Predicting time to asystole following withdrawal of life-sustaining treatment: a systematic review

The planned withdrawal of life-sustaining treatment is a common practice in the intensive care unit for patients where ongoing organ support is recognised to be futile. Predicting the time to asystole following withdrawal of life-sustaining treatment is crucial for setting expectations, resource utilisation and identifying patients suitable for organ donation after circulatory death. This systematic review evaluates the literature for variables associated with, and predictive models for, time to asystole in patients managed on intensive care units. We conducted a comprehensive structured search of the MEDLINE and Embase databases. Studies evaluating patients managed on adult intensive care units undergoing withdrawal of life-sustaining treatment with recorded time to asystole were included. Data extraction and PROBAST quality assessment were performed and a narrative summary of the literature was provided. Twenty-three studies (7387 patients) met the inclusion criteria. Variables associated with imminent asystole (<60 min) included: deteriorating oxygenation; absence of corneal reflexes; absence of a cough reflex; blood pressure; use of vasopressors; and use of comfort medications. We identified a total of 20 unique predictive models using a wide range of variables and techniques. Many of these models also underwent secondary validation in further studies or were adapted to develop new models. This review identifies variables associated with time to asystole following withdrawal of life-sustaining treatment and summarises existing predictive models. Although several predictive models have been developed, their generalisability and performance varied. Further research and validation are needed to improve the accuracy and widespread adoption of predictive models for patients managed in intensive care units who may be eligible to donate organs following their diagnosis of death by circulatory criteria.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Barriers to Care for Pediatric Rural Medulloblastoma Patients Receiving Craniospinal Proton Radiotherapy without In-State Facilities

PURPOSE/OBJECTIVE(S)

Medulloblastoma represents ∼20% of all pediatric brain malignancies. The preferred treatment modality for craniospinal irradiation (CSI) has evolved to be proton beam therapy to reduce late toxicities including secondary malignancy. Access to proton therapy centers is more limited in states without one. Barriers to access for rural patients are underreported in the literature.

MATERIALS/METHODS

Patients <25 years old with a diagnosis of medulloblastoma were identified from a tumor registry at a rural academic center. A chart review was conducted to identify specific barriers to proton beam CSI. Descriptive analyses were performed to describe this cohort and their barriers.

RESULTS

We identified a total of 18 patients diagnosed between 2000 and 2022. The mean age was 10 years old (range 11 months - 20 years). 2 patients were excluded who had minimal documentation. 7 patients were diagnosed before 1/1/2014, a cutoff after which protons were considered more often in this patient population. Patient demographics were 39% female, 61% male, 22% Black, and 72% White, 6% Hispanic. 3 patients received protons. 2 patients had recurrence and 3 patients developed secondary malignancy. Out of 18 patients, proton therapy was discussed with 11 patients. The rates of documented barriers to radiotherapy for the cohort at large (n = 18) and for those where proton therapy was discussed in particular (n = 11) are as follows (cohort at large / had discussion): 4(22%) / 4(36%) difficulty obtaining insurance approval, 4(22%) / 4(36%) inpatient medical needs, 5(28%) / 5(46%) outpatient medical needs, 4(22%) / 4(36%) family scheduling conflicts, 3(17%) / 3(27%) travel costs/financial burdens, 4(22%) / 4(36%) not a clinical trial candidate, 3(17%) / 3(27%) radiotherapy delay, 9(50%) / 5(46%) other barriers to non-radiotherapy care. For the cohort at large or for those with proton therapy discussions, there were no significant associations between white and underrepresented minorities for the aforementioned barriers to care.

CONCLUSION

To our knowledge, this is the first study that identifies patient barriers to accessing proton beam CSI for medulloblastoma patients from a rural tertiary care center without in-state proton radiotherapy centers. This study yields insight into the particular barriers encountered by these patients and their families, allowing clinical teams to identify potential issues in an effort to overcome those barriers. Advocacy for access to care on behalf of this vulnerable patient population may be required by our field on a state and national level.

Rural Pediatric Radiation Oncology in the Era of COVID-19: A Single Institution Analysis

PURPOSE/OBJECTIVE(S)

Health inequities have recently gained prominence in public consciousness as a result of the COVID-19 pandemic. Rural access to care was particularly impacted regarding delays in cancer screening, diagnosis, and treatment. The fractionated nature of radiotherapy creates transportation burdens in this population. We reviewed our institutional experience with pediatric radiotherapy at a tertiary academic center serving a primarily rural population over a large geographic area.

