Cost-Effectiveness of Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation in the Australian Health Care System

BACKGROUND

Heart transplantation is an effective treatment for end-stage congestive heart failure, however, achieving the right balance of immunosuppression to maintain graft function while minimising adverse effects is challenging. Serial endomyocardial biopsies (EMBs) are currently the standard for rejection surveillance, despite being invasive. Replacing EMB-based surveillance with cardiac magnetic resonance (CMR)-based surveillance for acute cardiac allograft rejection has shown feasibility. This study aimed to assess the cost-effectiveness of CMR-based surveillance in the first year after heart transplantation.

METHOD

A prospective clinical trial was conducted with 40 orthotopic heart transplant (OHT) recipients. Participants were randomly allocated into two surveillance groups: EMB-based, and CMR-based. The trial included economic evaluations, comparing the frequency and cost of surveillance modalities in relation to quality-adjusted life years (QALYs) within the first year post-transplantation. Sensitivity analysis encompassed modelled data from observed EMB and CMR arms, integrating two hypothetical models of expedited CMR-based surveillance.

RESULTS

In the CMR cohort, 238 CMR scans and 15 EMBs were conducted, versus (vs) 235 EMBs in the EMB group. CMR surveillance yielded comparable rejection rates (CMR 74 vs EMB 94 events, p=0.10) and did not increase hospitalisation risk (CMR 32 vs EMB 46 events, p=0.031). It significantly reduced the necessity for invasive EMBs by 94%, lowered costs by an average of AUD$32,878.61, and enhanced cumulative QALY by 0.588 compared with EMB. Sensitivity analysis showed that increased surveillance with expedited CMR Models 1 and 2 were more cost-effective than EMB (all p<0.01), with CMR Model 1 achieving the greatest cost savings (AUD$34,091.12±AUD$23,271.86 less) and utility increase (+0.62±1.49 QALYs, p=0.011), signifying an optimal cost-utility ratio. Model 2 showed comparable utility to the base CMR model (p=0.900) while offering the benefit of heightened surveillance frequency during periods of elevated rejection risk.

CONCLUSIONS

CMR-based rejection surveillance in orthotopic heart transplant recipients provides a cost-effective alternative to EMB-based surveillance. Furthermore, it reduces the need for invasive procedures, without increased risk of rejection or hospitalisation for patients, and can be incorporated economically for expedited surveillance. These findings have important implications for improving patient care and optimising resource allocation in post-transplant management.

Longitudinal analysis left ventricular chamber responses under durable LVAD support

BACKGROUND

Left ventricular assist device (LVAD) support offers remodeling potential in some patients. Our goal was to use noninvasively derived pressure-volume (PV) loops to understand the effect of demographic and device variables on serial changes in cardiac function under pump support.

METHODS

Thirty-two consecutive Medtronic HeartWare Ventricular Assist Device (HVAD) patients (mean 55.9 ± 12.3 years, 81.3% male) were prospectively recruited. Single-cycle ventricular pressure and volume were estimated using a validated algorithm. PV loops (n = 77) and corresponding cardiac chamber dynamics were derived at predefined postimplant timepoints (1, 3, 6 months). Changes in PV loop parameters sustained across the 6-month period were characterized using mixed-effects modeling. The influence of demographic and device variables on the observed changes was assessed.

RESULTS

Across a 6-month period, the mean ventricular function parameters remained stable. Significant predictors of monthly improvement of stroke work include: lower pump speeds (2400 rpm vs 2500-2800 rpm) [0.0.051 mm Hg/liter/month (p = 0.001)], high pulsatility index (>1.0 vs <1.0) [0.052 mm Hg/liter/month (p = 0.012)], and ischemic cardiomyopathy indication for LVAD implantation (vs nonischemic) [0.0387 mm Hg/liter/month (p = 0.007)]. Various other cardiac chamber function parameters including cardiac power, peak systolic pressure, and LV elastance also showed improvements in these cohorts.

CONCLUSIONS

Factors associated with improvement in ventricular energetics and hemodynamics under LVAD support can be determined with noninvasive PV loops. Understanding the basis of increasing ventricular load to optimize myocardial remodeling may prove valuable in selecting eligible recovery candidates.

How do mechanical circulatory support patients die? Autopsy findings for left-ventricular assist device/total artificial heart nonsurvivors

BACKGROUND

Although life saving for end-stage heart failure patients, permanent mechanical circulatory support (MCS) is often the proximate cause of death in those that do not survive to transplant. Autopsy remains the gold standard for diagnosing causes of death and a vital tool for better understanding underlying pathology of nonsurvivors. The aim of this study was to determine the frequency and outcomes of autopsy investigations and compare these with premortem clinical assessment.

METHODS

The autopsy findings and medical records of all patients who underwent left ventricular assist device (LVAD) or total artificial heart (TAH) insertion between June 1994 and April 2022 as a bridge to transplant, but subsequently died pre-heart transplantation were reviewed.

RESULTS

A total of 203 patients had a LVAD or TAH implanted during the study period. Seventy-eight patients (M=59, F=19) died prior to transplantation (age 55 [14] years, INTERMACS=2). Autopsies were conducted in 26 of 78 patients (33%). Three were limited studies. The leading contributor to cause of death was respiratory (14/26), either nosocomial infection or associated with multiorgan failure. Intracranial hemorrhage was the second most common cause of death (8/26). There was a major discrepancy rate of 17% and a minor discrepancy rate of 43%. Autopsy study added a total of 14 additional contributors of death beyond clinical assessment alone (Graphical Abstract).

CONCLUSIONS

Over an observational period of 26years, the frequency of autopsy was low. To improve LVAD/TAH patient survival to transplant, better understanding as to cause of death is required. Patients with MCS have complex physiology and are at high risk of infection and bleeding complications.

Major adverse kidney events predict reduced survival in ventricular assist device supported patients

AIMS

There is limited data describing major adverse kidney events (MAKE) in patients supported with ventricular assist devices (VAD). We aim to describe the association between MAKE and survival, risk factors for MAKE, and renal trajectory in VAD supported patients.

