HeartWare HVAD Research Articles

Driveline Site Is Not a Predictor of Infection After Ventricular Assist Device Implantation

Driveline infections (DLIs) remain a major source of morbidity for patients requiring long-term ventricular assist device (VAD) support. We aimed to assess whether VAD driveline exit site (DLES) (abdomen versus chest wall) is associated with DLI. All adult patients who underwent insertion of a HeartWare HVAD or HeartMate II (HMII) between 2009 and 2016 were included. Driveline infection was defined as clinical evidence of DLI accompanied by a positive bacterial swab and need for antibiotics. Competing risks analysis was used to assess the association between patient characteristics and DLI. Ninety-two devices (59 HMII) were implanted in 85 patients (72 men; median age 57.4 years) for bridge to transplant or destination therapy. VAD DLES was chest in 28 (30.4%) devices. Median time on VAD support was 347.5 days (IQR 145.5, 757.5), with 28 transplants and 29 deaths (27 on device). DLI occurred in 24 patients (25 devices) at a median of 140 days (IQR 67, 314) from implant. Staphylococcus aureus accounted for 15 infections (60%). Freedom from infection was 72.8% (95% confidence interval [CI] 53.1-78.0%) at 1 year and 41.9% (95% CI 21.1-61.5%) at 3 years. In competing risks regression, abdominal DLES was not predictive of DLI (hazard ratio, HR 1.65 [95% CI 0.63, 4.29]), but body mass index (BMI) >30 kg/m was (HR 2.72 [95% CI 1.25, 5.92]). In conclusion, risk of DLI is high among patients on long-term VAD support, and a nonabdominal DLES does not reduce this risk. The only predictor of DLI in this series was an elevated BMI.

Accelerometer Detects Pump Thrombosis and Thromboembolic Events in an In vitro HVAD Circuit.

Pump thrombosis and stroke are serious complications of left ventricular assist device (LVAD) support. The aim of this study was to test the ability of an accelerometer to detect pump thrombosis and thromboembolic events (TEs) using real-time analysis of pump vibrations. An accelerometer sensor was attached to a HeartWare HVAD and tested in three in vitro experiments using different pumps for each experiment. Each experiment included thrombi injections sized 0.2-1.0 mL and control interventions: pump speed change, afterload increase, preload decrease, and saline bolus injections. A spectrogram was calculated from the accelerometer signal, and the third harmonic amplitude was used to test the sensitivity and specificity of the method. The third harmonic amplitude was compared with the pump energy consumption. The acceleration signals were of high quality. A significant change was identified in the accelerometer third harmonic during the thromboembolic interventions. The third harmonic detected thromboembolic events with higher sensitivity/specificity than LVAD energy consumption: 92%/94% vs. 72%/58%, respectively. A total of 60% of thromboembolic events led to a prolonged third harmonic amplitude change, which is indicative of thrombus mass residue on the impeller. We concluded that there is strong evidence to support the feasibility of real-time continuous LVAD monitoring for thromboembolic events and pump thrombosis using an accelerometer. Further in vivo studies are needed to confirm these promising findings.

Normal fluid stresses are prevalent in rotary ventricular assist devices: A computational fluid dynamics analysis.

Despite the evolution of ventricular assist devices, ventricular assist device patients still suffer from complications due to the damage to blood by fluid dynamic stress. Since rotary ventricular assist devices are assumed to exert mainly shear stress, studies of blood damage are based on shear flow experiments. However, measurements and simulations of cell and protein deformation show normal and shear stresses deform, and potentially damage, cells and proteins differently. The aim was to use computational fluid dynamics to assess the prevalence of normal stress, in comparison with shear stress, in rotary ventricular assist devices. Our calculations showed normal stresses do occur in rotary ventricular assist devices: the fluid volumes experiencing normal stress above 10 Pa were 0.011 mL (0.092%) and 0.027 mL (0.39%) for the HeartWare HVAD and HeartMate II (HMII), and normal stresses over 100 Pa were present. However, the shear stress volumes were up to two orders of magnitude larger than the normal stress volumes. Considering thresholds for red blood cell and von Willebrand factor deformation by normal and shear stresses, the fluid volumes causing deformation by normal stress were between 2.5 and 5 times the size of those causing deformation by shear stress. The exposure times to the individual normal stress deformation regions were around 1 ms. The results clearly show, for the first time, that while blood within rotary ventricular assist devices experiences more shear stress at much higher magnitudes as compared with normal stress, there is sufficient normal stress exposure present to cause deformation of, and potentially damage to, the blood components. This study is the first to quantify the fluid stress components in real blood contacting devices.

