National trends in utilization of transatrial transcatheter mitral valve replacement and postoperative outcomes.

OBJECTIVE: Transatrial transcatheter mitral valve replacement reduces complexity during mitral valve replacements involving high-risk patients with mitral annular calcification. This study examines trends in transatrial transcatheter mitral valve replacement use and outcomes. METHODS: Patients in the Society of Thoracic Surgeons database from 2014 to 2021 with mitral annular calcification undergoing transatrial transcatheter mitral valve replacement were included. Exclusion criteria were hypertrophic cardiomyopathy, congenital mitral valve disease, ventricular assist device placement, or prior mitral valve surgery. Primary outcomes were operative mortality and major adverse cardiac events compared between the Early (2014-2017, N = 71) and Recent (2018-2021, N = 151) eras. Parsimonious multivariable regression assessed select possible confounders for trends in major adverse cardiac events. RESULTS: Overall, 222 transatrial transcatheter mitral valve replacements at 104 hospitals were identified. Annual volume increased from 6 in 2014 to 43 in 2021. Median hospital volume was 1, maximum hospital volume was 17, and 10 or more replacements were performed at 4 hospitals. Mortality and major adverse cardiac events occurred in 10.4% and 22.5% of patients, respectively. Compared with the Early era patients, Recent era patients were more often elective (79.5% vs 64.8%) and were approached via sternotomy (90.1% vs 80.3%, all P < .05). Despite similar predicted risk of mortality (9.6% ± 11.1% vs 11.0% ± 6.0%; P = .61), Recent patients had reduced mortality (3.3% vs 25.4%, P < .001) and major adverse cardiac events (18.5% vs 31.0%; P = .057). On univariate and multivariable analyses, the Recent surgical era was significantly associated with lower mortality (0.10 [0.04-0.29]; P < .001) and lower major adverse cardiac events (0.48 [0.25-0.94]; P = .032), respectively. There were no preoperative characteristics that were significant confounders for the difference in major adverse cardiac events. CONCLUSIONS: Mortality and major adverse cardiac events after transatrial transcatheter mitral valve replacement have decreased significantly in the contemporary era independent of changes in major patient and operative characteristics. Transatrial transcatheter mitral valve replacement will have a future role in patients with mitral annular calcification.

Impact of reintervention after index aortic valve replacement on the risk of subsequent mortality.

Objectives: The use of bioprosthetic aortic valve replacement (AVR) is inherently associated with a risk of structural valve degeneration (SVD) and the need for aortic valve (AV) reintervention. We sought to evaluate whether AV reintervention, in the form of repeat surgical AVR (SAVR) or valve-in-valve transcatheter aortic valve replacement (ViV-TAVR), negatively affects patients' subsequent long-term survival after index SAVR. Methods: We identified patients who had undergone bioprosthetic SAVR from 2002 to 2017 at our institution. Median longitudinal follow-up after index SAVR was 7.3 years (10.9 years for those with and 7.2 years for those without AV reintervention), and median follow-up after AV reintervention was 1.9 years. Cox regression analyses using AV reintervention (re-SAVR and ViV-TAVR) as a time-varying covariate were used to determine the impact of reintervention on subsequent survival. Results: Of 4167 patients who underwent index SAVR, 139 (3.3%) required AV reintervention for SVD, with re-SAVR being performed in 65 and ViV-TAVR in 74. Median age at the index SAVR was 73 years (interquartile range, 64-79 years), and 2541 (61%) were male. Overall, there were total of 1171 mortalities observed, of which 13 occurred after re-SAVR and 9 after ViV-TAVR. AV reintervention was associated with a greater risk of subsequent mortality compared with those patients who did not require AV reintervention (hazard ratio, 2.53; 95% confidence interval, 1.64-3.88, P < .001). This increased risk of subsequent mortality was more pronounced for those who received their index AVR when <65 years of age (hazard ratio, 5.60; 95% confidence interval, 2.57-12.22, P < .001) versus those ≥65 years (2.06, 1.21-3.52, P = .008). Direct comparison of survival between those who underwent re-SAVR versus ViV-TAVR showed 5-year survival to be comparable (re-SAVR: 74% vs ViV-TAVR: 80%, P = .67). Conclusions: Among patients receiving bioprosthetic AVR, an AV reintervention for SVD is associated with an increased risk of subsequent mortality, regardless of re-SAVR or ViV-TAVR, and this risk is greater among younger patients. These findings should be balanced with individual preferences at index AVR in the context of patients' lifetime management of aortic stenosis.

