Perceived self-efficacy and empowerment in patients at increased risk of sudden cardiac arrest

Background

The role of multidisciplinary clinics for psychosocial care is increasingly recognized for those living with inherited cardiac conditions (ICC). In Canada, access to healthcare providers differ between clinics. Little is known about the relationship between access to specialty care and a patient's ability to cope with, and manage their condition.

Methods

We leveraged the Hearts in Rhythm Organization (HiRO) to conduct a cross-sectional, community-based survey of individuals with ICC and their family members. We aimed to describe access to services, and explore the relationships between participants' characteristics, cardiac history and self-reported health status and self-efficacy (GSE: General Self-Efficacy Scale) and empowerment (GCOS-24: Genetic Counseling Outcome Scale).

Results

We collected 235 responses from Canadian participants in 10 provinces and territories. Overall, 63% of participants reported involvement of a genetic counsellor in their care. Access to genetic testing was associated with greater empowerment [mean GCOS-24: 121.14 (SD = 20.53) vs. 105.68 (SD = 21.69); p = 0.004]. Uncertain genetic test results were associated with lower perceived self-efficacy (mean GSE: uncertain = 28.85 vs. positive = 33.16, negative = 34.13; p = 0.01). Low global mental health scores correlated with both lower perceived self-efficacy and empowerment scores, with only 11% of affected participants reporting involvement of psychology services in their care.

Conclusion

Differences in resource accessibility, clinical history and self-reported health status impact the perceived self-efficacy and empowerment of patients with ICC. Future research evaluating interventions to improve patient outcomes is recommended.

Continuous non-invasive remote automated blood pressure monitoring with novel wearable technology: A Validation Study

Background

Wearable continuous monitoring biosensor technologies have the potential to transform postoperative care with early detection of impending clinical deterioration.

Objective

Our aim was to validate the accuracy of Cloud DX Vitaliti continuous vital signs monitor (CVSM) continuous noninvasive blood pressure (cNIBP) measurements in postsurgical patients. A secondary aim was to examine user acceptance of the Vitaliti CVSM with respect to comfort, ease of application, sustainability of positioning, and aesthetics.

Methods

Included participants were ≥18 years old and recovering from surgery in a cardiac intensive care unit (ICU). We targeted a maximum recruitment of 80 participants for verification and acceptance testing. We also oversampled to minimize the effect of unforeseen interruptions and other challenges to the study. Validation procedures were according to the International Standards Organization (ISO) 81060-2:2018 standards for wearable, cuffless blood pressure (BP) measuring devices. Baseline BP was determined from the gold-standard ICU arterial catheter. The Vitaliti CVSM was calibrated against the reference arterial catheter. In static (seated in bed) and supine positions, 3 cNIBP measurements, each 30 seconds, were taken for each patient with the Vitaliti CVSM and an invasive arterial catheter. At the conclusion of each test session, captured cNIBP measurements were extracted using MediCollector BEDSIDE data extraction software, and Vitaliti CVSM measurements were extracted to a secure laptop through a cable connection. The errors of these determinations were calculated. Participants were interviewed about device acceptability.

Results

The validation analysis included data for 20 patients. The average times from calibration to first measurement in the static position and to first measurement in the supine position were 133.85 seconds (2 minutes 14 seconds) and 535.15 seconds (8 minutes 55 seconds), respectively. The overall mean errors of determination for the static position were –0.621 (SD 4.640) mm Hg for systolic blood pressure (SBP) and 0.457 (SD 1.675) mm Hg for diastolic blood pressure (DBP). Errors of determination were slightly higher for the supine position, at 2.722 (SD 5.207) mm Hg for SBP and 2.650 (SD 3.221) mm Hg for DBP. The majority rated the Vitaliti CVSM as comfortable. This study was limited to evaluation of the device during a very short validation period after calibration (ie, that commenced within 2 minutes after calibration and lasted for a short duration of time).

Conclusions

We found that the Cloud DX’s Vitaliti CVSM demonstrated cNIBP measurement in compliance with ISO 81060-2:2018 standards in the context of evaluation that commenced within 2 minutes of device calibration; this device was also well-received by patients in a postsurgical ICU setting. Future studies will examine the accuracy of the Vitaliti CVSM in ambulatory contexts, with attention to assessment over a longer duration and the impact of excessive patient motion on data artifacts and signal quality.

Trial Registration

ClinicalTrials.gov NCT03493867; https://clinicaltrials.gov/ct2/show/NCT03493867

Beyond wellness monitoring: Continuous multiparameter remote automated monitoring of patients

The pursuit of more efficient patient-friendly health systems and reductions in tertiary health services use has seen enormous growth in the application and study of remote patient monitoring systems for cardiovascular patient care. While there are many consumer-grade products available to monitor patient wellness, the regulation of these technologies varies considerably, with most products having little to no evaluation data. As the science and practice of virtual care continues to evolve, clinicians and researchers can benefit from an understanding of more comprehensive solutions, capable of monitoring three or more biophysical parameters (e.g., oxygen saturation, heart rate) continuously and simultaneously. These devices, herein referred to as continuous multiparameter remote automated monitoring (CM-RAM) devices, have the potential to revolutionize virtual patient care. Through seamless integration of multiple biophysical signals, CM-RAM technologies can allow for the acquisition of high-volume big data for the development of algorithms to facilitate early detection of negative changes in patient health status and timely clinician response. In this article, we review key principles, architecture, and components of CM-RAM technologies. Work to date in this field and related implications are also presented, including strategic priorities for advancing the science and practice of CM-RAM.

Testing a nurse-led, pre-implantation educational intervention for primary prevention implantable cardioverter-defibrillator candidates: a randomized feasibility trial

AIMS

Implantable cardioverter-defibrillators (ICDs) deliver therapy for life-threatening arrhythmias. Evidence suggests that ICD candidates have misconceptions regarding ICD therapy and unmet information needs. We undertook a pilot feasibility trial comparing a nurse-led educational intervention plus standard care, vs. standard pre-ICD implantation care. Secondary aims included examination of anxiety, quality of life, and shock anxiety.

METHODS AND RESULTS

Implantable cardioverter-defibrillator candidates were consented and randomized to standard pre-ICD implantation care vs. standard care plus a nurse-led educational intervention. The primary feasibility outcomes included: recruitment rate, consent rate, randomization rate, proportion of participants able to complete all questionnaires, time to deliver intervention, and intervention topics completion. At baseline, demographic and Patient-Reported Outcomes Measurement Information System (PROMIS) anxiety scores were collected. Four weeks post-ICD implantation, participants completed the PROMIS, Florida Patient Acceptance Survey (FPAS), and Florida Shock Anxiety Scale (FSAS). Twenty patients consented (10 per group). Feasibility targets were achieved for all but two outcomes: consent rate was 87% vs. 95% target, and completion of data collection measures was 85% vs. 90% target. Consent rate was lower than expected as one patient declined, and two could not be approached. Completion rate was lower than expected as two patients were lost to follow-up, and one did not receive an ICD during the study period, leading to incomplete post-implantation survey collections.

CONCLUSION

The results demonstrate the feasibility of conducting a trial comparing a nurse-led pre-implantation educational intervention to standard care in an outpatient setting. Further study to evaluate the effectiveness of this intervention on patient-reported outcomes is warranted.

Impact of nurse scientist-led digital health interventions on management of chronic conditions

BACKGROUND

Chronic conditions are a major contributor to the burden of disease worldwide. Using innovative digital health technologies, nurse scientists are well-positioned to lead efforts to reduce the burden of chronic conditions on individuals, communities, and systems.

PURPOSE

The purpose of this review was to summarize the outcomes commonly measured in nurse-led digital health interventions that target chronic conditions and pose recommendations for the education of future nurse scientists to lead these studies.

METHODS

A rapid review of the literature was completed using CINAHL and Ovid Emcare. Studies were included if the research: a) was led by a nurse; b) described outcomes of a digital health intervention; and c) included any population with a prevalent chronic condition.

FINDINGS

26 studies were included in this review. Nurse-led digital health interventions are being used to support and manage a range of chronic conditions in varied settings.

DISCUSSION

Digital health interventions are changing the delivery of healthcare for individuals living with chronic conditions. These interventions are bridging the gaps between the digital and physical worlds and are rapidly evolving.

CONCLUSION

The recommendations posed in this review reiterate the importance of robust content and methods education for nurse scientists to address future research needs in a digital era.

Preparing for patient partnership: A scoping review of patient partner engagement and evaluation in research

BACKGROUND

Realizing patient partnership in research requires a shift from patient participation in ancillary roles to engagement as contributing members of research teams. While engaging patient partners is often discussed, impact is rarely measured.

