HeartWare Ventricular Assist Device Research Articles

Nine Years of Continuous Flow LVAD (HeartMate 3): Survival and LVAD-Related Complications before and after Hospital Discharge.

End-stage heart failure is associated with high mortality. Recent developments such as the left ventricular assist device (LVAD) have improved patient outcomes. The HeartMate 3 LVAD is a novel centrifugal pump that was developed to provide hemodynamic support in heart failure patients, either as a bridge-to-transplant (BTT), myocardial recovery, or destination therapy (DT). Our objective was to evaluate the survival rates and LVAD-related complications of the HeartMate 3 LVAD before and after hospital discharge in our center. We retrospectively reviewed all patients implanted with the HeartMate 3 LVAD in our institute between September 2015 and June 2024. Patients who received a Heart Ware Ventricular Assist Device (HVAD) and HeartMate 2 LVAD devices were excluded. The primary endpoint was survival before and after hospital discharge. The secondary endpoints included an incidence of serious LVAD adverse events (bleeding, major infection, hemolysis, device thrombosis and malfunction, and neurological dysfunction) and the causes of re-admission along the follow-up period. A total of 48 consecutive HeartMate 3 LVAD patients were enrolled in this study. The mean age was 56.1 ± 10.6 years. A total of 72.9% of patients received LVAD therapy as a BTT, 14.6% as DT, 10.4% as a bridge-to-decision, and 2.1% as a bridge-to-recovery. A total of 85.4% of patients were discharged after implantation. The main cause for in-hospital mortality was right ventricular failure (8.3%), followed by stroke, abdominal bleeding, and multi-organ failure (2.1% each). One patient (2.1%) had successful heart transplantation, 26 patients (63.4%) are still on LVAD support, and 11 (26.8%) patients have died during follow-up. The main cause of mortality after hospital discharge was sepsis, which occurred in 9.8% of patients, followed by right ventricular failure, non-LVAD-related causes, unknown causes with two (4.9%) cases each, and one case of fatal stroke (2.4%). During the follow-up, there was no need for LVAD replacement. HeartMate 3 LVAD is associated with excellent in-hospital survival rates in patients with end-stage heart failure. Right ventricular failure was the main cause of death before hospital discharge, whereas sepsis was the main cause of death after hospital discharge.

Cardiac Reverse Remodeling Mediated by HeartMate 3 Left Ventricular Assist Device: Comparison to Older Generation Devices.

Currently, the fully magnetically levitated left ventricular assist device (LVAD) HeartMate 3 (HM3) is the only commercially available device for advanced heart failure (HF) patients. However, the left ventricular (LV) functional and structural changes following mechanical unloading and circulatory support (MCS) with the HM3 have not been investigated. We compared the reverse remodeling induced by the HM3 to older generation continuous-flow LVADs. Chronic HF patients (n = 405) undergoing MCS with HeartWare Ventricular Assist Device (HVAD, n = 115), HM3 (n = 186), and HeartMate II (HM2, n = 104) at four programs were included. Echocardiograms were obtained preimplant and at 1, 3, 6, and 12 months following LVAD implantation. There were no differences in the postimplant serial LV ejection fraction (LVEF) between the devices. The postimplant LV internal diastolic diameter (LVIDd) was significantly lower for HM2 at 3 and 6 months compared with HVAD and HM3. The proportion of patients achieving "cardiac reverse remodeling responder" status (defined as LVEF improvement to ≥40% and LVIDD ≤5.9 cm) was 11.9%, and was similar between devices. HeartMate 3 appears to result in similar cardiac reverse remodeling as older generation CF-LVADs, suggesting that the fully magnetically levitated device technology could provide an effective platform to further study and promote cardiac reverse remodeling.

Surgical Outcomes of Centrifugal Continuous-Flow Implantable Left Ventricular Assist Devices: Heartmate 3 versus Heartware Ventricular Assist Device.