MATERIALS/METHODS

The financial burden of radiotherapy in pediatric patients in our database was modeled using cost-analysis. The cost of transportation using distance to our facility and the IRS-assessed tax value per mile was calculated. Correlative analyses were conducted to evaluate the association of radiotherapy delivered pre- vs. post-COVID with patient race, age at diagnosis, and distance from our institution. Analyses were conducted with two-tailed Pearson correlations for transportation cost vs. age at diagnosis. Mann-Whitney U testing was used to analyze transportation cost vs. patient race. Fisher's Exact Test was used to analyze the trends between tumor primary sites pre- and post-COVID.

RESULTS

There was a statistically significant increase in brain tumors vs. all others from 9.1% to 66.7% post-COVID (p = 0.029). When comparing patients treated prior to the onset of the COVID-19 pandemic in 2020 to those treated during the peak years of the pandemic in 2020-2021, there was no difference in the average distance traveled for treatment. However, the mean cost of transportation for pediatric patients undergoing radiotherapy prior to COVID-19 was $266 USD (median = $331), vs. a mean of $535 (median = $378) for patients treated during 2020-2021. For patients treated in 2022, after the height of COVID-19, the mean cost of transportation was $501 (median = $432). No statistically significant differences were found between the cost of transportation and patient race or age at diagnosis before vs. after the onset of COVID-19.

CONCLUSION

Our results highlight the importance of understanding barriers to care and what type of resources are most impactful to rural pediatric patients at our center. The rise of transportation costs for radiotherapy following the COVID-19 pandemic may indicate an additional barrier to care, potentially associated with increasing inflation, for rural pediatric patients that is underreported in the literature. The rise in the relative prevalence of brain tumors at our institution during this period warrants further investigation.

A SEER Database Cohort of 547 Patients with Non-Squamous Cell Carcinoma of the Penis: Clinical Characteristics and Outcomes

PURPOSE/OBJECTIVE(S)

Little research has investigated the prevalence and distribution of the diverse pathologies of non-squamous cell carcinoma (non-SCC) of the penis. Although rare in clinical practice, these cancers have become a focus of greater importance among patients, clinicians, and researchers, particularly in developing countries. The principal objective of this study was to analyze the major types of penile non-squamous cell carcinoma, elucidate common treatment pathways, and highlight outcomes including 5-year survival.

MATERIALS/METHODS

The Surveillance, Epidemiology and End Results (SEER) database was queried between 2000 to 2018 to identify a retrospective cohort of patients with penile non-SCC. Demographic information, cancer characteristics, diagnostic methods, treatments administered, and survival were investigated.

RESULTS

A total of 547 cases of penile non-SCC were included in the analysis. The most prevalent non-SCC cancers included epithelial neoplasms, not otherwise specified (15.4%), unspecified neoplasms (15.2%), basal cell neoplasms (13.9%), blood vessel tumors (13.0%), nevi and melanomas (11.7%), and ductal and lobular neoplasms (9.9%). Data for the nine most prevalent neoplasms are included in Table 1. Over half (56.7%) of patients elected to undergo surgical intervention. Patients rarely received systemic therapy (3.8%) or radiation (4.0%). Five-year survival was 35.5%. Median survival was 5.2 years (62.7 months). Patients who underwent surgery had greater annual survival for 0 to 10 years compared to those who did not have surgery. Significant differences in survival were found between patients who had regional, localized, and distant metastases (p<0.05). A significant difference in survival was found for patients married at diagnosis versus those who were unmarried at diagnosis (p<0.05). Lower survival rates were observed for patients older than 70 years.

CONCLUSION

Although less prevalent than squamous cell carcinoma, penile non-SCC encompasses a diverse set of neoplasms. Patients in this cohort had a high utilization of surgical management leading to superior outcomes compared to those not receiving surgery. Radiation is an uncommonly pursued treatment pathway. Patient demographics and socioeconomic variables such as marital status may be valuable when investigating cancer outcomes. This updated database analysis can help inform diagnosis, management, and clinical outcomes for this rare group of malignancies.