Two implantable continuous-flow ventricular assist devices in a biventricular configuration: technique and results†

No continuous-flow right ventricular assist device for long-term support is available at the moment. Two continuous-flow ventricular assist devices used in a continuous-flow biventricular assist device configuration is an emerging option which has proven its feasibility but still is not approved for routine use. We present our technique and results of modifying the left ventricular assist device and making it suitable for right ventricular support. Between September 2009 and October 2017, 39 patients received implantation of a continuous-flow ventricular assist device for right ventricular support in a continuous-flow biventricular assist device configuration. For implantation of the HeartWare® manufacturers name of the pump HeartWare HVAD pump (HVAD)® centrifugal ventricular assist device, we performed 2 major modifications: banding of the outflow graft and reducing the intracaval length of the inflow cannula. The HVAD® could be safely implanted into the right atrium or ventricle. The HeartMate 3® left ventricular assist device needed no banding, but we increased the extraventricular part of the inflow cannula. The overall 30-day survival for the group receiving primarily a continuous-flow biventricular assist device was 72.7% (9.5% standard error of the mean (SEM)), and the 1-year survival was 45.0% (10.7% SEM). The overall 30-day survival for the group receiving a subsequent pump for right ventricular support in a continuous-flow biventricular assist device configuration after temporary right ventricular support was 71.4% (12.1% SEM), and 1-year survival was 40.8% (13.6% SEM). At the moment, there is a lack of a continuous-flow right ventricular assist device especially designed and approved for right ventricular support. Therefore, modifications in continuous-flow ventricular assist devices designed for the left ventricle are done to make them suitable for right ventricular support. However, more information is needed regarding the optimal surgical technique, patient selection and the optimal time point of implantation.

Percutaneous Deactivation of Ventricular Assist Device: A Case Series from a Tertiary Care Center

Introduction Left ventricular assist device (LVAD) deactivation is considered in certain situations e.g. myocardial recovery, device complication such as pump thrombosis or drive line infection. Surgical pump explantation remains the main method for device deactivation, however it carries its own risks and complications. Aim To assess the feasibility and safety of percutaneous device deactivation. Methods retrospective observational case series of all patients underwent percutaneous device deactivation using Amplatzer Vascular Plug II (AVP II) (St. Jude Medical, St. Paul, Minn) at our institute. Results A total of 4 patients underwent percutaneous LVAD deactivation between August 2017 and March 2018. The 1st patient was a 68 y.o male who underwent LVAD placement with HeartWare HVAD (HeartWare, Inc., Framingham, MA) for ischemic cardiomyopathy (ICMP). He presented in August 2017 with significant pump thrombosis and recurrent TIAs. Given his prohibited surgical risk for a repeat sternotomy, the decision was made to proceed with percutaneous deactivation of his LVAD using two 14 mm AVP II placed at the LVAD outflow graft at each end. Two months later, he underwent successful heart transplant and he continued to do well since then. The 2nd patient was a 35 y.o male with a history of non-ICMP. He underwent placement of Heartmate II (Thoratec Corp., Pleasanton, CA) in November 2014 which was complicated with pump thrombosis requiring pump exchange in March 2017. He presented again in November 2017 with a recurrent pump thrombosis. Given recovery of his cardiac function and patient's request to avoid further surgery, the device was deactivated percutaneously. This was achieved using a 16 mm AVP proximally and a 18 mm distally to the outflow graft. The 3rd patient was a 53 y.o male with a history of non-ICMP s/p HeartWare HVAD placement in October 2017. Given the recovery of his cardiac function, he presented in February 2018 for device deactivation using two 14 mm APV II at the 2 ends with another 12 mm AVP II at mid segment of the outflow graft. The 4th patient was a 57 y.o female with non-ICMP s/p Heartmate III placement in March 2017. She was complicated with recurrent GI bleed secondary to the chronic anticoagulation use. Given this reason along with cardiac recovery, decision was to proceed with device activation percutaneously using two 18 mm AVP at the distal end with another 16 mm AVP II at the proximal end of the outflow graft. The procedure was successful in all the 4 patients, and they continued on anticoagulation afterwards. See Table 1 Conclusion Percutaneous device deactivation is safe and a feasible approach for all different types of LVAD.

