Perceptions and attitudes toward COVID-19 vaccination among health professional students in Australia: a qualitative study.

Using two qualitative data sources: free-text responses to an open-ended question of an online survey and subsequent interviews and focus groups, we explored perceptions and attitudes toward COVID-19 vaccination among health professional students enrolled in Australian universities during the pandemic with data collected from October 2021 to April 2022. Students provided free-text responses to the open-ended question (n = 313) in the online survey and participated in interviews or focus groups (n = 17). Data analysis revealed three themes, including perceptions of COVID-19 seriousness and the risk of contracting the virus, information dissemination, and attitudes toward the vaccine mandate. The study identified evolving perceptions of COVID-19 seriousness among Australian health professional students and their sentiments toward the vaccine mandate. There is a need to ensure the quality of information dissemination related to the vaccine mandate. This may not only support students' uptake of mandatory vaccination but also provide a means for them to address vaccination with healthcare consumers and patients.

Strategies for improving diversity, equity, and inclusion in cardiovascular research: a primer.

This paper aims to empower cardiovascular (CV) researchers by promoting diversity, equity, and inclusion (DE&I) principles throughout the research cycle. It defines DE&I and introduces practical strategies for implementation in recruitment, retention, and team dynamics within CV research. Evidence-based approaches supporting underrepresented populations' participation are outlined for each research phase. Emphasizing the significance of inclusive research environments, the paper offers guidance and resources. We invite CV researchers to actively embrace DE&I principles, enhancing research relevance and addressing longstanding CV health disparities.

Barriers and facilitators to COVID-19 vaccine uptake among Australian health professional students during the pandemic: a nationwide study.

Using a cross-sectional online survey we investigated knowledge, attitudes, and risk perception about COVID-19 vaccination and identified factors influencing vaccine uptake among Australian health professional students from October 2021 to January 2022. We analysed data from 1114 health professional students from 17 Australian universities. Most participants were enrolled in nursing programs (n = 958, 86.8%), and 91.6% (n = 858) of the participants received COVID-19 vaccination. Approximately 27% believed COVID-19 was no more serious than seasonal influenza and that they had a low risk of acquiring COVID-19. Nearly 20% disagreed that COVID-19 vaccines in Australia were safe and perceived they were at higher-risk of acquiring COVID infection than the general population. Higher-risk perception viewing vaccination as their professional responsibility, and vaccine mandate strongly predicted vaccination behaviour. Participants consider COVID-19 information from health professionals, government websites, and World Health Organization as the most trusted information sources. The findings highlight that healthcare decision-makers and university administrators need to monitor students' hesitancy with vaccination to improve students' promotion of the vaccination to the general population.

Comparison of six frailty instruments in adults with heart failure: a prospective cohort pilot study.

AIMS: To compare the frailty prevalence and predictive performance of six frailty instruments in adults with heart failure and determine the feasibility of study methods. METHODS AND RESULTS: Prospective cohort pilot study. Adults aged 18 years or older with a confirmed diagnosis of heart failure in Sydney, New South Wales, Australia. The Frailty Phenotype; the Survey of Health, Ageing, and Retirement in Europe Frailty Instrument (SHARE-FI); St Vincent's Frailty instrument; St Vincent's Frailty instrument plus cognition and mood; The Fatigue, Resistance, Ambulation, Illnesses, and Loss of Weight (FRAIL) scale; and the Deficit Accumulation Index (DAI) were compared. Multiple logistic regression was used to develop six frailty instrument models to evaluate the association between each frailty instrument and composite all-cause rehospitalization and mortality at 12 months. One hundred and thirty-one patients were included with a mean age of 54 [± 14(SD)]. Frailty prevalence ranged from 33 to 81%. All instruments except one (the FRAIL scale) appeared to signal an increased odds of rehospitalization and/or mortality, yet these results were non-significant. The six frailty instrument models displayed sensitivity between 88-92% and C-statistic values of 0.71-0.73, suggesting satisfactory discrimination. CONCLUSION: The prevalence of frailty varied across six frailty instruments yet was in the higher range despite a 'younger' heart failure cohort. Further research is required to confirm the psychometric properties of these instruments for routine clinical use in an adequately powered and more diverse heart failure cohort.

