Repeatability of fractional flow reserve despite variations in systemic and coronary hemodynamics

Objectives This study classified and quantified the variation in fractional flow reserve (FFR) due to fluctuations in systemic and coronary hemodynamics during intravenous adenosine infusion. Background Although FFR has become a key invasive tool to guide treatment, questions remain regarding its repeatability and stability during intravenous adenosine infusion because of systemic effects that can alter driving pressure and heart rate. Methods We reanalyzed data from the VERIFY (VERification of Instantaneous Wave-Free Ratio and Fractional Flow Reserve for the Assessment of Coronary Artery Stenosis Severity in EverydaY Practice) study, which enrolled consecutive patients who were infused with intravenous adenosine at 140 μg/kg/min and measured FFR twice. Raw phasic pressure tracings from the aorta (Pa) and distal coronary artery (Pd) were transformed into moving averages of Pd/Pa. Visual analysis grouped Pd/Pa curves into patterns of similar response. Quantitative analysis of the Pd/Pa curves identified the “smart minimum” FFR using a novel algorithm, which was compared with human core laboratory analysis. Results A total of 190 complete pairs came from 206 patients after exclusions. Visual analysis revealed 3 Pd/Pa patterns: “classic” (sigmoid) in 57%, “humped” (sigmoid with superimposed bumps of varying height) in 39%, and “unusual” (no pattern) in 4%. The Pd/Pa pattern repeated itself in 67% of patient pairs. Despite variability of Pd/Pa during the hyperemic period, the “smart minimum” FFR demonstrated excellent repeatability (bias −0.001, SD 0.018, paired p = 0.93, r2 = 98.2%, coefficient of variation = 2.5%). Our algorithm produced FFR values not significantly different from human core laboratory analysis (paired p = 0.43 vs. VERIFY; p = 0.34 vs. RESOLVE). Conclusions Intravenous adenosine produced 3 general patterns of Pd/Pa response, with associated variability in aortic and coronary pressure and heart rate during the hyperemic period. Nevertheless, FFR – when chosen appropriately – proved to be a highly reproducible value. Therefore, operators can confidently select the “smart minimum” FFR for patient care. Our results suggest that this selection process can be automated, yet comparable to human core laboratory analysis

Phasic pressure measurements for coronary and valvular interventions using fluid-filled catheters: Errors, automated correction, and clinical implications.

We sought to develop an automatic method for correcting common errors in phasic pressure tracings for physiology-guided interventions on coronary and valvular stenosis. Effective coronary and valvular interventions rely on accurate hemodynamic assessment. Phasic (subcycle) indexes remain intrinsic to valvular stenosis and are emerging for coronary stenosis. Errors, corrections, and clinical implications of fluid-filled catheter phasic pressure assessments have not been assessed in the current era of ubiquitous, high-fidelity pressure wire sensors. We recruited patients undergoing invasive coronary physiology assessment. Phasic aortic pressure signals were recorded simultaneously using a fluid-filled guide catheter and 0.014″ pressure wire before and after standard calibration as well as after pullback. We included additional subjects undergoing hemodynamic assessment before and after transcatheter aortic valve implantation. Using the pressure wire as reference standard, we developed an automatic algorithm to match phasic pressures. Removing pressure offset and temporal shift produced the largest improvements in root mean square (RMS) error between catheter and pressure wire signals. However, further optimization <1 mmHg RMS error was possible by accounting for differential gain and the oscillatory behavior of the fluid-filled guide. The impact of correction was larger for subcycle (like systole or diastole) versus whole-cycle metrics, indicating a key role for valvular stenosis and emerging coronary pressure ratios. When calibrating phasic aortic pressure signals using a pressure wire, correction requires these parameters: offset, timing, gain, and oscillations (frequency and damping factor). Automatically eliminating common errors may improve some clinical decisions regarding physiology-based intervention

Identification of optimal assisted aspiration conditions of oocytes for use in porcine in vitro maturation: a re-evaluation of the relationship between the cumulus oocyte complex and oocyte quality