METHODS AND RESULTS

We conducted a single-centre retrospective analysis of consecutive VAD implants between 2010 and 2019. Baseline demographics, biochemistry, and adverse events were collected for the duration of VAD support. MAKE was defined as the first event to occur of sustained drop (>50%) in estimated glomerular filtration rate (eGFR), progression to stage V chronic kidney disease, initiation or continuation of renal replacement therapy beyond implant admission or death on renal replacement therapy at any time. One-hundred and seventy-three patients were included, median age 56.8 years, 18.5% female, INTERMACS profile 1 or 2 in 75.1%. Thirty-seven patients experienced MAKE. On multivariate analysis, post-implant clinical right ventricular failure and the presence of chronic haemolysis, defined by the presence of schistocytes on blood film analysis, were significantly associated with increased risk of MAKE (adjusted odds ratio 9.88, P < 0.001 and adjusted odds ratio 3.33, P = 0.006, respectively). MAKE was associated with reduced survival (hazard ratio 4.80, P < 0.001). Patients who died or experienced MAKE did not demonstrate the expected transient 3-month improvement in eGFR, seen in other cohorts.

CONCLUSIONS

MAKE significantly impacts survival. In our cohort, MAKE was predicted by post-implant right ventricular failure and chronic haemolysis. The lack of early eGFR improvement on VAD support may indicate higher risk for MAKE.

Safety and tolerability of sodium-glucose cotransporter-2 inhibitors in bridge-to-transplant patients supported with centrifugal-flow left ventricular assist devices

BACKGROUND

The safety and tolerability of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with end-stage heart failure supported with left-ventricular-assist-devices (LVADs), irrespective of diabetes mellitus, is not known.

METHODS

A retrospective analysis of 31 outpatients implanted with LVADs as bridge-to-transplant (BTT) was conducted. Patients with biventricular support, aged under 18 years, who were discharged from the index hospitalisation, or were prescribed SGLT2i prior to their first outpatient clinic were excluded. Patient demographics, laboratory studies, pump haemodynamic and adverse event data was collected.

RESULTS

Sixteen (51.6%) of 31 patients were prescribed SGLT2i over median 101.5 days (37.5-190.8). No patients discontinued SGLT2i use or reported attributable adverse symptoms. No significant differences between patients prescribed SGLT2i compared to those SGLT2i-naïve were seen in: [1] renal function; [2] weight; [3] mean arterial pressure. There were numerically lower infection-related (n = 4 vs 7, HR 0.32 (0.08-1.28), p = 0.11) and haemocompatibility-related (n = 3 vs 4, HR 0.52 (0.09-2.83), p = 0.45) adverse events in the SGLT2i group, albeit non-significant.

CONCLUSIONS

We found SGLT2i to be safe and well-tolerated in the BTT LVAD cohort with no significant difference in rates of infection or haemocompatibility-related adverse events with SGLT2i use. Larger studies will inform further beneficial effects of SGLT2i prescription in this cohort.

Safety and Performance of the Aortix Device in Acute Decompensated Heart Failure and Cardiorenal Syndrome

BACKGROUND

Cardiorenal syndrome (CRS) complicates 33% of acute decompensated heart failure (ADHF) admissions, and patients with persistent congestion at discharge have high 30-day event rates.

OBJECTIVES

The purpose of this study was to evaluate a novel catheter-deployed intra-aortic entrainment pump (IAEP) in patients with ADHF with CRS and persistent congestion.

METHODS

A multicenter (n = 14), nonrandomized, single-arm, safety and feasibility study of IAEP therapy was conducted. Within patient changes (post-pre IAEP therapy) in fluid loss, hemodynamics, patient-reported dyspnea, and serum biomarkers were assessed using Wilcoxon signed-rank testing.

RESULTS

Of 21 enrolled patients, 18 received Aortix therapy. Mean ± SD patient age was 60.3 ± 7.9 years. The median left ventricular ejection fraction was 22.5% (25th-75th percentile: 10.0%-53.5%); 27.8% had a left ventricular ejection fraction ≥50%. Pre-therapy, patients received 8.7 ± 4.1 days of loop diuretic agents and 44% were on inotropes. Pump therapy averaged 4.6 ± 1.6 days, yielding net fluid losses of 10.7 ± 6.5 L (P < 0.001) and significant (P < 0.01) reductions in central venous pressure (change from baseline: -8.5 mm Hg [25th-75th percentile: -3.5 to -10.0 mm Hg]), pulmonary capillary wedge pressure (-11.0 mm Hg [25th-75th percentile: -5.0 to -14.0 mm Hg]), and serum creatinine (-0.2 mg/dL [25th-75th percentile: -0.1 to -0.5 mg/dL]) with improved estimated glomerular filtration rate (+5.0 mL/min/1.73 m2 [25th-75th percentile: 2.0-9.0 mL/min/1.73 m2]) and patient-reported dyspnea score (+16 [25th-75th percentile: 3-37]). Dyspnea scores, natriuretic peptides, and renal function improvements persisted through 30 days.

CONCLUSIONS

This pilot study of patients with ADHF, persistent congestion, and worsening renal function due to CRS supports the potential for safely achieving decongestion using IAEP therapy. These initial promising results provide the basis for future randomized clinical trials of this novel pump. (An Evaluation of the Safety and Performance of the Aortix System for Intra-Aortic Mechanical Circulatory Support in Patients with Cardiorenal Syndrome [The Aortix CRS Pilot Study]; NCT04145635).

DMD-Associated Dilated Cardiomyopathy: Genotypes, Phenotypes, and Phenocopies

BACKGROUND

Variants in the DMD gene, that encodes the cytoskeletal protein, dystrophin, cause a severe form of dilated cardiomyopathy (DCM) associated with high rates of heart failure, heart transplantation, and ventricular arrhythmias. Improved early detection of individuals at risk is needed.

METHODS

Genetic testing of 40 male probands with a potential X-linked genetic cause of primary DCM was undertaken using multi-gene panel sequencing, multiplex polymerase chain reaction, and array comparative genomic hybridization. Variant location was assessed with respect to dystrophin isoform patterns and exon usage. Telomere length was evaluated as a marker of myocardial dysfunction in left ventricular tissue and blood.

RESULTS

Four pathogenic/likely pathogenic DMD variants were found in 5 probands (5/40: 12.5%). Only one rare variant was identified by gene panel testing with 3 additional multi-exon deletion/duplications found following targeted assays for structural variants. All of the pathogenic/likely pathogenic DMD variants involved dystrophin exons that had percent spliced-in scores >90, indicating high levels of constitutive expression in the human adult heart. Fifteen DMD variant-negative probands (15/40: 37.5%) had variants in autosomal genes including TTN, BAG3, LMNA, and RBM20. Myocardial telomere length was reduced in patients with DCM irrespective of genotype. No differences in blood telomere length were observed between genotype-positive family members with/without DCM and controls.

