4D display of CT LV endocardial and epicardial models morphed from PET Rb-82 perfusion studies accurately quantifies segmental myocardial thickening.

BACKGROUND: MPI-derived LV wall thickening assessments for diagnostic purposes has been part of clinical guidelines for two decades. It relies on visual evaluation of tomographic slices or regional quantification displayed in 2D polar maps. 4D displays have not entered clinical usage nor have they been validated on their potential to provide equivalent information. The purpose of this work was to validate a 4D realistic display recently designed to quantitatively represent the thickening information from gated MPI into CT-morphed endocardial and epicardial moving surfaces. METHODS: Forty patients who underwent 82Rb PET were selected based on LV perfusion quantification. CTA templates of heart anatomy were selected to represent the LV anatomy. Generic CT-derived LV endocardial and epicardial surfaces were modified to represent the end diastolic (ED) phase according to PET-derived ED LV dimensions and wall thickness. These CT myocardial surfaces were then morphed by means of thin plate spline (TPS) techniques, according to the gated PET slices count changes (WThPET) and LV wall motion (WMoPET). A geometric thickening (GeoTh) equivalent to LV WThPET was defined on epicardial and endocardial CT surfaces over the cardiac cycle and the two measures compared. WThPET and GeoTh correlations were performed on a case-by-case basis, by segment and by pooling all 17 segments. Pearson's correlation coefficients (PCC) were calculated to assess the equivalence of the two measures. RESULTS: Two cohorts of patients (normal and abnormal) were identified based on SSS. R coefficients were as follows: for all pooled segments PCCstress and PCCrest were respectively 0.91 and 0.89 (normal), and 0.9 and 0.91 (abnormal); when individual 17 segments were considered mean PCCstress = 0.92 [0.81-0.98] and mean PCCrest = 0.93 [0.83-0.98] for the abnormal perfusion group; mean PCCstress = 0.89 [0.78-0.97] and mean PCCrest = 0.89 [0.77-0.97] for the normal. When individual studies were considered, R was always > .70 with the exception of five abnormal studies. Inter-user analysis was also conducted. CONCLUSIONS: Our novel technique for the visualization of LV wall thickening by means of 4D CT endocardial and epicardial surface models accurately replicated 82Rb slice thickening results showing promise for its usage for diagnostic purposes.

Quantitation of diffuse myocardial ischemia with mental stress and its association with cardiovascular events in individuals with recent myocardial infarction.

Microcirculatory dysfunction during psychological stress may lead to diffuse myocardial ischemia. We developed a novel quantification method for diffuse ischemia during mental stress (dMSI) and examined its relationship with outcomes after a myocardial infarction (MI). We studied 300 patients ≤ 61 years of age (50% women) with a recent MI. Patients underwent myocardial perfusion imaging with mental stress and were followed for 5 years. dMSI was quantified from cumulative count distributions of rest and stress perfusion. Focal ischemia was defined in a conventional fashion. The main outcome was a composite outcome of recurrent MI, heart failure hospitalizations, and cardiovascular death. A dMSI increment of 1 standard deviation was associated with a 40% higher risk for adverse events (HR 1.4, 95% CI 1.2-1.5). Results were similar after adjustment for viability, demographic and clinical factors and focal ischemia. In sex-specific analysis, higher levels of dMSI (per standard deviation increment) were associated with 53% higher risk of adverse events in women (HR 1.5, 95% CI 1.2-2.0) but not in men (HR 0.9, 95% CI 0.5-1.4), P 0.001. A novel index of diffuse ischemia with mental stress was associated with recurrent events in women but not in men after MI.

Clinical implications of compromised 82Rb PET data acquisition.