Left ventricular assist devices (LVADs) are widely employed as a therapeutic option for end-stage heart failure. We evaluated the outcomes associated with centrifugal-flow LVAD implantation, comparing 2 device models: the Heartmate 3 (HM3) and the Heartware Ventricular Assist Device (HVAD). Data were collected from patients who underwent LVAD implantation between June 1, 2015 and December 31, 2022. We analyzed overall survival, first rehospitalization, and early, late, and LVAD-related complications. In total, 74 patients underwent LVAD implantation, with 42 receiving the HM3 and 32 the HVAD. A mild Interagency Registry for Mechanically Assisted Circulatory Support score was more common among HM3 than HVAD recipients (p=0.006), and patients receiving the HM3 exhibited lower rates of preoperative ventilator use (p=0.010) and extracorporeal membrane oxygenation (p=0.039). The overall early mortality rate was 5.4% (4 of 74 patients), with no significant difference between groups. Regarding early right ventricular (RV) failure, HM3 implantation was associated with a lower rate (13 of 42 [31.0%]) than HVAD implantation (18 of 32 [56.2%], p=0.051). The median rehospitalization-free period was longer for HM3 recipients (16.9 months) than HVAD recipients (5.3 months, p=0.013). Furthermore, HM3 recipients displayed a lower incidence of late hemorrhagic stroke (p=0.016). In the multivariable analysis, preoperative use of continuous renal replacement therapy (odds ratio, 22.31; p=0.002) was the only significant predictor of postoperative RV failure. The LVAD models (HM3 and HVAD) demonstrated comparable overall survival rates. However, the HM3 was associated with a lower risk of late hemorrhagic stroke.

Impact of HeartWare ventricular assist device discontinuation on the pediatric population: An Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry analysis

BackgroundThe HeartWare ventricular assist device (HVAD) was discontinued in July 2021. The aim of this study is to describe the impact the discontinuation the HVAD had on pediatric ventricular assist device utilization and outcomes. MethodsThe Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry was queried for type of VAD utilization and outcomes/adverse event rates in patients with a body surface area of 0.7-1.4 m2. Results were compared from before and after July 2021. All patients in the registry implanted with a HVAD were reported to determine overall outcomes of these patients and define who remains on the device. ResultsThe HeartMate 3 (HM3) primarily replaced the HVAD in pediatric patients increasing from 29 of 258 (11%) of implants before July 2021 to 31 of 109 (29%) of implants after. A small increase in the use of the Berlin Heart EXCOR (40 of 258, 16% before to 20 of 109, 18% after) and paracorporeal continuous flow devices (116 of 258, 45% before to 58 of 109, 53% after) was also observed. The rate of ischemic stroke increased in the overall population and a decrease in bleeding complications in the EXCOR group was observed. Of the 187 pediatric patients implanted with a HVAD in the registry, 7 patients remain supported, one patient transitioned from the HVAD to a HM3, and 6 patients were lost to follow-up. ConclusionThe HM3 has been the primary replacement for the HVAD in the medium sized pediatric population. The rate of ischemic stroke was higher after July 2021.

Extracorporeal driveline vibrations to detect left ventricular assist device thrombosis – A porcine model study

Pump thrombosis (PT) and related adverse complications contributed to the HeartWare Ventricular Assist Device (HVAD) market withdrawal. Many patients still receive lifelong support, with deficient PT surveillance based on pump power trends. Analysis of pump vibrations is better for detecting PT. Here, we investigated the feasibility of an extracorporeal accelerometer to detect PT from pump vibrations propagated out on the driveline. In a porcine HVAD model (n=6), an accelerometer was attached to the pump as a reference and another to the driveline for comparisons of signals. In total, 59 thrombi were injected into the heart to induce PT, followed by intermittent thrombus washout maneuvers. Signals were compared visually in spectrograms and quantitatively in third harmonic saliences (S3H) by correlation analysis. Receiver operating characteristic curves expressed the method's outcome in sensitivity vs specificity, with the overall diagnostic performance in the area under the curve (AUC) score. Five experiments had good driveline signal strength, with clear spectrographic relationships between the 2 accelerometers. Third harmonic driveline vibrations were visible 20 vs 30 times in the reference. The comparison in S3H showed a strong correlation and yielded an AUC of 0.85. Notably, S3H proved robust regarding noise and false PT detections. An extracorporeal accelerometer on the driveline can be a readily available method for accurate HVAD PT detection before an accelerometer integration with left ventricular assist device is feasible.