Clinician Estimates of Frailty Compared to Formal Frailty Assessment in Adults With Heart Failure: A Cross-Sectional Analysis.

BACKGROUND: Frailty assessment is recommended for patients with heart failure. Despite the availability of instruments to assess frailty, there are no clear recommendations regarding the optimal instrument to use in a heart failure context. This ambiguity combined with a lack of education and resources, often leads clinicians to rely on subjective estimates of frailty, such as 'the end-of-the-bed' or 'eyeball' test. AIM: To examine the association between clinician-estimated frailty and formal frailty assessment in adults with heart failure. METHODS: Cross-sectional analysis of the FRAilty MEasurement in Heart Failure (FRAME-HF) study. PARTICIPANTS: (1) Adults aged ≥18 years in the outpatient heart failure clinic and cardiology ward; (2) and cardiovascular clinicians (nurses, physicians, and allied-health professionals). Following participant recruitment, cardiovascular clinicians were asked to rate the participant's frailty status based on their routine clinical assessment as either: frail, pre-frail, or non-frail, which was then compared to a formal frailty assessment using a modified version of the Frailty Phenotype. The association between clinician-estimated frailty and formal frailty assessment were examined using a weighted Kappa statistic and Spearman's correlation coefficient. RESULTS: A total of 75 patients and 39 clinicians were recruited, producing 194 paired frailty assessments. Mean age of the patients was 54 (±13) years. Correlation of pooled clinician-estimated frailty to formal frailty was fair (0.52, p=0.00). Correlation was highest between allied-health estimated frailty and formal frailty (0.70, p=0.00). Agreement between pooled clinician-estimated frailty and formal frailty was fair (0.33) and was highest between allied health-estimated frailty and formal frailty (0.45). CONCLUSION: Subjective clinician-estimated frailty is not a reliable replacement for formal frailty assessment in adults with heart failure, underscoring the need for assessment using a valid and reliable instrument.

Discrepancies between proxy estimates and patient reported, health related, quality of life: minding the gap between patient and clinician perceptions in heart failure.

PURPOSE: Health related quality of life (HRQoL) is rarely routinely measured in the clinical setting. In the absence of patient reported data, clinicians rely on proxy and informal estimates to support clinical decisions. This study compares clinician estimates (proxy) with patient reported HRQoL in patients with advanced heart failure and examines factors influencing discrepancies. METHODS: Seventy-five patients with heart failure, (22 females, 53 males) completed the EQ-5D-5L questionnaire. Thirty-nine clinicians (11 medical, 23 nursing, 5 allied health) completed the proxy version (V1) producing 194 dyads. Correlation was assessed using Spearman's rank tests, systematic bias was examined with Bland-Altman analyses. Inter-rater agreement at the domain level, was investigated using linear weighted Kappa statistics while factors influencing the IRG were explored using independent student t-tests, analysis of variance and regression. RESULTS: There was a moderate positive correlation between clinician HRQoL estimates and patient reported utility (r = 0.38; p < .0005). Mean clinician estimates were higher than patient reported utility (0.60 vs 0.54; p = 0.008), with significant underestimation of reported problems apparent in three of the five EQ-5D-5L domains. Patient sex (female), depressed mood and frailty were all associated with an increased inter-rater gap. CONCLUSION: Clinicians in this sample overestimated HRQoL. Factors affecting the inter-rater gap, including sex and depression, support formal HRQoL screening to enhance clinical conversations and decision making. The discrepancy also supports regulatory restriction on the use of expert opinion in the development of QALYs in health economic analysis.

mHealth education interventions in heart failure.

