Pilot Programs in Medical Research

Scientific Reports - Prediction of corneal graft rejection using central endothelium/Descemet’s membrane complex thickness in high-risk corneal transplants

Objectives This study aimed to investigate the performance of computed tomography derived fractional flow reserve based interactive planner (FFRCT planner) to predict the physiological benefits of p...

Fractional flow reserve (FFR) is a technique to evaluate the hemodynamic relevance of coronary artery stenoses 1,2. It is defined as "the ratio of maximal flow achievable in the stenotic coronary artery to the maximal flow achievable in the same ...

Background Coronary CT angiography with noninvasive fractional flow reserve (FFR) predicts lesion-specific ischemia when compared with invasive FFR. The longer term prognostic value of CT-derived FFR (FFRCT) is unknown. Purpose To determine the prognostic value of FFRCT when compared with coronary CT angiography and describe the relationship of the numeric value of FFRCT with outcomes. Materials and Methods This prospective subanalysis of the NXT study (Clinicaltrials.gov: NCT01757678) evaluated participants suspected of having stable coronary artery disease who were referred for invasive angiography and who underwent FFR, coronary CT angiography, and FFRCT. The incidence of the composite primary end point of death, myocardial infarction, and any revascularization and the composite secondary end point of major adverse cardiac events (MACE: cardiac death, myocardial infarction, unplanned revascularization) were compared for an FFRCT of 0.8 or less versus stenosis of 50% or greater on coronary CT angiograms, with treating physicians blinded to the FFRCT result. Results Long-term outcomes were obtained in 206 individuals (age, 64 years ± 9.5), including 64% men. At median follow-up of 4.7 years, there were no cardiac deaths or myocardial infarctions in participants with normal FFRCT. The incidence of the primary end point was more frequent in participants with positive FFRCT compared with clinically significant stenosis at coronary CT angiography (73.4% [80 of 109] vs 48.7% [91 of 187], respectively; P < .001), with the majority of outcomes being planned revascularization. Corresponding hazard ratios (HRs) were 9.2 (95% confidence interval [CI]: 5.1, 17; P < .001) for FFRCT and 5.9 (95% CI: 1.5, 24; P = .01) for coronary CT angiography. FFRCT was a superior predictor compared with coronary CT angiography for primary end point (C-index FFRCT, 0.76 vs coronary CT angiography, 0.54; P < .001) and MACE (FFRCT, 0.71 vs coronary CT angiography, 0.52; P = .001). Frequency of MACE was higher in participants with positive FFRCT compared with coronary CT angiography (15.6% [17 of 109] vs 10.2% [19 of 187], respectively; P = .02), driven by unplanned revascularization. MACE HR was 5.5 (95% CI: 1.6, 19; P = .006) for FFRCT and 2.0 (95% CI: 0.3, 14; P = .46) for coronary CT angiography. Each 0.05-unit FFRCT reduction was independently associated with greater incidence of primary end point (HR, 1.7; 95% CI: 1.4, 1.9; P < .001) and MACE (HR, 1.4; 95% CI: 1.1, 1.8; P < .001). Conclusion In stable patients referred for invasive angiography, a CT-derived fractional flow reserve (FFRCT) value of 0.8 or less was a predictor of long-term outcomes driven by planned and unplanned revascularization and was superior to clinically significant stenosis on coronary CT angiograms. Additionally, the numeric value of FFRCT was an independent predictor of outcomes. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Dennie and Rubens in this issue.

