Changes in referral pathway and phenotypic status of patients diagnosed with ATTR cardiac amyloidosis during the past 20 years

Background

Diagnostic and therapeutic advances have led to much increased awareness of transthyretin (ATTR) cardiac amyloidosis (CA).

Purpose

We sought to characterise the impact of this on referral practice, cardiac phenotype at diagnosis and specifically to determine whether patients are now being diagnosed at an earlier stage in their disease process.

Methods

We studied 1845 patients diagnosed with ATTR-CA at the National Amyloidosis Centre (NAC) from 2002–2021, all of whom underwent deep clinical phenotyping and follow-up.

Results

Analysis by 5-year quartiles revealed a substantial incremental increase in patients diagnosed with ATTR-CA (35 vs 260 vs 704 vs 846), which was associated with greater proportions of patients referred following advanced cardiac imaging (referrals following cardiac magnetic resonance and bone scintigraphy: 3% vs 44% vs 67% vs 76%; P<0.001). Over time, median duration of symptoms prior to diagnosis diminished from 36-months between 2002–2006 to 12-months between 2017–2021 (P<0.001) and a greater proportion of patients presented with milder disease across the 5-yearly quartiles (NAC stage 1: 40% vs 43% vs 44% vs 57%; P<0.001). The latter was associated with more favourable echocardiographic parameters of structure and function, including an incremental reduction in maximal left ventricular wall thickness (18.26mm vs 17.41mm vs 17.09mm vs 16.68mm; P=0.017). This was associated with improved survival in the overall population (2007–2011 vs 2012–2016: HR=1.65, 95% CI [1.33–2.06]; P<0.001 and 2012–2016 vs 2017–2021: HR =1.83, 95% CI [1.45–2.31]; P<0.001) and in each genotype (wtATTR, T60A and V122I). Despite a significant increase in the proportion of patients enrolled into clinical trials (0.0% vs 0.0% vs 2.6% vs 23.9%; P<0.001) and prescribed disease modifying therapy (5.7% vs 0.4% vs 4.8% vs 13.5%; P<0.001); the improved survival remained significant even after adjusting for clinical trials and disease modifying therapy (2012–2016 vs. 2017–2021: HR=1.65 95% CI [1.29–2.11], P<0.001).

Conclusion

Increased awareness and advances in cardiac imaging have been associated with a substantial increase in the diagnosis of ATTR-CA and at a progressively earlier stage of the disease, which has contributed to improved survival in recent years. These changes may have important implications for initiation and outcome of therapy. Given that ATTR-CA is now being diagnosed earlier, more data are needed to guide decisions on in whom and when to initiate treatment, and which treatments should be used at each disease stage. Furthermore, the changes in ATTR-CA phenotype at diagnosis urgently need to be factored into clinical trial design, given that pre-determined end-points based on trials performed in the past may no longer be appropriate, or at least sufficiently powered, or of adequate duration to evaluate efficacy of novel agents.

Funding Acknowledgement

Type of funding sources: None.

Locomotor characteristics of horses with navicular disease

OBJECTIVE

To determine whether force-plate evaluation of horses with navicular disease would reveal an abnormal gait that persists despite loss of sensation to the palmar foot region, which may predispose such horses to navicular disease.

ANIMALS

17 clinically normal Thoroughbreds and 8 Thoroughbreds with navicular disease.

PROCEDURE

Data on ground reaction forces were obtained in trotting horses, using a force plate. Force-time curve variables for clinically normal horses were derived from 4 points at the beginning and 4 points at the end of the vertical and craniocaudal horizontal plots. Principal component analysis was undertaken separately on beginning-of-stride and end-of-stride data, and the first 2 components were represented graphically. Rotation matrices were applied to equivalent data for horses with navicular disease before and after disruption of sensation by administration of a palmar digital nerve blockade.

RESULTS

Prior to nerve block, horses with navicular disease differed significantly from normal horses for beginning-of-stance phase and end-of-stance phase variables. After nerve block, horses with navicular disease maintained the same significant differences from clinically normal horses only for variables at the beginning-of-stance phase.

CONCLUSIONS AND CLINICAL RELEVANCE

Horses with navicular disease have abnormal limb-loading force patterns that are not altered by loss of sensation in the palmar region. These abnormal patterns were detected in a horse without navicular disease. Some horses are predisposed to navicular disease as a result of an inherent abnormal gait pattern. Analysis of gait patterns could be used for detection and appropriate management of horses susceptible to development of navicular disease.