OBJECTIVE

Our primary aim was to conduct a scoping review of the impact of patient partnership on research outcomes. The secondary aim was to describe barriers and facilitators to realizing effective partnerships.

SEARCH STRATEGY

A comprehensive bibliographic search was undertaken in EBSCO CINAHL, and Embase, MEDLINE and PsycINFO via Ovid. Reference lists of included articles were hand-searched.

INCLUSION CRITERIA

Included studies were: (a) related to health care; (b) involved patients or proxies in the research process; and (c) reported results related to impact/evaluation of patient partnership on research outcomes.

DATA EXTRACTION AND SYNTHESIS

Data were extracted from 14 studies meeting inclusion criteria using a narrative synthesis approach.

MAIN RESULTS

Patient partners were involved in a range of research activities. Results highlight critical barriers and facilitators for researchers seeking to undertake patient partnerships to be aware of, such as power imbalances between patient partners and researchers, as well as valuing of patient partner roles.

DISCUSSION

Addressing power dynamics in patient partner-researcher relationships and mitigating risks to patient partners through inclusive recruitment and training strategies may contribute towards effective engagement. Further guidance is needed to address evaluation strategies for patient partnerships across the continuum of patient partner involvement in research.

CONCLUSIONS

Research teams can employ preparation strategies outlined in this review to support patient partnerships in their work.

Health-Related Quality of Life in Patients With Atrial Fibrillation Treated With Catheter Ablation or Antiarrhythmic Drug Therapy: A Systematic Review and Meta-analysis

Background

Catheter ablation (CA) is performed in patients with atrial fibrillation (AF) to reduce symptoms and improve health-related quality of life (HRQL).

Methods

This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CA of any energy modality compared with antiarrhythmic drugs (AADs) using inverse-variance random-effects models. We searched for RCTs reporting HRQL and AF-related symptoms at 3, 6, 12, 24, 48, and 60 months after treatment as well as the number of repeat ablations.

Results

Of 15,878 records, we included 13 RCTs of CA vs AADs for the analyses of HRQL, 7 RCTs for the analyses of AF-related symptoms, and 13 RCTs for the number of repeat ablations. For the HRQL analyses at 3 months, there were significant increases in both the Physical Component Summary score (3 months' standardized mean difference = 0.58 [0.39-0.78]; P < 0.00001, I ² = 6%, 3 trials, n = 443) and the Mental Component Summary score (3 months' standardized mean difference = 0.57 [0.37-0.77]; P < 0.00001, I ² = 0%, 3 trials, n = 443), favouring CA over AADs. These differences were sustained at 12 months but not >24 months after randomization. Similar results were seen for AF-related symptoms. The number of repeat ablations and success rates after procedure varied considerably across trials.

Conclusions

Evidence from few trials suggests that CA improves physical and mental health and AF-related symptoms in the short term, but these benefits decrease with time. More trials, reporting both HRQL and AF-related symptoms, at consistent time points are needed to assess the effectiveness of CA for the treatment of AF.

Preparing for patient partnership: A scoping review of patient partner engagement and evaluation in research

Background

Realizing patient partnership in research requires a shift from patient participation in ancillary roles to engagement as contributing members of research teams. While engaging patient partners is often discussed, impact is rarely measured.

Objective

Our primary aim was to conduct a scoping review of the impact of patient partnership on research outcomes. The secondary aim was to describe barriers and facilitators to realizing effective partnerships.

Search Strategy

A comprehensive bibliographic search was undertaken in EBSCO CINAHL, and Embase, MEDLINE and PsycINFO via Ovid. Reference lists of included articles were hand‐searched.

Inclusion Criteria

Included studies were: (a) related to health care; (b) involved patients or proxies in the research process; and (c) reported results related to impact/evaluation of patient partnership on research outcomes.

Data Extraction and Synthesis

Data were extracted from 14 studies meeting inclusion criteria using a narrative synthesis approach.

Main Results

Patient partners were involved in a range of research activities. Results highlight critical barriers and facilitators for researchers seeking to undertake patient partnerships to be aware of, such as power imbalances between patient partners and researchers, as well as valuing of patient partner roles.

Discussion

Addressing power dynamics in patient partner‐researcher relationships and mitigating risks to patient partners through inclusive recruitment and training strategies may contribute towards effective engagement. Further guidance is needed to address evaluation strategies for patient partnerships across the continuum of patient partner involvement in research.

Conclusions

Research teams can employ preparation strategies outlined in this review to support patient partnerships in their work.

Transition Experiences of Caregivers of Older Adults With Dementia and Multiple Chronic Conditions: An Interpretive Description Study

INTRODUCTION

Family caregivers provide most of the care for older persons living with dementia (PLWD) and multiple chronic conditions (MCCs) in the community. Caregivers experience transitions, such as changes to their health, roles, and responsibilities, during the process of caring. Transitions encompass a time when caregivers undergo stressful responses to change. However, we know little about the transition experiences of caregivers of persons living with both dementia and MCCs.

OBJECTIVE

This qualitative study explored the transition experiences of caregivers of PLWD within the context of MCCs, from the perspective of both caregivers and practitioners. The research question was the following: What are the transition experiences of family caregivers in providing care to older PLWD and MCCs living in the community?

METHODS

This study was conducted using an interpretive description approach. Semistructured interviews were conducted with 19 caregivers of older community-dwelling PLWD and MCCs and 7 health-care providers working with caregivers in Ontario, Canada. Concurrent data collection and inductive data analysis were used.

RESULTS

Caregivers of older PLWD and MCCs experienced four key transitions: (a) taking on responsibility for managing multiple complex conditions, (b) my health is getting worse, (c) caregiving now defines my social life, and (d) expecting that things will change. Findings highlight how the coexistence of MCCs with dementia complicates caregiver transitions and the importance of social networks for facilitating transitions.

CONCLUSION

The study provided insight on the transition experiences of caregivers of older PLWD and MCCs. MCCs increased the care load and further complicated caregivers' transition experiences. Health-care providers, such as nurses, can play important roles in supporting caregivers during these transitions and engage them as partners in care.

Examination of psychological risk factors for chronic pain following cardiac surgery: protocol for a prospective observational study

INTRODUCTION

Approximately 400 000 Americans and 36 000 Canadians undergo cardiac surgery annually, and up to 56% will develop chronic postsurgical pain (CPSP). The primary aim of this study is to explore the association of pain-related beliefs and gender-based pain expectations on the development of CPSP. Secondary goals are to: (A) explore risk factors for poor functional status and patient-level cost of illness from a societal perspective up to 12 months following cardiac surgery; and (B) determine the impact of CPSP on quality-adjusted life years (QALYs) borne by cardiac surgery, in addition to the incremental cost for one additional QALY gained, among those who develop CPSP compared with those who do not.

METHODS AND ANALYSES

In this prospective cohort study, 1250 adults undergoing cardiac surgery, including coronary artery bypass grafting and open-heart procedures, will be recruited over a 3-year period. Putative risk factors for CPSP will be captured prior to surgery, at postoperative day 3 (in hospital) and day 30 (at home). Outcome data will be collected via telephone interview at 6-month and 12-month follow-up. We will employ generalised estimating equations to model the primary (CPSP) and secondary outcomes (function and cost) while adjusting for prespecified model covariates. QALYs will be estimated by converting data from the Short Form-12 (version 2) to a utility score.

ETHICS AND DISSEMINATION

This protocol has been approved by the responsible bodies at each of the hospital sites, and study enrolment began May 2015. We will disseminate our results through CardiacPain.Net, a web-based knowledge dissemination platform, presentation at international conferences and publications in scientific journals.

TRIAL REGISTRATION NUMBER

NCT01842568.

Shared medical appointments for patients with a nondiabetic physical chronic illness: A systematic review

OBJECTIVES

Shared medical appointments are group appointments, with an optional individual consultation, for patients diagnosed with chronic illnesses. Shared medical appointments improve diabetes management, but little is known about their use for other illnesses. The objective was to determine the effect that shared medical appointments have on patients with a physical chronic illness, healthcare providers, and the healthcare system.

METHODS

A systematic review was conducted searching databases from January 1970 to September 2016. Eligible trials evaluated shared medical appointments for patients with a homogeneous chronic illness, excluding diabetes and mental illness. Screening, data extraction, and risk of bias were conducted independently by two authors. Analysis was descriptive.

RESULTS

Of 2364 citations, nine randomized trials were included. Shared medical appointments were evaluated for cardiovascular illnesses (four studies), breast cancer, chronic kidney disease, Parkinson's disease, stress urinary incontinence, and carpal tunnel syndrome. Compared to usual care, no negative effects on patient quality of life, knowledge and satisfaction were reported. One study reported no difference in healthcare provider satisfaction. Another study showed fewer hospital admissions for patients who attended shared medical appointments.