BACKGROUND: Heart failure (HF) is a chronic disease with significant impact on quality of life and presents many challenges to those diagnosed with the condition, due to a seemingly complex daily regimen of self-care which includes medications, monitoring of weight and symptoms, identification of signs of deterioration and follow-up and interaction with multiple healthcare services. Education is vital for understanding the importance of this regimen, and adhering to it. Traditionally, education has been provided to people with heart failure in a face-to-face manner, either in a community or a hospital setting, using paper-based materials or video/DVD presentations. In an age of rapidly-evolving technology and uptake of smartphones and tablet devices, mHealth-based technology (defined by the World Health Organization as mobile and wireless technologies to achieve health objectives) is an innovative way to provide health education which has the benefit of being able to reach people who are unable or unwilling to access traditional heart failure education programmes and services. OBJECTIVES: To systematically review and quantify the potential benefits and harms of mHealth-delivered education for people with heart failure. SEARCH METHODS: We performed an extensive search of bibliographic databases and registries (CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, IEEE Xplore, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) Search Portal), using terms to identify HF, education and mHealth. We searched all databases from their inception to October 2019 and imposed no restriction on language of publication. SELECTION CRITERIA: We included studies if they were conducted as a randomised controlled trial (RCT), involving adults (≥ 18 years) with a diagnosis of HF. We included trials comparing mHealth-delivered education such as internet and web-based education programmes for use on smartphones and tablets (including apps) and other mobile devices, SMS messages and social media-delivered education programmes, versus usual HF care. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risks of bias, and extracted data from all included studies. We calculated the mean difference (MD) or standardised mean difference (SMD) for continuous data and the odds ratio (OR) for dichotomous data with a 95% confidence interval (CI). We assessed heterogeneity using the I2 statistic and assessed the quality of evidence using GRADE criteria. MAIN RESULTS: We include five RCTs (971 participants) of mHealth-delivered education interventions for people with HF in this review. The number of trial participants ranged from 28 to 512 participants. Mean age of participants ranged from 60 years to 75 years, and 63% of participants across the studies were men. Studies originated from Australia, China, Iran, Sweden, and The Netherlands. Most studies included participants with symptomatic HF, NYHA Class II - III. Three studies addressed HF knowledge, revealing that the use of mHealth-delivered education programmes showed no evidence of a difference in HF knowledge compared to usual care (MD 0.10, 95% CI -0.2 to 0.40, P = 0.51, I2 = 0%; 3 studies, 411 participants; low-quality evidence). One study assessing self-efficacy reported that both study groups had high levels of self-efficacy at baseline and uncertainty in the evidence for the intervention (MD 0.60, 95% CI -0.57 to 1.77; P = 0.31; 1 study, 29 participants; very low-quality evidence).Three studies evaluated HF self-care using different scales. We did not pool the studies due to the heterogenous nature of the outcome measures, and the evidence is uncertain. None of the studies reported adverse events. Four studies examined health-related quality of life (HRQoL). There was uncertainty in the evidence for the use of mHealth-delivered education on HRQoL (MD -0.10, 95% CI -2.35 to 2.15; P = 0.93, I2 = 61%; 4 studies, 942 participants; very low-quality evidence). Three studies reported on HF-related hospitalisation. The use of mHealth-delivered education may result in little to no difference in HF-related hospitalisation (OR 0.74, 95% CI 0.52 to 1.06; P = 0.10, I2 = 0%; 3 studies, 894 participants; low-quality evidence). We downgraded the quality of the studies due to limitations in study design and execution, heterogeneity, wide confidence intervals and fewer than 500 participants in the analysis. AUTHORS' CONCLUSIONS: We found that the use of mHealth-delivered educational interventions for people with HF shows no evidence of a difference in HF knowledge; uncertainty in the evidence for self-efficacy, self-care and health-related quality of life; and may result in little to no difference in HF-related hospitalisations. The identification of studies currently underway and those awaiting classification indicate that this is an area of research from which further evidence will emerge in the short and longer term.

Costs Before and After Left Ventricular Assist Device Implant and Preceding Heart Transplant: A Cohort Study.