Effects of mercury on health and first-year survival of free-ranging great egrets (Ardea albus) from southern Florida

The objectives of this study were to determine whether elevated mercury (Hg) concentrations have a negative impact on the health and survival of nestling and juvenile free-ranging great egrets (Ardea albus) from southern Florida. During 1994, when health and survival was monitored in a cohort of young birds with naturally variable concentrations of Hg, packed cell volume was positively correlated with blood Hg concentrations, and high Hg concentration in blood was not related to the probability of surviving during the first 10.5 months of life. During 1995, 70 first-hatched great egret chicks were included in a Hg field-dosing experiment to compare the effects of elevated Hg on health and survival. Birds were dosed while in the nest orally every 2.5 days for 15 days with 0.5 mg of methyl mercury chloride (MeHgCl) for an estimated intake of 1.54 mg MeHgCl/kg food intake. These birds were compared with controls, which received an estimated 0.41 mg MeHgCl/kg food. No differences were observed in health parameters or in the probability of surviving during the first 8 months of age between egrets that were dosed with Hg and those that were not. A likely explanation for the lack of any effects on health and survival between both groups could be that chicks at this age were eliminating most of the dietary Hg through the production of new feathers.

Disease-specific changes in equine ground reaction force data documented by use of principal component analysis

OBJECTIVE

To assess the force plate as a diagnostic aid in equine locomotor abnormalities, particularly for abnormalities such as navicular disease that do not have specific diagnostic criteria.

ANIMALS

17 Thoroughbreds without observable locomotor abnormalities (group A), 6 Thoroughbreds with superficial digital flexor tendon injury (group B), and 8 Thoroughbreds with navicular disease (group C).

PROCEDURE

Using a force plate, ground reaction force patterns were recorded at the trot. Peak limb vertical force and force/time curve parameters were derived from 4 identifiable points at the beginning and end of vertical and craniocaudal horizontal plots. Principal component analysis (PCA) of group-A data was undertaken on beginning and end of stride data, and the first 2 components were represented graphically. The PCA rotation matrices were applied to equivalent data for horses of groups B and C.

RESULTS

Asymmetry of peak vertical force (PVF) could not be differentiated among groups A, B, and C. Values for group-B horses, however, were significantly outside mean group-A values on the PCA plot for beginning of stride phase variables. Group-B data were within the group-A range for end of stride phase variables. Values for group-C horses were significantly outside the group-A range for beginning of stride phase variables and were outside mean group-A values for end of stride phase variables.

CONCLUSIONS

PCA of force/time data provides a sensitive method to evaluate the force/time curve associated with 2 specific injury/disease processes.

CLINICAL RELEVANCE

Horses alter weight-bearing in biomechanically distinct ways, thus creating potential for the force plate to become an important diagnostic and prognostic tool.

The d-wave of the rod electroretinogram of rat originates in the cone pathway

We studied the off-response of the rat ERG evoked with long duration, mesopic stimuli during light and dark adaptation, and after intravitreal injection of aspartate and (+/-)-cis-piperidine-2,3-dicarboxylic acid (PDA). At stimulus offset, the dark-adapted ERG always showed a rapid negative deflection followed by a positive deflection after which the potential returned to baseline. When the stimulus was turned off in the presence of a background of scotopic intensity, the positive deflection consisted of two components. One component was relatively small, fast, and insensitive to rod light adaptation. It resembled the d-wave of the rod ERG. The other component was slow and its amplitude grew with rod light adaptation. In the presence of aspartate, the fast-positive component was absent from the ERG while the remaining positive-going decay of the receptor potential had a time course similar to that of the slow-positive component in the untreated eye. Scotopically matched red and blue stimuli of mesopic intensity elicited equal ERG responses from the dark-adapted eye, including the two positive components in the off-response. These stimuli were also used to assess changes in the ERG off-response during recovery from a strong bleach. Even though the cone contribution to the rat ERG is very small, the presence of a small positive-going component in the off-response following an intense bleach suggested that this response originated from the cone pathway. PDA which suppresses the light response of hyperpolarizing bipolar cells and horizontal cells selectively eliminated the fast-positive component from the ERG. The findings of this study are inconsistent with the idea that the d-wave reflects the decay of the rod receptor potential. They support the possibility that signals from rods cross rod-cone gap junctions at mesopic light intensities, and drive second-order neurons in the cone pathway.