DISCUSSION

Few rigorous studies evaluated the use of shared medical appointments for chronic illnesses. Overall, there appears to be no patient harms. Further studies should include more objective outcomes and larger sample sizes.

Patients’ Perspectives on End-Of-Life Issues and Implantable Cardioverter Defibrillators

Increasing numbers of cardiovascular patients are receiving implantable cardioverter defibrillators (ICDs) for primary prevention of sudden cardiac death (SCD). This report examines patients’ perspectives on related end-of-life issues. Using a grounded theory approach, audiotaped, semi-structured interviews were undertaken with 30 participants from two ICD referral centres in southwestern Ontario (24 who accepted an ICD and 6 who declined). Interview transcripts, verification with interviewees, researcher memos, published literature, and participant demographics were analyzed using NVivo7. Most participants were male, had comorbidities and an ejection fraction of less than 30 percent, and ranged in age from 26 to 87. Consensus was reached by three research team members on three main themes: quality versus quantity of life, preferred mode of death, and the technical realities of the ICD. The ICD was considered in relation to both quantity and quality of life. Most participants focused on the prevention of SCD, not the implications of the ICD for death by any other cause. Participants advocated for incorporating the ICD into advance care planning. Our findings have implications for the development of advance care plans and education of health professionals.

Usp9X Regulates Cell Death in Malignant Peripheral Nerve Sheath Tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of death in neurofibromatosis type 1 (NF1) patients. Current treatment modalities have been largely unsuccessful in improving MPNST patient survival, making the identification of new therapeutic targets urgent. In this study, we found that interference with Usp9X, a deubiquitinating enzyme which is overexpressed in nervous system tumors, or Mcl-1, an anti-apoptotic member of the Bcl-2 family whose degradation is regulated by Usp9X, causes rapid death in human MPNST cell lines. Although both Usp9X and Mcl-1 knockdown elicited some features of apoptosis, broad spectrum caspase inhibition was ineffective in preventing knockdown-induced MPNST cell death suggesting that caspase-independent death pathways were also activated. Ultrastructural examination of MPNST cells following either Usp9X interference or pharmacological inhibition showed extensive cytoplasmic vacuolization and swelling of endoplasmic reticulum (ER) and mitochondria most consistent with paraptotic cell death. Finally, the Usp9X pharmacological inhibitor WP1130 significantly reduced human MPNST growth and induced tumor cell death in an in vivo xenograft model. In total, these findings indicate that Usp9X and Mcl-1 play significant roles in maintaining human MPNST cell viability and that pharmacological inhibition of Usp9X deubiquitinase activity could be a therapeutic target for MPNST treatment.

Postoperative Remote Automated Monitoring: Need for and State of the Science

Worldwide, more than 230 million adults have major noncardiac surgery each year. Although surgery can improve quality and duration of life, it can also precipitate major complications. Moreover, a substantial proportion of deaths occur after discharge. Current systems for monitoring patients postoperatively, on surgical wards and after transition to home, are inadequate. On the surgical ward, vital signs evaluation usually occurs only every 4-8 hours. Reduced in-hospital ward monitoring, followed by no vital signs monitoring at home, leads to thousands of cases of undetected/delayed detection of hemodynamic compromise. In this article we review work to date on postoperative remote automated monitoring on surgical wards and strategy for advancing this field. Key considerations for overcoming current barriers to implementing remote automated monitoring in Canada are also presented.

"I don't know exactly what you're referring to": the challenge of values elicitation in decision making for implantable cardioverter-defibrillators

PURPOSE

Patients' values are a key component of patient-centered care and shared decision making in health care organizations. There is limited understanding on how patients' values guide their health related decision making or how patients understand the concept of values during these processes. This study investigated patients' understanding of their values in the context of considering the risks/benefits of receiving an implantable cardioverter-defibrillator (ICD).

PATIENTS AND METHODS

A qualitative substudy was conducted within a feasibility trial with first-time ICD candidates randomized to receive a patient decision aid or usual care prior to specialist consultation. Semi-structured interviews were conducted with participants post-implantation or post-specialist consultation.

RESULTS

Sixteen patients (ten male) aged 47-87 years participated. Of these, ten (62.5%) received the patient decision aid prior to specialist consultation. Findings revealed patients were confused by the word "values" and had difficulty expressing values related to risks/benefits during ICD decision making. When probed, values were conceptualized broadly capturing other factors such as desire to live, good quality of life, family's views, ICD information, control over decision, and medical authority.

CONCLUSION

This study revealed the difficulty patients considering an ICD had with articulating their values in the context of an ICD health decision and highlighted the challenge to effectively elicit patients' values within health decisions overall. It is suggested that there should be a shift away from the use of the word "values" when speaking directly to patients toward language such as "what matters to you the most" or "what is most important to you".

Evaluating the feasibility of conducting a trial using a patient decision aid in implantable cardioverter defibrillator candidates: a randomized controlled feasibility trial

BACKGROUND

Patient decision aids (PtDA) support quality decision-making. The aim of this research was to evaluate the feasibility of conducting a randomized controlled trial delivering an implantable cardioverter defibrillator (ICD)-specific PtDA to new ICD candidates and examining preliminary estimates of differences in outcomes.

METHODS

Prior to recruitment, ICD candidacy was determined. Consented patients were randomized to (1) usual care or (2) PtDA intervention. Feasibility outcomes included referral and recruitment rates, successful PtDA delivery, and completion of measures. The PtDA intervention was administered prior to specialist consultation and baseline demographics, and measures of decision quality including decisional conflict (DCS), SURE test (Sure of myself, Understand information, Risk-benefit ratio, Encouragement), patient's ICD specific values, ICD knowledge, and health-related quality of life were recorded. Post-consultation, participant's DCS was repeated and decisions to proceed, decline, or defer ICD implantation were collected. Feasibility data was determined using descriptive statistics (continuous and categorical). Preliminary estimates of differences in outcomes were assessed using mean differences. Concordance between values and decision choice was assessed using logistic regression of the intervention group.

RESULTS

We identified 135 eligible patients. Eighty-two consented to the trial randomizing patients to usual care (n = 41) or PtDA intervention (n = 41). Feasibility outcome results were (1) referral rate at approximately 20/month, (2) recruitment rate 61%, and (3) successful delivery of PtDA and study management. Pre-consultation, PtDA patients scored lower on the DCS scale (mean, standard deviation [SD] 27.3 (18.4) compared to usual care, 49.4 (18.6); the between-group difference in means [95% confidence interval (CI)] was - 22.1[- 30.23, - 13.97]. A difference remained post-implantation 21.2 (11.7), PtDA intervention 29.9 (13.3), and usual care - 8.7 [- 14.61, - 2.86]. SURE test results supported DCS differences. The PtDA group scored higher on the ICD-related knowledge questions, with 47.50% scoring greater than 3/5 of the knowledge questions correct, compared to 23.09% receiving usual care. The mean [SD] number of correct knowledge responses out of 5 was 3.33(1.19) in the PtDA group and 2.62 (1.16) in usual care pre-implant. Concordance between values and decision choice found a strong association between predicted and actual ICD implant status in the intervention group.

CONCLUSION

Our results suggest that a future definitive trial is feasible. The ICD-specific PtDA shows promise with respect to preliminary estimates of differences in outcomes.

TRIAL REGISTRATION

NCT01876173.

Questioning patient engagement: research scientists' perceptions of the challenges of patient engagement in a cardiovascular research network

BACKGROUND

Patient engagement in research is a dominant discourse in clinical research settings as it is seen as a move toward sustainable and equitable health care systems. In Canada, a key driver is the Strategy for Patient-Oriented Research of the Canadian Institutes of Health Research, which asserts that meaningful patient engagement can only be fostered when stakeholders understand its value. This study assessed researchers' perceptions of the meaning and value of patient engagement in research within a Canadian cardiovascular research network. In doing so, the secondary aim was to inform the development of a structured patient engagement initiative by identifying potential challenges and related mitigation strategies.

METHODS

We employed a multi-method strategy involving electronic surveys and semi-structured telephone interviews with network research scientists across Canada. Interview data were analyzed using thematic and content analysis. Survey data were analyzed using descriptive statistics.

RESULTS

Thirty-eight electronic surveys (response rate =33%) and 16 interviews were completed with network members. Some participants were uncertain about the meaning and value of patient engagement. While voicing guarded support, four challenges relating to patient engagement were identified from the interviews: 1) identification of representative and appropriate patients, 2) uncertainty about the scope of patients' roles given concerns about knowledge discrepancies, 3) a perceived lack of evidence of the impact of patient engagement, and 4) the need for education and culture change as a prerequisite for patient engagement. Research scientists were largely concerned that patients untrained in science and tasked with conveying an authentic patient experience and being a conduit for the voices of others might unsettle a traditional model of conducting research.