CONCLUSIONS

Primary genetic testing using multi-gene panels has a low yield and specific assays for structural variants are required if DMD-associated cardiomyopathy is suspected. Distinguishing X-linked causes of DCM from autosomal genes that show sex differences in clinical presentation is crucial for informed family management.

Metabolic Sequelae of Everolimus Treatment After Cardiac Transplant: A Hypothesis-Generating Study

BACKGROUND

Although modern immunosuppressants improve survival post-transplant, they are associated with long-term metabolic complications, such as post-transplant diabetes mellitus (PTDM). Calcineurin inhibitor-sparing regimens using everolimus attenuate some complications such as left ventricular hypertrophy. However, the metabolic effects of everolimus following transplant are less clear.

METHODS

Post-hoc analysis to compare PTDM and other metabolic outcomes in participants of a randomised open-label clinical trial of low-dose everolimus and tacrolimus versus standard-dose tacrolimus in heart transplant recipients (RADTAC1 study).

RESULTS

There were 39 participants in the trial; mean follow-up was 6.4±1.5 years. There was a high rate of pre-existing diabetes (26%) and newly diagnosed PTDM (36%) during follow-up. Half the patients who developed PTDM in the everolimus-tacrolimus group (n=4/8) ceased diabetes medications during follow-up, which was not observed in patients on standard tacrolimus (n=0/6). In the first 12 months there was a higher use of non-insulin treatment for diabetes in the everolimus-tacrolimus group compared to the standard tacrolimus group.

CONCLUSIONS

This study suggests that treatment with everolimus may be associated with improved glycaemic control of PTDM relative to treatment with standard doses of calcineurin inhibitor. These findings should be further studied in prospective randomised trials.

Machine learning prediction of progressive subclinical myocardial dysfunction in moderate aortic stenosis

Background

Moderate severity aortic stenosis (AS) is poorly understood, is associated with subclinical myocardial dysfunction, and can lead to adverse outcome rates that are comparable to severe AS. Factors associated with progressive myocardial dysfunction in moderate AS are not well described. Artificial neural networks (ANNs) can identify patterns, inform clinical risk, and identify features of importance in clinical datasets.

Methods

We conducted ANN analyses on longitudinal echocardiographic data collected from 66 individuals with moderate AS who underwent serial echocardiography at our institution. Image phenotyping involved left ventricular global longitudinal strain (GLS) and valve stenosis severity (including energetics) analysis. ANNs were constructed using two multilayer perceptron models. The first model was developed to predict change in GLS from baseline echocardiography alone and the second to predict change in GLS using data from baseline and serial echocardiography. ANNs used a single hidden layer architecture and a 70%:30% training/testing split.

Results

Over a median follow-up interval of 1.3 years, change in GLS (≤ or >median change) could be predicted with accuracy rates of 95% in training and 93% in testing using ANN with inputs from baseline echocardiogram data alone (AUC: 0.997). The four most important predictive baseline features (reported as normalized % importance relative to most important feature) were peak gradient (100%), energy loss (93%), GLS (80%), and DI < 0.25 (50%). When a further model was run including inputs from both baseline and serial echocardiography (AUC 0.844), the top four features of importance were change in dimensionless index between index and follow-up studies (100%), baseline peak gradient (79%), baseline energy loss (72%), and baseline GLS (63%).

Conclusions

Artificial neural networks can predict progressive subclinical myocardial dysfunction with high accuracy in moderate AS and identify features of importance. Key features associated with classifying progression in subclinical myocardial dysfunction included peak gradient, dimensionless index, GLS, and hydraulic load (energy loss), suggesting that these features should be closely evaluated and monitored in AS.

The safe use of metformin in heart failure patients both with and without T2DM: a cross-sectional and longitudinal study

AIMS

This study investigated the safe use of metformin in patients with (1) type 2 diabetes mellitus (T2DM) and heart failure on metformin, and (2) heart failure without T2DM and metformin naïve.

METHODS

Two prospective studies on heart failure patients were undertaken. The first was a cross-sectional study with two patient cohorts, one with T2DM on metformin (n=44) and one without T2DM metformin naive (n=47). The second was a 12-week interventional study of patients without T2DM (n=27) where metformin (500 mg immediate release, twice daily) was prescribed. Plasma metformin and lactate concentrations were monitored. Individual pharmacokinetics were compared between cohorts. Univariable and multivariable analysis analysed the effects of variables on plasma lactate concentrations.

RESULTS

Plasma metformin and lactate concentrations mostly (99.9%) remained below safety thresholds (5 mg/L and 5 mmol/L, respectively). Metformin concentration had no significant relationship with lactic acidosis safety markers. In the interventional study, New York Heart Association (NYHA) II (p<0.03) and III (p<0.001) grading was associated with higher plasma lactate concentrations, whereas male sex was associated with 47% higher plasma lactate concentrations (p<0.05). The pharmacokinetics of heart failure patients with and without T2DM were similar.

CONCLUSIONS

We observed no unsafe plasma lactate concentrations in patients with heart failure treated with metformin. Metformin exposure did not influence plasma lactate concentrations; however, NYHA class and sex did. The pharmacokinetics of metformin in heart failure patients are similar irrespective of T2DM. These findings may support the safe use of metformin in heart failure patients with and without T2DM.

Diabetes medication following heart transplantation: a focus on novel cardioprotective therapies-a joint review from endocrinologists and cardiologists

There is accumulating evidence that novel glucose-lowering agents infer potent cardiovascular and renal benefits. Therefore, it is imperative to reassess the management of post-transplant diabetes mellitus and consider the role of newer agents. With improved transplant-related survival and high prevalence of post-transplant diabetes, management of long-term complications such as diabetes are increasingly important. There are limited guidelines to assist in choice of appropriate agents after solid organ transplantation. Traditional therapies including insulin and sulfonylureas may still have a role; however, other agents should be considered prior. The evidence of novel glucose-lowering agents in post-transplant care is limited, and most studies have focused on kidney transplant recipients. While there are some parallels between renal and cardiac transplant recipients, the potential cardiovascular benefits, particularly on cardiac fibrosis are unique to cardiac transplantation. The treatment of diabetes, with a focus on additional cardiac and renal benefits, needs to be brought to the forefront of post-transplant care with incorporation of recent evidence outside of transplantation. The role for novel glucose-lowering agents in cardiac transplant recipients will be explored, with a summary of available evidence.