Revisiting the Achilles Heel of Exercise Capacity in Continuous Flow LVAD Patients Using Invasive Exercise Hemodynamics

Background Continuous flow left ventricular assist devices (cfLVADs) have greatly improved survival and quality of life for patients with end-stage heart failure. However, exercise capacity remains poor and little is known about hemodynamics during exercise. We describe observations from invasive cardiopulmonary exercise (iCPEX) tests in 3 patients with continuous flow LVADs. Methods Three patients with cfLVADs (HeartMate II, HeartMate 3 and HeartWare HVAD) underwent iCPEX with a pulmonary artery catheter placed via the right internal jugular vein and using an exercise bicycle protocol with a 10 Watt ramp. Ventilatory measurements were made with a Sensormedics CPX testing unit (Sensormedics, VMAX Encore 29C). One subject also had a radial arterial line for blood pressure monitoring. Results The peak oxygen consumption averaged 1.03 ± 0.32 L/min (36.8% mean max. predicated) or 9.5± 1.7 mL/kg/min. Respiratory quotient averaged 1.2 ±0.1. With exercise, cardiac output increased modestly from 7.8 ± 2.8 to 10.8 ± 2.6 L/min. There was a progressive increase in pulmonary capillary wedge pressure (PCW) in all patients, from 25 ± 12 to 34 ± 13 mmHg. Right atrial pressure changed minimally in 2 subjects (20 to 24 mmHg and 6 to 10 mmHg), while there was a rise in RA pressure towards the end of exercise in one subject with known poor right ventricular function (14 to 28 mmHg). In the subject monitored with an arterial line, there was a rise in blood pressure from 94 to 106 mmHg mean and an increase in pulse pressure from 18 to 54 mmHg. Conclusion Hemodynamics during exercise in patients with cfLVADs demonstrates a modest increase in cardiac output that is associated with a non-physiologic increase PCW. Peak oxygen consumption was well below predicted. The rise in PCW with only a modest increase in exercise cardiac output raise the question of whether automated circulatory control to increase pump performance with exercise could lead to improved exercise capacity in cfLVAD patients. Figure 1

Waitlist Outcomes in a Contemporary Cohort of Heart Transplant Candidates with Continuous Flow Left Ventricular Assist Device Complications: Anticipated Performance of The New Heart Allocation Policy

Introduction The United Network for Organ Sharing (UNOS) has recently approved a revision of the allocation system which will discriminate between patients stable on left ventricular assist device (LVAD) support and those with device complications warranting status upgrade. This system was based upon allocation modeling from a cohort of heart transplant candidates/recipients from 2009-11, and specifically prioritizes patients with malignant ventricular tachycardia on LVAD (Tier 1), followed by device malfunctions (Tier 2), and the remainder of complications (Tier 3). We sought to determine whether the recently approved Tier system for device complications reflects waitlist outcomes in a more contemporary cohort. Methods The UNOS database was queried to identify all adult patients listed for a single-organ HT between January 1, 2011 and December 31, 2015. Those patients who had a contemporary continuous flow LVAD (Heartmate II (Abbott, Abbott Park, Illinois) or Heartware HVAD (Heartware, Framingham, MA) at listing, during listing, or at the time of transplant were identified. Only those patients who were upgraded to Status 1A (b) for device complication as defined by the 2013 OPTN/UNOS device complication guidance document were included in the analysis. The primary outcome of interest was death or delisting for worsening status at 60 days after status upgrade. Results We identified 15,518 patients who were listed for HT during the study period. Among these, 6584 (34.4%) were bridged to transplant LVAD. A total of 2252 (34.2%) were upgraded to Status 1A (b) for device complication, including infection (35.8%), device malfunction (13.9%), device thrombus (15.1%), life threatening ventricular arrhythmia (6.9%), with the remainder for other complications including right ventricular failure. The prevalence of death or delisting at 60 days after status 1A upgrade was higher in patients with life threatening arrhythmias (8.4%) as compared to those with device infection (p Conclusion Our analysis in this cohort of patients upgraded to Status 1A while awaiting HT with LVAD bridge supports the impending allocation system with regards to priority of device complications.