CONCLUSION

Concerns about patient involvement in research were related to a lack of clarity about the meaning, process, and impact of involvement. This study highlights the need for education on the meaning of patient engagement, evidence of its impact, and guidance on practical aspects of implementation within this research community.

The Canadian Arrhythmogenic Right Ventricular Cardiomyopathy Registry: Rationale, Design, and Preliminary Recruitment

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a complex and clinically heterogeneous arrhythmic condition. Incomplete penetrance and variable expressivity are particularly evident in ARVC, making clinical decision-making challenging.

METHODS

Pediatric and adult cardiologists, geneticists, genetic counsellors, ethicists, nurses, and qualitative researchers are collaborating to create the Canadian ARVC registry using a web-based clinical database. Biological samples will be banked and systematic analysis will be performed to examine potentially causative mutations, variants, and biomarkers. Outcomes will include syncope, ventricular arrhythmias, defibrillator therapies, heart failure, and mortality.

RESULTS

Preliminary recruitment has enrolled 365 participants (aged 42.7 ± 17.1 years; 50% women), including 129 probands and 236 family members. Previous cardiac arrest occurred in 28 (8%) participants, syncope occurred in 43 (12%) participants, and 46% of probands had a family history of sudden death. Overall yield of genetic testing was 36% for a disease-causing mutation and 20% for a variant of unknown significance. Target enrollment is 1000 affected patients and 500 unaffected family member controls over 7 years. The cross-sectional and longitudinal data collected in this manner will allow a robust assessment of the natural history and clinical course of genetic subtypes.

CONCLUSIONS

The Canadian ARVC Registry will create a population-based cohort of patients and their families to inform clinical decisions regarding patients with ARVC.

Factors influencing the decision of older adults to be assessed for transcatheter aortic valve implantation: An exploratory study

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is the recommended therapy for patients with severe symptomatic aortic stenosis at increased surgical risk and likely to derive benefit. Multimodality and multidisciplinary assessment is required for the heart team to determine eligibility for TAVI in a primarily older population. Little is known about patients' motivation and perspectives on making the decision to undergo the complex assessment.

AIMS

To explore factors influencing patients' decision making to undergo TAVI eligibility assessment to inform practice, programme development, health policy and future research.

METHODS

An exploratory qualitative approach was used. Semistructured interviews were conducted with 15 patients at the time of their referral for assessment to a quaternary cardiac and high volume TAVI centre.

RESULTS

Multiple, intersecting factors that included biomedical, functional, social and environmental considerations influenced patients' decision. The six distinct factors were symptom burden, participants' perception as 'experienced' patients, expectations of benefit and risks, healthcare system and informal support, logistical barriers and facilitators, and obligations and responsibilities.

CONCLUSIONS

The decision to undergo TAVI eligibility assessment is multifaceted and complex. Programmatic processes of care must be in place to facilitate appropriate and patient-centered decision making and access to TAVI. Strategies are required to mitigate the risks associated with the rapid deterioration of severe aortic stenosis, address patient and referring physicians' education needs, and provide individualised care and equitable access. Future research must focus on patients' experiences throughout the trajectory of TAVI care.

The CREATE Method for Expressing Continuous Outcome Data in Absolute Terms for Use in Patient Treatment Decision Aids: A Validation Study

BACKGROUND

Patient decision aids (PtDAs) supplement advice from health care professionals by communicating the absolute risk or benefit of treatment options (i.e., X/100). As such, PtDAs have been amenable to binary outcomes only. We aimed to develop and test the validity of the Conversion to Risk Estimates through Application of Normal Theory (CREATE) method for estimating absolute risk based on continuous outcome data.

METHODS

CREATE is designed to derive an estimate of the proportion of those who experience a clinically relevant degree of change (CRDoC). We used a 2-stage validation process using real and simulated change score data, respectively. First, using raw data from published intervention trials, we calculated the proportion of patients with a CRDoC and compared that with our CREATE-derived estimate using chi-square tests of association. Second, 200,000 simulated distributions of change scores were generated with widely varying distribution characteristics. Actual and CREATE-derived estimates were compared for each simulated distribution, and relative differences were summarized graphically.

RESULTS

The absolute difference between the estimated and actual CRDoC did not exceed 5% for any of the samples based on real data. Applying the CREATE method to 200,000 simulated scenarios demonstrated that the CREATE method should be avoided for outcomes where the underlying distribution can be reasonably assumed to have high levels of skew or kurtosis.

CONCLUSION

Our results suggest that standard statistical theory can be used to estimate continuous outcomes in absolute terms with reasonable accuracy for use in PtDAs; caution is advised if outcome summary statistics are assumed to have been derived from highly skewed distributions.

Assessment of oncolytic HSV efficacy following increased entry-receptor expression in malignant peripheral nerve sheath tumor cell lines

Limited expression and distribution of nectin-1, the major herpes simplex virus (HSV) type-1 entry-receptor, within tumors has been proposed as an impediment to oncolytic HSV (oHSV) therapy. To determine whether resistance to oHSVs in malignant peripheral nerve sheath tumors (MPNSTs) was explained by this hypothesis, nectin-1 expression and oHSV viral yields were assessed in a panel of MPNST cell lines using γ134.5-attenuated (Δγ134.5) oHSVs and a γ134.5 wild-type (wt) virus for comparison. Although there was a correlation between nectin-1 levels and viral yields with the wt virus (R=0.75, P =0.03), there was no correlation for Δγ134.5 viruses (G207, R7020 or C101) and a modest trend for the second-generation oHSV C134 (R=0.62, P=0.10). Nectin-1 overexpression in resistant MPNST cell lines did not improve Δγ134.5 oHSV output. While multistep replication assays showed that nectin-1 overexpression improved Δγ134.5 oHSV cell-to-cell spread, it did not confer a sensitive phenotype to resistant cells. Finally, oHSV yields were not improved with increased nectin-1 in vivo. We conclude that nectin-1 expression is not the primary obstacle of productive infection for Δγ134.5 oHSVs in MPNST cell lines. In contrast, viruses that are competent in their ability to counter the antiviral response may derive benefit with higher nectin-1 expression.

Impact of self-management interventions on stable angina symptoms and health-related quality of life: a meta-analysis

Background

Chronic stable angina (CSA) has a major negative impact on health-related quality of life (HRQL) including poor general health status, psychological distress, and inability to self-manage.

Methods

We used meta-analysis to assess the effectiveness of self-management interventions for improving stable angina symptoms, HRQL and psychological well-being. Nine trials, involving 1,282 participants in total, were included. We used standard inverse-variance random-effects meta-analysis to combine the trials. Heterogeneity between trials was evaluated using chi-square tests for the tau-squared statistic and quantified using the I² statistic.

Results

There was significant improvement in the frequency of angina symptoms (Seattle Angina Questionnaire [SAQ], symptom diary) across trials, standardized mean difference (SMD): 0.30 (95% Confidence interval [CI] 0.14, 0.47), as well as reduction in the use of sublingual (SL) nitrates, SMD: -0.49 (95% CI -0.77, -0.20). Significant improvements for physical limitation (SAQ), SMD: 0.38 (95% CI 0.20, 0.55) and depression scores (Hospital Anxiety and Depression Scale), SMD: -1.38 (95% CI -2.46, -0.30) were also found. The impact of SM on anxiety was uncertain due to statistical heterogeneity across trials for this outcome, I² = 98%. SM did not improve other HRQL dimensions including angina stability, disease perception, and treatment satisfaction.

Conclusions

SM interventions significantly improve angina frequency and physical limitation; they also decrease the use of SL nitrates and improve depression in some cases. Further work is needed to make definitive conclusions about the impact of SM on cardiac-specific anxiety.

Caregivers' contributions to heart failure self-care: a systematic review

AIMS

The purpose of this study was to conduct a systematic review answering the following questions: (a) what specific activities do caregivers (CGs) contribute to patients' self-care in heart failure (HF)?; and (b) how mature (or developed) is the science of the CG contribution to self-care?

METHODS

MEDLINE, EMBASE, Cumulative Index of Nursing and Allied Health Literature (CINAHL), the Cochrane Library and ClinicalTrials.gov were searched using the terms heart failure and caregiv* as well as the keywords 'careers', 'family members' and 'lay persons' for studies published between 1948 and September 2012. Inclusion criteria for studies were: informal CGs of adult HF patients-either as dependent/independent variable in quantitative studies or participant in qualitative studies; English language. Exclusion criteria for studies were: formal CGs; pediatric, adult congenital, or devices or transplant CGs; mixed diagnosis; non-empiric reports or reports publishing duplicate results. Each study was abstracted and confirmed by two authors. After CG activities were identified and theoretically categorized, an analysis across studies was conducted.