Atrial cardiomyopathy: Current and future imaging methods for assessment of atrial structure and function

Changes in atrial size and function have historically been considered a surrogate marker of ventricular dysfunction. However, it is now recognized that atrial cardiomyopathy (ACM) may also occur as a primary myocardial disorder. Emerging evidence that ACM is a major risk factor for atrial fibrillation, heart failure, and thromboembolic stroke, has highlighted the significance of this disorder and the need for better assessment of atrial metrics in clinical practice. Key barriers in this regard include a lack of standardized criteria or hierarchy for the diagnosis of ACM and lack of consensus for the most accurate phenotyping methods. In this article we review existing literature on ACM, with a focus on current and future non-invasive imaging methods for detecting abnormalities of atrial structure and function. We discuss the relative advantages and disadvantages of transthoracic echocardiography and cardiac magnetic resonance imaging for assessing a range of parameters, including atrial size and contractile function, strain, tissue characteristics, and epicardial adipose tissue. We will also present the potential application of novel imaging methods such as sphericity index and four- or five-dimensional flow.

Sodium glucose co-transporter 2 inhibition with empagliflozin on metabolic, cardiac and renal outcomes in recent cardiac transplant recipients (EMPA-HTx): protocol for a randomised controlled trial

INTRODUCTION

Cardiac transplantation (CTx) is a life-saving operation that can improve the quality and length of a recipient's life. Immunosuppression medication, required to prevent rejection, can result in adverse metabolic and renal effects. Clinically significant complications include metabolic effects such as diabetes and weight gain, renal impairment, and cardiac disease such as allograft vasculopathy and myocardial fibrosis. Sodium glucose co-transporter 2 (SGLT2) inhibitors are a class of oral medication that increase urinary excretion of glucose. In patients with type 2 diabetes, SGLT2 inhibitors improve cardiovascular, metabolic and renal outcomes. Similar benefits have been shown in patients with heart failure and reduced ejection fraction irrespective of diabetes status. In patients with post-transplant diabetes mellitus, SGLT2 inhibitors improve metabolic parameters; however, their benefit and safety have not been evaluated in randomised prospective studies. This study will potentially provide a novel therapy to improve or prevent complications (diabetes, kidney failure and heart fibrosis) that occur with immunosuppressive medications.

METHODS

The EMPA-HTx study is a randomised, placebo-controlled trial of the SGLT2 inhibitor empagliflozin 10 mg daily versus placebo in recent CTx recipients. One hundred participants will be randomised 1:1 and commence the study medication within 6-8 weeks of transplantation with treatment and follow-up until 12 months after transplantation. Demographic information, anthropomorphic measurements, pathology tests and cardiac magnetic resonance (CMR) scan will be recorded at baseline and follow-up. Patients will be reviewed monthly during the study until 12 months post-CTx and data will be collected for each patient at each study visit. The overall aim of the study is to assess the safety and efficacy of empagliflozin in CTx recipients. The primary outcome is glycaemic improvement measured as change in glycated haemoglobin and/or fructosamine. Key secondary outcomes are cardiac interstitial fibrosis measured by CMR and renal function measured by estimated glomerular filtration rate.

ETHICS AND DISSEMINATION

This study has been approved by St Vincent's Hospital Human Research Ethics Committee (2021/ETH12184). The findings will be presented at national and international scientific meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12622000978763.

Arterial Compliance and Continuous-Flow Left Ventricular Assist Device Pump Function

Durable continuous-flow left ventricular assist devices (cfLVADs) demonstrate superior survival, cardiac functional status, and overall quality of life compared to medical therapy alone in advanced heart failure. Previous studies have not considered the impact arterial compliance may have on pump performance or developed arterial pressure. This study assessed the impact of alterations in arterial compliance, preload, and afterload on continuous-flow pump function and measured hemodynamics using an in-vitro pulsatile mock circulatory loop. Decreased arterial compliance was associated with a significant increase in arterial pressure pulsatility which was not evident in the flow pulsatility, as displayed in pump flow waveforms. There were marked changes in the pump flow waveforms due to the significant alteration in the aortoventricular gradient during diastole according to the changes in compliance. This study demonstrates that changes in systemic blood pressure, afterload, and left ventricular contractility each significantly affects the flow waveform. The association of hypertension with lower aortic compliance results in markedly decreased diastolic flow rates which may be important in contributing to a greater risk of adverse events under cfLVAD support.

Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation

BACKGROUND

Endomyocardial biopsy (EMB) is the gold standard method for surveillance of acute cardiac allograft rejection (ACAR) despite its invasive nature. Cardiovascular magnetic resonance (CMR)-based myocardial tissue characterization allows detection of myocarditis. The feasibility of CMR-based surveillance for ACAR-induced myocarditis in the first year after heart transplantation is currently undescribed.

METHODS

CMR-based multiparametric mapping was initially assessed in a prospective cross-sectional fashion to establish agreement between CMR- and EMB-based ACAR and to determine CMR cutoff values between rejection grades. A prospective randomized noninferiority pilot study was then undertaken in adult orthotopic heart transplant recipients who were randomized at 4 weeks after orthotopic heart transplantation to either CMR- or EMB-based rejection surveillance. Clinical end points were assessed at 52 weeks.

RESULTS

Four hundred one CMR studies and 354 EMB procedures were performed in 106 participants. Forty heart transplant recipients were randomized. CMR-based multiparametric assessment was highly reproducible and reliable at detecting ACAR (area under the curve, 0.92; sensitivity, 93%; specificity, 92%; negative predictive value, 99%) with greater specificity and negative predictive value than either T1 or T2 parametric CMR mapping alone. High-grade rejection occurred in similar numbers of patients in each randomized group (CMR, n=7; EMB, n=8; P=0.74). Despite similarities in immunosuppression requirements, kidney function, and mortality between groups, the rates of hospitalization (9 of 20 [45%] versus 18 of 20 [90%]; odds ratio, 0.091; P=0.006) and infection (7 of 20 [35%] versus 14 of 20 [70%]; odds ratio, 0.192; P=0,019) were lower in the CMR group. On 15 occasions (6%), patients who were randomized to the CMR arm underwent EMB for clarification or logistic reasons, representing a 94% reduction in the requirement for EMB-based surveillance.

CONCLUSIONS

A noninvasive CMR-based surveillance strategy for ACAR in the first year after orthotopic heart transplantation is feasible compared with EMB-based surveillance.

REGISTRATION

HREC/13/SVH/66 and HREC/17/SVH/80.

AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY

ACTRN12618000672257.