Disciplining young children: the role of verbal instructions and reasoning

Pediatricians are often asked to advise parents who are having difficulty managing the oppositional behaviors of their toddlers and preschool-age children. A large number of articles provide advice to pediatricians and parents on effective disciplinary strategies. However, despite the fact that verbal explanations, reasoning, and instructions are commonly used by parents, few articles directly address the use of these strategies to affect children's behavior. In this paper, we review studies that explicitly investigate the ability of adults' verbal explanations or instructions to alter the behavior of young children. These studies suggest that under most circumstances, verbal explanations and instructions are not effective in changing young children's problem behaviors. We then discuss how theories in developmental and behavioral psychology help explain the limitations of using verbal reasoning and instructions to change young children's problem behaviors. Finally, we provide some recommendations for parents on the use of verbal explanations and instructions in disciplining young children.

Pediatric feeding disorders

Feeding problems occur in children who have normal development, who have failure to thrive, and who have developmental disabilities. This article focuses on the latter two groups. The characteristics and developmental concerns include family characteristics, parent-child interactions, cognitive development, and oral-motor development. The evaluation process for children with feeding problems should include an interdisciplinary approach with a medical, nutritional, occupational therapy, and behavioral evaluation. The behavioral treatments include the Premack principle, time-out plus reinforcement, and negative reinforcement. Future research should focus on the parent-child interaction process in both mealtime and nonmealtime situations, along with demonstrating parents' and teachers' ability to implement mealtime treatment protocols.

The effect of chlamydial infection on the initiation of premature labour: serial measurements of intrauterine prostaglandin E2 in amniotic fluid, allantoic fluid and utero-ovarian vein, using catheterised sheep experimentally infected with an ovine abortion strain of Chlamydia psittaci

The initiation of premature labour by an ovine abortion strain of Chlamydia psittaci was studied in relation to Prostaglandin E2 (PGE2), which plays a major role in parturition. The local intrauterine concentration of PGE2 was monitored after experimental infection with C. psittaci, during late gestation, using a catheterised sheep model. Indwelling catheters were implanted into the amniotic and allantoic cavities of six control sheep, and into six sheep infected with an ovine abortion of C. psittaci. The release of PGE2 into the utero-ovarian vein of these sheep was also monitored. Infection with C. psittaci was associated with a premature rise in PGE2 in the amniotic fluid between days 122 and 135 of gestation (P less than 0.01). A premature increase in PGE2 was defected between days 127 and 136 of gestation (P less than 0.05) in the allantoic fluid of sheep infected with C. psittaci, but not in the control uninfected sheep. Chlamydial infection significantly decreased the secretion of PGE2 into the utero-ovarian vein. The mean concentration of PGE2 in the utero-ovarian vein of infected sheep was 68.8 +/- 5.2% of the PGE2 concentration of control sheep between days 122 to 141 of gestation (P less than 0.01). The release of PGE2 into the utero-ovarian vein increased between days 126 to 136 of gestation in infected and control sheep (P less than 0.01). The results from the catheterised sheep model indicated that C. psittaci infection is associated with a local intrauterine release of PGE2. The magnitude of this release was similar to the PGE2 release in control sheep prior to parturition.(ABSTRACT TRUNCATED AT 250 WORDS)

The Acraman Impact Structure: Source of Ejecta in Late Precambrian Shales, South Australia

A major probable impact structure occurs in middle Proterozoic dacitic volcanics in the Gawler Ranges, central South Australia. The structure has an inner depressed area about 30 kilometers in diameter that contains the Lake Acraman salina, an intermediate depression or ring about 90 kilometers in diameter, and a possible outer ring approximately 160 kilometers in diameter. Outcrops of dacite in Lake Acraman are intensely shattered and contain shatter cones and multiple sets of shock lamellac in quartz grains. The Acraman structure is the largest probable impact structure known in Australia and is the likely source of dacitic ejecta found in late Precambrian marine shales some 300 kilometers to the east.

Training apartment upkeep skills to rehabilitation clients: a comparison of task analytic strategies

The research was designed to validate procedures to teach apartment upkeep skills to severely handicapped clients with various categorical disabilities. Methodological features of this research included performance comparisons between general and specific task analyses, effect of an impasse correction baseline procedure, social validation of training goals, natural environment assessments and contingencies, as well as long-term follow-up. Subjects were taught to perform upkeep responses on their air conditioner-heating unit, electric range, refrigerator, and electrical appliances within the context of a multiple-probe across subjects experimental design. The results showed acquisition, long-term maintenance, and generalization of the upkeep skills to a nontraining apartment. General task analyses were recommended for assessment and specific task analyses for training. The impasse correction procedure generally did not produce acquisition.