RESULTS

Forty papers were reviewed from a pool of 283 papers. CGs contribute substantively to HF patients' self-care characterized from concrete (weighing the patient) to interpersonal (providing understanding). Only two studies attempted to quantify the impact of CGs' activities on patients' self-care reporting a positive impact. Our analysis provides evidence for a rapidly developing science that is based largely on observational research.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

To our knowledge, this is the first systematic review to examine CGs' contributions in depth. Informal caregivers play a major role in HF self-care. Longitudinal research is needed to examine the impact of CGs' contributions on patient self-care outcomes.

Development and feasibility testing of decision support for patients who are candidates for a prophylactic implantable defibrillator: a study protocol for a pilot randomized controlled trial

BACKGROUND

Patients, identified to be at risk for but who have never experienced a potentially lethal cardiac arrhythmia, have the option of receiving an implantable cardioverter defibrillator (ICD) as prophylaxis against sudden cardiac death - a primary prevention indication. In Canada, there is no clear framework to support patients' decision-making for these devices. Decision support, using a decision aid, could moderate treatment-related uncertainty and prepare patients to make well-informed decisions. Patient decision aids provide information on treatment options, risks, and benefits, to help patients clarify their values for outcomes of treatment options. The objectives of this research are: 1) develop a decision aid, 2) evaluate the decision aid, and 3) determine the feasibility of conducting a trial.

METHODS/DESIGN

A development panel comprised of the core investigative team, health service researchers, decision science experts, cardiovascular healthcare practitioners, and ICD patient representatives will collaborate to provide input on the content and format of the aid. To generate probabilities to include in the aid, we will synthesize primary prevention ICD evidence. To obtain anonymous input about the facts and content, we will employ a modified Delphi process. To evaluate the draft decision aid will invite ICD patients and their families (n = 30) to rate its acceptability. After we evaluate the aid, to determine the feasibility, we will conduct a feasibility pilot randomized controlled trial (RCT) in new ICD candidates (n = 80). Participants will be randomized to receive a decision aid prior to specialist consultation versus usual care. Results from the pilot RCT will determine the feasibility of research processes; inform sample size calculation, measure decision quality (knowledge, values, decision conflict) and the influence of health related quality of life on decision-making.

DISCUSSION

Our study seeks to develop a decision aid, for patients offered their first ICD for prophylaxis against sudden cardiac death. This paper outlines the background and methods of a pilot randomized trial which will inform a larger multicenter trial. Ultimately, decision support prior to specialist consultation could enhance the decision-making process between patients, physicians, and families, associated with life-prolonging medical devices like the ICD.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01876173.

Abstract 117: Application Of A Delphi Method To Develop A Patient Decision Aid For Implantable Cardioverter Defibrillator Candidates

Background: Development of patient decision aids (PtDA) requires decision making about the facts, risks, and benefits to present to patients. Delphi process methodology has been employed successfully as a consensus-building tool across several disciplines. This work represents the first phase of a Canadian study that is developing a PtDA for prophylactic implantable cardioverter defibrillator (ICD) candidates. Our aim was to engage healthcare providers, ICD stakeholders, and patients in decisions about the content and format of the PtDA, using a modified Delphi process.

Method: Twenty healthcare professionals, 1 stakeholder representative, and 16 people living with ICDs were invited to participate. Our Delphi approach utilized electronic and paper based response systems that included 1) anonymity, 2) iteration, 3) controlled feedback and, 4) statistical group response options. The first Delphi round comprised 39 evidence-based survey items including ICD facts, risks, benefits, and values. A review panel of decision aid experts, cardiovascular researchers, and electrophysiologists selected the content items. Participants completed the survey by rating each category item on a 5-point likert scale from “1= not important” to “5 = extremely important”. A predetermined cut-off of > 75%, wherein participants rated an item as “very important” or higher, guided the selection of items during the two Delphi rounds completed. To provide participants with statistical group responses, the second round participants received the anonymous first round item rankings prior to rating the 11 remaining items.

Results: Twenty-seven participants completed round one of the Delphi (14 ICD patients). Mean (SD) age of ICD patients was 66.8 (7.1) years. The number of years of experience in healthcare reported by non-ICD respondents ranged from 2 to30 years. Of the 39 items included in round one, 14 items were retained ( > 75% agreement), 14 items were removed (<60% agreement), and 11 items proceeded to the second round (60-74% agreement). During the second Delphi round (n=27), 6 of the 11 items that did not reach agreement in round one were retained ( > 75% agreement). Examples from item categories include:

1) Risk items - i ) Lead problems over the long term, ii ) Possible complications during the surgical procedure to insert the ICD.

2) Benefit items- i ) Prevent cardiac arrest from a dangerous heart rhythm, ii ) Assurance that a dangerous heart rhythm can be corrected.

3) Fact, Value & Preferences - i ) What a standard ICD cannot do, ii ) The wish for a natural death, iii ) Driving restrictions if the ICD delivers a shock.

Conclusion: The results from this Delphi survey informed the content that will be incorporated into a PtDA for new ICD candidates. The next phase will include field-testing of the PtDA. Ultimately, the goal is to support quality decision making in ICD candidates.

Abstract 189: Expressing Continuous Cardiovascular Outcome Data in Absolute Terms for use in Patient Treatment Decision Aids: Validation of a Proposed Method

Background: Patient decision aids (DA) supplement advice from health care professionals through provision of information on the likelihood of risks and benefits of treatment options. Ideally, these data are expressed in both visual and written form to communicate absolute risk or benefit (i.e., X/100). However, this well-accepted methodology lends itself to outcomes which are binary only. Valid methods for conversion of continuous outcomes for presentation in DAs are not well-established. The difficulty in converting these outcomes is compounded by the need to extract and pool aggregate standardized score data from multiple published sources to generate a single estimate of treatment effect. Our team was met with this challenge when developing a DA for refractory angina; the main outcome was angina frequency (AF) as measured by the AF subscale of the Seattle Angina Questionnaire. We aimed to develop and test the validity of a proposed method, based on statistical theory, for estimating absolute angina reduction based on AF scores.

Methods: AF summary statistics, M(SD), were extracted from 2 distinct intervention studies for which raw data were accessible. A clinically important difference in AF scores was identified through expert consultation. Based on normal distribution theory, aggregate data from both studies were used to estimate the proportion of those who experienced a clinically significant change in AF. Chi-square comparisons of proportions was then used to determine if these estimates were dissimilar from true numbers reflected in the raw data. We then generated 500,000 simulated datasets using the same AF summary statistics, but with widely varying distribution characteristics (e.g., positive skew). Multiple comparisons of estimates to actual proportions of those experiencing a clinically significant change in AF were generated under simulated scenarios and expressed graphically. The effect of summary statistic on these comparisons was examined by conducting the simulations using both M(SD) and medians and interquartile ranges (IQR).

Results: Overall agreement between estimated and actual proportions of those experiencing a clinically significant change in AF was excellent for the real study data; there were no significant differences (p >0.45), and no difference exceeded 5%. These results remained stable when data were pooled from the 2 studies using meta-analysis. For the simulated data sets, concordance between the estimated and actual proportions was also moderate to good in cases where data were not highly skewed (i.e. skewness <2.5); agreement improved in the context of medians and IQRs.

Conclusion: Our results suggest that standard statistical theory can be used to estimate continuous outcomes in absolute terms with reasonable accuracy for use in DAs; caution is advised if outcomes are expected to be highly skewed in distribution.

Age and mental health predict early device-specific quality of life in patients receiving prophylactic implantable defibrillators

BACKGROUND

Ventricular arrhythmia is a significant cause of sudden death. Implantable cardioverter-defibrillators (ICDs) offer at-risk patients a prophylactic treatment option. This prophylaxis is largely responsible for growth in utilization of ICDs. Identification of factors that may impact device-specific quality of life (QOL) is warranted. The influence of preimplant patient variables on postimplant device-specific QOL is unknown. The study aimed to determine whether preimplant psychosocial, generic health-related quality of life (HRQOL), personality disposition, or demographic factors predicted early postimplant device-specific QOL.

METHODS

A prospective cohort study design was employed in 70 adults receiving an ICD for primary prevention. Preimplant, we measured generic HRQOL, personality disposition, depressive symptoms, age, and sex. The primary outcome was 3-month ICD device-specific QOL as measured by the Florida Patient Acceptance Scale (FPAS). We applied hierarchical multivariate regression analysis.

