Validation of 2D flow MRI for helical and vortical flows.

Purpose: The main objective of this study was to develop two-dimensional (2D) phase contrast (PC) methods to quantify the helicity and vorticity of blood flow in the aortic root.

Methods: This proof-of-concept study used four-dimensional (4D) flow cardiovascular MR (4D flow CMR) data of five healthy controls, five patients with heart failure with preserved ejection fraction and five patients with aortic stenosis (AS). A PC through-plane generated by 4D flow data was treated as a 2D PC plane and compared with the original 4D flow.

Aortic valve and left ventricular outflow tract calcium volume and distribution in transcatheter aortic valve replacement: Influence on the risk of significant paravalvular regurgitation.

Objectives: We sought to determine the impact of aortic root calcium on the risk of significant paravalvular regurgitation (sPAR) in transcatheter aortic valve replacement (TAVR).

Methods: In 302 consecutive patients from 3 centers, aortic root calcium was quantified volumetrically on pre-TAVR multidetector computed tomography (MDCT) in three regions: 1) the aortic valve region, 2) the overall left ventricular outflow tract (LVOT) and 3) the upper LVOT. Transcathether heart valve (THV) oversizing was calculated as (THV nominal area/MDCT annular area-1) × 100.

Donor Variability in Growth Kinetics of Healthy hMSCs Using Manual Processing: Considerations for Manufacture of Cell Therapies.

Human mesenchymal stromal cells (hMSCs) are excellent candidates for cell therapy but their expansion to desired clinical quantities can be compromised by ex vivo processing, due to differences between donor material and process variation. The aim of this article is to characterize growth kinetics of healthy baseline "reference" hMSCs using typical manual processing. Bone-marrow derived hMSCs from ten donors are isolated based on plastic adherence, expanded, and analyzed for their growth kinetics until passage 4.

Optimization of Axial Pump Characteristic Dimensions and Induced Hemolysis for Mechanical Circulatory Support Devices.

The application of axial pumps as ventricular assist devices (VADs) requires significant modifications to the size and characteristics of industrial pumps due to the difference in flow fields of industrial and medical pumps. Industrial pumps operate in the region of Reynolds number Re = 10, whereas axial blood pumps operate in Re < 10. The common pump design technique is to rely on the performance of previously designed pumps using the concept of fluid dynamic similarity.

Computational Parametric Study of the Axial and Radial Clearances in a Centrifugal Rotary Blood Pump.

In centrifugal rotary blood pumps (RBP), clearances are a critical parameter in determining blood trauma. This study investigates the effect of axial clearance (Cax) and radial clearance (Crad) on the hydrodynamic and hemolytic performance of a centrifugal RBP. A centrifugal pump was parameterized so that it could be defined by geometric variables Cax and Crad.

A quantitative, multi-national and multi-stakeholder assessment of barriers to the adoption of cell therapies.

Cellular therapies, such as stem cell-based treatments, have been widely researched and numerous products and treatments have been developed. Despite this, there has been relatively limited use of these technologies in the healthcare sector. This study sought to investigate the perceived barriers to this more widespread adoption.

One-year outcomes after successful chronic total occlusion percutaneous coronary intervention: The impact of dissection re-entry techniques.

We aimed to determine clinical outcomes 1 year after successful chronic total occlusion (CTO) PCI and, in particular, whether use of dissection and re-entry strategies affects clinical outcomes. Hybrid approaches have increased the procedural success of CTO percutaneous coronary intervention (PCI) but longer-term outcomes are unknown, particularly in relation to dissection and re-entry techniques. Data were collected for consecutive CTO PCIs performed by hybrid-trained operators from 7 United Kingdom (UK) centres between 2012 and 2014.

Impact of Oral Chlorhexidine on Bloodstream Infection in Critically Ill Patients: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Objectives: Oropharyngeal overgrowth of microorganisms in the critically ill is a risk factor for lower respiratory tract infection and subsequent invasion of the bloodstream. Oral chlorhexidine has been used to prevent pneumonia, but its effect on bloodstream infection never has been assessed in meta-analyses. The authors explored the effect of oral chlorhexidine on the incidence of bloodstream infection, the causative microorganism, and on all-cause mortality in critically ill patients.

Aligning the planets: The role of nurses in the care of patients with non-ST elevation myocardial infarction.

Background: Studies have shown variation in care for patients with non-ST elevation myocardial infarction (NSTEMI), including in the roles of specialist and advanced practice nurses in diagnosis, treatment and coordination of care.

Aim: The aim of this study was to describe the roles and responsibilities of specialist and advanced practice nurses in providing care for patients with NSTEMI.

Methods: Secondary analysis of observational field notes and interviews from an ethnographic study of variation in care for NSTEMI patients in 10 UK hospitals conducted 2011-2012.

In-vitro investigation of the hemodynamic responses of the cerebral, coronary and renal circulations with a rotary blood pump installed in the descending aorta.

This study investigates the hemodynamic responses of the cardiovascular system when a rotary blood pump is operating in the descending aorta, with a focus on the cerebral, coronary and renal autoregulation, using our in-house cardiovascular emulator. Several improvements have been made from our previous studies. A novel coronary system was developed to replicate the native coronary perfusion.

The Effect of Geometry on the Efficiency and Hemolysis of Centrifugal Implantable Blood Pumps.

The application of centrifugal pumps as heart assist devices imposes design limitations on the impeller geometry. Geometry and operating parameters will affect the performance and the hemocompatibility of the device. Among all the parameters affecting the hemocompatibility, pressure, rotational speed, blade numbers, angle, and width have significant impact on the blood trauma.

Cocoa flavanols reduce N-terminal pro-B-type natriuretic peptide in patients with chronic heart failure.

Aims: Poor prognosis in chronic heart failure (HF) is linked to endothelial dysfunction for which there is no specific treatment currently available. Previous studies have shown reproducible improvements in endothelial function with cocoa flavanols, but the clinical benefit of this effect in chronic HF has yet to be determined. Therefore, the aim of this study was to assess the potential therapeutic value of a high dose of cocoa flavanols in patients with chronic HF, by using reductions in N-terminal pro-B-type natriuretic peptide (NT-proBNP) as an index of improved cardiac function.

Optimization of Centrifugal Pump Characteristic Dimensions for Mechanical Circulatory Support Devices.

The application of artificial mechanical pumps as heart assist devices impose power and size limitations on the pumping mechanism, and therefore requires careful optimization of pump characteristics. Typically new pumps are designed by relying on the performance of other previously designed pumps of known performance using concepts of fluid dynamic similarity. Such data are readily available for industrial pumps, which operate in Reynolds numbers region of 10.

Hybrid approach improves success of chronic total occlusion angioplasty.

Objectives: Treatment options for coronary chronic total occlusions (CTO) are limited, with low historical success rates from percutaneous coronary intervention (PCI). We report procedural outcomes of CTO PCI from 7 centres with dedicated CTO operators trained in hybrid approaches comprising antegrade/retrograde wire escalation (AWE/RWE) and dissection re-entry (ADR/RDR) techniques.

Methods: Clinical and procedural data were collected from consecutive unselected patients with CTO between 2012 and 2014.