Squamous Cell Carcinoma of the Bladder: Analysis of Treatments and Outcomes

PURPOSE/OBJECTIVE(S)

Squamous cell carcinoma (SCC) of the bladder is a rare disease composing 2-5% of all bladder cancers. Currently, no consensus exists regarding treatment recommendations for this rare malignancy, although established regimens include various permutations of chemotherapy, radiation, laser treatments, immunotherapies, and surgeries, ranging from pelvic exenteration to local excision. The present study aims to analyze outcomes of the aforementioned treatments to guide clinical decision-making for patients with the disease.

MATERIALS/METHODS

Patients with bladder SCC diagnosed between 2000 and 2018 were reviewed utilizing data from the Surveillance, Epidemiology, and End Results Registry (SEER) program. Data was analyzed using SPSS and Python. Examined variables included presence of metastases at diagnosis, surgery, radiotherapy, and chemotherapy reception. Five-year overall survival (OS) curves were analyzed using Kaplan-Meier probability stratified by treatment modality.

RESULTS

A total of 5,635 patients with bladder SCC were identified; the most abundantly reported demographics were white race (86%), patient age > 70 years (61%), and male sex (63%). Median survival was 13 months and was significantly decreased in patients treated with chemotherapy or radiation (median survival of nine months or 12 months, respectively). Patients treated with radiation and surgery saw a decreased 10-year survival rate of about 10% if no chemotherapy was administered; this difference narrowed to about a 4% decrease in patients treated with chemotherapy. All radical surgical procedures (to include partial and total cystectomy, and total and posterior exenteration) resulted in a statistically significant increase in survival, except for patients that underwent radical cystectomy including anterior exenteration (p = 0.101). Patients that underwent surgery saw an increased median survival of 15 months. Heatmap analysis demonstrated a significant correlation between tumor size and distant metastases (r = 0.898). Preliminary unsupervised cluster analysis identified two distinct patient subgroups characterized most strongly by race and treatment modality used.

CONCLUSION

Bladder SCC carries a high mortality burden, with a median survival time of 13 months after diagnosis. Based on this study's analysis, radical surgery may be the most effective treatment for this disease. This study also sets a precedent for future research, as more advanced machine learning methods (including cluster and binary tree analysis, as was done in this analysis) can be used to identify the most explanatory variables related to improved patient outcomes.

Host brood traits, independent of adult behaviours, reduce Varroa destructor mite reproduction in resistant honeybee populations

The ectoparasitic mite Varroa destructor is an invasive species of Western honey bees (Apis mellifera) and the largest pathogenic threat to their health world-wide. Its successful invasion and expansion is related to its ability to exploit the worker brood for reproduction, which results in an exponential population growth rate in the new host. With invasion of the mite, wild honeybee populations have been nearly eradicated from Europe and North America, and the survival of managed honeybee populations relies on mite population control treatments. However, there are a few documented honeybee populations surviving extended periods without control treatments due to adapted host traits that directly impact Varroa mite fitness. The aim of this study was to investigate if Varroa mite reproductive success was affected by traits of adult bee behaviours or by traits of the worker brood, in three mite-resistant honey bee populations from Sweden, France and Norway. The mite's reproductive success was measured and compared in broods that were either exposed to, or excluded from, adult bee access. Mite-resistant bee populations were also compared with a local mite-susceptible population, as a control group. Our results show that mite reproductive success rates and mite fecundity in the three mite-resistant populations were significantly different from the control population, with the French and Swedish populations having significantly lower reproductive rates than the Norwegian population. When comparing mite reproduction in exposed or excluded brood treatments, no differences were observed, regardless of population. This result clearly demonstrates that Varroa mite reproductive success can be suppressed by traits of the brood, independent of adult worker bees.

The archaeological potential of the northern Luangwa Valley, Zambia: The Luwumbu basin

The Luangwa Basin, Zambia, which forms part of the Zambezi drainage, is strategically located between the Central African plateau and the East African Rift system. The Luangwa River and major tributaries, such as the Luwumbu River, are perennial water sources supporting essential resources that sustain human communities and a rich and diverse fauna and flora. The archaeological record of Luangwa is relatively unknown, despite early archaeological exploration hinting at its potential. Recent research in the southern Luangwa valley, however, suggests that it preserves a long record of hominin occupation spanning the Early to Late Stone Age. The research described here details fieldwork carried out in northeastern Luangwa, in the Luwumbu Basin, that confirms that a relatively deep package of Quaternary deposits, containing evidence of the Stone Age occupation of the region persists in the upper piedmont zone.