RESULTS

Mean age was 64.8 ± 9.4 years; 12.9% were women. Most had ischemic heart disease (77%) and a heart failure history (54.3%). Preimplant prevalence of elevated depressive symptoms was 30%. Three months post implant, the mean adjusted FPAS score was 76.8 ± 12.98. Of the variance in FPAS scores, 37% was explained by the independent variables. Younger age and poor preimplant mental HRQOL contributed most to lower FPAS scores.

CONCLUSIONS

Patient support and psychosocial interventions should target younger ICD candidates and those reporting poor preimplant mental HRQOL; these patients may be at risk for poor postimplant device-specific QOL.

Patients' decision making to accept or decline an implantable cardioverter defibrillator for primary prevention of sudden cardiac death

BACKGROUND

Patients are offered implantable defibrillators (ICDs) for the prevention of sudden cardiac death (SCD). However, patients' decision-making process (DMP) of whether or not to accept an ICD has not been explored. We asked patients about their decision making when offered an ICD.

DESIGN/SETTING

A grounded theory methodology was employed. Patients were recruited from three ICD centres. Those who received an ICD underwent interviews the first month after implant. Declining patients had interviews at their convenience. In-depth analysis of transcripts was completed. Identified themes were placed along process pathways in a DMP model and tested.

FINDINGS

Forty-four patients consented to participate (25% women). Thirty-four accepted an ICD and 10 (23%) declined. Ages ranged from 26 to 87 (mean = 65; SD = 12.5). Participants were retired (65%), had ischaemic heart disease (64%) and some post-secondary education (52%). The DMP was triggered when patient's risk for SCD was communicated. The physician's recommendation and a new awareness SCD risk were motivators to accept the ICD. Patient's decision-making approaches fell along a continuum, from active and engaged to passive and indifferent. Patient's approaches were influenced most by the following: (i) trust; (ii) social influences and (iii) health state.

CONCLUSIONS

Health-care providers need to recognize the DMP pathways in which ICD candidacy and SCD risk are understood. The factors that influence a patient's decision warrant discussion pre-implant. It is imperative that patients comprehend the meaning of ICD candidacy to make an informed decision. Participants did not recall alternatives to receiving ICD therapy.

Patients' perspectives on end-of-life issues and implantable cardioverter defibrillators

Increasing numbers of cardiovascular patients are receiving implantable cardioverter defibrillators (ICDs) for primary prevention of sudden cardiac death (SCD). This report examines patients' perspectives on related end-of-life issues. Using a grounded theory approach, audiotaped, semi-structured interviews were undertaken with 30 participants from two ICD referral centres in southwestern Ontario (24 who accepted an ICD and 6 who declined). Interview transcripts, verification with interviewees, researcher memos, published literature, and participant demographics were analyzed using NVivo7. Most participants were male, had comorbidities and an ejection fraction of less than 30 percent, and ranged in age from 26 to 87. Consensus was reached by three research team members on three main themes: quality versus quantity of life, preferred mode of death, and the technical realities of the ICD. The ICD was considered in relation to both quantity and quality of life. Most participants focused on the prevention of SCD, not the implications of the ICD for death by any other cause. Participants advocated for incorporating the ICD into advance care planning. Our findings have implications for the development of advance care plans and education of health professionals.

A comparative study of uncertainty, optimism and anxiety in patients receiving their first implantable defibrillator for primary or secondary prevention of sudden cardiac death

BACKGROUND

Increasingly, patients are receiving implantable cardioverter defibrillators (ICDs) for prevention of sudden cardiac death. ICDs are implanted for primary prevention (patients at risk for ventricular arrhythmia [PP]) and secondary prevention (patients who have had/survived a sustained ventricular arrhythmia or cardiac arrest [SP]). Few prospective studies have examined psychosocial factors associated with these patients.

OBJECTIVES

To determine if patients receiving their first ICD for PP versus SP differed in uncertainty, anxiety, and optimism, before, 1 week, and 1 month after implant.

DESIGN

Prospective, descriptive, correlational pilot.

PARTICIPANTS AND SETTING

Fifteen PP and 15 SP patients receiving their first ICD were enrolled. Mean ages (+/- SD) were 65.7+/-11.3 and 67.9+/-7.7 respectively.

METHODS

Mishel's Uncertainty in Illness Scale (MUIS-C), State-Trait Anxiety Inventory (STAI) and the Life Orientation Test (LOT-R) were taken pre-implant, at the first post-implant visit, and at 1 month. Measures were compared using Student't-tests and ANOVA.

RESULTS

Pre-implant, both groups had moderately high MUIS-C scores (mean+/-SD; PP=67.67+/-13.36; SP=70.27+/-6.80; t=0.67; t(df)=28; p=0.507). LOT-R scores were 15.67+/-3.8 for PP and 16.47+/-3.6 for SP; t=0.59; t(df)=28; p=0.557. Pre-implant state anxiety scores were (mean PP=37.40+/-10.0, SP=37.73+/-13.6; t=0.076; t(df)=28; p=0.940). At 1-month PP patients had significantly lower uncertainty scores than the SP group (mean 62.33+/-4.17 versus 67.87+/-4.61; t=3.45; t(df)=28; p=0.002). A main effect for time, between pre-implant and 1-month, was found for uncertainty (F(2,56)=3.26; p<0.05) and state anxiety (F(2,56)=3.61, p<0.05), where both groups showed lower scores.

CONCLUSION

This study identified moderately high uncertainty in PP and SP patients prior to receiving their ICD. Though uncertainty was high, both groups reported an optimistic disposition and normal anxiety. At 1-month, SP patients had higher uncertainty scores than PP patients. This post-intervention uncertainty among patients who experienced an arrhythmic event warrants attention from nurses caring for ICD patients. Interventions to ameliorate uncertainty should be tailored to consider ICD indication.

Knockout of plasminogen activator inhibitor 1 gene reduces amyloid beta peptide burden in a mouse model of Alzheimer's disease

Accumulation of amyloid beta peptide (Aβ) in the brain is a pathological hallmark of Alzheimer's disease (AD); the underlying mechanism, however, is not well understood. In this study, we show that expression of plasminogen activator inhibitor 1 (PAI-1), a physiological inhibitor of tissue type and urokinase type plasminogen activators (tPA and uPA), increases with age in the brain of wild type and Aβ precursor protein-presenilin 1 (APP/PS1) transgenic mice as well as in AD patients. Most importantly, we show that knocking out the PAI-1 gene dramatically reduces Aβ burden in the brain of APP/PS1 mice but has no effect on the levels of full-length APP, alpha or beta C-terminal fragments. Furthermore, we show that knocking out the PAI-1 gene leads to increases in the activities of tPA and plasmin, and the plasmin activity inversely correlates with the amounts of SDS insoluble Aβ40 and Aβ42. Together, these data suggest that increased PAI-1 expression/activity contributes importantly to Aβ accumulation during aging and in AD probably by inhibiting plasminogen activation and thus Aβ degradation.

Phylogenetic and functional biomakers as indicators of bacterial community responses to mixed-waste contamination

Few studies have demonstrated changes in community structure along a contaminant plume in terms of phylogenetic, functional, and geochemical changes, and such studies are essential to understand how a microbial ecosystem responds to perturbations. Clonal libraries of multiple genes (SSU rDNA, nirK, nirS, amoA, pmoA, and dsrAB) were analyzed from groundwater samples (n = 6) that varied in contaminant levels, and 107 geochemical parameters were measured. Principal components analyses (PCA) were used to compare the relationships among the sites with respect to the biomarker (n = 785 for all sequences) distributions and the geochemical variables. A major portion of the geochemical variance measured among the samples could be accounted for by tetrachloroethene, 99Tc, No3, SO4, Al, and Th. The PCA based on the distribution of unique biomarkers resulted in different groupings compared to the geochemical analysis, but when the SSU rRNA gene libraries were directly compared (deltaC(xy) values) the sites were clustered in a similar fashion compared to geochemical measures. The PCA based upon functional gene distributions each predicted different relationships among the sites, and comparisons of Euclidean distances based upon diversity indices for all functional genes (n = 432) grouped the sites by extreme or intermediate contaminant levels. The data suggested that the sites with low and high perturbations were functionally more similar than sites with intermediate conditions, and perhaps captured the overall community structure better than a single phylogenetic biomarker. Moreover, even though the background site was phylogenetically and geochemically distinct from the acidic sites, the extreme conditions of the acidic samples might be more analogous to the limiting nutrient conditions of the background site. An understanding of microbial community-level responses within an ecological framework would provide better insight for restoration strategies at contaminated field sites.