The quality of porcine oocytes for use in IVF is commonly graded according to the number of layers of cumulus cells surrounding the oocyte; together these form the cumulus oocyte complex (COC). At least three compact layers of cumulus cells is regarded as important for efficient IVP. To test this, oocytes were scored according to cumulus investment, with grade A representing COCs with three or more cumulus layers including granulosa cell-cumulus oocyte complexes, grade B those with an intact corona radiata surrounded by another layer of cumulus cells and grades C and D representing COCs with lower cumulus cell investment. These oocytes were then monitored for in vitro maturation (IVM), as assessed by tubulin immunostaining for meiotic progression, the development of a cortical granule ring, and by glutathione levels. Results indicate that grading correlates closely with nuclear maturation and cytoplasmic maturation, suggesting that grading oocytes by cumulus investment is a reliable method to predict IVM success. Importantly, Grade A and B oocytes showed no significant differences in any measure and hence using a cut-off of two or more cumulus cell layers may be optimal. We also determined the effect of assisted aspiration for oocyte retrieval, comparing the effect of needle size and applied pressure on the retrieval rate. These data indicated that both variables affected oocyte recovery rates and the quality of recovered oocytes. In combination, these experiments indicate that grade A and B oocytes have a similar developmental potential and that the recovery of oocytes of these grades is maximised by use of an 18-gauge needle and 50mmHg aspiration pressure

Self-help interventions for anxiety disorders: An overview.

Anxiety disorders are highly prevalent and are associated with a marked impairment in quality of life and a huge economic cost to society. Unfortunately, a considerable number of people who struggle with anxiety do not seek or receive adequate treatment. Self-help interventions have been proposed to constitute a relatively cheap, effective, efficient, and low-threshold intervention for anxiety disorders. This paper offers a critical discussion of their advantages and disadvantages and the evidence for their effectiveness. We conclude that guided self-help can play a major role in mental health care for patients with anxiety disorders. However, several research questions need to be answered before broad-scale dissemination is possible. The Internet will continue to play a prominent role in the further development of this field of research and clinical practice

Acceptance and commitment therapy for late-life treatment-resistant generalised anxiety disorder: a feasibility study.

Background Generalised anxiety disorder (GAD) is the most common anxiety disorder in older people. First-line management includes pharmacological and psychological therapies, but many do not find these effective or acceptable. Little is known about how to manage treatment-resistant generalised anxiety disorder (TR-GAD) in older people. Objectives To examine the acceptability, feasibility and preliminary estimates of the effectiveness of acceptance and commitment therapy (ACT) for older people with TR-GAD. Participants People aged ≥65 years with TR-GAD (defined as not responding to GAD treatment, tolerate it or refused treatment) recruited from primary and secondary care services and the community. Intervention Participants received up to 16 one-to-one sessions of ACT, developed specifically for older people with TR-GAD, in addition to usual care. Measurements Co-primary outcomes were feasibility (defined as recruitment of ≥32 participants and retention of ≥60% at follow-up) and acceptability (defined as participants attending ≥10 sessions and scoring ≥21/30 on the satisfaction with therapy subscale). Secondary outcomes included measures of anxiety, worry, depression and psychological flexibility (assessed at 0 and 20 weeks). Results Thirty-seven participants were recruited, 30 (81%) were retained and 26 (70%) attended ≥10 sessions. A total of 18/30 (60%) participants scored ≥21/30 on the satisfaction with therapy subscale. There was preliminary evidence suggesting that ACT may improve anxiety, depression and psychological flexibility. Conclusions There was evidence of good feasibility and acceptability, although satisfaction with therapy scores suggested that further refinement of the intervention may be necessary. Results indicate that a larger-scale randomised controlled trial of ACT for TR-GAD is feasible and warranted

A randomised controlled trial of acceptance and commitment therapy plus usual care compared to usual care alone for improving psychological health in people with motor neuron disease (COMMEND): study protocol