Malaria risk and receptivity: Continuing development of insecticide resistance in the major malaria vector Anopheles arabiensis in northern KwaZulu-Natal, South Africa

Malaria incidence in South Africa is highest in the three endemic provinces: KwaZulu-Natal, Mpumalanga and Limpopo. The contribution to malaria transmission by several mosquito species, variation in their resting behaviours and low levels of insecticide resistance makes it necessary to periodically monitor Anopheles species assemblages and resistance phenotypes in vector populations. The aim of this study was therefore to assess Anopheles species assemblage in northern KwaZulu-Natal and to collect insecticide susceptibility data for An. arabiensis, the primary vector of malaria in that province. Anopheles specimens were collected from Mamfene, Jozini, northern KwaZulu-Natal from November 2019 to April 2021. Progeny of wild-collected An. arabiensis females were used for standard insecticide susceptibility tests and synergist bioassays. Anopheles arabiensis contributed 85.6% (n=11 062) of the total catches. Samples for subsequent insecticide susceptibility bioassays were selected from 212 An. arabiensis families. These showed low-level resistance to DDT, permethrin, deltamethrin, and bendiocarb, as well as full susceptibility to pirimiphos-methyl. Synergist bioassays using piperonyl butoxide and triphenyl phosphate suggest oxygenase-based pyrethroid and esterase-mediated sequestration of bendiocarb. These low levels of resistance are unlikely to be operationally significant at present. It is concluded that northern KwaZulu-Natal Province remains receptive to malaria transmission despite ongoing control and elimination interventions. This is due to the perennial presence of the major vector An. arabiensis and other secondary vector species. The continued detection of low-frequency insecticide resistance phenotypes in An. arabiensis is cause for concern and requires periodic monitoring for changes in resistance frequency and intensity.

Promoting resilience in healthcare workers during the COVID-19 pandemic with a brief online intervention

INTRODUCTION

The psychological wellbeing of healthcare workers has been impacted by the high levels of stress many have experienced during the Coronavirus Disease 2019 (COVID-19) pandemic. This study aimed to examine the feasibility and acceptability of a brief online course focused on introducing evidence-based skills that could increase resilience and decreases emotional distress in healthcare workers during the pandemic.

MATERIALS AND METHODS

Employees of a large healthcare system completed a mental health survey at baseline, and then one month and two months after some employees participated in an online resilience-enhancement course consisting of three 12-19 min videos focused on mindfulness, mentalization, and self-compassion.

RESULTS

A total of 554 participants completed the baseline survey, endorsing moderate to high levels of emotional distress. Of those who completed all three assessments and participated in the course (n = 38), significant improvements in resilience and reductions in emotional distress were found one and two months later, in comparison to those who did not participate in the course (n = 110).

DISCUSSION

These findings suggest that a brief, online intervention can improve the mental health of healthcare workers during a crisis such as the COVID-19 pandemic.

Age effects on clinical and neurocognitive risk factors for suicide attempt in depression - Findings from the AFSP lifespan study

BACKGROUND

Studies of risk factors for suicidal behavior are typically restricted to narrow age ranges, making it difficult to determine if they have the same relevance or potency across the full adult lifespan.

METHODS

This study examined selected clinical and neurocognitive risk factors for suicidal behavior - borderline personality traits, aggression, depressive rumination, memory performance, and language fluency- in a multi-site sample (N = 309, ages 16-80) of depressed patients with a recent (last 5 years) suicide attempt or no history of attempt, and demographically similar non-psychiatric controls. We examined cross-sectional age and attempter/non-attempter differences on these risk factors, and whether certain risk factors were more prominent discriminators of past suicide attempt earlier or later in the lifespan. Correlations with age were computed, and logistic regression was used to classify attempter status based on each risk factor and its interaction with age.