BACKGROUND: We wished to document the prevalence and quantitative effects of compromised 82Rb PET data acquisitions on myocardial flow reserve (MFR). METHODS AND RESULTS: Data were analyzed retrospectively for 246 rest and regadenoson-stress studies of 123 patients evaluated for known or suspected CAD. An automated injector delivered pre-determined activities of 82Rb. Automated quality assurance algorithms identified technical problems for 7% (9/123) of patients. Stress data exhibited 2 instances of scanner saturation, 1 blood peak detection, 1 blood peak width, 1 gradual patient motion, and 2 abrupt patient motion problems. Rest data showed 1 instance of blood peak width and 2 abrupt patient motion problems. MFR was lower for patients with technical problems flagged by the quality assurance algorithms than those without technical problems (1.5 ± 0.5 versus 2.1 ± 0.7, P = 0.01), even though rest and stress ejection fraction, asynchrony and relative myocardial perfusion measures were similar for these two groups (P > 0.05), suggesting that MFR accuracy was adversely affected by technical errors. CONCLUSION: It is important to verify integrity of 82Rb data to ensure MFR computation quality.

Development, diagnostic performance, and interobserver agreement of a 18F-flurpiridaz PET automated perfusion quantitation system.

BACKGROUND: Computerized methodologies standardize the myocardial perfusion imaging (MPI) interpretation process. METHODS: To develop an automated relative perfusion quantitation approach for 18F-flurpiridaz, PET MPI studies from all phase III trial participants of 18F-flurpiridaz were divided into 3 groups. Count distributions were obtained in N = 40 normal patients undergoing pharmacological or exercise stress. Then, N = 90 additional studies were selected in a derivation group. Following receiver operating characteristic curve analysis, various standard deviations below the mean normal were used as cutoffs for significant CAD, and interobserver variability determined. Finally, diagnostic performance was compared between blinded visual readers and blinded derivations of automated relative quantitation in the remaining N = 548 validation patients. RESULTS: Both approaches yielded comparable accuracies for the detection of global CAD, reaching 71% and 72% by visual reads, and 72% and 68% by automated relative quantitation, when using CAD ≥ 70% or ≥ 50% stenosis for significance, respectively. Similar results were observed when analyzing individual coronary territories. In both pharmacological and exercise stress, automated relative quantitation demonstrated significantly more interobserver agreement than visual reads. CONCLUSIONS: Our automated method of 18F-flurpiridaz relative perfusion analysis provides a quantitative, objective, and highly reproducible assessment of PET MPI in normal and CAD subjects undergoing either pharmacological or exercise stress.

Determination of [N-13]-ammonia extraction fraction in patients with coronary artery disease by calibration to invasive coronary and fractional flow reserve.

BACKGROUND: This study presents a new extraction fraction (EF) model based on physiological measures of invasive coronary flow reserve (CFR) and fractional flow reserve (FFR) in patients with suspected coronary artery disease (CAD) and normal index microcirculatory resistance (IMR). To ascertain the clinical relevance of the new EFs, flow measurements using the newly patient-determined EFs were compared to flow measurements using traditional animal-determined EFs. METHODS: 39 patients were retrospectively selected that included a total of 91 vascular territories with invasive coronary angiography physiological measures. [N-13]-ammonia dynamic rest/adenosine-stress PET imaging was conducted in all patients and absolute myocardial flow was estimated using four published compartmental models. The extraction fraction during hyperemic flow was iteratively estimated by maximizing the agreement between invasive CFR and FFR with the non-invasive analogs myocardial flow reserve (MFR) and relative flow reserve (RFR) at similar physiological states, respectively. RESULTS: Using the new patient-determined EFs, agreement between CFR vs MFR for Model 1 and 2 was moderate and poor for Model 3 and 4. All models showed moderate agreement for FFR vs RFR. When using published models of animal-determined EFs, agreement between CFR vs MFR remained moderate for Model 1 and 2, and poor for Model 3 and 4. Similarly, all models showed moderate agreement for FFR vs RFR using animal-determined EF values. None of the observed differences were statistically significant. CONCLUSIONS: Flow measurements using extraction fraction correction for [N-13]-ammonia based on calibration to invasive intracoronary angiography physiological measures in patients with CAD were not discordant from those reported in the literature. Either patient-determined or traditional animal-determined EF correction, when used with the appropriate flow model, yields moderate agreement with invasive measurements of coronary flow reserve and fractional flow reserve.

Early onset of left ventricular regional asynchrony in arteries with sub-clinical stenosis.