Hyponatremia is Associated with Poor Prognosis in Left Ventricular Assist Device Patients

IntroductionSerum sodium is an important prognostic marker in heart failure patients, with lower values associated with increased risk of mortality. However, prognostic value of serum sodium has not been assessed in left ventricular assist device (LVAD) patients.HypothesisWe hypothesized lower serum sodium is associated with increased risk of mortality in LVAD patients.MethodsWe retrospectively identified 253 consecutive patients that had LVAD implantation at a single center between 2008-2016. To minimize confounding by peri-operative factors, we evaluated serum sodium at 3 months after implantation and time to all-cause mortality with a univariate Cox proportional hazards analysis. A secondary outcome was time to hospital readmission. Groups were defined as having lower and higher sodium levels relative to the median value. Censoring occurred at death, transplant, or pump exchange. A multivariate Cox proportional hazards analysis included estimated GFR and bicarbonate levels to account for effects of renal dysfunction and acid-base disturbance on sodium levels.ResultsThere were 195 eligible LVAD patients with a sodium value at 3 months. Average age was 53 ± 14 yrs, 77% were male, 26% black. Half (50%) received a Heartmate II device and 50% received a Heartware HVAD. Median serum sodium was 137 mmol/L. Median follow-up was 346 days with 26 deaths (13%). In a univariate analysis, increasing serum sodium at 3 months was associated with a lower risk of all-cause mortality (HR 0.826, p=0.006). Pre-operative sodium levels were not associated with mortality (HR 1.004, p=0.941). Serum sodium at 3 months remained predictive of mortality in a multivariate model with estimated GFR and HCO3 (Table). When stratified by the median, the lower sodium group had a significantly shorter time to all-cause mortality (Figure). Sodium levels at 3 months were not associated with time to readmission.ConclusionsHyponatremia in LVAD patients (sodium <137 mmol/L) is associated with significantly higher risk of all-cause mortality. Whether hyponatremia in an LVAD patient represents ongoing neurohormonal activation due to heart failure or is due to other etiologies associated with increased risk needs to be elucidated. Serum sodium is an important prognostic marker in heart failure patients, with lower values associated with increased risk of mortality. However, prognostic value of serum sodium has not been assessed in left ventricular assist device (LVAD) patients. We hypothesized lower serum sodium is associated with increased risk of mortality in LVAD patients. We retrospectively identified 253 consecutive patients that had LVAD implantation at a single center between 2008-2016. To minimize confounding by peri-operative factors, we evaluated serum sodium at 3 months after implantation and time to all-cause mortality with a univariate Cox proportional hazards analysis. A secondary outcome was time to hospital readmission. Groups were defined as having lower and higher sodium levels relative to the median value. Censoring occurred at death, transplant, or pump exchange. A multivariate Cox proportional hazards analysis included estimated GFR and bicarbonate levels to account for effects of renal dysfunction and acid-base disturbance on sodium levels. There were 195 eligible LVAD patients with a sodium value at 3 months. Average age was 53 ± 14 yrs, 77% were male, 26% black. Half (50%) received a Heartmate II device and 50% received a Heartware HVAD. Median serum sodium was 137 mmol/L. Median follow-up was 346 days with 26 deaths (13%). In a univariate analysis, increasing serum sodium at 3 months was associated with a lower risk of all-cause mortality (HR 0.826, p=0.006). Pre-operative sodium levels were not associated with mortality (HR 1.004, p=0.941). Serum sodium at 3 months remained predictive of mortality in a multivariate model with estimated GFR and HCO3 (Table). When stratified by the median, the lower sodium group had a significantly shorter time to all-cause mortality (Figure). Sodium levels at 3 months were not associated with time to readmission. Hyponatremia in LVAD patients (sodium <137 mmol/L) is associated with significantly higher risk of all-cause mortality. Whether hyponatremia in an LVAD patient represents ongoing neurohormonal activation due to heart failure or is due to other etiologies associated with increased risk needs to be elucidated.

Aortic root thrombosis in patients supported with continuous-flow left ventricular assist devices.