Intermittent Papillary Muscle Suction: A Rare Cause of Left Ventricular Assist Device Low Flow

Low flow alarms represent a management challenge in patients with left ventricular assist devices because they are often a consequence of complex patient-device interactions. We present a case of intermittent suction of the postero-medial papillary muscle into the left ventricular assist device inflow cannula during diastole, causing low flows. This case highlights the importance of a systematic approach and use of multiple investigation modalities in making an accurate diagnosis. (Level of Difficulty: Advanced.).

Ageing, Hypertension and Aortic Valve Stenosis: A Conscious Uncoupling

Aortic valve stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload (due to an obstructive valve), but rather, functions as a series circuit with important contributions from both the valve and ageing vasculature. Patients with AS are frequently elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizable, and yet, the contribution of ventricular afterload has been difficult to determine. Arterial stiffening increases the speed of propagation of the blood pressure wave along the central arteries (estimated as the pulse wave velocity), which results in an earlier return of reflected waves. The effect is to augment blood pressure in the proximal aorta during systole, increasing the central pulse pressure and, in turn, placing even greater afterload on the heart. Elevated global LV afterload is known to have adverse consequences on LV remodelling, function and survival in patients with AS. Consequently, there is renewed focus on methods to estimate the relative contributions of local versus global changes in arterial mechanics and valvular haemodynamics in patients with AS. We present a review on existing and upcoming methods to quantify valvulo-arterial impedance and thereby global LV load in patients with AS.

Ex Vivo Assessment of Different Oral Anticoagulant Regimens on Pump Thrombosis in a HeartWare Ventricular Assist Device

BACKGROUND

In light of decreased intracranial hemorrhage with direct oral anticoagulants and concerns about their safety in continuous flow left ventricular assist devices, we conducted an ex vivo study of thrombus formation using multiple anticoagulation agents.

METHODS

A continuous flow left ventricular assist device (HeartWare ventricular assist device) hemocompatibility loop was run using human blood under 7 conditions: control (no anticoagulation or antiplatelet); in vitro addition of aspirin; in vitro addition of apixaban at low dose (equivalent 2.5 mg twice daily); addition of apixaban at high dose (equivalent 5 mg twice daily); patients on warfarin; patients on apixaban (5 mg twice daily); and patients on dabigatran (150 mg twice daily). The primary outcome was time to formation of intrapump thrombosis. Secondary outcomes were reduction in clotting times over 1 hour, hemolysis, reduced platelet aggregation, and von Willebrand activity.

RESULTS

Twenty-one runs were completed. Times to thrombosis in median (interquartile range) were control, 131 (127-134.5); in vitro aspirin, 124 (114.5-137); and patients on dabigatran, 131 (130.5-135.5) minutes, respectively. Times in patients on warfarin were, 137 (136.5-143.5); in vitro low-dose apixaban, 141 (138.5-142); and patients on apixaban, 140 (138-142.5) minutes, respectively. No thrombus formed in the in vitro high-dose apixaban group. There were no significant differences between the individual groups. When all apixaban groups were compared with nonapixaban groups, the time to thrombosis formation was significantly longer, 143 (137-150) versus 133.5 (128.5-140) minutes, P=0.02. There were similar changes in lactate dehydrogenase levels and other secondary end points.

CONCLUSIONS

In an in vitro study of anticoagulation using human blood in a mock loop with a HeartWare HVAD, we demonstrated similar thrombosis times for apixaban and warfarin. Time to clotting was longer in the combined apixaban groups compared with combined other groups, but thrombosis times between individual groups were not significantly different.

Everolimus for the Prevention of Calcineurin-Inhibitor-Induced Left Ventricular Hypertrophy After Heart Transplantation (RADTAC Study)

OBJECTIVES

This study aimed to determine the safety and efficacy of combined low-dose everolimus and low-dose tacrolimus compared with standard-dose tacrolimus in attenuating left ventricular hypertrophy (LVH) after orthotopic heart transplantation (OHT).

BACKGROUND

Calcineurin inhibitors (CNIs) such as tactrolimus are important in preventing cardiac allograft rejection and reducing mortality after OHT. However CNIs are causatively linked to the development of LVH, and are associated with nephrotoxicity and vasculopathy. CNI-sparing agents such as everolimus have been hypothesized to inhibit adverse effects of CNIs.

METHODS

In this prospective, randomized, open-label study, OHT recipients were randomized at 12 weeks after OHT to a combination of low-dose everolimus and tacrolimus (the RADTAC group) or standard-dose tacrolimus (the TAC group), with both groups coadministered mycophenolate and prednisolone. The primary endpoint was LVH indexed as the change in left ventricular mass (ΔLVM) by cardiovascular magnetic resonance (CMR) imaging from 12 to 52 weeks. Secondary endpoints included CMR-based myocardial performance, T1 fibrosis mapping, blood pressure, and renal function. Safety endpoints included episodes of allograft rejection and infection.

RESULTS

Forty stable OHT recipients were randomized. Recipients in the RADTAC group had significantly lower tacrolimus levels compared with the TAC group (6.5 ± 3.5 μg/l vs. 8.6 ± 2.8 μg/l; p = 0.02). The mean everolimus level in the RADTAC group was 4.2 ± 1.7 μg/l. A significant reduction in LVM was observed in the RADTAC group compared with an increase in LVM in the TAC group (ΔLVM = -13.0 ± 16.8 g vs. 2.1 ± 8.4 g; p < 0.001). Significant differences were also noted in secondary endpoints measuring function and fibrosis (Δ circumferential strain = -2.9 ± 2.8 vs. 2.1 ± 2.3; p < 0.001; ΔT1 mapping values = -32.7 ± 51.3 ms vs. 26.3 ± 90.4 ms; p = 0.003). No significant differences were observed in blood pressure (Δ mean arterial pressure = 4.2 ± 18.8 mm Hg vs. 2.8 ± 13.8 mm Hg; p = 0.77), renal function (Δ creatinine = 3.1 ± 19.9 μmol/l vs. 9 ± 21.8 μmol/l; p = 0.31), frequency of rejection episodes (p = 0.69), or frequency of infections (p = 0.67) between groups.

CONCLUSIONS

The combination of low-dose everolimus and tacrolimus compared with standard-dose tacrolimus safely attenuates LVH in the first year after cardiac transplantation with an observed reduction in CMR-measured fibrosis and an improvement in myocardial strain.

Phenotyping of Stable Left Ventricular Assist Device Patients Using Noninvasive Pump Flow Responses to Acute Loading Transients

BACKGROUND

Although it has been established that continuous flow left ventricular assist devices are sensitive to loading conditions, the effect of acute load and postural changes on pump flow have not been explored systematically.