Changes in bacterial community structure correlate with initial operating conditions of a field-scale denitrifying fluidized bed reactor

High levels of nitrate are present in groundwater migrating from the former waste disposal ponds at the Y-12 National Security Complex in Oak Ridge, TN. A field-scale denitrifying fluidized bed reactor (FBR) was designed, constructed, and operated with ethanol as an electron donor for the removal of nitrate. After inoculation, biofilms developed on the granular activated carbon particles. Changes in the bacterial community of the FBR were evaluated with clone libraries (n = 500 partial sequences) of the small-subunit rRNA gene for samples taken over a 4-month start-up period. Early phases of start-up operation were characterized by a period of selection, followed by low diversity and predominance by Azoarcus-like sequences. Possible explanations were high pH and nutrient limitations. After amelioration of these conditions, diversification increased rapidly, with the appearance of Dechloromonas, Pseudomonas, and Hydrogenophaga sequences. Changes in NO3, SO4, and pH also likely contributed to shifts in community composition. The detection of sulfate-reducing-bacteria-like sequences closely related to Desulfovibrio and Desulfuromonas in the FBR have important implications for downstream applications at the field site.

Neuregulin-1β modulates in vivo entorhinal–hippocampal synaptic transmission in adult rats

Neuregulin-1 (NRG-1) proteins and their erbB receptors are essential for neuronal development during embryogenesis and may contribute importantly to neuronal function in the adult brain. This study tests the hypothesis that NRG-1beta acts as a modulator of synaptic activity in the adult brain, specifically at hippocampal formation synapses. Adult, male Sprague-Dawley rats were anesthetized and a recording electrode with an attached stainless steel microinjector was stereotaxically positioned to record field potentials (fEPSP) in either the dentate gyrus or the cornu ammonis (CA) 1 field of the hippocampus. The entorhinal cortex was continuously stimulated via a paired stainless steel electrode. Microinjection of NRG-1beta significantly increased the slope of the fEPSP in the dentate gyrus in a dose-dependent manner. Compared with a low dose (20 nM), a high dose (100 nM) of NRG-1beta induced a shorter latency response that was of greater magnitude. Responses to NRG-1beta were abolished by pretreatment with a selective, reversible erbB tyrosine kinase inhibitor, PD158780 (100 microM). Further, PD158780 (100 microM) itself significantly decreased the entorhinal-dentate fESPS slope by about 15%. Neither equimolar (100 nM) nor hypermolar (100 microM) sucrose or heat-inactivated NRG-1beta (100 nM) significantly altered the entorhinal-dentate fEPSP slope. In contrast to its effect at the entorhinal-dentate synapse, NRG-1beta (100 nM) depressed, and PD158780 potentiated entorhinal-CA1 synaptic transmission. Thus, in adult rats NRG-1beta potentiates transmission at the entorhinal-dentate synapse but suppresses transmission at the entorhinal-CA1 synapse. These observations indicate that NRG-1 is not only a developmental growth factor, but also modifies synaptic transmission in adult rat brain.

Targeting and functional role of N-RAP, a nebulin-related LIM protein, during myofibril assembly in cultured chick cardiomyocytes

Targeting and functional effects of N-RAP domains were studied by expression as GFP-tagged fusion proteins in cultured embryonic chick cardiomyocytes. GFP-tagged N-RAP was targeted to myofibril precursors, myofibril ends and cell contacts, expression patterns that are similar to endogenous N-RAP. The GFP-tagged N-RAP LIM domain (GFP-N-RAP-LIM) was targeted to the membrane in cells with myofibril precursors and cell-cell contacts. The GFP-tagged super repeats (N-RAP-SR) and the GFP-tagged domain normally found in between the super repeats and the LIM domain (N-RAP-IB) were each observed at sites of myofibril assembly, incorporating into myofibril precursors in a manner similar to full length N-RAP. However, unlike full-length N-RAP, N-RAP-SR and N-RAP-IB were also found in mature myofibrils, associating with the sarcomeric actin filaments and the Z-lines, respectively. N-RAP-IB was also colocalized with α-actinin at cell contacts. Each of the N-RAP constructs could inhibit the formation of mature myofibrils in cultured cardiomyocytes, with the effects of N-RAP-SR and N-RAP-IB depending on the time of transfection. The results show that each region of N-RAP is crucial for myofibril assembly. Combining the targeting and functional effects of N-RAP domains with information in the literature, we propose a new model for initiation of myofibrillogenesis.

ErbB transmembrane tyrosine kinase receptors are differentially expressed throughout the adult rat central nervous system

The neuregulin (NRG) family of growth and differentiation factors and their erbB receptors contribute importantly to the development of the nervous system, but their distribution and function in the adult brain are poorly understood. The present study showed that erbB2, erbB3, and erbB4 transcripts and protein are distributed throughout all areas of adult rat brain. These three receptors were differentially expressed in neurons and glia. Some neurons expressed only a subset of erbB kinases, whereas other neurons expressed all three erbB receptors but sequestered each of these polypeptides into distinct cellular compartments. In synapse-rich regions, erbB immunoreactivity appeared as punctate-, axon-, and/or dendrite-associated staining, suggesting that NRGs are involved in the formation and maintenance of synapses in adult brain. ErbB labeling also was present in neuronal soma, indicating that NRGs act at sites in addition to the synapse. Glia in adult brain also differentially expressed erbB3 and erbB4. Approximately half of the erbB3 labeling in white matter was associated with S100beta+/glial fibrillary acidic protein negative macroglia (i.e., oligodendrocytes or glial fibrillary acidic protein negative astrocytes). In contrast, macroglia in gray matter did not express erbB3. The remaining erbB3 immunoreactivity in white matter and erbB4 glial staining seemed to be associated with microglia. These results showed that erbB receptors are expressed widely in adult rat brain and that each erbB receptor subtype has a distinct distribution. The differential distributions of erbB receptors in neurons and glia and the known functional differences between these kinases suggest that NRGs have distinct effects on these cells. The continued expression of NRGs and their erbB receptors in mature brain also implies that these molecules perform important functions in the brain throughout life.

Attenuation of experimental autoimmune demyelination in complement-deficient mice

The exact mechanisms leading to CNS inflammation and myelin destruction in multiple sclerosis and in its animal model, experimental allergic encephalomyelitis (EAE) remain equivocal. In both multiple sclerosis and EAE, complement activation is thought to play a pivotal role by recruiting inflammatory cells, increasing myelin phagocytosis by macrophages, and exerting direct cytotoxic effects through the deposition of the membrane attack complex on oligodendrocytes. Despite this assumption, attempts to evaluate complement's contribution to autoimmune demyelination in vivo have been limited by the lack of nontoxic and/or nonimmunogenic complement inhibitors. In this report, we used mice deficient in either C3 or factor B to clarify the role of the complement system in an Ab-independent model of EAE. Both types of complement-deficient mice presented with a markedly reduced disease severity. Although induction of EAE led to inflammatory changes in the meninges and perivascular spaces of both wild-type and complement-deficient animals, in both C3(-/-) and factor B(-/-) mice there was little infiltration of the parenchyma by macrophages and T cells. In addition, compared with their wild-type littermates, the CNS of both C3(-/-) and factor B(-/-) mice induced for EAE are protected from demyelination. These results suggest that complement might be a target for the therapeutic treatment of inflammatory demyelinating diseases of the CNS.

Glutamate transporter EAAT2 splice variants occur not only in ALS, but also in AD and controls

OBJECTIVE

To ascertain the specificity of alternatively spliced mRNA variants of the astroglial glutamate transporter EAAT2 for ALS.

BACKGROUND

An important hypothesis for ALS pathogenesis is that motor neuron injury may result from chronically elevated glutamate levels in the CNS. Supporting this idea are reports of decreased glutamate transport in ALS. This in turn has recently been suggested to be due to the presence of aberrant mRNA splice variants for EAAT2 in ALS.

METHODS

Postmortem human brain tissue was obtained from different brain regions of patients with ALS, normal controls (NC), and patients with AD and Lewy body dementia (LB)-neurodegenerative diseases in which motor neurons are unaffected. Brain RNA was analyzed for EAAT2 isoforms using reverse transcription PCR and cDNA cloning/sequencing methods.

RESULTS

Splice variants lacking exons 7 or 9 were present in ALS brain, as previously reported, but were also present in brains from NC, AD, and LB patients. PCR product sequence analyses from non-ALS brain show variant splicing identical to that reported for ALS. Quantitative PCR analysis shows that these isoforms may be somewhat more abundant in ALS than AD, LB, and NC brains.

