Somatic Symptoms of Depression Lose Association with Mortality upon Adjustment for Frailty: Analysis from the Fitness Haemodialysis Cohort.

Introduction: The somatic symptom component of depression is associated with increased hospitalisation and mortality and poorer health-related quality of life (HRQOL). However, the relationship of subsets of depression symptoms with frailty and outcomes is not known. This study aimed to (1) explore the relationship between the Clinical Frailty Scale (CFS) and components of depression and (2) their association with mortality, hospitalisation, and HRQOL in haemodialysis recipients. Methods: We conducted a prospective cohort study of prevalent haemodialysis recipients, with deep bio-clinical phenotyping including CFS and PHQ-9 somatic (fatigue, poor appetite, and poor sleep) and cognitive component scores. EuroQol EQ-5D summary index assessed HRQOL at the baseline. Electronic linkage to English national administration datasets ensured robust follow-up data for hospitalisation and mortality events. Findings. Somatic (ß = 0.067; 95% C.I. 0.029 to 0.104; P < 0.001) and cognitive (ß = 0.062; 95% C.I. 0.034 to 0.089; P<0.001) components were associated with increased CFS scores. Both somatic (ß = -0.062; 95% C.I. -0.104 to -0.021; P<0.001) and cognitive (ß = 0.052; 95% C.I. -0.081 to -0.024; P < 0.001) scores were associated with lower HRQOL. Somatic scores lost mortality association on addition of CFS to the multivariable model (HR1.06; 95% C.I. 0.977 to 1.14; P=0.173). Cognitive symptoms were not associated with mortality. Neither the component score was associated with hospitalisation on multivariable analyses. Conclusions: Both somatic and cognitive depression symptoms are associated with frailty and poorer HRQOL in haemodialysis recipients but were not associated with mortality or hospitalisation when adjusted for frailty. The risk profile of depression somatic scores may be related to overlap with symptoms of frailty.

Gender Disparity in Expression of Sarcopenia in Haemodialysis Recipients: Analysis from the FITNESS Cohort.

Background: There has been little exploration of the interplay between sarcopenia and frailty in haemodialysis, particularly regarding gender difference. We aimed to (1) assess whether ultrasound-derived low muscle mass (LMM) and sarcopenia are more common in male or female haemodialysis recipients; (2) assess whether age influences any observed gender difference, and (3) explore the interplay between sarcopenia, frailty, and gender in haemodialysis recipients. Methods: This was an exploratory analysis of a subgroup of adult prevalent (≥3 months) haemodialysis with frailty phenotype (FP) scores. Bilateral anterior thigh thickness (BATT) was obtained according to an established ultrasound protocol. Associations with frailty were explored via both linear and logistic regressions for BATT, LMM, and sarcopenia with a priori covariables, stratified by gender. Results: In total of 223 studies, participants had ultrasound measurements. Males showed greater prevalence of LMM. On adjusted analyses, LMM was associated with lower hand grip strength in males (ß = -4.17; 95% C.I. -7.57 to -0.77; P=0.02), but not females (ß = -1.88; 95% C.I. -5.41 to 1.64; P=0.29). LMM was also associated with slower walking speed in both males (ß = -0.115; 95% C.I. -0.258 to -0.013; P=0.03) and females (ß = -0.152; 95% C.I. -0.300 to -0.005; P=0.04). Sarcopenia was associated with greater odds of frailty on adjusted models in males (OR = 9.86; 95% C.I. 1.8 to 54.0; P=0.01), but not females (OR = 5.16; 95% C.I. 0.22 to 124; P=0.31). Conclusions: The clinical expression and significance of sarcopenia differ substantially between males and females on haemodialysis. Further work is required to elucidate underlying mechanisms and guide tailored treatment.

A clinical frailty scale obtained from MDT discussion performs poorly in assessing frailty in haemodialysis recipients.