Widening care gap in VAD therapy

The removal of the HeartWare ventricular assist device (HVAD) due to pump malfunctions and inferior outcomes compared to HeartMate 3 (HM3) in adults has created a care gap for younger patients. It is unclear if the reported HVAD survival differs by age and if the initial experience with HM3 can bridge the gap. Using the Society of Thoracic Surgeons (STS) Intermacs and Pedimacs registries, durable ventricular assist device (VAD) implants between September 2012 and December 2021 were identified. Young adults (YA) were defined as <40years old in Intermacs. Patients were excluded if they had an isolated right VAD (RVAD) or were implanted as destination therapy (DT). Survival analysis by Kaplan-Meier (KM) and competing outcomes curveswas performed, and 1-year survival is reported. The Intermacs cohort consisted of YA (n=1226; HVAD 818; HM3 408) with a median age of YA of 32.07 (26.66-36.27) yearsand weight (wt) of83.2 (68-104.2) kg. Most had cardiomyopathy (CM) (92.2%). The Pedimacs cohort was 668patients (median age 9.47 [1.82-14.23] years, wt 27.2 [10-57.05]kg), and most also had CM (70.5%). Device breakdown includedHVAD (n=326), Berlin EXCOR(n=277), and HM3 (n=65). HVAD survival differed by age in adults, with YA fairing better than adults >40 years old (88.8%vs79.4% at 1year, p<0.0001). YA survival was also better compared to Pedimacs patient (88.9%vs83.7%, p=0.0002), but when competing events were analyzed, mortality was similar to YA (9.2% vs9.6%, p=0.1) with a higher proportion of patient undergoing transplant at 1 year in Pedimacs (74% vs31.3%, p<0.0001). Survival by device differed between HVAD and HM3 in YA (88.8% vs94.4%, p=0.0025). This difference in device survival was not seen in all children (83.7% vs87.3%, p=0.21), including those ≥25kg. Adverse event profiles also differed across the groups with adults seeing less adverse events with the HM3, but the same was not found (including stroke) in the pediatric cohort. Survival outcomes for patients between 10 and 25kg were similar with the HVAD compared to the Berlin Heart EXCOR(p=0.4290), with similarities in stroke risk. The removal of the HVAD device may result in a care gap in younger patient whose survival outcomes do not mirror that of older adults. The HM3 can fill a portion of this gap with good survival, but there remains a subset of pediatric patients that, based on initial HM3 use, will no longer have access to intracorporeal support and therefore, despite reasonable outcomes with the Berlin Heart EXCOR,will not be able to be discharged home. Lastly, it is essential that future changes to the availability of devices take into account the various patient populations that utilize the device to avoid unintended consequences of access inequality.

Acute Outflow Graft Occlusion-A Novel Predictable Complication of Lysis Therapy for the Treatment of Left Ventricular Assist Device Intra-Pump Thrombosis.