Gender Disparities in Cardiogenic Shock Treatment and Outcomes.

Cardiogenic shock is associated with a high risk for morbidity and mortality. The impact of gender on treatment and outcomes is poorly defined. This study aimed to evaluate whether gender influences the clinical management and outcomes of patients with prehospital cardiogenic shock. Consecutive adult patients with cardiogenic shock who were transferred to hospital by emergency medical services (EMS) between January 1, 2015 and June 30, 2019 in Victoria, Australia were included. Data were obtained from individually linked ambulance, hospital, and state death index datasets. The primary outcome assessed was 30-day mortality, stratified by patient gender. Propensity score matching was performed for risk adjustment. Over the study period a total of 3,465 patients were identified and 1,389 patients (40.1%) were women. Propensity score matching yielded 1,330 matched pairs with no differences observed in baseline characteristics, including age, initial vital signs, pre-existing co-morbidities, etiology of shock, and prehospital interventions. In the matched cohort, women had higher rates of 30-day mortality (44.7% vs 39.2%, p = 0.009), underwent less coronary angiography (18.3% vs 27.2%, p <0.001), and revascularization with percutaneous coronary intervention (8.9% vs 14.2%, p <0.001), compared with men. In conclusion, in this large population-based study, women with cardiogenic shock who were transferred by EMS to hospital had significantly worse survival outcomes and reduced rates of invasive cardiac interventions compared to men. These data underscore the urgent need for targeted public health measures to redress gender differences in outcomes and variation with clinical care for patients with cardiogenic shock.

Mitral Valve Regurgitation After Lung Transplantation: Aetiology, Management and Outcome.

BACKGROUND: Problematic mitral regurgitation (MR) may develop following lung transplantation (LTx). There is limited information on the management of MR in LTx patients, as such we sought to evaluate our centre's experience. METHODS: From 2000 to 2019, 1,054 patients underwent LTx at our centre (896 bilateral, 158 single). We identified patients in whom significant MR developed at any point post-LTx. The aetiology of MR, management and outcome were retrospectively analysed. RESULTS: Eight (8) patients developed severe MR post-LTx, six following bilateral LTx and two following single LTx. Lung transplantation indications included interstitial lung disease (n=5), chronic obstructive pulmonary disease (n=2) and pulmonary arterial hypertension (n=1). Severe MR occurred intraoperatively (n=1), postoperative day 1 (n=1) with the remaining six cases between 80 and 263 days post-LTx. The aetiology was noted to be due to severe left ventricular dysfunction following unmasking of a chronically pulmonary hypertension-related under-preloaded left ventricle in one case, and in the remaining seven patients causes included myxomatous degeneration, ischaemic MR, and functional MR due to annular dilatation. In the patient with intraoperative severe MR, the MR became mild with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and in the remaining seven patients a variety of procedures were used, including mitral valve repair, valve replacement and transcatheter edge-to-edge mitral valve repair. All patients survived the mitral procedure. Two (2) deaths occurred at 12.9 years (stroke) and 5 years (cancer) from mitral valve surgery. CONCLUSIONS: Development of significant mitral valve regurgitation is a rare but morbid complication after lung transplantation. This may represent the progressive natural history of pre-existing degenerative mitral valve disease and rarely, early after transplantation may be related to changes in ventricular geometry. Management of severe MR can follow the same management approach as in the non-transplant community, with the expectation of similarly good results.

Pre-hospital heparin use for ST-elevation myocardial infarction is safe and improves angiographic outcomes.

