Publications by authors named "Mathew Williams"

The impacts of degradation and deforestation on tropical forests are poorly understood, particularly at landscape scales. We present an extensive ecosystem analysis of the impacts of logging and conversion of tropical forest to oil palm from a large-scale study in Borneo, synthesizing responses from 82 variables categorized into four ecological levels spanning a broad suite of ecosystem properties: (i) structure and environment, (ii) species traits, (iii) biodiversity, and (iv) ecosystem functions. Responses were highly heterogeneous and often complex and nonlinear.

View Article and Find Full Text PDF
Article Synopsis
  • Transcatheter mitral valve-in-valve replacement is a less invasive option for high-risk patients with failed bioprosthetic mitral valves, and this study focuses on its outcomes in intermediate-risk patients.
  • A total of 50 patients, mostly around 70 years old, were treated using a balloon-expandable valve, and results showed no deaths or strokes within one year post-procedure.
  • The procedure led to significant improvement in patients' symptoms and quality of life, with most experiencing low levels of mitral regurgitation and overall better heart function after one year.
View Article and Find Full Text PDF

Aim: This analysis aimed to compare the clinical outcomes associated with heart failure (HF) readmissions and to identify associations with HF hospitalizations (HFH) in patients treated with the MitraClip™ NTR/XTR System in the EXPAND study.

Methods And Results: The global, real-world EXPAND study enrolled 1041 patients with primary or secondary mitral regurgitation (MR) treated with the MitraClip NTR/XTR System. Echocardiograms were analysed by an independent echocardiographic core laboratory.

View Article and Find Full Text PDF

Background: The next generation supra-annular, self-expanding Evolut FX transcatheter aortic valve (TAV) system was designed to improve catheter deliverability, provide stable and symmetric valve deployment, and assess commissural alignment during the procedure. The impact of these modifications has not been clinically evaluated.

Methods: Procedural information was collected by survey in 2 Stages: Stage I comprised 23 centers with extensive experience with Evolut TAV systems, and Stage II comprised an additional 46 centers with a broad range of balloon- and self-expanding system experience.

View Article and Find Full Text PDF
Article Synopsis
  • The study compares the 5-year rates of valve reintervention after transcatheter aortic valve replacement (TAVR) using CoreValve/Evolut versus surgical aortic valve replacement (SAVR).
  • It found that TAVR had a higher overall reintervention rate (2.2%) compared to SAVR (1.5%), particularly within the first year.
  • Evolut TAVR showed significantly fewer reinterventions than CoreValve TAVR, but its rates were comparable to SAVR, indicating varying risks associated with different valve types.
View Article and Find Full Text PDF

Introduction: The membranous septum (MS) length measured by cardiac computed tomography (CT) is useful for the prediction of permanent pacemaker implantation (PPMI) and new left bundle branch block (LBBB) after transcatheter aortic valve replacement. However, its predictive value for patients undergoing surgical aortic valve replacement (SAVR) is unknown.

Methods: A total of 2531 consecutive patients were registered in the institutional Society of Thoracic Surgeons database between July 2017 and June 2020.

View Article and Find Full Text PDF

Coronary artery obstruction caused by sinus sequestration is well described after transcatheter aortic valve implantation in failed bioprosthetic valves, which usually occurs during or shortly after the transcatheter aortic valve implantation procedure. We report the presentation, management, and outcomes of 2 cases of very late sinus sequestration in native aortic annuli, which has not been described before to our knowledge. ().

View Article and Find Full Text PDF

Background: Favorable 6-month outcomes from the CLASP IID Registry (Edwards PASCAL transcatheter valve repair system pivotal clinical trial) demonstrated that mitral valve transcatheter edge-to-edge repair with the PASCAL transcatheter valve repair system is safe and beneficial for treating prohibitive surgical risk degenerative mitral regurgitation (DMR) patients with complex mitral valve anatomy.

Objectives: The authors sought to assess 1-year safety, echocardiographic and clinical outcomes from the CLASP IID Registry.