BACKGROUND: Up to 50% of heart transplant candidates require bridging with left ventricular assist devices (VAD). This study describes hospital activity and cost 1 year preceding and 1 year following VAD implant (pre-VAD) and for the year before transplant (pre-HTX). The sample comprises an Australian cohort and is the first study to investigate costs using both institutional and linked administrative data. METHODS: Institutional activity was established for 77 consecutive patients actively listed for transplant between 2009 and 2012. Costs were sourced from the institution or Australian refined diagnosis groups (arDRGs) and the National Efficient Price for admissions to other public and private institutions. Data from 25/77 VAD recipients were analysed and compared with data from 52/77 pre-transplant patients. Total and per day at risk costs were assessed, as well as totals per resource. RESULTS: Fifty per cent (50%) of the hospital costs in the pre-VAD year occurred during admission of VAD implant. Sixty-four per cent (64%) of costs in the pre-HTX and 38% in the pre-VAD period occurred outside the implanting centre. Costs in the year prior to VAD, $97,565 (IQR $86,907-$153,916), were significantly higher than costs accrued in the year prior to transplant, $40,250 ($13,493-$81,260), p < 0.0001. Once discharged, costs per day at risk for post-VAD patients approximated those from the pre-admission period, p = 0.16 and in the more clinically stable pre-HTX cohort, p = 0.08. CONCLUSION: Compared with the year prior, VAD implant stabilised hospital cost in patients discharged home. A high proportion of the hospital costs in the pre-implant year occur outside the implanting centre and should be considered in economic models assessing the impact of VAD implant.

Evaluating the convergent and discriminant validity of three versions of the frailty phenotype in heart failure: results from the FRAME-HF study.

BACKGROUND: Frailty is an important predictive measure of mortality and rehospitalisation in people with heart failure. To date, there are no frailty instruments validated for use in people with heart failure. AIM: The aim of this study was to evaluate the convergent and discriminant validity of three versions of the frailty phenotype in those with heart failure. METHODS: A single site, prospective cohort study was undertaken among individuals with a confirmed diagnosis of heart failure. Frailty was assessed concurrently using three versions of the frailty phenotype: the original frailty phenotype and two modified versions; the Survey of Health, Ageing and Retirement in Europe frailty instrument (SHARE-FI) and the St Vincent's frailty instrument. Convergent and discriminant validity were assessed by reporting the correlations between each version and related heart failure subconstructs, and by evaluating the ability of each version to discriminate between normal and abnormal scores of other physical and psychosocial scales specific to heart failure-related subconstructs. RESULTS: The New York Heart Association classes were moderately correlated with the St Vincent's frailty instrument (r=0.47, P⩽0.001), SHARE-FI (r=0.42, P⩽0.001) and the frailty phenotype (r=0.42, P⩽0.001). The SHARE-FI and the St Vincent's frailty instrument were both able to discriminate consistently between normal and abnormal scores in three out of five of the physical and psychosocial subconstructs that were assessed. The SHARE-FI was also able to discriminate between inpatients and outpatients who were classified as frail. CONCLUSIONS: Both the SHARE-FI and the St Vincent's frailty instrument displayed good convergent and discriminant validity.

Left Ventricular Device Implantation Impacts on Hospitalisation Rates, Length of Stay and Out of Hospital Time.

BACKGROUND: Widespread application of left ventricular assist devices (LVADs) in advanced heart failure, is limited by costs, and access to technical expertise. Hospitalisation drives both cost and inversely, quality of life - but cross institutional and pre-surgical inpatient length of stay data is missing in the Australian literature. We describe changes in hospitalisation rates, in the year before and after bridge to transplant LVAD therapy and preceding heart transplant (HTX). METHODS: Hospitalisation, Australian refined diagnosis group (ArDRG), and clinical data were assessed for 77/100 consecutive patients listed for heart transplant between July of 2009 and June of 2012. Twenty-five of the patients required ventricular assist device (VAD) therapy whilst waitlisted. Hospitalisation was defined as the proportion of "days at risk" that were spent in hospital and included all public and private admissions identified in the year before and after VAD implant, or before HTX, in a linked administrative dataset of admissions across New South Wales. RESULTS: Patients requiring VADs were clinically more unstable and spent proportionally more time in hospital than pre-HTX patients, (13% (IQR 10-20%) vs 4% (IQR1-10%), p<0.01). During the index admission, they spent 22days (IQR 10-33) in hospital before implantation, including 13 days in non-transplant centres (IQR 7-20). Following implantation, median inpatient stay was 31(IQR 26-70) - including rehabilitation in 8 of the 25 patients. The number of admissions per patient reduced in the year after VAD-implant to two (IQR1-3), from five pre-implant (IQR 3-7) p=0.002. This was similar to the pre-HTX group's three admissions (IQR1-6), p=0.33. Overall hospitalisation decreased in VAD patients beyond the first year - from 14% (IQR 10-20%) at 1-year to 0.5% (IQR 0-10%) at 2-years (p=0.002). A high percentage of hospitalisation prior to VAD (41%) and HTX (66%) occurred outside the transplant centre. CONCLUSIONS: A high proportion of activity in the pre-implant and transplant year occurs outside the implanting hospital with higher pre-implant hospitalisation in VAD patients reflecting clinical severity. Ventricular assist device implantation is significantly associated with reduced admissions, and hospitalisation once reconditioning has occurred.