AIMS: This study aims to evaluate if pre-hospital heparin administration by paramedics is safe and improves clinical outcomes. METHODS AND RESULTS: Using the multicentre Victorian Cardiac Outcomes Registry, linked with state-wide ambulance records, we identified consecutive patients undergoing primary percutaneous coronary intervention for STEMI between January 2014 and December 2018. Information on thrombolysis in myocardial infarction (TIMI) flow at angiography was available in a subset of cases. Patients receiving pre-hospital heparin were compared to those who did not receive heparin. Findings at coronary angiography and 30-day clinical outcomes were compared between groups. Propensity-score matching was performed for risk adjustment. We identified a total of 4720 patients. Of these, 1967 patients had TIMI flow data available. Propensity-score matching in the entire cohort yielded 1373 matched pairs. In the matched cohort, there was no observed difference in 30-day mortality (no-heparin 3.5% vs. heparin 3.0%, P = 0.25), MACCE (no-heparin 7% vs. heparin 6.2%, P = 0.44), and major bleeding (no-heparin 1.9% vs. heparin 1.4%, P = 0.64) between groups. Propensity-score analysis amongst those with TIMI data produced 552 matched pairs. The proportion of cases with TIMI 0 or 1 flow in the infarct-related artery (IRA) was lower among those receiving pre-hospital heparin (66% vs. 76%, P < 0.001) compared to those who did not. CONCLUSION: In this multicentre, propensity-score matched study, the use of pre-hospital heparin by paramedics was safe and is associated with fewer occluded IRAs in patients presenting with STEMI.

Pulmonary Valve Function Late After Ross Procedure in 443 Adult Patients.

BACKGROUND: Limited data exist on long-term pulmonary valve function after the Ross procedure. This study sought to determine the long-term function of the pulmonary valve in 443 consecutive adult patients who underwent a Ross procedure. METHODS: All 443 patients who underwent a Ross procedure between November 1992 and March 2018 were reviewed retrospectively. All underwent pulmonary valve replacement using a cryopreserved pulmonary allograft. Freedom from the study's outcomes were calculated using Kaplan Meier survival. Risk factors for valve failure were analyzed using Cox regression. RESULTS: Mean age at time of operation was 39 years (range: 15-66 years). There was 1 (0.2%, 1 of 443) operative mortality. Nine patients required reintervention on the pulmonary allograft at a mean 6.1 years (range: 1-12 years) after Ross procedure. Patients required pulmonary allograft reintervention for infective endocarditis (n = 4), severe pulmonary stenosis (n = 4), or severe pulmonary regurgitation (n = 1). Freedom from pulmonary allograft reintervention was 98.9% (95% confidence interval [CI] 97.1%-99.6%), 97.7% (95% CI 95.1%-98.9%), 96.6% (95% CI 93.3%-98.3%), and 96.6% (95% CI 93.3%-98.3%) at 5, 10, 15, and 20 years, respectively. Freedom from pulmonary allograft dysfunction (at least moderate pulmonary regurgitation and/or mean systolic gradient ≥ 25 mm Hg and/or reintervention) was 94.5% (95% CI 91.6%-96.4%), 88.1% (95% CI 83.6%-91.4%), 84.9% (95% CI 79.6%-88.9%), and 78.3% (95% CI 69.5%-84.9%) at 5, 10, 15, and 20 years, respectively. No risk factors were identified to influence pulmonary valve durability. CONCLUSIONS: The pulmonary valve allograft gives excellent long-term function when used in adults undergoing the Ross procedure. Reintervention on the pulmonary valve is rare and significant pulmonary allograft dysfunction is uncommon.

Two Ventricles Are Not Better Than One in the Fontan Circulation: Equivalent Late Outcomes.

BACKGROUND: A subset of patients who underwent Fontan operations has two adequate-sized ventricles, but an anatomic biventricular circulation cannot be achieved because of complex morphology or for technical reasons. This study sought to determine whether these patients with two-ventricle Fontan circulation had superior outcomes compared with those with a single ventricle. METHODS: A binational Fontan Registry of patients (n = 1,377) was analyzed to identify those patients with two adequate ventricles. This cohort was compared with patients with single-ventricle Fontan circulation. The primary end point was a composite end point called "Fontan failure" encompassing death, heart transplantation, Fontan takedown or conversion, protein-losing enteropathy, plastic bronchitis, or New York Heart Association functional class III or IV. RESULTS: A total of 79 Fontan patients with two adequate ventricles (2V) were compared with 1,291 single ventricle (1V) Fontan patients. Median follow-up for the entire cohort was 11.5 years (interquartile range, 5.1 to 18.8 years). There was no difference in unadjusted 15-year freedom from Fontan failure (2V: 81% [95% confidence interval (CI), 69% to 94%] vs 1V: 86% [95% CI, 83% to 88%], p = 0.4). Propensity-score matching for potential confounding factors yielded 75 two-ventricle Fontan patients matched with 604 single-ventricle Fontan patients, in which 15-year freedom from Fontan failure was also not different (2V: 79% [95% CI, 67% to 94%] vs 1V: 87% [95% CI, 84% to 91%], p = 0.3). CONCLUSIONS: The two-ventricle Fontan circulation does not have better outcomes compared with the single-ventricle Fontan circulation. Late outcomes may depend more on other characteristics of the Fontan circulation. This finding is relevant when the Fontan procedure is being considered as an alternative to anatomic repair in patients with complex two-ventricle morphologies.