BACKGROUND: The Clinical Frailty Scale (CFS) is a commonly utilised frailty screening tool that has been associated with hospitalisation and mortality in haemodialysis recipients, but is subject to heterogenous methodologies including subjective clinician opinion. The aims of this study were to (i) examine the accuracy of a subjective, multidisciplinary assessment of CFS at haemodialysis Quality Assurance (QA) meetings (CFS-MDT), compared with a standard CFS score via clinical interview, and (ii) ascertain the associations of these scores with hospitalisation and mortality. METHODS: We performed a prospective cohort study of prevalent haemodialysis recipients linked to national datasets for outcomes including mortality and hospitalisation. Frailty was assessed using the CFS after structured clinical interview. The CFS-MDT was derived from consensus at haemodialysis QA meetings, involving dialysis nurses, dietitians, and nephrologists. RESULTS: 453 participants were followed-up for a median of 685 days (IQR 544-812), during which there were 96 (21.2%) deaths and 1136 hospitalisations shared between 327 (72.1%) participants. Frailty was identified in 246 (54.3%) participants via CFS, but only 120 (26.5%) via CFS-MDT. There was weak correlation (Spearman Rho 0.485, P < 0.001) on raw frailty scores and minimal agreement (Cohen's κ = 0.274, P < 0.001) on categorisation of frail, vulnerable and robust between the CFS and CFS-MDT. Increasing frailty was associated with higher rates of hospitalisation for the CFS (IRR 1.26, 95% C.I. 1.17-1.36, P = 0.016) and CFS-MDT (IRR 1.10, 1.02-1.19, P = 0.02), but only the CFS-MDT was associated with nights spent in hospital (IRR 1.22, 95% C.I. 1.08-1.38, P = 0.001). Both scores were associated with mortality (CFS HR 1.31, 95% C.I. 1.09-1.57, P = 0.004; CFS-MDT HR 1.36, 95% C.I. 1.16-1.59, P < 0.001). CONCLUSIONS: Assessment of CFS is deeply affected by the underlying methodology, with the potential to profoundly affect decision-making. The CFS-MDT appears to be a weak alternative to conventional CFS. Standardisation of CFS use is of paramount importance in clinical and research practice in haemodialysis. TRIAL REGISTRATION: Clinicaltrials.gov : NCT03071107 registered 06/03/2017.

Cognitive Impairment, Frailty, and Adverse Outcomes Among Prevalent Hemodialysis Recipients: Results From a Large Prospective Cohort Study in the United Kingdom.

Rationale & Objective: Frailty and cognitive impairment are common in hemodialysis recipients and have been associated with high mortality. There is considerable heterogeneity in frailty reporting, with little comparison between commonly used frailty tools and little exploration of the interplay between cognition and frailty. The aims were to explore the relationship between frailty scores and cognition and their associations with hospitalization and mortality. Study Design: Prospective cohort study. Setting & Population: Prevalent hemodialysis recipients linked to national datasets for hospitalization and mortality. Predictors: Montreal Cognitive Assessment (MoCA), Frailty Phenotype, Frailty Index (FI), Edmonton Frailty Scale, and Clinical Frailty Scale (CFS) were performed at baseline. Cognitive impairment was defined as MoCA scores of <26, or <21 in dexterity impairment, <18 in visual impairment. Outcomes: Mortality, hospitalization. Analytical Approach: Cox proportional hazards model for mortality, censored for end of follow-up. Negative binomial regression for admission rates, censored for death/end of follow-up. Results: In total, 448 participants were recruited with valid MoCAs and followed up for a median of 685 days. There were 103 (23%) deaths and 1,120 admissions of at least one night. Cognitive impairment was identified in 346 (77.2%) participants. Increasing frailty by all definitions was associated with poorer cognition. Cognition was not associated with mortality (HR, 0.99; 95% CI, 0.95-1.03; P = 0.41) or hospitalization (IRR, 1.01; 95% CI, 0.99-1.04; P = 0.39) on multivariable analyses. There were interactions between MoCA scores and increasing frailty by FI (P = 0.002) and Clinical Frailty Scale (P = 0.005); admissions were highest when both MoCA and frailty scores were high, and when both scores were low. Limitations: As frailty is a dynamic state, a single cross-sectional assessment may not accurately reflect its year-to-year variability. In addition, these findings are in maintenance dialysis and may not be transferable to incident hemodialysis. There were small variations in application of frailty tool criteria from other studies, which may have influenced the results. Conclusions: Cognitive impairment is highly prevalent in this hemodialysis cohort. The interaction between cognition and frailty on rates of admission suggests the MoCA offers value in identifying higher risk hemodialysis populations with both high and low degrees of frailty.