Lysis therapy is an established treatment option for intra-pump thrombosis of left ventricular assist devices (LVADs). In clinical routine, we observed repeated cases of acute outflow graft occlusions (OGO) associated with lysis therapy with need for urgent intervention. The aim of this investigation was to gain understanding of this observation. We screened data of 962 HeartWare ventricular assist device (HVAD) patients. One hundred twenty (13.8%) had intra-pump thromboses; 58 were treated with recombinant tissue-type plasminogen activator (rtPA). Mean age was 53.0 ± 11.1 years; 84.9% were male. In 13 (24.5%) patients, OGO occurred following rtPA-lysis. These patients showed an increase in left ventricular function (18.45% ± 12.62% to 27.73% ± 10.57%; p = 0.056), more frequent 1:1 aortic valve opening (OGO+: +36.4%; OGO-: +7.4%; p = 0.026), a decrease in LVAD pulsatility within 12 months prior intra-pump thrombosis (OGO+: -0.8 L/min [interquartile range {IQR}, -1.4 to -0.4 L/min]; OGO-: -0.3 L/min [IQR, -0.9 to 0.1 L/min]; p = 0.038) and lower HVAD flows at admission (OGO+: 6.7 L/min [IQR, 6.1-7.4 L/min]; OGO-: 8.3 L/min [IQR, 6.9-9.3 L/min]; p = 0.013), indicating a subclinical OGO prior intra-pump thrombosis. There were no differences in implantation techniques, blood parameters, and lysis strategy. Subclinical OGO represented a major risk factor for acute OGO following rtPA lysis therapy. We here propose an algorithm for risk stratification and dealing with patients presenting this first-described complication. Further research is required to confirm our results and decipher the underlying pathomechanism. http://links.lww.com/ASAIO/B97.

A mathematical model for assessing shear induced bleeding risk

PurposeThe objective of this study is to develop a bleeding risk model for assessing device-induced bleeding risk in patients supported with blood contact medical devices (BCMDs). MethodsThe mathematical model for evaluating bleeding risk considers the effects of shear stress on von Willebrand factor (vWF) unfolding, high molecular weight multimers-vWF (HMWM-vWF) degradation, platelet activation and receptor shedding and platelet-vWF binding ability. Functions of the effect of shear stress on the above factors are fitted/employed and solved by the Eulerian transport equation. An axial flow-through Couette device and two clinical VADs which are HeartWare Ventricular Assist Device (HVAD) and HeartMate II (HM II) blood pump were employed to perform the simulation to evaluate platelet receptor shedding (GPIbα and GPIIb/IIIa), loss of HWMW-vWF, platelet-vWF binding ability and bleeding risk for validating the accuracy of our model. ResultsThe platelet-vWF binding ability after being subjected to high shear region in the axial flow-through Couette device predicted by our bleeding model was highly consistent with reported experimental data. As indicated by our CFD simulation results in the axial flow-through Couette device, it can find that an increase in shear stress led to a decrease in the adhesion ability of platelets on vWF, while the binding ability of vWF with platelets first increase and then decrease as shear stress elevates gradually beyond a threshold. The factor of exposure time can enhance the effect of shear stress. Additionally, the shear-induced bleeding risk predicted by our model increases with increasing shear stress and exposure time in an axial flow-through Couette device. As indicated by our numerical model, the bleeding risk in HVAD was higher than HMII, which is highly consistent with the meta-analysis based on clinical statistics. Our simulation investigations in these two clinical VADs also found that HVAD caused a higher rate of platelet receptor shedding and lower damage to HWMW-vWF than HeartMate II. The high shear stress generated in the narrow and turbulent regions of both VADs was the underlying cause of device-induced bleeding. ConclusionIn this study, the shear-induced bleeding risk predicted by our bleeding model in axial flow-through Couette device and two clinical VADs is consistent or highly correlated with experimental and clinical findings, which proves the accuracy of our bleeding model. Our bleeding model can be used to aid the development of new BCMDs with improved functional characteristics and biocompatibility, and help to reduce risk of device-induced adverse events in patients.

Weld Malfunction in Heartware Ventricular Assist Devices

Biomedical Safety & Standards: September 01, 2022 - Volume 52 - Issue 15 - p 113-114 doi: 10.1097/01.BMSAS.0000854832.24880.03

Hemolytic Footprint of Rotodynamic Blood Pumps.