RESULTS

Nearly all risk factors were negatively correlated with age. Borderline traits, aggression, memory, and category fluency each predicted attempter status (p < 0.05), but these effects were not different across ages. In contrast, the association between rumination and suicide attempt status differed across the lifespan, becoming a stronger discriminator of past suicidal behavior at older ages.

LIMITATIONS

The cross-sectional design limits our developmental findings.

CONCLUSIONS

Despite age-related changes in symptom severity or neurocognitive performance, key risk factors for suicidal behavior previously identified in studies with more restricted age-ranges are salient throughout the adult lifespan. In contrast, depressive rumination may be particularly salient in later life.

Overturning circulation, nutrient limitation, and warming in the Glacial North Pacific

Although the Pacific Ocean is a major reservoir of heat and CO₂, and thus an important component of the global climate system, its circulation under different climatic conditions is poorly understood. Here, we present evidence that during the Last Glacial Maximum (LGM), the North Pacific was better ventilated at intermediate depths and had surface waters with lower nutrients, higher salinity, and warmer temperatures compared to today. Modeling shows that this pattern is well explained by enhanced Pacific meridional overturning circulation (PMOC), which brings warm, salty, and nutrient-poor subtropical waters to high latitudes. Enhanced PMOC at the LGM would have lowered atmospheric CO₂-in part through synergy with the Southern Ocean-and supported an equable regional climate, which may have aided human habitability in Beringia, and migration from Asia to North America.

Clinic time required to manage cardiac implantable electronic device patients: a time and motion workflow evaluation

Background

The population with cardiac implantable electronic devices (CIEDs) is growing, creating workload for device clinics to manage these patients. However, the CIED follow-up workflow is poorly understood. This study sought to characterize the workflow and staff time for CIED patient management.

Methods

A time and motion workflow evaluation was performed in 6 U.S. CIED clinics, which manage an average of 4,217 patients. Each task involved in CIED management was repeatedly timed, including all manufacturers, during 1 business week at each clinic. Mean staff time for a remote transmission and an in-person visit were calculated, including all clinical and administrative (e.g: scheduling, documentation) activities related to the encounter. Annual staff time for follow-up of 1 patient was modeled using CIED transmission data for the 6 clinics, guidelines for CIED follow-up, and published literature.

Results

124 clinic visits and 1,374 remote monitoring activities were observed. Staff time required per remote transmission ranged from 12.1–13.4 minutes (depending on the CIED type), and time per visit was 43.4–51.0 minutes. Including all remote and in-person follow-ups, the estimated total staff time per year to manage one pacemaker, ICD, CRT, and ICM patient was 2.3, 2.4, 2.4, and 9.3 hours, respectively (Table 1).

Conclusion

CIED clinic workflow is complex and requires significant staff time. Remote monitoring is an efficient complement to in-office visits, allowing for continuous follow-up of patients. Future research should examine heterogeneity in clinic processes to identify the most efficient workflow.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic

Brain cytochrome-c-oxidase as a marker of mitochondrial function: A pilot study in major depression using NIRS

BACKGROUND

Brain mitochondrial dysfunction is implicated in the pathophysiology of mood disorders. Brain cytochrome-c-oxidase (COX) activity is associated with the mitochondrial function. Near-infrared spectroscopy (NIRS) noninvasively measures oxidized COX (oxCOX) and tissue oxygenation index (TOI) reflecting cerebral blood flow and oxygenation.

METHODS

oxCOX and TOI were assessed in prefrontal cortex (Fp1/2, Brodmann area 10) in patients in a major depressive episode (N = 13) with major depressive disorder (MDD; N = 7) and bipolar disorder (BD; N = 6) compared with the controls (N = 10). One patient with MDD and all the patients with BD were taking medications. Computational modeling estimated oxCOX and TOI related indices of mitochondrial function and cerebral blood flow, respectively.

RESULTS

oxCOX was lower in patients than controls (p = .014) correlating inversely with depression severity (r = -.72; p = .006), driven primarily by lower oxCOX in BD compared with the controls. Computationally modeled mitochondrial parameters of the electron transport chain, such as the nicotinamide adenine dinucleotide ratio (NAD⁺ /NADH; p = .001) and the proton leak rate across the inner mitochondrial membrane (k_lk2 ; p = .008), were also lower in patients and correlated inversely with depression severity. No such effects were found for TOI.