Aortic root thrombosis (ART) is a recently recognized complication of continuous-flow left ventricular assist device (CF-LVAD) therapy. However, little is known about the prevalence or clinical significance of this complication. The aim of our study was to systematically evaluate the incidence and significance of ART on CF-LVAD support. We retrospectively reviewed all patients who underwent HeartMate II or HeartWare HVAD CF-LVAD implantation from April 2004 through June 2016 at the Columbia University Medical Center. Echocardiography studies were systematically reviewed to identify patients who developed ART. Study outcomes included post-ART survival on CF-LVAD support, stroke, pump thrombosis, and clinically significant myocardial infarction (MI). The study cohort consisted of 436 CF-LVAD patients with 21 patients (4.8%) diagnosed with confirmed ART at a median time of 22 days (interquartile range [IQR] 3 to 56 days) after CF-LVAD implantation. Involvement of the non-coronary cusp was the most common location of the ART (n = 15, 71.4%) and concomitant RV failure occurred in 14 patients (66.7%). Actuarial survival at 1 and 2 years after diagnosis of ART was 73.8% and 44.3%, respectively. ART was associated with a high rate of complications, including stroke (28.6%, 0.337 episode per patient-year [EPPY]) and clinically significant MI (28.6%, 0.337 EPPY). ART is not uncommon after CF-LVAD implantation and is associated with significant morbidity and mortality in CF-LVAD patients. Given the early occurrence and high incidence of stroke and MI in patients who develop ART, surveillance and treatment strategies should be implemented to address this potentially devastating complication.

In vitro study for the evaluation of transluminal aspiration as a novel treatment option for thrombosis in the HeartWare HVAD.

Pump thrombosis of left ventricular assist devices remains a devastating complication with high morbidity and mortality. Despite the improvements made, the matter affects many patients and the treatment options are limited to thrombolysis and surgical replacement. An alternative approach using the aspiration Indigo catheter was tested. An Indigo thrombectomy catheter was used within an in vitro model to assess the direct aspiration of prefabricated clots from three different positions within the HeartWare HVAD (inlet, outlet, and housing). The experiments were conducted with a straight and an angled catheter. The aspiration pressure was constant. The flow, power consumption, and pressure head of the left ventricular assist devices were measured at pre-defined measuring points. The device was more effective (success rate 71%) at inlet and outlet of the left ventricular assist device. In addition, the duration of aspiration and the aspiration volume were shorter in comparison to the aspiration in the housing (inlet M = 19.75 s, outlet M = 60.50 s, and housing M = 38.75 s). Moreover, the aspiration volume was associated with the aspiration duration and the weight of thrombi but not with their volume. Noteworthy, the angled catheter showed an improved performance compared to the straight one (67%-33%). The recorded parameters showed no major changes during the use of the catheter. After application of the Indigo catheter, flow and pressure head of the pump could be restored. The aspiration system showed promising results under specific conditions for the treatment of pump thrombosis in an in vitro model. However, further examination, including in vivo experiments, will justify its effectiveness.

HVAD: The ENDURANCE Supplemental Trial

ObjectivesThe aim of this study was to prospectively evaluate the impact of blood pressure management on stroke rates in patients receiving the HeartWare HVAD System. BackgroundThe ENDURANCE trial demonstrated noninferiority of the HeartWare HVAD System versus control (HeartMate II) in patients with advanced heart failure ineligible for heart transplantation. However, stroke was more common in HVAD subjects. Post hoc analyses demonstrated increased mean arterial blood pressure as a significant independent risk factor for stroke. MethodsThe ENDURANCE Supplemental Trial was a prospective, multicenter evaluation of 465 patients with advanced heart failure ineligible for transplantation, randomized 2:1 to HVAD (n = 308) or control (n = 157). The primary endpoint was the 12-month incidence of transient ischemic attack or stroke with residual deficit 24 weeks post-event. Secondary endpoints included the composite of freedom from death, disabling stroke, and need for device replacement or urgent transplantation, as well as comparisons of stroke or transient ischemic attack rates in HVAD cohorts in ENDURANCE Supplemental and ENDURANCE. ResultsThe enhanced blood pressure protocol significantly reduced mean arterial blood pressure. The primary endpoint was not achieved (14.7% with HVAD vs. 12.1% with control, noninferiority [margin 6%] p = 0.14). However, the secondary composite endpoint demonstrated superiority of HVAD (76.1%) versus control (66.9%) (p = 0.04). The incidence of stroke in HVAD subjects was reduced 24.2% in ENDURANCE Supplemental compared with ENDURANCE (p = 0.10), and hemorrhagic cerebrovascular accident was reduced by 50.5% (p = 0.02). ConclusionsThe ENDURANCE Supplemental Trial failed to demonstrate noninferiority of HVAD versus control regarding the pre-specified primary endpoint. However, the trial confirmed that BP management is associated with reduced stroke rates in HVAD subjects. HVAD subjects, relative to control subjects, more commonly achieved the composite endpoint (freedom from death, disabling stroke, and device replacement or urgent transplantation). (A Clinical Trial to Evaluate the HeartWare™ Ventricular Assist System [ENDURANCE SUPPLEMENTAL TRIAL] [DT2]; NCT01966458)

