuspid valve intervention (TTVI). Background: The use of TTVI to treat symptomatic severe TR has been increasing rapidly, but little is known regarding the impact of massive or torrential TR b...

Aim: To describe six cases using the bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction technique to prevent coronary artery obstruction during transcatheter aortic valve-in-valve procedures. Methods: All patients presented degeneration of a bovine pericardium bioprosthesis [four Trife...

Post-operative systolic anterior motion associated with mitral regurgitation can be a challenging combination. We present the case of a 64-year-old male patient managed by MitraClip (Abbott Laboratories, Abbott Park, Illinois) implantation for systolic anterior motion and severe mitral regurgitation in the early post-operative period after aortic d...

Despite significant improvements in transcatheter aortic valve implantation (TAVI) outcomes, periprocedural conduction disturbances, such as new-onset left bundle branch block (LBBB) and new pacemaker implantation (PMI), remain relatively frequent concerns. The development of periprocedural conduction disturbances can be explained by the proximity...

Improvements in procedural technique and intra-procedural imaging have progressively expanded the indications of percutaneous edge-to-edge technique. To date in higher volume centres and by experienced operators MitraClip is used for the treatment of complex anatomies and challenging cases in high risk-inoperable patients. This progressive step is...

Objectives The goal of this study was to evaluate the effect of transcatheter edge-to-edge tricuspid valve repair (TTVR) for severe tricuspid regurgitation (TR) on hospitalization for heart failure (HHF) and HF-related endpoints. Background Patients with severe TR need effective therapies beyond conservative treatment. The impact of TTVR on HHF an...

Transcatheter tricuspid valve intervention (TTVI) is an emerging treatment for patients with symptomatic severe tricuspid regurgitation (TR). Currently, the issues that arise during TTVI are unclear. Here, a 78‐year‐old woman with severe TR underwent transcatheter tricuspid valve annuloplasty using a Cardioband (Edwards Lifesciences, Irvine, CA). W...

Cardiac resynchronization therapy (CRT) has been associated to left ventricle (LV) remodelling, reduction of functional mitral regurgitation (FMR) and clinical improvement in patients with heart failure and reduced ejection fraction (HFrEF). The prevalence of significant FMR in patients with LV dyssynchrony that are candidate to CRT is up to 40%. C...

This second chapter is dedicated to the preoperative screening of patients, when the aortic disease has assumed a degree of severity that requires a thorough understanding in view of the treatment. Which imaging tests are indicated for the diagnosis and quantification of the associated coronary artery disease, as well as mitral and tricuspidal valv...

This chapter is dedicated to the preoperative multimodality imaging necessary for a thorough surgical or interventional aortic planning.

This chapter covers the fundamental aspects of intraprocedural imaging, related to the surgical replacement or repair of the aortic valve and its corresponding transcatheter, the TAVI.

This chapter covers the fundamental aspects of post-procedural follow-up imaging, after surgical aortic valve replacement and after TAVI procedure.

In this first chapter, the role taken by the different imaging modalities for the diagnosis and timing of the aortic valvular diseases will be described.

Objectives: The aim of this study was to investigate the safety and efficacy of coronary protection by preventive coronary wiring and stenting across the coronary ostia in patients at high risk for coronary obstruction after transcatheter aortic valve replacement (TAVR). Background: Coronary obstruction following TAVR is a life-threatening compl...

Background/Introduction. In step by step guidance of percutaneous mitral valve (MV) repair with MitraClip System (Abbott Vascular, Santa Clara, CA, USA) evaluation of step by step MR reduction by color-Doppler echocardiography can be challenging requiring multiparametric approach and to freeze and process images while the procedure is going. Purpos...

Introduction: Transcatheter tricuspid valve (TV) procedures emerged as an alternative to surgery for symptomatic high-risk patients with severe tricuspid regurgitation. Areas covered: A literature search was performed using PubMed. Authors review clinical evidence in this field, the imaging features and the developments in TV transcatheter technolo...

Objectives: The aim of this study was to evaluate and compare the outcomes of transcatheter self-expandable prostheses in patients with small annuli. Background: Transcatheter aortic heart valves appear to have better performance than surgical valves in terms of prosthesis-patient mismatch, especially in patients with aortic stenosis with small...

Background The influence of improved mitral regurgitation(MR) on the outcomes of transcatheter aortic valve replacement(TAVR) is unknown. Our aim was to determine the impact of significant preprocedural MR and the improvement of MR after TAVR. Methods A population of 1,587 patients from the OCEAN–TAVI registry were evaluated. Preprocedural MR was...

Introduction Intraprocedural guidance and monitoring with transesophageal echocardiography (TEE) and invasive hemodynamic assessment are currently the best available options for evaluating procedural success of percutaneous mitral valve (MV) repair with Mitraclip System (Abbott Vascular, Santa Clara, CA, USA). However, despite its crucial importanc...