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Invasive fractional flow reserve (FFR) is the gold standard to assess the functional coronary stenosis. The non-invasive assessment of diameter stenosis (DS) using coronary computed tomography angiography (CTA) has high false positive rate in contrast to FFR. Combining CTA with computational fluid dynamics (CFD), recent studies have shown promising predictions of FFRCT for superior assessment of lesion severity over CTA alone. The CFD models tend to be computationally expensive, however, and require several hours for completing analysis. Here, we introduce simplified models to predict noninvasive FFR at substantially less computational time. In this retrospective pilot study, 21 patients received coronary CTA. Subsequently a total of 32 vessels underwent invasive FFR measurement. For each vessel, FFR based on steady-state and analytical models (FFRSS and FFRAM, respectively) were calculated non-invasively based on CTA and compared with FFR. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value were 90.6% (87.5%), 80.0% (80.0%), 95.5% (90.9%), 88.9% (80.0%) and 91.3% (90.9%) respectively for FFRSS (and FFRAM) on a per-vessel basis, and were 75.0%, 50.0%, 86.4%, 62.5% and 79.2% respectively for DS. The area under the receiver operating characteristic curve (AUC) was 0.963, 0.954 and 0.741 for FFRSS, FFRAM and DS respectively, on a per-patient level. The results suggest that the CTA-derived FFRSS performed well in contrast to invasive FFR and they had better diagnostic performance than DS from CTA in the identification of functionally significant lesions. In contrast to FFRCT, FFRSS requires much less computational time.

Phoenix, Arizona--(Newsfile Corp. - July 16, 2021) - The Stock Day Podcast welcomed Pressure BioSciences, Inc. (OTCQB: PBIO) ("the Company"),...

Fractional flow reserve is the gold standard for assessing the haemodynamic significance of intermediate coronary artery stenoses. Cumulative evidence has shown that FFR-guided revascularisation reduces stent implantations and improves patient outcomes. However, despite the wealth of evidence and guideline recommendations, its use in clinical practice remains minimal. Patient and technical limitations of FFR as well as the need for intracoronary instrumentation, use of adenosine, and increased costs have limited FFR&#x2019;s applicability in clinical practice. Over the last decade, several angiography-derived FFR software packages have been developed which do not require intracoronary pressure assessment with a guidewire or need for administration of hyperaemic agents. At present, there are 3 commercially available software packages and several other non-commercial technologies that have been described in the literature. These technologies have been validated against invasive FFR showing good accuracy and correlation. However, the methodology behind these solutions is different&#x2014;some algorithms are based on solving the governing equations of fluid dynamics such as the Navier&#x2013;Stokes equation while others have opted for a more simplified mathematical formula approach. The aim of this review is to critically appraise the methodology behind all the known angiography-derived FFR technologies highlighting the key differences and limitations.

Describes the changes to the default dynamic port range for TCP/IP in Windows Vista and in Windows Server 2008. Also describes commands that you can use to modify or show the dynamic port range for TCP/IP ports.

### Learning objectives Coronary computed tomographic angiography (CTA) is now established as a clinically valuable non-invasive anatomical test for the detection and exclusion of significant coronary disease. A number of prospective multicentre trials have shown coronary CTA to be an ideal test for the exclusion and detection of coronary disease using invasive angiography as the reference.1–3 Despite this, owing to its relatively low positive predictive value of 48% and inability to determine functional significance,1 its use in international guidelines has generally been restricted to patients with chest pain at a low-intermediate risk of having coronary artery disease (CAD).4 For patients at an intermediate risk of CAD, functional testing is generally indicated, and for high-risk patients, invasive coronary angiography (ICA) remains the recommended diagnostic test. Although this strategy is designed to determine whether a patient’s symptoms are attributable to CAD, and specifically myocardial ischaemia, recent studies indicate that this approach has important flaws. In a study of almost 400 000 patients, Patel et al showed that up to 62% of the patients who underwent ICA in the USA were subsequently found to have no significant obstructive disease. Furthermore, of those patients with a positive stress test, approximately two-thirds had no obstructive disease and, conversely, 28% of the patients with a negative stress …

There is a global need for trained researchers who can address the increasing burden of illness and injury and prepare future generations of researchers. Developing countries have a special need for practical, action-oriented interventions to address workplace problems, based on identification of ne …

The aim of the study was to analyze the dynamic changes and diagnostic and prognostic significance of serum procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP) and s-100 protein in central nervous system infection. A total of 110 patients ...