Hypothyroidism associated with therapy for multi-drug-resistant tuberculosis in Australia.

BACKGROUND: Reports from resource-poor countries have associated thionamide- and para-aminosalicylate sodium (PAS)-based treatment of multi-drug-resistant tuberculosis (MDR-TB) with the development of hypothyroidism. AIM: To identify predictors and assess the cumulative proportions of hypothyroidism in patients treated for MDR-TB with these agents in Australia. METHODS: Retrospective multicentre study of MDR-TB patients from five academic centres covering tuberculosis (TB) services in Victoria, Australia. Patients were identified using each centre's pharmacy department and cross checked with the Victorian Tuberculosis Program. Hypothyroidism was categorised as subclinical if the thyroid-stimulating hormone was elevated and as overt if free thyroxine (fT4) was additionally reduced on two separate occasions. Our main outcome measured was the cumulative proportion of hypothyroidism (at 5 years from treatment initiation). RESULTS: Of the 29 cases available for analysis, the cumulative proportion of hypothyroidism at 5 years was 37% (95% confidence interval (CI): 0-57.8%). Eight of the nine affected cases developed hypothyroidism within the first 12 months of treatment. Hypothyroidism was marginally (P = 0.06) associated with higher prothionamide/PAS dosing and was reversible with cessation of the anti-tuberculosis medication. CONCLUSIONS: Prothionamide/PAS treatment-associated hypothyroidism is common in MDR-TB patients in Australia, emphasising the importance of regular thyroid function monitoring during this treatment. Thyroid hormone replacement, if initiated, may not need to be continued after MDR-TB treatment is completed.

Detection and Surveillance of Bladder Cancer Using Urine Tumor DNA.

Current regimens for the detection and surveillance of bladder cancer are invasive and have suboptimal sensitivity. Here, we present a novel high-throughput sequencing (HTS) method for detection of urine tumor DNA (utDNA) called utDNA CAPP-Seq (uCAPP-Seq) and apply it to 67 healthy adults and 118 patients with early-stage bladder cancer who had urine collected either prior to treatment or during surveillance. Using this targeted sequencing approach, we detected a median of 6 mutations per patient with bladder cancer and observed surprisingly frequent mutations of the PLEKHS1 promoter (46%), suggesting these mutations represent a useful biomarker for detection of bladder cancer. We detected utDNA pretreatment in 93% of cases using a tumor mutation-informed approach and in 84% when blinded to tumor mutation status, with 96% to 100% specificity. In the surveillance setting, we detected utDNA in 91% of patients who ultimately recurred, with utDNA detection preceding clinical progression in 92% of cases. uCAPP-Seq outperformed a commonly used ancillary test (UroVysion, P = 0.02) and cytology and cystoscopy combined (P ≤ 0.006), detecting 100% of bladder cancer cases detected by cytology and 82% that cytology missed. Our results indicate that uCAPP-Seq is a promising approach for early detection and surveillance of bladder cancer. SIGNIFICANCE: This study shows that utDNA can be detected using HTS with high sensitivity and specificity in patients with early-stage bladder cancer and during post-treatment surveillance, significantly outperforming standard diagnostic modalities and facilitating noninvasive detection, genotyping, and monitoring.This article is highlighted in the In This Issue feature, p. 453.

Long-Term Outcomes of Childhood Left Ventricular Noncompaction Cardiomyopathy: Results From a National Population-Based Study.