BACKGROUND: Asynchrony has been reported to be a marker of ischemic-induced left ventricular dysfunction, the magnitude of which correlates with extent of epicardial coronary disease. We wished to determine whether normal-appearing arterial territories with mild degrees of asynchrony have lower 82Rb PET absolute myocardial blood flow (MBF) and/or lower myocardial flow reserve (MFR). METHODS AND RESULTS: Data were examined retrospectively for 105 patients evaluated for known/suspected CAD who underwent rest/regadenoson-stress 82Rb PET/CT and quantitative coronary angiography. Rest and stress absolute MBF and MFR were quantified from first-pass 82Rb PET curves. Regional relative myocardial perfusion summed stress score (SSS), summed rest score (SRS), regional phase bandwidth (BW), and regional semi-quantitative asynchrony visual scores of (Asynch) were assessed. We found that in apparently normal arteries (SSS < 4, SRS < 4 and stenosis < 70%), those with abnormally low MFR < 2.0 compared to those with MFR ≥ 2.0 had larger phase BW (186 ± 79° vs 158 ± 67°, P = .02), and more visually apparent Asynch (5.7 ± 4.2 vs 3.9 ± 3.6, P = .02), which was associated with increasing stenosis values (ρ = 0.44, P < .0001). CONCLUSION: A subgroup of coronary territories with normal relative perfusion and normal or non-obstructive coronary disease may have reduced MFR, which is signaled physiologically by a mild degree of left ventricular asynchrony.

Relationship of 82Rb PET territorial myocardial asynchrony to arterial stenosis.

OBJECTIVE: 82Rb PET/CT rest/regadenoson-stress data enable quantification of left ventricular rest and stress function, perfusion, and asynchrony. Our study was conducted to determine which parameters best identify patients with multi-vessel disease (MVD) and individual stenosed arteries. METHODS: PET/CT data were reviewed retrospectively for 105 patients referred for evaluation of CAD, who also underwent angiography. % arterial stenosis was determined quantitatively at a core laboratory. Severe stenosis was defined as ≥ 70%, and MVD as 2 or more stenosed arteries. Segmental MBF was calculated from first-pass data for arterial territories. Regional rest and stress systolic and diastolic asynchrony (Asynch) scores were determined from visual examination of phase polar maps. RESULTS: 65 vessels had stenoses ≥ 70%. 15 patients had MVD. ROC area under curve (ROC AUC) for identifying patients with MVD was 83% for Asynch and 73% for MFR. ROC AUC for identifying individual arterial territories with stenoses ≥ 70% was 81% and 72% for Asynch and MFR. CONCLUSION: 82Rb PET/CT accurately identified patients with MVD and individual stenosed territories, with regional asynchrony measurements contributing significantly to identify patients with CAD.

Diagnostic performance of an artificial intelligence-driven cardiac-structured reporting system for myocardial perfusion SPECT imaging.

OBJECTIVES: To describe and validate an artificial intelligence (AI)-driven structured reporting system by direct comparison of automatically generated reports to results from actual clinical reports generated by nuclear cardiology experts. BACKGROUND: Quantitative parameters extracted from myocardial perfusion imaging (MPI) studies are used by our AI reporting system to generate automatically a guideline-compliant structured report (sR). METHOD: A new nonparametric approach generates distribution functions of rest and stress, perfusion, and thickening, for each of 17 left ventricle segments that are then transformed to certainty factors (CFs) that a segment is hypoperfused, ischemic. These CFs are then input to our set of heuristic rules used to reach diagnostic findings and impressions propagated into a sR referred as an AI-driven structured report (AIsR). The diagnostic accuracy of the AIsR for detecting coronary artery disease (CAD) and ischemia was tested in 1,000 patients who had undergone rest/stress SPECT MPI. RESULTS: At the high-specificity (SP) level, in a subset of 100 patients, there were no statistical differences in the agreements between the AIsr, and nine experts' impressions of CAD (P = .33) or ischemia (P = .37). This high-SP level also yielded the highest accuracy across global and regional results in the 1,000 patients. These accuracies were statistically significantly better than the other two levels [sensitivity (SN)/SP tradeoff, high SN] across all comparisons. CONCLUSIONS: This AI reporting system automatically generates a structured natural language report with a diagnostic performance comparable to those of experts.