The Portico™ transcatheter aortic valve implantation (TAVI) system (Abbott Vascular, Santa Clara, CA, USA) was specifically designed to reduce some of the limitations associated with first-generation TAVI devices. Most of the currently available clinical evidence was obtained from randomized studies that compared TAVI to aortic valve replacement us...

Aortic complex rupture is one of the most critical complications associated with transcatheter aortic valve implantation (TAVI). Its incidence is rare, and its mechanism varies by case; therefore, it is difficult to identify the predictors of complex rupture. Herein, we report a clinical case series of aortic complex rupture. Within our cohort, the...

Despite the increasing knowledge of the long-term adverse consequence of severe tricuspid regurgitation (TR), most patients with moderateto-severe TR are still treated conservatively because of the high risk of surgery. Percutaneous procedures have emerged as an attractive alternative treatment. Transcatheter edge-to-edge repair is a validated tech...

A 74-year-old man presented with dyspnea due to severe mitral regurgitation (MR) caused by rupture of the chordae tendineae. Percutaneous edge-to-edge mitral valve repair was performed using the MitraClip system (Abbott Vascular, Santa Clara, CA). After leaflet grasping via an XTR clip, transesophageal echocardiography (TEE) revealed marked reducti...

The Portico TAVI system (Abbott Vascular, Santa Clara, CA, USA) has been specifically designed to mitigate some of the complications associated with first-generation valves. Most of the data generated from randomized studies comparing transcatheter aortic valve implantation with surgery stem from reported experiences with first generation transcath...

Until recently, tricuspid valve (TV) disease has been relatively neglected for a long time, but recently tricuspid regurgitation (TR) has attracted attention. Although the prognosis of patients with these disorders is poor, the high mortality and morbidity associated with TV surgery have resulted in many patients not receiving surgical therapy. Cur...

Transcatheter aortic valve implantation (TAVI) often causes intraventricular conduction abnormalities (ICA), particularly left bundle branch block (LBBB) and advanced atrioventricular block, requiring pacemaker implantation (PMI). However, the relation between ICA and clinical outcomes after TAVI with balloon-expandable valves remains unclear, part...

Background Although transcatheter aortic valve replacement (TAVR) is the least invasive treatment for patients with symptomatic aortic stenosis, some patients hesitate to undergo the procedure. We investigated the clinical impact of treatment delay after patient refusal of TAVR. Methods and Results We used the Japanese OCEAN (Optimized Catheter va...

Video 2. The TPS body was caught in the inferior vena cava and was successfully retrieved.

Video 1. Retrieval of the old TPS obstructed by the chordae tendineae of the tricuspid valve and the pacemaker lead.

We report the case of a 74-year-old man with a previously implanted pacemaker lead. He had undergone Medtronic™ Micra Transcatheter Pacing System (TPS, Medtronic plc, MN, USA) implantation because of lead fracture. We implanted a new TPS and retrieved the dislodged one. We used a multiple-loop snare (EN snare®) and an 8.5F steerable sheath (Agilis...

Aortography showing blood flow from the aortic annulus to right ventricle.

Transthoracic echocardiography showing atypical annulus rupture and a continuous shunt from the aorta to right ventricle.

As Japan has one of the most rapidly aging populations in the world, transcatheter aortic valve implantation (TAVI) is likely to be performed in increasing numbers of older people. There is little information on either the efficacy or the safety of TAVI in nonagenarians in Asia. From October 2013 to June 2015, 112 consecutive patients underwent TAV...

Background:Percutaneous coronary intervention for heavily calcified lesions requires rotational atherectomy (RA). Long-term clinical outcomes after drug-eluting stent (DES) implantation following (RA) for heavily calcified lesions remain unclear. We assessed 5-year clinical outcomes after DES implantation following RA. Methods and Results:Between M...

The incidence and long-term clinical impact of stent fracture (SF) occurred beyond 1-year after sirolimus-eluting stent (SES) implantation remains unclear. From April 2004 and March 2008, 985 consecutive patients with 1307 lesions were treated only with SES. Of these, 868 patients (88.1%) with 1140 lesions underwent follow-up angiography within 1-y...

Background: Previous trials have found that low low-density lipoprotein-cholesterol (LDL-C) on admission was associated with increased mortality in patients with acute myocardial infarction (AMI). There are few reports, however, on the effect of low LDL-C with or without in-hospital statin treatment on short-term prognosis in AMI patients.Methods...

Background: Previous trials showed that low low-density lipoprotein-cholesterol (LDL-C) levels on admission were associated with increased mortality in patients with acute myocardial infarction (AMI). However there are few reports evaluating the effect of low LDL-C levels with or without statin administration in hospital regarding the prognosis in...