Background Motor neuron disease (MND) is a rapidly progressive, fatal neurodegenerative disease that predominantly affects motor neurons from the motor cortex to the spinal cord and causes progressive wasting and weakening of bulbar, limb, abdominal and thoracic muscles. Prognosis is poor and median survival is 2–3 years following symptom onset. Psychological distress is relatively common in people living with MND. However, formal psychotherapy is not routinely part of standard care within MND Care Centres/clinics in the UK, and clear evidence-based guidance on improving the psychological health of people living with MND is lacking. Previous research suggests that Acceptance and Commitment Therapy (ACT) may be particularly suitable for people living with MND and may help improve their psychological health. Aims To assess the clinical and cost-effectiveness of ACT modified for MND plus usual multidisciplinary care (UC) in comparison to UC alone for improving psychological health in people living with MND. Methods The COMMEND trial is a multi-centre, assessor-blind, parallel, two-arm RCT with a 10-month internal pilot phase. 188 individuals aged ≥ 18 years with a diagnosis of definite, laboratory-supported probable, clinically probable, or possible familial or sporadic amyotrophic lateral sclerosis, and additionally the progressive muscular atrophy and primary lateral sclerosis variants, will be recruited from approximately 14 UK-based MND Care Centres/clinics and via self-referral. Participants will be randomly allocated to receive up to eight 1:1 sessions of ACT plus UC or UC alone by an online randomisation system. Participants will complete outcome measures at baseline and at 6- and 9-months post-randomisation. The primary outcome will be quality of life at six months. Secondary outcomes will include depression, anxiety, psychological flexibility, health-related quality of life, adverse events, ALS functioning, survival at nine months, satisfaction with therapy, resource use and quality-adjusted life years. Primary analyses will be by intention to treat and data will be analysed using multi-level modelling. Discussion This trial will provide definitive evidence on the clinical and cost-effectiveness of ACT plus UC in comparison to UC alone for improving psychological health in people living with MND

Modelling thirty-day mortality in the acute respiratory distress syndrome (ARDS) in an adult ICU

Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsVariables predicting thirty-day outcome from Acute Respiratory Distress Syndrome (ARDS) were analysed using Cox regression structured for time-varying covariates. Over a three-year period, 1996-1998, consecutive patients with ARDS (bilateral chest X-ray opacities, PaO₂/FiO₂ ratio of <200 and an acute precipitating event) were identified using a prospective computerized data base in a university teaching hospital ICU. The cohort, 106 mechanically ventilated patients, was of mean (SD) age 63.5 (15.5) years and 37% were female. Primary lung injury occurred in 45% and 24% were postoperative. ICU-admission day APACHE II score was 25 (8); ARDS onset time from ICU admission was 1 day (median: range 0-16) and 30 day mortality was 41% (95% CI: 33%-51%). At ARDS onset, PaO₂/FiO₂ ratio was 92 (31), 81% had four-quadrant chest X-ray opacification and lung injury score was 2.75 (0.45). Average mechanical ventilator tidal volume was 10.3 ml/ predicted kg weight. Cox model mortality predictors (hazard ratio, 95% CI) were: APACHE II score, 1.15 (1.09-1.21); ARDS lag time (days), 0.72 (0.58-0.89); direct versus indirect injury, 2.89 (1.45-5.76); PaO₂/FiO₂ ratio, 0.98 (0.97-0.99); operative versus non-operative category, 0.24 (0.09-0.63). Time-varying effects were evident for PaO₂/FiO₂ ratio, operative versus non-operative category and ventilator tidal volume assessed as a categorical predictor with a cut-point of 8 ml/kg predicted weight (mean tidal volumes, 7.1 (1.9) vs 10.7 (1.6) ml/kg predicted weight). Thirty-day survival was improved for patients ventilated with lower tidal volumes. Survival predictors in ARDS were multifactorial and related to patient-injury-time interaction and level of mechanical ventilator tidal volume.J. L. Moran, P. J. Solomon, V. Fox, M. Salagaras, P. J. Williams, K. Quinlan, A. D. Berstenhttp://www.aaic.net.au/Article.asp?D=200332

What Drives Fitness Apps Usage? An Empirical Evaluation

Part 3: Creating Value through ApplicationsInternational audienceThe increased health problems associated with lack of physical activity is of great concern around the world. Mobile phone based fitness applications appear to be a cost effective promising solution for this problem. The aim of this study is to develop a research model that can broaden understanding of the factors that influence the user acceptance of mobile fitness apps. Drawing from Unified Theory of Acceptance and Use of Technology (UTAUT) and Elaboration Likelihood Model (ELM), we conceptualize the antecedents and moderating factors of fitness app use. We validate our model using field survey. Implications for research and practice are discussed