Depression is associated with frailty and lower quality of life in haemodialysis recipients, but not with mortality or hospitalization.

Background: Frailty and depression are highly prevalent in haemodialysis recipients, exhibit a reciprocal relationship, and are associated with increased mortality and hospitalization, and lower quality of life. Despite this, there has been little exploration of the relationship between depression and frailty upon patient outcomes. We aimed to explore the relationship between depression and frailty, and their associations with mortality, hospitalization and quality of life. Methods: We performed a prospective cohort study of prevalent haemodialysis recipients linked to national datasets for outcomes including mortality and hospitalization. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9), frailty using the Clinical Frailty Scale (CFS) and quality of life using the EuroQol 5-Dimension (EQ-5D) Summary Index. Results: A total of 485 prevalent haemodialysis recipients were recruited, with 111 deaths and 1241 hospitalizations during follow-up. CFS was independently associated with mortality [hazard ratio (HR) 1.31; 95% confidence interval (CI) 1.08, 1.59; P = .006], hospitalization [incidence rate ratio (IRR) 1.13; 95% CI 1.03, 1.25; P = .010] and lower quality of life (Coef. -0.401; 95% CI -0.511, -0.292; P < .001). PHQ-9 score was independently associated with lower quality of life (Coef. -0.042; 95% CI -0.063, -0.021; P < .001), but not mortality (HR 1.00; 95% CI 0.96, 1.04; P = .901) or hospitalization (IRR 0.99; 95% CI 0.97, 1.01; P = .351). In an adjusted model including CFS, moderate depression was associated with reduced hospitalization (IRR 0.72; 95% CI 0.56, 0.93; P = .013). Conclusions: With the addition of frailty, depression was associated with lower hospital admissions, but poorer quality of life. The relationship between frailty and depression, and their influence on outcomes is complex, requiring further study.

Ultrasound quadriceps muscle thickness is variably associated with frailty in haemodialysis recipients.

BACKGROUND: Ultrasonographic quantitation of quadriceps muscle mass is increasingly used for assessment of sarcopenia, but its relationship with frailty in haemodialysis recipients is not known. This study explores the relationship between ultrasound-derived bilateral anterior thigh thickness (BATT), sarcopenia, and frailty by common frailty tools (Frailty Phenotype [FP], Frailty Index [FI], Edmonton Frailty [EFS], and Clinical Frailty Scale [CFS]). METHODS: This was an exploratory analysis of a subgroup of adult prevalent (≥3 months) haemodialysis recipients deeply phenotyped for frailty. Ultrasound assessment of BATT was obtained with participants at an angle of ≤45°, with legs outstretched and knees resting at 10°-20°, according to an established protocol. Associations with frailty were explored via both linear and logistic regressions for BATT, Low Muscle Mass (LMM), and sarcopenia with stepwise adjustment for a priori covariables. RESULTS: In total 223 study participants had ultrasound measurements. Frailty ranged from 34% for FP to 58% for FI. BATT was associated with increasing frailty on simple linear regression by all frailty tools, but lost significance on addition of covariables. Upon dichotomising frailty tools into Frail/Not Frail, BATT was associated with frailty by all tools on univariable analyses, but only retained association for EFS on the fully adjusted model (OR 0.97, 95% C.I. 0.94-1.00, P = 0.05). CONCLUSIONS: Ultrasound measures of quadriceps thickness is variably associated with frailty in prevalent haemodialysis recipients, dependent upon the frailty tool used, but not independent of other variables. Further work is required to establish the added value of sarcopenia measurement in frail haemodialysis patients. TRIAL REGISTRATION: Clinicaltrials.gov : NCT03071107 registered 06/03/2017.