METHODS AND RESULTS

Fifteen stable outpatients were studied. Patients sequentially transitioned from the seated position to supine, passive leg raise, and standing with transition effects documented. A modified Valsalva maneuver, consisting of a forced expiration with an open glottis, was performed in each position. A sustained, 2-handed handgrip was performed in the supine position. The pump flow waveform was recorded continuously and left ventricular end-diastolic diameter measured during each stage using transthoracic echocardiography. Transitioning from seated to supine posture produced a significant increase in the flow and the ventricular end-diastolic diameter, consistent with an increased preload. The transition from supine to standing produced a transient increase in the mean flow and decreased the flow pulsatility index. At steady state, these changes were reversed with a decrease in the mean and trough flow and increased pulsatility index, consistent with venous redistribution and possible baroreflex compensation. Four distinct patterns of standing-induced flow waveform effects were identified, reflecting varying preload, afterload, and individual compensatory effects. A sustained handgrip produced a significant decrease in flow and increase in flow pulsatility across all patients, reflecting an increased afterload pressure. A modified Valsalva maneuver produced a decrease in the flow pulsatility while seated, supine, and standing, but not during leg raise. Five patterns of pulsatility effect during Valsalva were observed: (1) minimal change, (2) pulsatility recovery, (3) rapid flatline, (4) slow flatline with delayed flow recovery, and (5) primary suction.

CONCLUSIONS

Acute disturbances in loading conditions produce heterogeneous pump flow responses reflecting their complex interactions with pump and ventricular function as well as reflex compensatory mechanisms. Differences in responses and individual variabilities have significant implications for automated pump control algorithms.

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.

A RandomisEd ControLled TrIal of ChEwing Gum to RelieVE Thirst in Chronic Heart Failure (RELIEVE-CHF)

BACKGROUND

Thirst is a common and troublesome symptom of patients with chronic heart failure (CHF). To date, there are no interventions to help alleviate thirst in this cohort. Chewing gum is a novel intervention, which has been tested in people undergoing haemodialysis, also prescribed with a fluid restricted therapy. The aim of this study was to determine the effect of chewing gum on the level of thirst in the short-term (average of 24 hours each day for 4 days) and in the longer-term (Days 7, 14 and 28) individuals with CHF.

METHODS

Seventy-one (71) individuals with CHF on oral loop diuretics were randomised to chewing gum (n=36) or control (n=35) for 2 weeks. Both groups were assessed for their level of thirst at Days 1-4, 7, 14 and 28.

RESULTS

Significant improvements in the level of thirst of those who received chewing gum compared to the control group at Day 4 (p=0.04) and Day 14 (p=0.02) were observed.

CONCLUSION

Chewing gum provided relief from thirst in the short-term and in the longer term. This trial provides important information to inform future clinical trials on ways to relieve thirst.

International experience using a durable, centrifugal-flow ventricular assist device for biventricular support

BACKGROUND

Heart transplantation is limited by the scarcity of suitable donors. Patients with advanced biventricular failure may require biventricular support to provide optimal cardiac output and end-organ perfusion. We highlight the outcomes of using the HeartWare HVAD System (HVAD) in a biventricular configuration.

METHODS

This retrospective study included patients implanted with HVAD as a biventricular assist device (BiVAD) between 2009 and 2017 at 12 participating centers. When used as a right ventricular assist device (VAD) (RVAD), the HVAD can be attached to the right ventricle (RV) or the right atrium (RA). Kaplan-Meier survival estimates were calculated comparing the 2 RVAD implant locations. Comparisons were also made between the timing of RVAD implantation (primary vs staged) on adverse event (AE) profiles and survival.

RESULTS

Among the 93 patients who were implanted with a HVAD BiVAD, Kaplan-Meier survivals at 1-year and 2-year were 56% and 47%, respectively. Survival was independent of the location of the HVAD RVAD implant or whether there was an interval between left VAD and RVAD implantation. The most common AEs were bleeding (35.5%), infection (25.8%), and respiratory failure (20.4%).

CONCLUSIONS

This study illustrated similar survival in patients receiving a primary or staged HVAD BiVAD implant at 1 year and 2 years. This study also established that the locations of the RVAD implant (RV or RA) result in similar AE profiles.

COVID-19 and Acute Heart Failure: Screening the Critically Ill - A Position Statement of the Cardiac Society of Australia and New Zealand (CSANZ)

Up to one-third of COVID-19 patients admitted to intensive care develop an acute cardiomyopathy, which may represent myocarditis or stress cardiomyopathy. Further, while mortality in older patients with COVID-19 appears related to multi-organ failure complicating acute respiratory distress syndrome (ARDS), the cause of death in younger patients may be related to acute heart failure. Cardiac involvement needs to be considered early on in critically ill COVID-19 patients, and even after the acute respiratory phase is passing. This Statement presents a screening algorithm to better identify COVID-19 patients at risk for severe heart failure and circulatory collapse, while balancing the need to protect health care workers and preserve personal protective equipment (PPE). The significance of serum troponin levels and the role of telemetry and targeted transthoracic echocardiography (TTE) in patient investigation and management are addressed, as are fundamental considerations in the management of acute heart failure in COVID-19 patients.

Assessment of Predictors of Left Atrial Volume Response to a Transcatheter InterAtrial Shunt Device (from the REDUCE LAP-HF Trial)

In patients with heart failure and preserved or mildly reduced ejection fractions (EF ≥40%), implantation of an interatrial shunt device (IASD) resulted in heterogenous changes of the left atrial (LA) volume. Baseline characteristics that correlate with a favorable decrease in LA volume are unknown. We hypothesized that a larger ratio of left to right atrial volume at baseline would correlate strongly with LA volume decongestion following IASD implantation. Reduce Elevated LA Pressure in Patients With Heart Failure was a multicenter study of the safety and feasibility of IASD implantation. Sixty-four patients with EF ≥40% underwent device implantation along with baseline conventional echocardiograms, speckle tracking echocardiography, and resting and exercise hemodynamics. Higher LA compliance (-4.2%, p = 0.048) and right atrial reservoir strain (-0.8%, p = 0.005) were independently associated with a percent decrease in the systolic LA volume index from baseline to 6-months. In conclusion, greater LA volume reduction following IASD implantation is associated with higher baseline compliance of the left atrium and higher reservoir strain of the right atrium.