Vessel-specific quantification of absolute myocardial blood flow, myocardial flow reserve and relative flow reserve by means of fused dynamic 13NH3 PET and CCTA: Ranges in a low-risk population and abnormality criteria.

OBJECTIVES: The goal of the present work is to present a novel methodology for the extraction of MBF, MFR and RFR along coronary arteries by means of multimodality image fusion of dynamic PET and CCTA images. BACKGROUND: FFR is the reference standard to identify flow-limiting lesions, but its invasiveness limits broad application. New noninvasive methodologies are warranted to stratify patients and guide treatment. METHODS: A group of 16 low-risk CAD subjects who underwent both 13NH3 PET and CCTA were analyzed. Image fusion techniques were employed to align the studies and CCTA-derived anatomy used to identify coronaries trajectories. MBF was calculated by means of a 1-tissue compartmental model for the standard vascular territories and along patient-specific vessel paths from the base to the apex of the heart. RESULTS: Low-risk ranges for MBF. MFR and RFR for LAD, LCX and rPDA were computed for the entire cohort and separated by gender. Computed low-risk ranges were used to assess a prospective patient with suspected CAD. CONCLUSIONS: Our vessel-specific functional indexes and 3D displays offer promise to more closely replicate what is commonly performed during a catheterization session and have the potential of providing effective noninvasive tools for the identification of flow-limiting lesions and image-guided therapy.

Inspiratory muscle training at sea level improves the strength of inspiratory muscles during load carriage in cold-hypoxia.

Inspiratory muscle training (IMT) and functional IMT (IMTF: exercise-specific IMT activities) has been unsuccessful in reducing respiratory muscle fatigue following load carriage. IMTF did not include load carriage specific exercises. Fifteen participants split into two groups (training and control) walked 6 km loaded (18.2 kg) at speeds representing ∼50%V̇O2max in cold-hypoxia. The walk was completed at baseline; post 4 weeks IMT and 4 weeks IMTF (five exercises engaging core muscles, three involved load). The training group completed IMT and IMTF at a higher maximal inspiratory pressure (Pimax) than controls. Improvements in Pimax were greater in the training group post-IMT (20.4%, p = .025) and post-IMTF (29.1%, p = .050) compared to controls. Respiratory muscle fatigue was unchanged (p = .643). No other physiological or subjective measures were improved by IMT or IMTF. Both IMT and IMTF increased the strength of respiratory muscles pre-and-post a 6 km loaded walk in cold-hypoxia. Practitioner Summary: To explore the interaction between inspiratory muscle training (IMT), load carriage and environment, this study investigated 4 weeks IMT and 4 weeks functional IMT on respiratory muscle strength and fatigue. Functional IMT improved inspiratory muscle strength pre-and-post a loaded walk in cold-hypoxia but had no more effect than IMT alone. Abbreviations: ANOVA: analysis of variance; BF: breathing frequency; CON: control group; EELV: end-expiratory lung volume; EXP: experimental group; FEV1: forced expiratory volume in one second; FiO2: fraction of inspired oxygen; FVC: forced vital capacity; HR: heart rate; IMT: inspiratory muscle training; IMTF: functional inspiratory muscle training; Pemax: maximal expiratory pressure; Pimax: maximal inspiratory pressure; RMF: respiratory muscle fatigue; RPE: rate of perceived exertion; RWU: respiratory muscle warm-up; SaO2: arterial oxygen saturation; SpO2: peripheral oxygen saturation; V̇E: minute ventilation; V̇O2: rate of oxygen uptake.

Meta-analysis of the effect of perioperative intravenous lidocaine on return of gastrointestinal function after colorectal surgery.