BACKGROUND: Long-term outcomes for childhood left ventricular noncompaction (LVNC) are uncertain. We examined late outcomes for children with LVNC enrolled in a national population-based study. METHODS: The National Australian Childhood Cardiomyopathy Study includes all children in Australia with primary cardiomyopathy diagnosed before 10 years of age between 1987 and 1996. Outcomes for subjects with LVNC with a dilated phenotype (LVNC-D) were compared with outcomes for those with dilated cardiomyopathy. Propensity-score analysis was used for risk factor adjustment. RESULTS: There were 29 subjects with LVNC (9.2% of all cardiomyopathy subjects), with a mean annual incidence of newly diagnosed cases of 0.11 per 100 000 at-risk individuals. Congestive heart failure was the initial symptom in 24 of 29 subjects (83%), and 27 (93%) had LVNC-D. The median age at diagnosis was 0.3 (interquartile interval, 0.08-1.3) years. The median duration of follow-up was 6.8 (interquartile interval, 0.7-24.0) years for all subjects and 24.7 (interquartile interval, 23.3 - 27.7) years for surviving subjects. Freedom from death or transplantation was 48% (95% confidence interval [CI], 30-65) at 10 years after diagnosis and 45% (95% CI, 27-63) at 15 years. In competing-risk analysis, 21% of subjects with LVNC were alive with normal left ventricular systolic function, and 31% were alive with abnormal function at 15 years. Propensity-score matching between subjects with LVNC-D and those with dilated cardiomyopathy suggested a lower freedom from death/transplantation at 15 years after diagnosis in the subjects with LVNC-D (LVNC-D, 46% [95% CI, 26-66] versus dilated cardiomyopathy, 70% [95% CI, 42-97]; P=0.08). Using propensity-score inverse probability of treatment-weighted Cox regression, we found evidence that LVNC-D was associated with a greater risk of death or transplantation (hazard ratio, 2.3; 95% CI, 1.4-3.8; P=0.0012). CONCLUSIONS: Symptomatic children with LVNC usually present in early infancy with a predominant dilated phenotype. Long-term outcomes are worse than for matched children with dilated cardiomyopathy.

Improved Survival After the Ross Procedure Compared With Mechanical Aortic Valve Replacement.

BACKGROUND: It is unclear whether the Ross procedure offers superior survival compared with mechanical aortic valve replacement (AVR). OBJECTIVES: This study evaluated experience and compared long-term survival between the Ross procedure and mechanical AVR. METHODS: Between 1992 and 2016, a total of 392 Ross procedures were performed. These were compared with 1,928 isolated mechanical AVRs performed during the same time period as identified using the University of Melbourne and Australia and New Zealand Society of Cardiac and Thoracic Surgeons' Cardiac Surgery Databases. Only patients between 18 and 65 years of age were included. Propensity-score matching was performed for risk adjustment. RESULTS: Ross procedure patients were younger, and had fewer cardiovascular risk factors. The Ross procedure was associated with longer cardiopulmonary bypass and aortic cross-clamp times. Thirty-day mortality was similar (Ross, 0.3%; mechanical, 0.8%; p = 0.5). Ross procedure patients experienced superior unadjusted long-term survival at 20 years (Ross, 95%; mechanical, 68%; p < 0.001). Multivariable analysis showed the Ross procedure to be associated with a reduced risk of late mortality (hazard ratio: 0.34; 95% confidence internal: 0.17 to 0.67; p < 0.001). Among 275 propensity-score matched pairs, Ross procedure patients had superior survival at 20 years (Ross, 94%; mechanical, 84%; p = 0.018). CONCLUSIONS: In this Australian, propensity-score matched study, the Ross procedure was associated with better long-term survival compared with mechanical AVR. In younger patients, with a long life expectancy, the Ross procedure should be considered in centers with sufficient expertise.

Manual Braiding of GoreTex Neochords to Ensure Correct Length in Mitral Valve Repair.

Ascertaining the correct length of neochords during mitral valve repair is challenging. We describe a modified technique of chordal replacement where a GoreTex (W.L. Gore and Assoc, Inc, Flagstaff, AZ, USA) sutures are repeatedly tied so as to braid the suture to the optimal length before sutures are passed through the mitral leaflet. The length of the braided chord remains fixed when tying on the atrial side. For bileaflet repairs, a second suture is incorporated into the initial chord to create a "Y" braided neo-chord configuration. This technique facilitates precision in mitral repair.

Identifying low-grade cellular rejection after heart transplantation in children by using gene expression profiling.