Methods: Patients with 3+ or 4+ DMR who were at prohibitive surgical risk, had complex mitral valve anatomy based on the MitraClip Instructions for Use, and deemed suitable for treatment with the PASCAL system were enrolled prospectively.

View Article and Find Full Text PDF

Background: The fourth-generation mitral transcatheter edge-to-edge repair (M-TEER) device introduced an improved clip deployment sequence, independent leaflet grasping, and 2 wider clip sizes to tailor the treatment of patients with mitral regurgitation (MR) for a broad range of anatomies. The 30-day safety and effectiveness of the fourth-generation M-TEER device were previously demonstrated.

Objectives: The aim of this study was to evaluate 1-year outcomes in a contemporary, real-world cohort of subjects treated with the MitraClip G4 system.

View Article and Find Full Text PDF

Background: The benefits of fast-track extubation in the intensive care unit (ICU) after cardiac surgery are well established. Although extubation in the operating room (OR) is safe in carefully selected patients, widespread use of this strategy in cardiac surgery remains unproven. This study was designed to evaluate perioperative outcomes with OR vs ICU extubation in patients undergoing nonemergency, isolated coronary artery bypass grafting (CABG).

View Article and Find Full Text PDF
Article Synopsis
  • Previous studies showed that older balloon-expandable valves for transcatheter aortic valve replacement (TAVR) were as effective as surgical aortic valve replacement (SAVR) in preventing death and disabling strokes for intermediate-risk patients.
  • This study compared 5-year outcomes of TAVR using the newer SAPIEN 3 valve against SAVR in intermediate-risk patients with severe aortic stenosis.
  • The findings indicated that the rates of death and disabling stroke were similar for both TAVR and SAVR, but S3 TAVR patients experienced more mild paravalvular regurgitation, highlighting the need for further long-term studies on valve durability and complications.
View Article and Find Full Text PDF

Background: Anatomical and clinical criteria to define mitral transcatheter edge-to-edge repair (TEER) "unsuitability" have been proposed on the basis of a Heart Valve Collaboratory consensus opinion from physician experience with early-generation TEER devices but lacked an evidence-based approach.

Objectives: The aim of this study was to explore the spectrum of TEER suitability using echocardiographic and clinical outcomes from the EXPAND G4 real-world postapproval study.

Methods: EXPAND G4 is a global, prospective, multicenter, single-arm study that enrolled 1,164 subjects with mitral regurgitation (MR) treated with the MitraClip G4 System.

View Article and Find Full Text PDF

Background: The fourth-generation MitraClip G4 System builds on the previous NTR/XTR system with additional wider clip sizes (NTW and XTW), an independent grasping feature, and an improved clip deployment sequence.

Objectives: The primary objective of this study was to assess the safety and performance of the MitraClip G4 System within a contemporary real-world setting.

Methods: EXPAND G4 is a prospective, multicenter, international, single-arm, postapproval study that enrolled patients with primary (degenerative) mitral regurgitation (MR) and secondary (functional) MR at 60 centers.

View Article and Find Full Text PDF

Background: In patients with severe symptomatic aortic stenosis at low surgical risk, transfemoral transcatheter aortic valve replacement (TAVR) with the SAPIEN 3 valve has been shown to reduce the composite of death, stroke, or rehospitalization at 2-year follow-up compared with surgical aortic valve replacement (SAVR). Whether TAVR is cost-effective compared with SAVR for low-risk patients remains uncertain.

Methods: Between 2016 and 2017, 1000 low-risk patients with aortic stenosis were randomly assigned to TAVR with the SAPIEN 3 valve or SAVR in the PARTNER 3 trial (Placement of Aortic Transcatheter Valves).

View Article and Find Full Text PDF

Background: Surgical management of isolated tricuspid regurgitation (TR) is associated with high morbidity and mortality, thereby creating a significant need for a lower-risk transcatheter solution.