BACKGROUND: Return of normal gastrointestinal (GI) function is a critical determinant of recovery after colorectal surgery. The aim of this meta-analysis was to evaluate whether perioperative intravenous (IV) lidocaine benefits return of gastrointestinal function after colorectal resection. METHODS: A comprehensive search of Ovid Medline, PubMed, Embase, Cochrane library, and clinicaltrials.org was performed on 1st July 2018. A manual search of reference lists was also performed. Inclusion criteria were as follows: randomized controlled trials (RCTs) of intravenous (IV) lidocaine administered perioperatively compared to placebo (0.9% saline infusion) as part of a multimodal perioperative analgesic regimen, human adults (> 16 years), and open or laparoscopic colorectal resectional surgery. EXCLUSION CRITERIA: non-colorectal surgery, non-placebo comparator, children, non-general anaesthetic, and pharmacokinetic studies. The primary endpoint was time to first bowel movement. Secondary endpoints were time to first passage of flatus, time to toleration of diet, nausea and vomiting, ileus, pain scores, opioid analgesia consumption, and length of stay. RESULTS: One hundred and ninety one studies were screened, with 9 RCTs meeting inclusion criteria (405 patients, four laparoscopic and five open surgery studies). IV lidocaine reduced time to first bowel movement compared to placebo [seven studies, 325 patients, mean weighted difference - 9.54 h, 95% CI 18.72-0.36, p = 0.04]. Ileus, pain scores, and length of stay were reduced with IV lidocaine compared with placebo. CONCLUSIONS: Perioperative IV lidocaine may improve recovery of gastrointestinal function after colorectal surgery. Large-scale effectiveness studies to measure effect size and evaluate optimum dose/duration are warranted.

Diagnostic performance of the quantification of myocardium at risk from MPI SPECT/CTA 2G fusion for detecting obstructive coronary disease: A multicenter trial.

BACKGROUND: The effective non-invasive identification of coronary artery disease (CAD) and its proper referral for invasive treatment are still unresolved issues. We evaluated our quantification of myocardium at risk (MAR) from our second generation 3D MPI/CTA fusion framework for the detection and localization of obstructive coronary disease. METHODS: Studies from 48 patients who had rest/stress MPI, CTA, and ICA were analyzed from 3 different institutions. From the CTA, a 3D biventricular surface of the myocardium with superimposed coronaries was extracted and fused to the perfusion distribution. Significant lesions were identified from CTA readings and positioned on the fused display. Three estimates of MAR were computed on the 3D LV surface on the basis of the MPI alone (MARp), the CTA alone (MARa), and the fused information (MARf). The extents of areas at risk were used to generate ROC curves using ICA anatomical findings as reference standard. RESULTS: Areas under the ROC curve (AUC) for CAD detection using MARf was 0.88 (CI = 0.75-0.95) and for MARp and MARa were, respectively 0.82 (CI = 0.69-0.92) and 0.75 (CI = 0.60-0.86) using the ≥70% stenosis criterion. AUCs for CAD localization (all vessels) using MARf showed significantly higher performance than either MARa or MARp or both. CONCLUSIONS: Using ICA as the reference standard, MAR as the quantitative parameter, and AUC to measure diagnostic performance, MPI-CTA fusion imaging provided incremental diagnostic information compared to MPI or CTA alone for the diagnosis and localization of CAD.

Relationships between left ventricular asynchrony and myocardial blood flow.

OBJECTIVE: 82Rb PET protocols enable determination of left ventricular asynchrony (LVAS) at rest and stress, along with myocardial blood flow (MBF). We hypothesized that in patients with resting LVAS, MBF differs between those with stress-induced LVAS improvement and those with stress-induced LVAS deterioration. METHODS: We retrospectively analyzed 82Rb rest/regadenoson stress PET studies of 195 patients evaluated for known or suspected coronary artery disease. MBF was computed from first-pass data; function and relative perfusion were computed from myocardial equilibrium data. LVAS was defined as phase contraction bandwidth (BW) above 82Rb gender-specific normal limits, with changes defined as BW moving into or out of normal ranges. RESULTS: Among the 195 patients, 64 had LVAS at rest, of whom 13 reverted to normal and 51 continued to have LVAS with stress. Patients who did not improve had lower stress MBF (1.04 ± 0.69 vs 1.58 ± 0.67, p = .02) and coronary flow reserve (1.94 ± 1.16 vs 3.04 ± 1.22, p = .01) than those who did improve. ROC analysis indicated that the parameter most strongly associated with improvement in asynchrony for patients with resting LVAS was reduction in MBF heterogeneity (ROC area (accuracy) = 84%, sensitivity = 92%, and specificity = 67%). CONCLUSION: LVAS is highly correlated with MBF and CVR, with stress-induced improvement in synchronicity most strongly associated with improved MBF homogeneity.