Self-reported health change in haemodialysis recipients modulates the effect of frailty upon mortality and hospital admissions: outcomes from a large prospective UK cohort.

BACKGROUND: Frailty among haemodialysis patients is associated with hospitalization and mortality, but high frailty prevalence suggests further discrimination of risk is required. We hypothesized that incorporation of self-reported health with frailty measurement may aid risk stratification. METHODS: Prospective cohort study of 485 prevalent haemodialysis recipients linked to English national datasets. Frailty Phenotype (FP), Frailty Index (FI), Edmonton Frail Scale (EFS), Clinical Frailty Scale (CFS) and self-reported health change were assessed. Mortality was explored using Fine and Gray regression, and admissions by negative binomial regression. RESULTS: Over a median 678 (interquartile range 531-812) days, there were 111 deaths, and 1241 hospitalizations. Increasing frailty was associated with mortality on adjusted analyses for FP [subdistribution hazard ratio (SHR) 1.26, 95% confidence interval (CI) 1.05-1.53, P = .01], FI (SHR 1.21, 95% CI 1.09-1.35, P = .001) and CFS (SHR 1.32, 95% CI 1.11-1.58, P = .002), but not EFS (HR 1.08, 95% CI 0.99-1.18, P = .1). Health change interacted with frailty tools to modify association with mortality; only those who rated their health as the same or worse experienced increased mortality hazard associated with frailty by FP (Pinteraction = .001 and 0.035, respectively), FI (Pinteraction = .002 and .007, respectively) and CFS (Pinteraction = .009 and 0.02, respectively). CFS was the only frailty tool associated with hospitalization (incidence rate ratio 1.12, 95% CI 1.02-1.23, P = .02). CONCLUSIONS: We confirm the high burden of hospitalization and mortality associated with haemodialysis patients regardless of frailty tool utilized and introduce the discriminatory ability of self-reported health to identify the most at-risk frail individuals.

Correlations, agreement and utility of frailty instruments in prevalent haemodialysis patients: baseline cohort data from the FITNESS study.

BACKGROUND: Frailty is associated with poor outcomes for haemodialysis patients, but its prevalence is uncertain due to heterogeneous definitions. The aim of this study was to compare and contrast prevalence and features of commonly used frailty instruments in a British haemodialysis cohort. METHODS: The FITNESS (Frailty Intervention Trial iN End-Stage patientS on haemodialysis) study recruited adults aged ≥18 years after informed consent, with ≥3 months haemodialysis exposure and no hospital admission within 4 weeks unless for dialysis access. Study participants were clinically phenotyped with frailty instruments including the Frailty Index (FI), Frailty Phenotype (FP), Edmonton Frailty Scale (EFS) and Clinical Frailty Scale (CFS), alongside comprehensive baseline data collection of biochemical, clinical and social characteristics. RESULTS: Between 12 January 2018 and 18 April 2019, 485 haemodialysis patients were recruited. Baseline demographics were median age 63 years, male sex 58.6% and non-White ethnicity 42.1%. Prevalence of frailty was high; 41.9% of participants were frail by FP, 63.3% by FI, 50.2% by EFS and 53.8% by CFS. Female gender was associated with increased frailty, with no independent association observed with age or ethnicity. While correlation between frailty instruments was strong, intraclass correlation coefficient for frailty agreement was 0.628 (95% confidence interval 0.585-0.669) and only weak agreement between instrument pairs. CONCLUSION: Frailty is highly prevalent among haemodialysis patients regardless of criteria used. However, our data suggest caution when interpreting heterogenous definitions of frailty for haemodialysis patients as they are not interchangeable. Consensus agreement on the optimal frailty definition for haemodialysis patients must balance ease of use with predictive ability for adverse outcomes before determining clinical application.