CONCLUSIONS

In this pilot study, oxCOX and related mitochondrial parameters assessed by NIRS indicate an abnormal cerebral metabolic state in mood disorders proportional to depression severity, potentially providing a biomarker of antidepressant effect. Because the effect was driven by the medicated BD group, findings need to be evaluated in a larger, medication-free population.

Anopheles parensis contributes to residual malaria transmission in South Africa

BACKGROUND

Understanding the contribution of outdoor-resting Anopheles mosquitoes to residual malaria transmission is important in terms of scaling up vector control towards malaria elimination in South Africa. The aim of this project was to assess the potential role of Anopheles parensis and other Anopheles species in residual malaria transmission, using sentinel surveillance sites in the uMkhanyakude District of northern KwaZulu-Natal Province.

METHODS

Monthly vector surveillance was conducted at the sentinel sites from January 2017 to May 2018. Outdoor-placed clay pot resting traps were used to collect male and female adult Anopheles mosquitoes. All Anopheles gambiae complex and Anopheles funestus group specimens collected were identified to species and all females were screened for Plasmodium falciparum circumsporozoite protein (CSP) by enzyme-linked immunosorbent assay (ELISA). Samples showing infectivity for P. falciparum were further verified by a nested PCR and subsequent DNA sequence analysis.

RESULTS

From a sample of 491 anophelines, Anopheles arabiensis (n = 228) and An. parensis (n = 194) were the most abundant. Other species collected included Anopheles merus (n =11), Anopheles quadriannulatus (n = 10), Anopheles leesoni (n = 29), Anopheles rivulorum (n =18), and Anopheles vaneedeni (n =1). Of the 317 female specimens screened for P. falciparum CSP, one Anopheles arabiensis and one An. parensis showed positive by ELISA and Plasmodium nested PCR. For the An. parensis specimen, confirmation of its species identity was based on sequence analysis of the ITS2 region, and the presence of P. falciparum DNA was further confirmed by sequence analysis.

CONCLUSIONS

Anopheles parensis is a potential vector of malaria in South Africa although its contribution to transmission is likely to be minimal at best owing to its strong zoophilic tendency. By contrast, An. arabiensis is a major vector that is primarily responsible for the bulk of residual malaria transmission in South Africa. As all recently collected sporozoite-positive Anopheles mosquitoes were found in outdoor-placed resting traps, it is necessary to introduce interventions that can be used to control outdoor-resting vector populations while maintaining the efficacy of South Africa's indoor house spraying operations.

Improving North Atlantic Marine Core Chronologies Using 230Th Normalization

Producing independent and accurate chronologies for marine sediments is a prerequisite to understand the sequence of millennial-scale events and reveal potential temporal offsets between marine and continental records, or between different marine records, possibly from different regions. The last 40 ky is a generally well-constrained period since radiocarbon (14C) can be used as an absolute dating tool. However, in the northern North Atlantic, calendar ages cannot be directly derived from 14C ages, due to temporal and spatial variations of surface reservoir ages. Alternatively, chronologies can be derived by aligning Greenland ice-core time series with marine surface records. Yet this approach suffers from the lack of clearly defined climatic events between 14.7 and 23.3 cal ky BP (hereafter ka), a crucial period encompassing Heinrich Stadial 1 and the onset of the last deglaciation. In this study, (i) we assess the benefits of 230Th normalization to refine the sedimentation history between surface temperature alignment tie points and (ii) revisit the chronologies of three North Atlantic marine records. Our study supports the contention that the marked increase in the Greenland Ca2+ record at 17.48 ka ± 0.21 ky (1σ) occurred within dating uncertainty of sea surface temperature cooling in the North Atlantic at the onset of Heinrich Stadial 1. This sharp feature might be useful for future chronostratigraphic alignments to remedy the lack of chronological constraint between 14.7 and 23.3 ka for North Atlantic marine records that are subject to large changes in 14C surface reservoir age.

CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales

The cause of changes in atmospheric carbon dioxide (CO₂) during the recent ice ages is yet to be fully explained. Most mechanisms for glacial-interglacial CO₂ change have centred on carbon exchange with the deep ocean, owing to its large size and relatively rapid exchange with the atmosphere¹. The Southern Ocean is thought to have a key role in this exchange, as much of the deep ocean is ventilated to the atmosphere in this region². However, it is difficult to reconstruct changes in deep Southern Ocean carbon storage, so few direct tests of this hypothesis have been carried out. Here we present deep-sea coral boron isotope data that track the pH-and thus the CO₂ chemistry-of the deep Southern Ocean over the past forty thousand years. At sites closest to the Antarctic continental margin, and most influenced by the deep southern waters that form the ocean's lower overturning cell, we find a close relationship between ocean pH and atmospheric CO₂: during intervals of low CO₂, ocean pH is low, reflecting enhanced ocean carbon storage; and during intervals of rising CO₂, ocean pH rises, reflecting loss of carbon from the ocean to the atmosphere. Correspondingly, at shallower sites we find rapid (millennial- to centennial-scale) decreases in pH during abrupt increases in CO₂, reflecting the rapid transfer of carbon from the deep ocean to the upper ocean and atmosphere. Our findings confirm the importance of the deep Southern Ocean in ice-age CO₂ change, and show that deep-ocean CO₂ release can occur as a dynamic feedback to rapid climate change on centennial timescales.

Are comorbid anxiety disorders a risk factor for suicide attempts in patients with mood disorders? A two-year prospective study

BACKGROUND

Comorbid anxiety disorders have been considered a risk factor for suicidal behavior in patients with mood disorders, although results are controversial. The aim of this two-year prospective study was to determine if lifetime and current comorbid anxiety disorders at baseline were risk factors for suicide attempts during the two-year follow-up.

METHODS

We evaluated 667 patients with mood disorders (504 with major depression and 167 with bipolar disorder) divided in two groups: those with lifetime comorbid anxiety disorders (n=229) and those without (n=438). Assessments were performed at baseline and at 3, 12, and 24 months. Kaplan-Meier survival analysis and log-rank test were used to evaluate the relationship between anxiety disorders and suicide attempts. Cox proportional hazard regression was performed to investigate clinical and demographic variables that were associated with suicide attempts during follow-up.

RESULTS

Of the initial sample of 667 patients, 480 had all three follow-up interviews. During the follow-up, 63 patients (13.1%) attempted suicide at least once. There was no significant difference in survival curves for patients with and without comorbid anxiety disorders (log-rank test=0.269; P=0.604). Female gender (HR=3.66, P=0.001), previous suicide attempts (HR=3.27, P=0.001) and higher scores in the Buss-Durkee Hostility Inventory (HR=1.05, P≤0.001) were associated with future suicide attempts.

CONCLUSIONS

Our results suggest that comorbid anxiety disorders were not risk factors for suicide attempts. Further studies were needed to determine the role of anxiety disorders as risk factors for suicide attempts.

A Novel Polyurethane Film for Biomedical Use

Polyurethane films were prepared from toluene diisocyanate (TDI), and poly(propylene-ethylene)glycol without catalyst. These films had a decrease in tensile strength and an increase in ultimate elongation when the TDI content of the polymers was decreased. The effects of aging and accelerated aging on completion of polymerization and on mechanical properties were examined. In the case of accelerated aging samples, complete polymerization with no change in mechanical properties was observed. Blood compatibility tests were carried out and the examination of the surfaces revealed no clotting, aggregation of blood cells, or fibrin formation.

Polyurethane Membranes

Poly(ether urethane) membranes were synthesized from toluene diisocyanate (TDI), and poly(propylene-ethylene) glycol. Catalysts, chain extenders, solvents, or other reagents were not used during the preparation to make the biomedical grade membranes. Density, water content, oxygen diffusivity, and the surface thrombogenicity were examined and the presence of the extractables was searched. A decrease in density and an increase in water content and oxygen permeability was observed with an increase in polyol content of the mem branes. Extraction of leachables in solvents was observed which was prevented by accelerated aging that had no effect on the other properties examined.