The effect of combined supplementation of carbohydrates and creatine on anaerobic performance.

The purpose of the study was to examine the effect of creatine (Cr) supplementation on anaerobic performance when ingesting creatine and carbohydrates (CHO) together. Twenty male physical education students comprised the two experimental (CR and CRCHO) and one control (CON) groups of the study. All groups performed three 30 s anaerobic Wingate tests (AWTs) interspersed with 6 minutes of recovery. The CR group (n = 7) ingested 5 g of Cr 5 times per day for 4 days. Subjects in the CRCHO group (n = 6) ingested the same quantity but additionally after each 5 g dose of Cr consumed 500 ml of a commercially available energy drink containing 100 g of simple sugars. Over all three AWTs average mean power improved significantly compared to baseline for the CR group (5.51%) but not for the CRCHO group (3.06%). Mean power for the second AWT was improved following the acute loading for the CR group only (4.54%) and for the third AWT for both CR (8.49%) and CRCHO (5.75%) groups. Over all three AWTs a significant change was recorded in average peak power following the acute loading for the CR group (8.26%) but not for the CRCHO group (4.11%). Peak power was significantly improved following the loading only for the CR group during the third AWT (19.79%). No changes in AWT performance were recorded for the CON group after intervention. The findings of the present study suggest that ingesting creatine together with carbohydrates will not further improve performance compared to the ingestion of creatine only.

Considering maturation status and relative age in the longitudinal evaluation of junior rugby league players.

This study longitudinally evaluated whether maturation and relative age interact with time during adolescence to differentially affect the development of anthropometric and fitness characteristics in junior rugby league players. Anthropometric and fitness characteristics of 81 junior players selected into the UK Rugby Football League's talent identification and development process were assessed over three consecutive occasions (i.e., under-13s, -14s, -15s). Players were grouped and compared in relation to maturational status (i.e., early, average, late) and relative age quartile (i.e., quartile 1). Repeated measures multivariate analysis of variance identified significant (P < 0.001) overall main effects for maturation group, relative age quartile and importantly a maturation group by time interaction. Findings showed that the early-maturing group had the greatest anthropometric characteristics and medicine ball throw across the three occasions. However, the late-maturing group increased their height (early = 5.0 cm, late = 10.3 cm), medicine ball throw and 60-m sprint (early = -0.46 s, late = -0.85 s) the most throughout the 2-year period. Early (de)selection policies currently applied in talent identification and development programs are questionable when performance-related variables are tracked longitudinally. During adolescence, maturation status alongside relative age should be considered and controlled for when assessing athlete potential for future progression.

Effect of probiotics and prebiotics on the composition of the equine fecal and seminal microbiomes and sperm quality: A pilot study.

Probiotic and prebiotic effects on equine semen and gastrointestinal microbiome composition and sperm quality are unknown. This study aimed to evaluate the effects of pre-, pro- or synbiotic supplementation on fecal and semen microbiome composition and sperm quality parameters of stallions. This Latin square crossover trial involved four miniature pony stallions receiving control diet only, or addition of a pro-, pre- or synbiotic formulation. Full-length 16S rRNA gene amplicon sequencing was used to measure diversity of semen and fecal microbiomes. Total sperm count, total motility, progressive motility, DNA integrity, lipid peroxidation and mitochondrial oxidative stress, biomarkers of sperm quality, were measured after each intervention. A general linear model was employed to analyse and compare microbiome diversity measures and sperm quality data across four time points. Shannon's diversity index (alpha-diversity), and evenness of semen and gastrointestinal microbiomes were significantly different (p<0.001). A trend was observed for prebiotic effects on the diversity indices of the GI microbiome (p= 0.07). No effects of treatments were observed on either semen microbiome or sperm quality. Pre-, pro- and synbiotic supplements showed no negative effect on sperm quality parameters observed. This proof of concept provides preliminary data to inform future studies exploring the relationship between microbiomes and fertility.