In preclinical examinations, rotodynamic blood pumps (RBPs) are predominantly evaluated at design-point conditions. In clinical practice, however, they run at diversified modes of operation. This study aimed at extending current preclinical evaluation of hemolytic profiles in RBPs toward broader, clinically relevant ranges of operation. Two implantable RBPs - the HeartMate 3 (HM3) and the HeartWare Ventricular Assist Device (HVAD) - were analyzed at three pump speeds (HM3: 4300, 5600, 7000 rpm; HVAD: 1800, 2760, 3600 rpm) with three flow rates (1-9L/min) per speed setting. Hemolysis measurements were performed in heparinized bovine blood. The delta free hemoglobin (dfHb) and the normalized index of hemolysis (NIH) served as hemolytic measures. Statistical analysis was performed by multiple comparison of the 9 operating conditions. Moreover, computational fluid dynamics (CFD) was applied to provide mechanistic insights into the interrelation between hydraulics and hemolysis by correlating numerically computed hydraulic losses with in-vitro hemolytic measures. In both devices, dfHb increased toward increasing speeds, particularly during low but also during high flow condition. By contrast, in both RBPs magnitudes of NIH were significantly elevated during low flow operation compared to high flow conditions (p<0.0036). Maps of hemolytic metrics revealed morphologically similar trends to in-silico hydraulic losses (r>0.793). While off-design operation is associated with increased hemolytic profiles, the setting of different operating conditions render a preclinical prediction of clinical impact with current hemolysis metrics difficult. The identified increase in hemolytic measures during episodes of off-design operation is highlighting the need to consider worst-case operation during preclinical examinations.

Linking Hydraulic Properties to Hemolytic Performance of Rotodynamic Blood Pumps

AbstractIn rotodynamic blood pumps (RBPs) a substantial proportion of input energy is dissipated into the blood. This energy may propel damaging work on blood constituents. To date, the link between this hydraulic energy dissipation and respective hemolytic action in RBPs remains vastly unknown. In this study, computational fluid dynamics is applied to compute the hydraulic energy dissipation at 9 operating conditions in two RBPs (HM3: HeartMate 3; HVAD: HeartWare Ventricular Assist Device). Respective interrelations with hemolytic pump performance are elucidated by comparing these computations with in silico predicted and in vitro measured hemolysis. Despite different pump geometries, hydraulic loss magnitudes, and distributions, global hydraulic energy dissipation shows strong correlation (r &gt; 0.95) to in vitro hemolysis with scaling factors in the same order of magnitude for both devices (φHM3 = 0.599 (mL g) (J 100L)–1; φHVAD = 0.716 (mL g) (J 100L)–1). The analytical description of hydraulic energy dissipation reveals to be a function of shear stresses and exposure time, unmasking its analogy to the power‐law formulation of hemolysis. This hydraulics‐based analysis may denote a step ahead to relate turbomachinery to bioengineering and may provide mechanistic insights into the relation between RBP design, hydraulic properties, and hemolytic performance.

Outcomes in Patients With HeartMate3 Versus HeartWare Ventricular Assist Device Implanted as Destination Therapy

Donor organ shortage caused a growing interest in mechanical circulatory support not only as a bridge to transplant but also as a destination therapy. Improved results and increased applicability and durability of left ventricular assist devices (LVADs) have established this treatment option as an alternative for patients with end-stage heart failure. The aim of the study was to compare the early results, major complications, and the follow up of all patients undergoing HeartMate3 (HM3) LVAD and HeartWare Ventricular Assist Device (HVAD) system implantation in one of the most experienced Clinic in Poland between 2015 and 2020. There were 78 individuals (72 male, 92%; 6 female, 8%), with median age 57 years (range, 50-62 years). Until 2020 we implanted 47 (60%) HVADs and 31 (40%) HM3 LVADs. Patient characteristics were comparable between both groups apart from median left ventricle diameter (8.2 cm [range, 7.4-8.4 cm] in HM3 group vs 7.2 cm [range, 6.7-7.9 cm] in HVAD group; P < .01) The overall survival was 53.2% in the HVAD group and 77.4% in the HM3 group (P =.03). Mean survival time was higher in HM3 group (2.97 years [range, 2.43-3.5 years] vs 2.51 years [range, 1.94-3.08 years]; P < .05). Mean complication-free survival time was also higher in the HM3 group (2.16 years [range, 1.55-2.76] vs 1.61 [range, 1.16-2.06 years]; P < .05), with overall complication-free rate of 54.8% for HM3 vs 29.8% for HVAD (P=.27). Median hospitalization time was comparable (31 days [range, 25-39 days] in the HM3 group vs 32 days [range, 24-38 days] in the HVAD group; P=.49). Patients supported with the HM3 had significantly fewer major complications than HVAD. Moreover, the HVAD was associated with higher mortality.