Constituents of Cuscuto Reflexa are anti-HIV Agents

Crude water extracts of Cuscuta reflexa exhibited anti-HIV activity. Fractionation of the crude extract led to the isolation of nine pure compounds with closely related structures, showing interesting structure activity relationships. 3,5,7,4′-Tetrahydroxyflavanone (aromadendrin) inhibited infection by binding to V3 loop of gp 120 and inhibiting its interaction with CD4, whereas 3,5,7,3′,4′-pentahydroxyflavanone (taxifolin), with an extra OH group in the 3′ position in ring B was less specific and exhibited less selectivity in cell cultures. In general, flavanones containing an extra OH group in the 3′ position (taxifolin, taxifolin-7-O-β-D-glucopyranoside and coccinoside B) were less specific and inhibited viral protease, reverse transcriptase, CD4 /gp120 interaction in vitro and bound to non specific proteins. Other compounds isolated from C reflexa were derivatives of quinic acids; 3,4-O-dicaffeoylquinic acid was more active than 3-O-caffeoyl quinic acid. The anti-HIV activity of crude extract may be the result of combinatory effects with compounds of different modes of action.

Inhibition of the Production of HIV-1 from Chronically Infected H9 Cells by Metal Compounds and Their Complexes with L-cysteine or N-acetyl-L-cysteine

A number of metal compounds and their complexes with cysteine and N-acetyl-cysteine (NAC) were tested for their ability to inhibit HIV replication in vitro, specifically in chronically infected H9 cells (which produce virus continuously). Out of seven metal compounds tested, only bismuth nitrate and bismuth sodium tartrate inhibited virus production in chronically infected H9 cells. The complexes made with metals and cysteine or NAC had slightly improved selective indices.

A national house-staff audit of medical prophylaxis in medical patients for the PREVENTion of Venous ThromboEmbolism (PREVENT-VTE)

We established a national audit to assess the thromboprophylaxis rate for venous thromoembolism (VTE) in at risk medical patients in acute hospitals in the Republic of Ireland and to determine whether the use of stickers to alert physicians regarding thromboprophylaxis would double the rate prophylaxis in a follow-up audit. 651 acute medical admission patients in the first audit and 524 in the second re-audit were recruited. The mean age was 66.5 yrs with similar numbers of male and female patients and 265 (22.6%) patients were active smokers. The first and second audits identified 549 (84%) and 487 (93%) of patients at-risk for VTE respectively. Of the at-risk patients, 163 (29.7%) and 132 (27.1%) received LMWH in the first and second audit respectively. Mechanical thromboprophylaxis was instigated in 75 (13.6%) patients in the first and 86 (17.7%) patients in the second audit. The placement of stickers in patient charts didn't produce a significant increase in the number of at risk patients treated in the second audit. There is unacceptably low adherence to the ACCP guidelines in Ireland and more complex intervention than chart reminders are required to improve compliance.

Cardiometabolic risk reduction in an intensive cardiovascular health program

BACKGROUND AND AIMS

Insulin and leptin are important markers of insulin resistance and vascular inflammation in metabolic and cardiovascular diseases. This study evaluated changes in circulating levels of insulin and leptin during a cardiovascular health program to improve our understanding of cardiometabolic risk reduction.

METHODS AND RESULTS

Participants (n=76) completed a prospective, nonrandomized program designed to stabilize or reverse progression of coronary artery disease through dietary changes, exercise, stress management, and group support. Controls (n=76) were matched to participants based on age, gender, and disease status. Traditional cardiovascular risk factors were assessed at baseline, 12 weeks, and 52 weeks by standard methods. Dietary data were collected by 72-h recall and evaluated by Food Processor® v8.4.0. Ultrasensitive insulin and leptin levels were measured by radioimmunoassay. Participants successfully reduced their total caloric intake from >2000 calories per day to ≈ 1700 calories per day (p<0.05 compared to controls), lowered daily fat intake by >60% (p<0.001 compared to controls), and increased carbohydrate intake by >30% (p<0.001). Repeated-measures ANOVA indicated significant beneficial changes (p<0.001 compared to controls) in plasma insulin (-19%) and leptin (-33%) during the lifestyle program, as well as improvement in traditional cardiovascular risk factors. Response was similar between men and women for most risk factors and was not markedly influenced by medication use.

CONCLUSION

Lifestyle changes focusing on diet, physical activity, and stress reduction can successfully modify both cardiovascular and metabolic risk factors, with the potential to mediate cardiometabolic risk through beneficial anti-inflammatory and anti-oxidative effects on the vasculature.