COMBINING INSTITUTIONAL AND ADMINISTRATIVE DATA TO ASSESS HOSPITAL COSTS FOR PATIENTS RECEIVING VENTRICULAR ASSIST DEVICES.

OBJECTIVES: The aim of this study was to describe patient level costing methods and develop a database of healthcare resource use and cost in patients with AHF receiving ventricular assist device (VAD) therapy. METHODS: Patient level micro-costing was used to identify documented activity in the years preceding and following VAD implantation, and preceding heart transplant for a cohort of seventy-seven consecutive patients listed for heart transplantation (2009-12). Clinician interviews verified activity, established time resource required for each activity, and added additional undocumented activities. Costs were sourced from the general ledger, salary, stock price, pharmacy formulary data, and from national medical benefits and prostheses lists. Linked administrative data analyses of activity external to the implanting institution, used National Weighted Activity Units (NWAU), 2014 efficient price, and admission complexity cost weights and were compared with micro-costed data for the implanting admission. RESULTS: The database produced includes patient level activity and costs associated with the seventy-seven patients across thirteen resource areas including hospital activity external to the implanting center. The median cost of the implanting admission using linked administrative data was $246,839 (interquartile range [IQR] $246,839-$271,743), versus $270,716 (IQR $211,740-$378,482) for the institutional micro-costing (p = .08). CONCLUSIONS: Linked administrative data provides a useful alternative for imputing costs external to the implanting center, and combined with institutional data can illuminate both the pathways to transplant referral and the hospital activity generated by patients experiencing the terminal phases of heart failure in the year before transplant, cf-VAD implant, or death.

Long distance heart transplantation: a tale of two cities.

In this 'paired' case report, we describe two heart transplants performed 3 days apart at our centre. Both cases involved very prolonged transportation time of the donor heart. In one case, the donor heart was transported in an ice chest, while in the other case the organ was transported using a normothermic ex vivo perfusion (NEVP) system. The additional retrieval costs incurred by the use NEVP were more than offset by the reduction in subsequent inpatient costs.

Adaptation and coping in patients living with an LVAD: A metasynthesis.

OBJECTIVE: To synthesize information supporting coping and adaptation of LVAD patients and to identify opportunities for future interventions. BACKGROUND: Left Ventricular Assist Device (LVAD) patients demonstrate improvements in quality of life and functional status, but qualitative research has not been meaningfully integrated. METHODS: Qualitative meta-synthesis using Lazarus and Folkmans' Transactional Model of stress and coping. RESULTS: Four distinct stages of adaptation were identified: Pre-LVAD, Implant Hospitalization, Early Home Adaptation and Late Home Adaptation. Each stage includes tasks in physical, psychological and social domains. Two themes emerged: 1) Primary Appraisal: Every stage is a new challenge and 2) Secondary Appraisal: Routines are achievable, emotions are more difficult. CONCLUSIONS: Emotional challenges including fear and anxiety related to life-limiting illness and changed social roles need to be honestly addressed. Individuals living with LVAD achieve a sense of independence, enjoy social interactions and meaningful activities through addressing practical and emotional problems to facilitate coping.