Insights Into Myocardial Oxygen Consumption, Energetics, and Efficiency Under Left Ventricular Assist Device Support Using Noninvasive Pressure-Volume Loops

Background:

Assessment of left ventricular (LV) recovery under continuous-flow LV assist device therapy is hampered by concomitant pump support. We describe derivation of noninvasive pressure-volume loops in continuous-flow LV assist device patients and demonstrate an application in the assessment of recovery.

Methods and Results:

Using pump controller parameters and noninvasive arterial pressure waveforms, central aortic pressure, outflow conduit pressure gradient, and instantaneous LV pressure were calculated. Instantaneous LV volumes were calculated from echocardiographic LV end-diastolic volume accounting for the integral of pump flow with respect to time and aortic ejection volume derived from the pump speed waveform. Pressure-volume loops were derived during pump speed adjustment and following bolus intravenous milrinone to assess changes in loading conditions and contractility, respectively. Fourteen patients were studied. Baseline noninvasive LV end-diastolic pressure correlated with invasive pulmonary arterial wedge pressure ( r 2 =0.57, root mean square error 5.0 mm Hg, P =0.003). Measured noninvasively, milrinone significantly increased LV ejection fraction (40.3±13.6% versus 36.8±14.2%, P <0.0001), maximum dP/dt (623±126 versus 555±122 mm Hg/s, P =0.006), and end-systolic elastance (1.03±0.57 versus 0.89±0.38 mm Hg/mL, P =0.008), consistent with its expected inotropic effect. Milrinone reduced myocardial oxygen consumption (0.15±0.06 versus 0.16±0.07 mL/beat, P =0.003) and improved myocardial efficiency (43.7±14.0% versus 41.2±15.5%, P =0.001). Reduced pump speed caused increased LV end-diastolic volume (190±80 versus 165±71 mL, P <0.0001) and LV end-diastolic pressure (14.3±10.2 versus 9.9±9.3 mm Hg, P =0.024), consistent with a predictable increase in preload. There was increased myocardial oxygen consumption (0.16±0.07 versus 0.14±0.06 mL O 2 /beat, P <0.0001) despite unchanged stroke work ( P =0.24), reflecting decreased myocardial efficiency (39.2±12.7% versus 45.2±17.0%, P =0.003).

Conclusions:

Pressure-volume loops are able to be derived noninvasively in patients with the HeartWare HVAD and can detect induced changes in load and contractility.

A-Band Titin Truncation in Zebrafish Causes Dilated Cardiomyopathy and Hemodynamic Stress Intolerance

Background Truncating variants in the TTN gene ( TTNtv) are common in patients with dilated cardiomyopathy (DCM) but also occur in the general population. Whether TTNtv are sufficient to cause DCM or require a second hit for DCM manifestation is an important clinical issue. Methods We generated a zebrafish model of an A-band TTNtv identified in 2 human DCM families in which early-onset disease appeared to be precipitated by ventricular volume overload. Cardiac phenotypes were serially assessed from 0 to 12 months using video microscopy, high-frequency echocardiography, and histopathologic analysis. The effects of sustained hemodynamic stress resulting from an anemia-induced hyperdynamic state were also evaluated. Results Homozygous ttna mutants had severe cardiac dysmorphogenesis and premature death, whereas heterozygous mutants ( ttna^tv/+) survived into adulthood and spontaneously developed DCM. Six-month-old ttna^tv/+ fish had reduced baseline ventricular systolic function and failed to mount a hypercontractile response when challenged by hemodynamic stress. Pulsed wave and tissue Doppler analysis also revealed unsuspected ventricular diastolic dysfunction in ttna^tv/+ fish with prolonged isovolumic relaxation and increased diastolic passive stiffness in the absence of myocardial fibrosis. These defects reduced diastolic reserve under stress conditions and resulted in disproportionately greater atrial dilation than observed in wild-type fish. Conclusions Heterozygosity for A-band titin truncation is sufficient to cause DCM in adult zebrafish. Abnormalities of systolic and diastolic reserve in titin-truncated fish reduce stress tolerance and may contribute to a substrate for atrial arrhythmogenesis. These data suggest that hemodynamic stress may be an important modifiable risk factor in human TTNtv-related DCM.

Survival After an Acute Heart Failure Admission. Twelve-Month Outcomes From the NSW HF Snapshot Study

BACKGROUND

The New South Wales (NSW) Heart Failure Snapshot sought to provide a contemporaneous profile of patients admitted with acute heart failure. We have previously reported the baseline results, and this paper reports the 30-day and 12-month outcomes.

METHODS

A prospective audit of consecutive patients admitted to 24 teaching hospitals across NSW and the Australian Capital Territory in July-August 2013 with acute heart failure. Follow-up data were obtained by integration of hospital administrative records and follow-up phone calls with the patients.

RESULTS

Eight hundred eleven (811) patients were recruited across the 24 sites. The NSW HF Snapshot was an elderly cohort (77 ± 14 yrs) with high comorbidity (mean Charlson Comorbidity Index 3.5 ± 2.6), and 71% were frail at baseline. Twenty-four per cent (24%) of patients were readmitted within 30-days post discharge. One hundred seventy-eight (178) patients died within 12 months post discharge. The independent predictors of death were frailty (Hazard Ratio 1.98 [95% Confidence interval 1.18-3.30]; p < 0.01) Charlson Comorbidity Index (HR 1.06 [95% CI 1.00-1.13]; p = 0.05); New York Heart Association (NYHA) class 4 (HR 2.62 [95% CI 1.32-5.22]; p < 0.01); eGFR<30 ml/min/1.73 m² (HR 2.16 [95% CI 1.45-3.21]; p < 0.01); hypokalaemia at discharge (HR 2.55 [95% CI 1.44-4.51]; p < 0.01) and readmission within 30 days of baseline admission (HR 2.13 [95% CI 1.49-3.13]; p < 0.01).

CONCLUSION

In one of the largest prospective audits of acute heart failure outcomes in Australia, we found that short-term readmissions and mortality at 12 months remain high but were largely driven by patient-level factors.