Does infection predispose to thrombosis during long-term ventricular assist device support?

Infections and thrombotic events remain life-threatening complications in patients with ventricular assist devices (VAD). We describe the relationship between both events in our cohort of patients (n=220) supported with the HeartWare VAD (HVAD). This is a retrospective analysis of patients undergoing HVAD implantation between July 2009 and March 2019 at the Freeman Hospital, Newcastle upon Tyne, United Kingdom. Infection was the most common adverse event in HVAD patients, with 125 patients (56.8%) experiencing ≥ one infection (n=168, 0.33 event per person year (EPPY)), followed by pump thrombosis (PT) in 61 patients (27.7%, 0.16 EPPY). VAD-specific infections were the largest group of infections. Of the 125 patients who had an infection, 66 (53%) had a thrombotic event. Both thrombotic events and infections were related to the duration of support, though there was only limited evidence that infections predispose to thrombosis. Those with higher than median levels of C-reactive protein during the infection were more likely to have an ischaemic stroke (IS) (34.5% vs 16.7%, p=.03), though not PT or a combined thrombotic event (CTE: first PT or IS). However, in multivariate analysis, there was no significant effect of infection predisposing to CTE. Infection and thrombotic events are significant adverse events related to the duration of support in patients receiving HVADs. Infections do not clearly predispose to thrombotic events.

Computational Evaluation of Cardiac Function in Children Supported with Heartware VAD, HeartMate 2 and HeartMate 3 Left Ventricular Assist Devices

Heart failure is one of the principal causes of morbidity and mortality in children. Treatment techniques may not work, and heart transplantation may be required as a result. The current state of donor-organ supply means that many patients cannot undergo transplantation. In these patients, ventricular assist devices (VADs) may be used to bridge the time until the transplantation. Continuous-flow VADs are increasingly being implanted to paediatric patients. The aim of this study was to evaluate cardiac function in children supported with Heartware HVAD, HeartMate2 and HeartMate3 devices using computational simulations. A lumped-parameter model simulating cardiac function in children around 12 years of age was used to simulate dilated cardiomyopathy and heart-pump support. The operating speeds in HVAD, HeartMate2 and HeartMate3 were selected as 2600 rpm, 8700 rpm and 5200 rpm constant speed, respectively, while the Lavare cycle and artificial-pulse modes were used to generate mean pump outputs at around 4.40 L/min and mean arterial pressures at around 82 mmHg in each device. Aortic pulse pressure was 11 mmHg, 14 mmHg and 6 mmHg under HVAD, HeartMate2 and HeartMate3 support, respectively. HVAD’s Lavare cycle and HeartMate3’s artificial pulse increased aortic pulse pressure to 15 mmHg and 20 mmHg. HeartMate3 with artificial-pulse mode may be more beneficial in reducing arterial-pulsatility-associated problems.

Heartmate 3 implantation in small patients: CT-guided chest diameter assessment.

In recent years, the Heartmate 3 (HM3) has largely replaced the use of other intracorporeal left ventricular assist devices in the adult field. Because the HM3 is larger than the Heartware Ventricular Assist Device, the general consensus was that for small patients, the Heartware Ventricular Assist Device was the most appropriate implantable device option. Our goal was to describe our experiences with the successful implantation of the HM3 in 2 children, aged 9 and 11. We report on the chest cavity dimensions, as measured on computed tomography, that can be used to assess the feasibility of HM3 implantation in small patients.