Mitochondrial genomes of two parasitic Cuscuta species lack clear evidence of horizontal gene transfer and retain unusually fragmented ccmFC genes.

BACKGROUND: The intimate association between parasitic plants and their hosts favours the exchange of genetic material, potentially leading to horizontal gene transfer (HGT) between plants. With the recent publication of several parasitic plant nuclear genomes, there has been considerable focus on such non-sexual exchange of genes. To enhance the picture on HGT events in a widely distributed parasitic genus, Cuscuta (dodders), we assembled and analyzed the organellar genomes of two recently sequenced species, C. australis and C. campestris, making this the first account of complete mitochondrial genomes (mitogenomes) for this genus. RESULTS: The mitogenomes are 265,696 and 275,898 bp in length and contain a typical set of mitochondrial genes, with 10 missing or pseudogenized genes often lost from angiosperm mitogenomes. Each mitogenome also possesses a structurally unusual ccmFC gene, which exhibits splitting of one exon and a shift to trans-splicing of its intron. Based on phylogenetic analysis of mitochondrial genes from across angiosperms and similarity-based searches, there is little to no indication of HGT into the Cuscuta mitogenomes. A few candidate regions for plastome-to-mitogenome transfer were identified, with one suggestive of possible HGT. CONCLUSIONS: The lack of HGT is surprising given examples from the nuclear genomes, and may be due in part to the relatively small size of the Cuscuta mitogenomes, limiting the capacity to integrate foreign sequences.

Recent range expansion in Australian hummock grasses (Triodia) inferred using genotyping-by-sequencing.

The Australian arid zone (AAZ) has undergone aridification and the formation of vast sandy deserts since the mid-Miocene. Studies on AAZ organisms, particularly animals, have shown patterns of mesic ancestry, persistence in rocky refugia and range expansions in arid lineages. There has been limited molecular investigation of plants in the AAZ, particularly of taxa that arrived in Australia after the onset of aridification. Here we investigate populations of the widespread AAZ grass Triodia basedowii to determine whether there is evidence for a recent range expansion, and if so, its source and direction. We also undertake a dating analysis for the species complex to which T. basedowii belongs, in order to place its diversification in relation to changes in AAZ climate and landscapes. We analyse a genomic single nucleotide polymorphism data set from 17 populations of T. basedowii in a recently developed approach for detecting the signal and likely origin of a range expansion. We also use alignments from existing and newly sequenced plastomes from across Poaceae for analysis in BEAST to construct fossil-calibrated phylogenies. Across a range of sampling parameters and outgroups, we detected a consistent signal of westward expansion for T. basedowii, originating in central or eastern Australia. Divergence time estimation indicates that Triodia began to diversify in the late Miocene (crown 7.0-8.8 million years (Ma)), and the T. basedowii complex began to radiate during the Pleistocene (crown 1.4-2.0 Ma). This evidence for range expansion in an arid-adapted plant is consistent with similar patterns in AAZ animals and likely reflects a general response to the opening of new habitat during aridification. Radiation of the T. basedowii complex through the Pleistocene has been associated with preferences for different substrates, providing an explanation why only one lineage is widespread across sandy deserts.

Frailty Intervention Trial iN End-Stage patientS on haemodialysis (FITNESS): study protocol for a randomised controlled trial.