CONCLUSIONS

EAAT2 mRNA splice variants are found in the brains of NC and AD patients, as in ALS. The authors cannot exclude the possibility that quantitative changes in variant EAAT2 isoforms might relate directly, or indirectly, to ALS pathology. However, the qualitative presence of these "abnormal" EAAT2 splice variants does not appear to be sufficient to explain motor neuron degeneration in ALS.

Myofibrillogenesis and formation of cell contacts mediate the localization of N-RAP in cultured chick cardiomyocytes

The expression of N-RAP was investigated in immuofluorescently stained embryonic chick cardiomyocyte cultures. After 1 day in culture, the cardiomyocytes were spherical and N-RAP, titin, alpha-actinin, and vinculin were all diffusely distributed. As the cardiomyocytes spread and formed myofibrils and cell contacts, N-RAP became localized to distinct areas in the cells. During myofibrillogenesis, N-RAP was found concentrated in premyofibrils. As the premyofibrils transformed into bundles of mature myofibrils, N-RAP became concentrated at the longitundal ends of the cells, and was not found in the mature sarcomeres. At sites of cell-cell contacts, N-RAP was localized to the cell junction even in cells without any significant myofibril formation. As the cell-cell contacts became more extensive and formed structures resembling the intercalated disks found in hearts, N-RAP became even more specifically concentrated at these junctions. The results show that myofibrillogenesis and cell contact formation can each independently target N-RAP to the longitudinal ends of cardiomyocytes.

Expression of JE (monocyte chemoattractant protein-1) is induced by sciatic axotomy in wild type rodents but not in C57BL/Wld(s) mice

Recruitment of hematogenous myelomonocytic cells into injured peripheral nerve is essential for axonal regeneration. The monocyte chemoattractant protein-1 (JE) and melanoma growth stimulatory activity/gro (KC) "immediate early" gene products may be important in this process as these proteins are potent chemoattractants for macrophages and neutrophils, respectively. To test this hypothesis, we examined JE and KC activation in rat sciatic nerve 0-30 days after surgical transection. RT-PCR and in situ hybridization analyses of JE and KC expression demonstrates these mRNAs are present in injured nerve, first being expressed by a cellular subpopulation within the zone of trauma by 1.5 hours after injury. By 16 hours posttransection a subpopulation of JE-positive endoneurial cells is found in the proximal stump and throughout the distal nerve segment, with maximal mRNA accumulation occurring 1 day after injury and expression persisting to 18 days postaxotomy, a period preceding and coincident with macrophage infiltration. In contrast, by 3 days postaxotomy KC expression is markedly diminished, consistent with the limited neutrophilic response to nerve injury. JE expression was also examined in C57BL/Wld(s) mice, which have delayed Wallerian degeneration associated with a failure of macrophage recruitment, and their parental C57BL/6J strain. Although JE mRNA is inducible in sciatic nerve from C57BL/6J mice, these transcripts are undetectable in injured nerve from C57BL/Wld(s) mice. Our findings suggest that activation of the JE locus is at least partially responsible for macrophage invasion of injured peripheral nerve. Furthermore, defective postaxotomy macrophage recruitment in C57BL/Wld(s) mice may involve a failure of JE induction.

Neurotrophin sensitivity of prevertebral and paravertebral rat sympathetic autonomic ganglia

Prevertebral and paravertebral sympathetic autonomic ganglia respond differently to a large number of experimental and clinical insults. The selective involvement of subpopulations of sympathetic neurons may reflect differences in their response to neurotrophic substances. To test this hypothesis, we investigated the response of prevertebral and paravertebral rat sympathetic ganglia to selected neurotrophic substances in vivo and in vitro and identified the ganglionic distribution of neurons expressing high affinity neurotrophin receptor mRNAs. Dissociated cultures of embryonic prevertebral and paravertebral ganglionic neurons showed comparable responses to NGF deprivation and only small differences in their response to rescue with other trophic substances. In situ hybridization studies of adult rat sympathetic ganglia using probes specific for the high-affinity neurotrophin receptor transcripts trks A, B, and C demonstrated that neurons in both prevertebral and paravertebral sympathetic ganglia express predominantly trkA receptors in vivo. In addition, increased tyrosine hydroxylase (TOH) activity was induced only by doses of neurotrophic substances that activate trkA and showed only small differences between neonatal prevertebral and paravertebral ganglia. Although small differences in the sensitivity of pre- and paravertebral sympathetic neurons to various neurotrophins have been identified in our studies, they are unlikely, in isolation, to explain major differences in the sensitivity of these ganglia to neuropathologic processes.

Clear cell neoplasms and pseudoneoplastic lesions of the central nervous system

Mass lesions of the central nervous system (CNS) that may assume a clear cell appearance are diverse in nature. Primary conditions in this category include oligodendroglioma, hemangioblastoma, germinoma (seminoma), clear cell and chordoid meningioma, pleomorphic xanthoastrocytoma, and lipid-rich glioblastoma. These proliferations usually can be identified by attention to clinical presentation, topographic location, radiographic details, and histological nuances. Occasionally, however, electron microscopy or immunohistological analysis may be necessary. A recommended panel of reagents for the evaluation of clear cell primary CNS lesions include antibodies to glial fibrillary acidic proteins, S-100 protein, epithelial membrane antigen, vimentin, keratins, placental-like alkaline phosphatase, and synaptophysin. This article reviews the salient clinicopathologic attributes of such proliferations, elaborates a practical approach to their diagnosis, and discusses important differential diagnostic considerations. The latter include malformative lesions, infarcts, inflammatory conditions, and secondary lymphomas, carcinomas, and melanomas.

Decay of calcium transients after electrical stimulation in rat fast- and slow-twitch skeletal muscle fibres

1. Calcium transients were calculated from fura-2 fluorescence signals (corrected for kinetic delays in the Ca(2+)-fura-2 reaction) from single rat skeletal muscle fibres, either fully dissociated from the fast-twitch flexor digitorum brevis (FDB) muscle or in small bundles from the slow-twitch soleus muscle. Fibres or bundles were embedded in agarose gel to inhibit movement and stimulated by single or trains of 1-2 ms electrical pulses (100 Hz, 2-400 ms train duration). 2. The rate constant of decay of [Ca2+] determined from single-exponential fits to the final decay phase of [Ca2+] after a single action potential was considerably faster in FDB fibres than in soleus fibres. As the stimulation duration increased, the rate constant of [Ca2+] decay decreased for both the FDB and soleus fibres, but the effect was greater in FDB than in soleus fibres. 3. Using the magnitude of the decline in the rate constant of [Ca2+] decay with increasing stimulation duration as an index of relative contribution of the saturable Ca2+ binding sites on parvalbumin, subpopulations termed 'high', 'medium' and 'low', referring to estimated parvalbumin content, were determined within each group of FDB and soleus fibres. In fibres assigned to the 'high' and 'medium' groups, parvalbumin was the major contributor (50-73%) to the [Ca2+] decay rate constant after a single action potential. In fibres in the 'low' group, parvalbumin contributed only 0-28% to the rate constant of [Ca2+] decay. 4. Fluorescence recordings using mag-fura-2, a lower-affinity Ca2+ indicator expected to be in equilibrium with myoplasmic Ca2+, gave similar values for both the [Ca2+] decay rate constant after a single action potential and the decrease in this rate constant with increased stimulation duration, as found for the fura-2 [Ca2+] transients from FDB and soleus fibres. Thus, the observed differences in decay rate of Ca2+ were not introduced by kinetic correction of the fura-2 recordings, but are attributed to differences in the Ca2+ binding and transport properties of fast- and slow-twitch mammalian fibres.

Calcium transients and calcium homeostasis in adult mouse fast-twitch skeletal muscle fibers in culture

Skeletal muscle fibers enzymatically dissociated from adult mouse flexor digitorum brevis muscles were maintained in culture for up to 8 days. After various times in culture, fibers were loaded with fura 2, and Ca2+ transients for trains of 1, 5, and 10 action potentials (100 Hz) triggered by external electrical stimulation were calculated from fluorescence ratio records corrected for noninstantaneous reaction of fura 2 with Ca2+. The decay rate constants of Ca2+ transients decreased with increasing stimulation duration, indicating a slowing of the Ca(2+)-removal properties with increased stimulation duration. After 6 days in culture, Ca2+ decay rate constants decreased dramatically for all stimulation durations and the differences in decay rate constants among 1, 5, and 10 pulses became smaller. Intracellular parvalbumin content measured by single-fiber immunofluorescence decreased with time in culture in parallel with the decrease in the decay rate constant of Ca2+ transients. Our results suggest that there is a correlation between parvalbumin content and the decay rate constant of the Ca2+ transient.