Solar Affinity of Sedimentary Cycles in the Late Precambrian Elatina Formation

Climatic cyclicity is recorded by regular variations in the thickness of siltstone-fine sandstone laminae interpreted as annual deposits (varves) within the Elatina Formation, a late Precambrian ( - 680 million years old) periglacial lake deposit in the Flinders Ranges, South Australia. Earlier conclusions, based on the study of limited rock outcrop, that the climatic cycles reflect solar variability are strongly supported by a complexity of periods revealed through study of drill cores of the - 10 m thick varved sequence. The wealth of new data generated by the drilling program, which was CSIRO-sponsored largely because of the support of R. G. Giovanelli, has application to solar physics and solar-planetary science.

Effects of transporting cows various distances on liveweight, carcase traits and muscle pH

Two experiments in Queensland in 1979 examined the ettect on liveweight, carcase weight, bruising and muscle pH of transporting cows 460,870 or 2055 km to three abattoirs for slaughter. Resting, feeding and watering procedures at the abattoirs were based on commercial practices in experiment 1, but were standardized in experiment 2. The effect of transportation alone was studied in experiment 1, by holding additional cattle at the nearest abattoir and slaughtering them on the same day as the group transported 2055 km. All cows came from the same property. The greatest losses in liveweight occurred before cows reached the first abattoir. In experiment 1, mean initial liveweight decreased from 439 to 398 kg for cows travelling 460 km and to 390 kg after 2055 km. In experiment 2, the decreases were 434 to 389 and 375 kg, respectively. It was concluded that time between mustering and slaughter had a greater effect on carcase weight than distance travelled. Between three and eight days after mustering in experiment 1, carcase weight decreased from 230 to 225 kg, whether cows were travelling or held at an abattoir. Between 4.5 and 11 d in experiment 2, the decrease was from 226 to 21 9 kg. Carcase bruising increased when travelling distance exceeded 460 km, but the increase was small relative to losses in carcase weiaht. The DH of M. longissimus dorsi 24 h post-mortem did not increase necessarily with distance travelled.

Belt-Flexing Test of the Du Pont Type

In general, flexing tests are subject to large errors, some of which have been studied using a test of the du Pont belt type. An improvement in the standardization of the test conditions can be effected by using a suitably designed belt balance arm and regularly adjusting the length of the belt. The rate of cracking and also the reproducibility of the results is affected by the design of the test-piece and also by the type of fastener used. Although the error between the results on replicate test-pieces is extremely large, more important are the large errors due to lack of reproducibility of replicate molded slabs, and this variability probably arises during vulcanization. Extremely large differences can also occur between nominally identical repeat experiments. This may be due to differences in the judgment of the stages of cracking in different experiments. Graded photographs were found not to be of any value in improving the reproducibility of results between two different operators. Attention is drawn to the differences in types of cracking obtained with the du Pont and De Mattia test-pieces. It is pointed out that with the du Pont test-piece the cracking tends to develop in depth more than is the case with the De Mattia, and therefore it is more difficult to construct or use graded photographs with the du Pont test. Accepting the fact that variations in the disposition of the stages of cracking do occur between two different experiments, a method of treating flex-cracking results graphically is suggested. By this method random variations in results are ignored and the average flex-cracking results obtained. It is suggested that flexing properties may be defined by two characteristics, viz., (1) Crack initiation time, and (2) Crack propagation time, and an example of the method of determining these characteristics is given.

Study of Bonded Units

The work was undertaken because no satisfactory and discriminating test is available for evaluating rubber-to-metal bonding agents. In former tests the testing of the bonding agent was confused with the testing of the test unit as a unit. A method was evolved which discriminated between bonding agents which had previously been regarded as equivalent. In the course of the work new facts such as the importance of the volume of the rubber rather than the shape factor (which must, of course be considered from the stability angle) came to light. The significance of the work lies in two directions—better testing of metal-to-rubber bonding agents and a better understanding of the facts underlying the design of rubber-metal spring units. A tentative method for measuring the tear strength of the rubber used in the unit was put forward.