BACKGROUND: Frailty is a state of low physiological reserve and multi-systemic dysregulation that leads to susceptibility to external stressors; it is associated with adverse outcomes. North American data suggest that haemodialysis recipients are more likely to be frail than the general population, although data on UK cohorts are lacking. Furthermore, with a multitude of assessment tools, it is difficult for the clinician to ascertain which is most suitable for this population. The FITNESS Study aims to measure the prevalence and outcomes associated with frailty in a large UK haemodialysis cohort to determine the optimum frailty tool as defined by predictive value for mortality/hospitalisation and to conduct a feasibility study exploring a multi-disciplinary clinical intervention to improve frailty among haemodialysis recipients. METHODS/DESIGN: The study will follow a cohort multiple randomised controlled trial design; the initial cohort study will identify participants to be invited into a subsequent open-label randomised controlled trial. Eligible patients will be identified and recruited from their usual haemodialysis session. They will be invited to complete tasks and questionnaires collecting data on sarcopenia, immunosenescence, mood, cognition, disability, and comorbidity. Fifty pre-frail participants with suitable English proficiency will be randomly selected from this cohort to participate in the randomised controlled trial phase of the study. Further stratified randomisation will occur to assign these 50 participants to active or passive groups. The active group will receive a psychologically supported, patient-centred, multi-disciplinary intervention into frailty, in what we believe to be a first within this patient group. The control group will receive usual haemodialysis standard of care. All participants will be followed up using electronic patient records for outcomes to include hospitalisation and mortality. Primary outcomes for this phase of the study will be feasibility and tolerability of the clinical intervention study. DISCUSSION: The study will collect data on multiple aspects of frailty allowing for a rich dataset for detailed analysis. We believe this will be the first study to explore a psychologically supported, patient-centred intervention in this patient group. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03071107 . Registered on 6 March 2017.

Genotyping-by-Sequencing in a Species Complex of Australian Hummock Grasses (Triodia): Methodological Insights and Phylogenetic Resolution.

Next-generation sequencing is becoming increasingly accessible to researchers asking biosystematic questions, but current best practice in both choosing a specific approach and effectively analysing the resulting data set is still being explored. We present a case study for the use of genotyping-by-sequencing (GBS) to resolve relationships in a species complex of Australian arid and semi-arid grasses (Triodia R.Br.), highlighting our solutions to methodological challenges in the use of GBS data. We merged overlapping paired-end reads then optimised locus assembly in the program PyRAD to generate GBS data sets for phylogenetic and distance-based analyses. In addition to traditional concatenation analyses in RAxML, we also demonstrate the novel use of summary species tree analyses (taking gene trees as input) with GBS loci. We found that while species tree analyses were relatively robust to variation in PyRAD assembly parameters, our RAxML analyses resulted in well-supported but conflicting topologies under different assembly settings. Despite this conflict, multiple clades in the complex were consistently supported as distinct across analyses. Our GBS data assembly and analyses improve the resolution of taxa and phylogenetic relationships in the Triodia basedowii complex compared to our previous study based on Sanger sequencing of nuclear (ITS/ETS) and chloroplast (rps16-trnK spacer) markers. The genomic results also partly support previous evidence for hybridization between species in the complex. Our methodological insights for analysing GBS data will assist researchers using similar data to resolve phylogenetic relationships within species complexes.

Outcomes After Weekend Admission for Deceased Donor Kidney Transplantation: A Population Cohort Study.

BACKGROUND: Outcomes for weekend hospital admissions or emergency procedures have become a topical and controversial issue for the UK National Health Service. Deceased-donor kidney transplantation is frequently performed at weekends and evidence for its relative safety are lacking. METHODS: We undertook a population-based cohort analysis, obtaining data from every deceased-donor kidney-alone transplant procedure performed in England between January 2003 and December 2014. Data were extracted from Hospital Episode Statistics, with linkage to the Office for National Statistics to create a comprehensive dataset for mortality, rehospitalization and kidney allograft failure/rejection for weekend (defined as Friday to Sunday) versus weekday transplantation. RESULTS: Data were extracted for 12 902 deceased-donor kidney alone transplants performed in all 19 English transplant centres between 2003 and 2014. Based on initial χ tests, no significant difference was observed when comparing weekend versus weekday transplantation in 30-day (0.9% vs 1.2%; P = 0.126) or 1-year mortality (3.7% vs 3.8%; P = 0.788), 1-year kidney allograft failure/rejection (16.7% vs 16.8%; P = 0.897), delayed graft function (29.97% vs 29.36%; P = 0.457) or 1-year risk for readmission (63.5% vs 63.3%; P = 0.774). In a Cox regression model, transplantation at the weekend was not associated with any increased risk for 1-year mortality, rehospitalization, or allograft failure/rejection. CONCLUSIONS: Deceased-donor kidney transplants performed at the weekend do not have inferior short-term outcomes on the basis of 1-year risk for rehospitalization, mortality, or allograft failure/rejection. Our data are reassuring for patients and professionals alike, but may also provide speculative insight into models of care that attenuate the weekend effect.