The semen microbiome of miniature pony stallions.

CONTEXT: Little is known about the microbial composition of stallion semen. AIMS: To describe the microbiota detected in equine semen of healthy miniature pony stallions. METHODS: Semen specimens were collected using a Missouri artificial vagina at a single time point. PacBio (Pacific Biosciences) genomic DNA sequencing of the 16S rRNA gene was performed on these specimens, following which next-generation microbiome bioinformatics platform QIIME2 was used to process fastq files and analyse the amplicon data. The data were categorised into genus, family, class, order and phylum. KEY RESULTS: Firmicutes and Bacteroidetes phyla predominated (76%), followed by Proteobacteria (15%). Bacteroidales, Clostridiales and Cardiobacteriales predominated the microbial rank of order (86%). Class was mainly composed of Bacteroidia, Clostridia and Gammaproteobacteria (87%), while family was mainly composed of Porphyromonadaceae , Family_XI and Cardiobacteriaceae (62%). At the level of genus, 80% of the abundance was composed of seven genera, namely Porphyromonas, Suttonella, Peptoniphilus, Fastidiosipila, Ezakiella, Petrimonas and an unknown taxon. CONCLUSIONS: The findings indicate that specific microbiota may be characteristic of healthy miniature pony stallions' semen with some inter-individual variations observed. IMPLICATIONS: Larger equine studies involving fertile and infertile subjects could be informed by this study and could explore the relationship of the semen microbiome to male fertility.

Myocardial perfusion imaging-derived left ventricular strain: Regional abnormalities associated with transthyretin cardiac amyloidosis.

Background: Transthyretin (ATTR) cardiac amyloidosis is associated with an apical-sparing strain pattern on TTE. We hypothesize that strain indices derived from myocardial perfusion imaging (MPI) can identify this abnormality. Methods: A group with ATTR amyloidosis was compared to age-matched controls with LVH but without amyloidosis who underwent PET or SPECT MPI. Strain values were used to calculate the apical strain index (ASI), apex-to-base ratio (ABR), and ejection fraction to global strain ratio in multiple planes. Results: A direct comparison using Welch's t-tests reveals 6 statistically significant metrics. After regression analysis, the circumferential ASI and ABR at rest remain significantly greater in the ATTR group compared to controls. Conclusion: MPI-derived strain from the circumferential plane at rest may distinguish cardiac amyloidosis from other forms of LVH. If these findings are confirmed with validation studies, routine MPI-derived strain analysis could identify patients with subclinical amyloidosis who may benefit from further testing.

Area-level deprivation and adiposity in children: is the relationship linear?

OBJECTIVE: It has been suggested that childhood obesity is inversely associated with deprivation, such that the prevalence is higher in more deprived groups. However, comparatively few studies actually use an area-level measure of deprivation, limiting the scope to assess trends in the association with obesity for this indicator. Furthermore, most assume a linear relationship. Therefore, the aim of this study was to investigate associations between area-level deprivation and three measures of adiposity in children: body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). DESIGN: This is a cross-sectional study in which data were collected on three occasions a year apart (2005-2007). SUBJECTS: Data were available for 13,333 children, typically aged 11-12 years, from 37 schools and 542 lower super-output areas (LSOAs). MEASURES: Stature, mass and WC. Obesity was defined as a BMI and WC exceeding the 95th centile according to British reference data. WHtR exceeding 0.5 defined obesity. The Index of Multiple Deprivation affecting children (IDACI) was used to determine area-level deprivation. RESULTS: Considerable differences in the prevalence of obesity exist between the three different measures. However, for all measures of adiposity the highest probability of being classified as obese is in the middle of the IDACI range. This relationship is more marked in girls, such that the probability of being obese for girls living in areas at the two extremes of deprivation is around half that at the peak, occurring in the middle. CONCLUSION: These data confirm the high prevalence of obesity in children and suggest that the relationship between obesity and residential area-level deprivation is not linear. This is contrary to the 'deprivation theory' and questions the current understanding and interpretation of the relationship between obesity and deprivation in children. These results could help make informed decisions at the local level.