Endomyocardial biopsy (EMB) remains the gold standard for detecting rejection after heart transplantation but is costly and invasive. This study aims to distinguish no rejection (0R) from low-grade rejection (1R/2R) after heart transplantation in children by using global gene expression profiling in blood. A total of 106 blood samples with corresponding EMB from 18 children who underwent heart transplantation from 2011 to 2014 were analyzed (18 baseline/pretransplantation samples, 88 EMB samples). Corresponding rejection grades for each blood sample were 0R in 39% (34/88), 1R in 51% (45/88), and 2R in 10% (9/88). mRNA from each sample was sequenced. Differential expression analysis was performed at the gene level. A k-nearest neighbor (kNN) analysis was applied to the most differentially expressed (DE) genes to identify rejection after transplantation. Mean age at transplantation was 10.0 ± 5.4 yr. Expression of B cell and T cell receptor sequences was used to measure the effect of posttransplantation immunosuppression. Follow-up samples had lower levels of immunoglobulin gene families compared with pretransplantation ( P < 3E-5) (lower numbers of activated B cells). T cell receptor alpha and beta gene families had decreased expression in 0R samples compared with pretransplantation ( P < 4E-5) but recovered to near baseline levels in 1R/2R samples. kNN using the most DE gene (MKS1) and k = 9 nearest neighbors correctly identified 83% (73/88) of 1R/2R compared with 0R by leave-one-out cross validation. Using a genomic approach we can distinguish low-grade cellular allograft rejection (1R/2R) from no rejection (0R) after heart transplantation in children despite a wide age range.

Twenty-Five Year Outcomes of the Lateral Tunnel Fontan Procedure.

The objective of this study was to characterize late outcomes of the lateral tunnel (LT) Fontan procedure. The outcomes of all patients who underwent an LT Fontan procedure in Australia and in New Zealand were analyzed. Original files were reviewed and outcomes data were obtained through a binational registry. Between 1980 and 2014, a total of 301 patients underwent an LT Fontan procedure across 6 major centers. There were 13 hospital mortalities, 21 late deaths, 8 Fontan conversions and revisions, 8 Fontan takedowns, and 4 heart transplantations. Overall survival at 15 and 25 years was 90% (95% confidence interval [CI]: 86%-93%) and 80% (95% CI: 69%-91%), respectively. Protein-losing enteropathy or plastic bronchitis was observed in 14 patients (5%). Freedom from late failure at 15 and 25 years was 88% (95% CI: 84%-92%) and 82% (95% CI: 76%-87%), respectively. Independent predictors of late Fontan failure were prolonged pleural effusions post Fontan operations (hazard ratio [HR] 3.06, 1.05-8.95, P = 0.041), age >7 years at Fontan (vs 3-5 years, HR 9.7, 2.46-38.21, P = 0.001) and development of supraventricular tachycardia (HR 4.67, 2.07-10.58, P < 0.001). Freedom from tachy- or bradyarrhythmias at 10 and 20 years was 87% (95% CI: 83%-91%) and 72% (95% CI: 66%-79%), respectively. Thromboembolic events occurred in 45 patients (16%, 26 strokes), and freedom from symptomatic thromboembolism at 10 and 20 years was 93% (95% CI: 89%-96%) and 80% (95% CI: 74%-86%), respectively. Over a 25-year period, the LT technique has achieved excellent late survival. As this population ages, it is at an increasing risk of failure and adverse events. We are likely to see an increasing proportion requiring heart transplantation and late reintervention.

Ventricular assist devices for the failing univentricular circulation.

INTRODUCTION: Improved survival following single ventricle palliation has led to a large population of patients with a univentricular circulation, many of whom develop heart failure. Increasing experience with ventricular assist devices (VAD) in children has paved the way for VAD support in those with failing univentricular circulation. Areas covered: The use of VADs to support the failing univentricular circulation is a relatively new concept. Most studies have focused on supporting patients with the failing systemic ventricle. There are limited reports of VAD support of the pulmonary circulation in patients with Fontan failure despite preserved ventricular function. None of the current VADs have been designed to support the pulmonary circulation. Novel low-pressure, high-flow pumps, specifically designed to support the pulmonary circulation, are under development. Expert commentary: The failing univentricular circulation is one of the great challenges in the field of congenital heart disease. While current VADs are designed to support the systemic circulation, many patients require support of the pulmonary circulation. A fully implantable VAD for support of the pulmonary circulation as destination therapy would be beneficial for patients with preserved systolic function, but must have low energy requirements, negligible risk of stroke and low risk of device thrombosis and failure.