My Journey with the HeartWare Ventricular Assist Device- An Obituary

My Journey with the HeartWare Ventricular Assist Device- An Obituary

Postimplant Phosphodiesterase-5 Inhibitor Use in Centrifugal Flow Left Ventricular Assist Devices

ObjectivesThis study examined the association between phosphodiesterase-5 inhibitor (PDE-5i) use and outcomes in patients with contemporary centrifugal flow left ventricular assist devices (LVADs). BackgroundPDE-5i use may affect outcomes in patients with continuous flow LVADs. MethodsPatients enrolled in INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support), with HeartMate 3 (n = 4,628) or HeartWare Ventricular Assist Device (HVAD) (n = 2,601) implant were included in the analysis. The mean duration of follow-up was 11.94 ± 8.65 months. PDE-5is were used in 2,173 patients. The primary endpoint was the composite of all-cause mortality, ischemic stroke, and pump thrombosis. Propensity matching and stabilized inverse probability of treatment weights were used to adjust for baseline differences between patients receiving and not receiving PDE-5i. Adjusted Cox proportional hazards analysis was performed for each outcome. ResultsThe primary endpoint was lower in the PDE-5i group (adjusted HR: 0.77; 95% CI: 0.69-0.86; P < 0.0001; HeartMate 3: adjusted HR: 0.77; 95% CI: 0.64-0.92; P = 0.0044; HVAD: adjusted HR: 0.76; 95% CI: 0.66-0.88; P = 0.0002). All-cause mortality was lower with PDE-5is (adjusted HR: 0.75; 95% CI: 0.65-0.86; P < 0.0001; HeartMate 3: adjusted HR: 0.70; 95% CI: 0.57-0.86; P = 0.0007; HVAD: adjusted HR: 0.78; 95% CI: 0.65-0.94; P = 0.0098) and fewer ischemic strokes with PDE-5is were observed (adjusted HR: 0.71; 95% CI: 0.56-0.89; P = 0.003; HeartMate 3: adjusted HR: 0.67; 95% CI: 0.45-0.99; P = 0.045; HVAD: adjusted HR: 0.73; 95% CI: 0.56-0.97; P = 0.03). LVAD thrombosis was unchanged with PDE-5is, with overall low event rates observed. ConclusionsPostimplant PDE-5i use was associated with lower mortality and ischemic strokes in patients with centrifugal flow LVADs.

Abstract 11384: Discharge and De-Escalation After VAD Implant in Children with Dilated Cardiomyopathy: A Multi-Center Quality Improvement Initiative

Introduction: Children with dilated cardiomyopathy (DCM) are increasingly bridged to heart transplant (Tx) with intracorporeal continuous flow ventricular assist devices (VADs), but there continues to be variability in hospital discharge. We sought to assess the impact of a quality improvement (QI) project promoting hospital discharge in pediatric VAD patients with DCM. Methods: Patients enrolled at sites participating in the Discharge and De-Escalation QI project of the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry were eligible. Patients with a HeartWare (HVAD) or HeartMate3 (HM3) VAD, implanted between April 2018 and February 2021, were included. Patient characteristics and outcomes were compared before and after the QI initiative, which targeted team and family expectations, was implemented in November 2019. Results: There were 85 patients (75%) with DCM and/or myocarditis who were included in this study (median age 14 years; median weight 57.1 kg; 67% male). Among 57 patients in the baseline group, 56% (n=32) were discharged with a mean post-implant hospital length of stay (LOS) of 36 days and 44% (n=25) underwent Tx during index VAD admission, with a mean of 52 days on device. There were 28 patients in the intervention group; 64% (n=18) were discharged with a mean LOS of 45 days, while 29% (n=8) patients underwent Tx during index VAD admission, with a mean of 44 hospital days on device. There was no significant difference in the frequency of hospital discharge or in hospital LOS between groups. Conclusions: Pediatric centers discharged just over half of DCM patients supported on an HVAD or HM3, with nearly one third of patients undergoing transplant during the index VAD admission. The QI intervention did not significantly alter the discharge rate. Further work is required to understand practice variation between centers with respect to Tx listing and organ acceptance for children on intracorporeal continuous flow VADs.