Objectives: The single-arm, multicenter, prospective CLASP TR (Edwards PASCAL TrAnScatheter Valve RePair System in Tricuspid Regurgitation [CLASP TR] Early Feasibility Study) evaluated 1-year outcomes of the PASCAL transcatheter valve repair system (Edwards Lifesciences) to treat TR.

Methods: Study inclusion required a previous diagnosis of severe or greater TR and persistent symptoms despite medical treatment.

View Article and Find Full Text PDF

Background: The third-generation MitraClip NTR/XTR transcatheter edge-to-edge repair system was introduced to assist in leaflet grasping with the longer clip arms of MitraClip XTR and to improve ease of use with the modified delivery catheter.

Objectives: The EXPAND study evaluated contemporary real-world outcomes in subjects with mitral regurgitation (MR) treated with the third-generation MitraClip NTR/XTR transcatheter edge-to-edge repair system.

Methods: EXPAND is a prospective, multicenter, international, single-arm study that enrolled patients with primary MR and secondary MR at 57 centers.

View Article and Find Full Text PDF
Article Synopsis
  • There is a significant variation in how different land models predict carbon dynamics, particularly in peatlands, which poses challenges for accurate climate change predictions.
  • A matrix approach was used to analyze and identify the reasons behind this variation, showing that differences in carbon residence time and environmental factors were key contributors to discrepancies among models.
  • Despite models generally recognizing the negative impact of warming on net ecosystem production (NEP), they incorrectly predicted responses to increased carbon dioxide levels, highlighting the complexities and limitations of current simulation models.
View Article and Find Full Text PDF

Background The current standard of care for the treatment of patients with primary mitral regurgitation (MR) is surgical mitral valve repair. Transcatheter edge-to-edge repair with the MitraClip device provides a less invasive treatment option for patients with both primary and secondary MR. Worldwide, >150 000 patients have been treated with the MitraClip device.

View Article and Find Full Text PDF

The perception of greater impact via new sinks, as opposed to through avoided emissions, has already led some large investors to focus on sink-related projects. This is a flawed perception when applied universally and carries a risk that effective routes to mitigation through avoiding emissions are side-lined. In reality, both emissions avoidance and emissions removal are needed, and both can be a cost-effective means of delivering mitigation.

View Article and Find Full Text PDF

Purpose Of Review: Percutaneous structural interventions have provided patients with an effective therapeutic option, and its growth has been aided by echocardiography. We describe the vital role that transesophageal echocardiography (TEE) plays in screening patients prior to their procedure.

Recent Findings: A multimodality imaging approach is employed by the valve team, but TEE plays a unique role in diagnosis and planning.

View Article and Find Full Text PDF

Aims: Mitral valve transcatheter edge-to-edge repair is a guideline-recommended treatment option for patients with secondary mitral regurgitation (SMR). The purpose of this analysis was to report contemporary real-world outcomes in SMR patients treated with third-generation MitraClip systems.

Methods And Results: EXPAND is a prospective, multicentre, international, single-arm study with 1041 patients treated for mitral regurgitation (MR) with MitraClip NTR/XTR, with 30-day and 1-year follow-up.

View Article and Find Full Text PDF

Accurate estimation and forecasts of net biome CO exchange (NBE) are vital for understanding the role of terrestrial ecosystems in a changing climate. Prior efforts to improve NBE predictions have predominantly focused on increasing models' structural realism (and thus complexity), but parametric error and uncertainty are also key determinants of model skill. Here, we investigate how different parameterization assumptions propagate into NBE prediction errors across the globe, pitting the traditional plant functional type (PFT)-based approach against a novel top-down, machine learning-based "environmental filtering" (EF) approach.

View Article and Find Full Text PDF
Article Synopsis
  • The 'Global Spectrum of Plant Form and Function Dataset' includes mean values for six key vascular plant traits, essential for understanding plant variation.
  • This dataset aggregates around 1 million trait records from the TRY database and other sources, encompassing 92,159 species mean values across 46,047 species.
  • Comprehensive data quality management and validation ensure this is the largest and most reliable collection of empirical data on vascular plant traits available.
View Article and Find Full Text PDF