Long-Term Follow-Up of Isolated Epicardial Left Ventricular Lead Implant Using a Minithoracotomy Approach for Cardiac Resynchronization Therapy.

BACKGROUND: Transvenous left ventricular (LV) lead placement for cardiac resynchronization therapy is unsuccessful in 5-10% of reported cases. These patients may benefit from isolated surgical placement of an epicardial LV lead via minithoracotomy approach. AIM: To evaluate the success of this approach at long-term follow-up. METHODS: Retrospective evaluation of all consecutive patients undergoing isolated epicardial LV lead placement after failed transvenous attempt over a 6-year period. Data collected on baseline parameters, procedural details, and outcome at follow-up (hospital stay, complications, mortality, and clinical response). RESULTS: Forty-two patients underwent epicardial lead implant. Five died within 1 year (11.9%): two (4.8%) died within 30-days post op (one from intraoperative hemorrhage, the other from multiple organ failure); 39 (95.1%) were admitted to the high dependency unit and transferred to the ward <24 hours. Median hospital stay was 3.4 ± 1.9 days. The overall complication rate was 17.5% (n = 7): 15.0% (n = 6) short term and 2.5% (n = 1) long term; these included three (7.5%) LV noncapture events all treated with reprogramming. There were two (5.0%) wound infections requiring oral antibiotics and two (5.0%) device infections requiring intravenous antibiotics (one had device resiting, the other developed septic shock requiring intensive care admission). Assessment of clinical response was possible in 34 (81.0%) at follow-up: 21 (61.8%) were responders and 13 (28.2%) nonresponders with no significant differences between these groups; no clinical predictors of response were identified. CONCLUSION: Isolated epicardial LV lead implant using minithoracotomy is relatively safe and effective at successful LV pacing. Response rate and postoperative recovery at long-term follow-up are reasonable in these high-risk patients.

Untangling a species complex of arid zone grasses (Triodia) reveals patterns congruent with co-occurring animals.

The vast Australian arid zone formed over the last 15million years, and gradual aridification as well as more extreme Pliocene and Pleistocene climate shifts have impacted the evolution of its biota. Understanding the evolutionary history of groups of organisms or regional biotas such as the Australian arid biota requires clear delimitation of the units of biodiversity (taxa). Here we integrate evidence from nuclear (ETS and ITS) and chloroplast (rps16-trnK spacer) regions and morphology to clarify taxonomic boundaries in a species complex of Australian hummock grasses (Triodia) to better understand the evolution of Australian arid zone plants and to evaluate congruence in distribution patterns with co-occurring organisms. We find evidence for multiple new taxa in the T. basedowii species complex, but also incongruence between data sets and indications of hybridization that complicate delimitation. We find that the T. basedowii complex has high lineage diversity and endemism in the biologically important Pilbara region of Western Australia, consistent with the region acting as a refugium. Taxa show strong geographic structure in the Pilbara, congruent with recent work on co-occurring animals and suggesting common evolutionary drivers across the biota. Our findings confirm recognition of the Pilbara as an important centre of biodiversity in the Australian arid zone, and provide a basis for future taxonomic revision of the T. basedowii complex and more detailed study of its evolutionary history and that of arid Australia.