Impact of left ventricular assist device speed adjustment on exercise tolerance and markers of wall stress.

INTRODUCTION: Left ventricular assist devices are crucial in rehabilitation of patients with end-stage heart failure. Whether cardiopulmonary function is enhanced with higher pump output is unknown. METHODS: 10 patients (aged 39±16 years, mean±SD) underwent monitored adjustment of pump speed to determine minimum safe low speed and maximum safe high speed at rest. Patients were then randomized to these speed settings and underwent three 6-minute walk tests (6MWT) and symptom-limited cardiopulmonary stress tests (CPX) on separate days. RESULTS: Pump speed settings (low, normal and high) resulted in significantly different resting pump flows of 4.43±0.6, 5.03±0.94, and 5.72±1.2 l/min (P<.001). There was a significant enhancement of pump flows (greater at higher speed settings) with exercise (P<0.05). Increased pump speed was associated with a trend to increased 6MWT distance (P=.10); and CPX exercise time (p=.27). Maximum workload achieved and peak oxygen consumption were significantly different comparing low to high pump speed settings only (P<.05). N-terminal-pro-B-type natriuretic peptide release was significantly reduced at higher pump speed with exercise (P<.01). CONCLUSIONS: We have found that alteration of pump speed setting resulted in significant variation in estimated pump flow. The high-speed setting was associated with lower natriuretic hormone release consistent with lower myocardial wall stress. This did not, however, improve exercise tolerance.

Effect of exercise and pump speed modulation on invasive hemodynamics in patients with centrifugal continuous-flow left ventricular assist devices.

BACKGROUND: Continuous-flow left ventricular assist devices (CF-LVADs) improve functional capacity in patients with end-stage heart failure. Pump output can be increased by increased pump speed as well as changes in loading conditions. METHODS: The effect of exercise on invasive hemodynamics was studied in two study protocols. The first examined exercise at fixed pump speed (n = 8) and the second with progressive pump speed increase (n = 11). Patients underwent simultaneous right-heart catheterization, mixed venous saturation, echocardiography and mean arterial pressure monitoring. Before exercise, a ramp speed study was performed in all patients. Patients then undertook symptom-limited supine bicycle exercise. RESULTS: Upward titration of pump speed at rest (by 11.6 ± 8.6% from baseline) increased pump flow from 5.3 ± 1.0 to 6.3 ± 1.0 liters/min (18.9% increase, p < 0.001) and decreased pulmonary capillary wedge pressure (PCWP; 13.6 ± 5.4 to 8.9 ± 4.1 mm Hg, p < 0.001). Exercise increased pump flow to a similar extent as pump speed change alone (to 6.2 ± 1.0 liters/min, p < 0.001), but resulted in increased right- and left-heart filling pressures (right atrial pressure [RAP]: 16.6 ± 7.5 mm Hg, p < 0.001; PCWP 24.8 ± 6.7 mm Hg, p < 0.001). Concomitant pump speed increase with exercise enhanced the pump flow increase (to 7.0 ± 1.4 liters/min, p < 0.001) in Protocol 2, but did not alleviate the increase in pre-load (RAP: 20.5 ± 8.0 mm Hg, p = 0.07; PCWP: 26.8 ± 12.7 mm Hg; p = 0.47). Serum lactate and NT-proBNP levels increased significantly with exercise. CONCLUSIONS: Pump flow increases with up-titration of pump speed and with exercise. Although increased pump speed decreases filling pressures at rest, the benefit is not seen with exercise despite concurrent up-titration of pump speed.

Six-minute walk distance predicts VO2 (max) in patients supported with continuous flow left ventricular assist devices.

BACKGROUND: Six-minute walk distance (6MWD) and maximal oxygen uptake (VO2 max ) are used as prognostic tools in patients with heart failure (HF). Whether these tests provide similar information in the LVAD population is not known. METHODS: Eight patients supported with VentrAssist rotary blood pump LVADs, underwent three days of testing that included 6MWD and VO2 max at normal, high or low speeds, generating twenty-four paired results. RESULTS: The mean 6MWD was 438 (+/- 90 SD) m and the mean VO2 (max) was 14.12 (+/-1.87) ml/kg/min. There was a modest correlation between VO2 (max) and 6MWD (r = 0.56 p = 0.004), which improved (r = 0.72 p = 0.002) when patients with higher resting Pro BNP levels and larger left ventricular end diastolic diameters (LVEDD) were excluded. CONCLUSIONS: 6MWD is correlated with VO2 (max) in LVAD supported patients, with higher correlations in patients with better underlying cardiac function.