A Novel Method to Safely De-Air a HeartWare System in a Single-Ventricle Patient by Utilizing ECMO and a Minimized CPB Circuit

The survival of congenital heart disease (CHD) patients with single-ventricle (SV) physiology has markedly increased as a result of advances in operative techniques and postsurgical management. Nonetheless, these patients remain highly susceptible to end-stage heart failure requiring cardiac replacement therapies at early ages. Given a worldwide shortage of transplantable organs, mechanical circulatory support (MCS) represents an alternative treatment option. The significant heterogeneity of the SV population presents unique indications for MCS that have begun to be evaluated. This case study describes a 12-year-old female with heterotaxy syndrome and an SV condition, previously palliated with a Fontan operation at another institution. The patient was placed on veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) during prolonged cardiopulmonary resuscitation, and later underwent HeartWare ventricular assist device (HVAD) implantation as a bridge to transplantation (BTT). A novel method was chosen to optimize careful de-airing of the heart through a minimized cardiopulmonary bypass (CPB) setup, during full ECMO support and surgical insertion of the HeartWare. The ascending aorta was vented proximal to the HVAD outflow graft anastomosis through a minimized CPB circuit at &lt;10% of the ECMO flow rate. This circuit adaption allowed for euvolemic resuscitation via connection from the minimized CPB circuit to the venous limb of the ECMO circuit. The transition from VA-ECMO to the HeartWare was well tolerated despite a challenging sternotomy and cardiac anomaly. A minimized bypass circuit proved efficacious for the benefit of volume resuscitation and safe de-airing of the HVAD while on ECMO support. The literature is limited concerning safe practices for implantation of durable VADs in complex SV patients coupled with those transitioning from varying modalities of MCS. As SV survivability regresses to heart failure, it is essential that we share techniques that aim to improve the long-term outcomes for successful BTT or bridge to decision (BTD).

Outflow cannula position for left ventricular assist device: A propensity score-matched study.

The clinical consequences of alternative outflow cannula positioning in patients undergoing left ventricular assist device implantation are unknown. We evaluated clinical outcomes in patients who underwent implantation with the outflow cannula implanted from the right side into the ascending aorta versus the left side of the pericardium. Fifty consecutive patients with terminal left heart failure underwent implantation using the Medtronic Heartware Ventricular Assist Device at Toronto General Hospital. Patients were divided between left and right outflow cannula positioning during implantation where anastomosis occurred in the ascending aorta. Propensity score matching using exact matching on the following pre-specified covariates: Interagency Registry for Mechanically Assisted Circulatory Support score, previous cardiac surgery, and preoperative inotrope use. Fifty consecutive patients (25 left implantation and 25 right implantation) were included in the unmatched cohort and 45 patients (25 left implantation and 20 right implantation) were included in the matched cohort. No significant differences in baseline demographics. Pump thrombosis occurred in 10% (n = 2) receiving right-sided implantation and 8% (n = 2) with left implantation (p = 1.00). Postoperative stroke occurred in 10% (2/20) with right implantation and 16% (4/25) with left implantation (p = .88). No difference in 1-year mortality between right 20% (5/25) and left 25% (5/20) implantation (p = .97). No observed difference in mortality when adjusting for competing risk of heart transplantation. There was also no difference in stroke, pump thrombosis, driveline infection. Larger studies are required to confirm these findings. These preliminary data support the use of left-sided anastomoses to facilitate subsequent re-entry during heart transplantation.