Impact of Pump Speed on Hemodynamics With Exercise in Continuous Flow Ventricular Assist Device Patients

At fixed speed, the spontaneous increase in pump flow accompanying exercise in patients with continuous flow left ventricular assist devices (cfLVADs) is slight in comparison to normal physiologic response, limiting exercise capacity. We systematically exercised 14 patients implanted with an isolated HeartWare HVAD undergoing routine right heart catheterization at baseline and at maximal safe pump speed. In addition to hemodynamics, mixed venous oxygen saturation (SvO2), echocardiography and noninvasive mean arterial pressure, and heart rate were measured. Significantly greater pump flows were achieved with maximum pump speed compared with baseline speed at rest (mean ± standard deviation [SD]: 5.0 ± 0.7 vs. 4.6 ± 0.8 L/min) and peak exercise (6.7 ± 1.0 vs. 5.9 ± 0.9 L/min, p = 0.001). Pulmonary capillary wedge pressure was significantly reduced with maximum pump speed compared to baseline pump speed at rest (10 ± 4 vs. 15 ± 5 mmHg, p < 0.001) and peak exercise (27 ± 8 vs. 30 ± 8 mmHg, p = 0.002). Mixed venous oxygen saturation decreased with exercise (p < 0.001) but was unaffected by changes in pump speed. In summary, although higher pump speeds synergistically augment the increase in pump flow associated with exercise and blunt the exercise-induced rise in left heart filling pressures, elevated filling pressures and markedly diminished SvO2 persist at maximal safe pump speed, suggesting that physiologic flow increases are not met by isolated cfLVADs in the supported failing heart.

Choosing Between Left Ventricular Assist Devices and Biventricular Assist Devices

Right ventricular failure following left ventricular assist devices implantation is a serious complication associated with high mortality. In patients with or at high risk of developing right ventricular failure, biventricular support is recommended. Because univentricular support is associated with high survival rates, biventricular support is often undertaken as a last resort. With the advent of newer right ventricular and biventricular systems under design and testing, better differentiation is required to ensure optimal patients care. Clear guidelines on patient selection, time of intervention and device selection are required to improve patient outcomes.

Epidemiology of infection in mechanical circulatory support: A global analysis from the ISHLT Mechanically Assisted Circulatory Support Registry

BACKGROUND

Despite advances in device technology and treatment strategies, infection remains a major cause of adverse events (AEs) in mechanical circulatory support (MCS) patients. To characterize the epidemiology of MCS infection, we examined the type, location, and timing of infection in the International Society for Heart and Lung Transplantation Registry (ISHLT) for Mechanically Assisted Circulatory Support (IMACS) over 3 years, 2013 to 2015.

METHODS

Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) definitions were used to categorize AE infections occurring in MCS patients within IMACS. The IMACS infection variables were mapped to ISHLT definitions for infection where feasible. Three categories of MCS infection were defined as ventricular assist device (VAD) specific, VAD related, and non-VAD.

RESULTS

There were 10,171 patients enrolled from January 2013 through December 2015. Infection was the most common AE, with 3,788 patients (37%) experiencing ≥ 1 infection, and 6,758 AE infections reported overall. Non-VAD infection was the largest category, 4,501: 34.0% pneumonias, 30.6% non-VAD-related bloodstream infections (BSIs), 24.15% urinary tract infections (UTIs), and 10.2% gastrointestinal infections. VAD-specific infection was the second largest category, 1,756: 82.9% driveline, 12.8% pocket, and 4.3% pump/or cannula infections. VAD-related infection was the smallest category, 501: 47.5% BSIs, 47.5% mediastinitis, and 5.0% mediastinitis/pocket infections. All 3 categories were more frequently reported ≤ 3 months after implant.

CONCLUSIONS

Non-VAD infection, including pneumonia, BSI, UTI, and gastrointestinal infection, was the leading category of infection in MCS patients and the most frequently reported ≤ 3 months after implant. These results provide evidence to support resourcing and strengthening infection prevention strategy early after implantation in MCS.

Comparison of continuous-flow ventricular assist device therapy with intensive medical therapy in fixed pulmonary hypertension secondary to advanced left heart failure

Aims

Both ventricular assist device (VAD) and pulmonary vasodilator therapy have been shown in uncontrolled studies to improve pulmonary hypertension secondary to advanced left heart failure (Group 2 PH). This study aimed to compare haemodynamic benefits and survival in patients with fixed Group 2 PH treated with continuous‐flow VAD to intensive medical therapy.

Methods and results

Ninety‐five patients listed for heart transplantation with sequential right heart catheters were studied, 24 patients having fixed Group 2 PH (as defined by cardiac index < 2.8 L/min/m², pulmonary capillary wedge pressure > 15 mmHg, and transpulmonary gradient ≥ 15 mmHg or pulmonary vascular resistance > 3.0 WU, unresponsive to vasodilator challenge). Ten patients received VAD therapy, and 14 patients received standard heart failure therapy with or without sildenafil, nitrates, or endothelin receptor antagonists.

At repeat right heart catheterization, patients treated with VAD therapy demonstrated significant improvement in both transpulmonary gradient (19 vs. 12 mmHg, P = 0.046) and pulmonary vascular resistance (6.5 vs. 2.9 WU, P = 0.003) compared with baseline, while those treated with medical therapy did not (20.9 vs. 20.3 mmHg and 6.5 vs. 6.4 WU, P = NS for both). Patients who received VAD therapy were significantly more likely to achieve normalized transpulmonary gradient (8/10 vs. 4/14, P = 0.013) and were more likely to be listed for orthotopic heart transplantation (7/10 vs. 4/14, P < 0.05). There were no significant differences between groups in terms of all‐cause mortality.

Conclusions

Continuous‐flow VAD therapy more effectively reverses fixed Group 2 PH compared with medical therapy alone and may allow a higher rate of listing for orthotopic heart transplantation.

Measurement of thirst in chronic heart failure - A review

Abstract Background: Thirst is a bothersome symptom of chronic heart failure (CHF) which impacts adversely on quality of life. Despite this, limited work has been done to investigate thirst as a symptom or to develop reliable and valid measures of thirst in CHF. The purpose of this manuscript is to establish which tools have been used in research to measure thirst in CHF.

METHODS

Medline, PubMed, Cumulative Index for Nursing and Allied Health, and Scopus were searched using following key words thirst, heart failure, measure, scale, randomised controlled trials and multicentre studies.

RESULTS

The search discovered 37 studies of which 6 studies met the inclusion criteria. One study was a research abstract and five were full-text studies. To date, there are only three measurement tools utilised in studies examining thirst in CHF patients [Visual Analogue Scale (VAS), Numeric Rating Scale and Thirst Distress Scale].

CONCLUSION

Thirst in CHF is measured in a non-systematic way. In recent studies, the VAS has been used to measure thirst intensity. While this measurement tool is very easy and quick to administer, using a uni-dimensional tool in conjunction with a multi-dimensional tool may be beneficial to capture all dimensions of thirst. In order to manage thirst efficiently, consistent measurement of thirst in CHF is vital.