Normalisation of haemodynamics in patients with end-stage heart failure with continuous-flow left ventricular assist device therapy.

BACKGROUND: New generation continuous-flow left ventricular assist devices (LVADs) utilise centrifugal pumps. Data concerning their effect on patient haemodynamics, ventricular function and tissue perfusion is limited. We aimed to document these parameters following HeartWare centrifugal continuous-flow LVAD (HVAD) implantation and to assess the impact of post-operative right heart failure (RHF). METHODS: We reviewed 53 consecutive patients (mean age 49.5 ± 14.1 yrs) with HVAD implanted in the left ventricle, at St. Vincent's Hospital, Sydney, between January 2007 and August 2012. Available paired right heart catheterisation (n=35) and echocardiography (n=39) data was reviewed to assess response of invasive haemodynamics and ventricular function to LVAD support. RESULTS: A total of 28 patients (53%) were implanted from interim mechanical circulatory support. Seventeen patients (32%) required short-term post-implant veno-pulmonary artery extracorporeal membrane oxygenation. At 100 ± 61 days post-implant, mean pulmonary artery pressure and mean pulmonary capillary wedge pressure decreased from 38.8 ± 7.7 to 22.9 ± 7.7 mmHg and 28.3 ± 6.4 to 13.4 ± 5.4 mmHg respectively (p<0.001). LV end diastolic diameter decreased from 71.3 ± 12.7 to 61.1 ± 13.7 mm and LV end-systolic diameter from 62.7 ± 12.3 to 53.9 ± 14.4mm (p<0.001). Aortic regurgitation remained trivial. Serum sodium increased from 133.3 ± 5.7 to 139.3 ± 2.8 mmol/L and creatinine decreased from 109.1 ± 42.5 to 74.3 ± 26.2 µmol/L (p<0.001). Across the entire cohort, the six-month survival/transplant rate was significantly lower for RHF patients (72.2%, n=18) compared to those without (96.9%, n=35, p=0.01). CONCLUSIONS: HVAD support improves haemodynamics, LV dimensions and renal function. Following implantation with a centrifugal continuous-flow LVAD, RHF remains a significant risk with a tendency to worse outcomes in the short to medium term.

Effect of alteration in pump speed on pump output and left ventricular filling with continuous-flow left ventricular assist device.

Third-generation continuous-flow left ventricular assist devices (LVAD) provide reduced pulsatility flow. We examined the safe working range for LVAD pump speed and the effect on pump output and cardiac function in 13 stable outpatients with VentrAssist-LVAD (Ventracor Ltd, Australia). Pump speed was decreased from a baseline mean of 2,073 ± 86 revolutions per minute (RPM, with corresponding mean flow of 5.59 ± 1.18 L/min, mean ± standard deviation) to an average low-speed of 1,835 ± 55 RPM (corresponding flow 4.68 ± 0.99 L/min) and up to high-speed of 2,315 ± 66 RPM (corresponding flow 6.30 ± 1.29 L/min). There was a strong linear relationship between alteration in speed and flow rates (r(2) = 0.89, p < 0.00001) but marked interpatient variation. Downward titration to preset minimum 1,800 RPM was achieved in 9/13 (69%) and upward titration to the preset maximum 2,400 RPM was achieved in 4/13 (31%). Upward titration was stopped due to ventricular suction or nonsustained ventricular tachycardia (VT) in 4/13 (31%). Ventricular suction or VT (in 4/13) tended to be more common in patients with poor right ventricular (RV) function (p = 0.07). In summary, pump flow is stable within a relatively small speed range and should not be altered without close monitoring due to variation in response between patients, particularly with concomitant RV impairment.