A Standardized Telephone Intervention Algorithm Improves the Survival of Ventricular Assist Device Outpatients.

Ventricular assist devices (VADs) are an established therapeutic option for patients with chronic heart failure. Continuous monitoring of VAD parameters and their adherence to guidelines are crucial to detect problems in an early stage to optimize outcomes. A telephone intervention algorithm for VAD outpatients was developed, clinically implemented and evaluated. During the phone calls, a structured inquiry of pump parameters, alarms, blood pressure, INR, body weight and temperature, exit‐site status and heart failure symptoms was performed and electronically categorized by an algorithm into 5 levels of severity. VAD outpatient outcomes without (n = 71) and with bi‐weekly telephone interviews in their usual care (n = 25) were conducted using proportional hazard Cox regression, with risk adjustment based on a propensity score model computed from demographics and risk factors. From February 2015 through October 2017, 25 patients (n = 3 HeartMate II, n = 4 HeartMate 3 and n = 18 HeartWare HVAD) underwent 637 telephone interventions. In 57.5% of the calls no problems were identified, 3.9% were recalled on the next day because of alarms. In 26.5% (n = 169), the VAD Coordinator had to refer to the physician due to elevated blood pressure (n = 125, >85 mm Hg), INR < 2.0 or > 4.0 (n = 24) or edema (n = 10), 11.9% of the calls led to a follow‐up because of equipment or exit‐site problems. Propensity‐adjusted 2‐year survival (89% vs. 57%, P = 0.027) was significantly higher for the telephone intervention group. Continuous, standardized communication with VAD outpatients is important for early detection of upcoming problems and leads to significantly improved survival.

Speed Modulation of the HeartWare HVAD to Assess In Vitro Hemocompatibility of Pulsatile and Continuous Flow Regimes in a Rotary Blood Pump.

Although rotary blood pumps (RBPs) sustain life, blood exposure to continuous supra-physiological shear stress induces adverse effects (e.g., thromboembolism); thus, pulsatile flow in RBPs represents a potential solution. The present study introduced pulsatile flow to the HeartWare HVAD using a custom-built controller and compared hemocompatibility biomarkers (i.e., platelet aggregation, concentrations for ADAMTS13, von Willebrand factor (vWf), and free-hemoglobin in plasma (pfHb), red blood cell (RBC) deformability, and RBC-nitric oxide synthase(NOS) activity) between continuous and pulsatile flow in a blood circulation loop over 5 h. The HeartWare HVAD was operated using a custom-built controller, atcontinuous speed (3282 rev/min) or in a pulsatile mode (mean speed = 3273 rev/min, amplitude = 430 rev/min, frequency = 1 Hz) to generate a blood flow rate of 5.0 L/min, HVAD differential pressure of 90 mm Hg for continuous flow and 92 mm Hg for pulsatile flow, and systolic and diastolic pressures of 121/80 mm Hg. For bothflow regimes, the current study found; (i) ADP- and collagen-induced platelet aggregation, and ADAMTS13 concentration significantly decreased after 5 h (P < 0.01; P < 0.05), (ii) ristocetin-induced platelet aggregation significantly increased after 45 min (P < 0.05), (iii) vWf concentration did not significantly differ at any time point, (iv) pfHb significantly increased after 5 h (P < 0.01), (v) RBC deformability improved during the continuous flow regime (P < 0.05) but not during pulsatile flow, and (vi) RBC-NOS activity significantly increased during continuous flow (15 min), and pulsatile flow (5 h; P < 0.05). The current study demonstrated: (i) speed modulation does not improve hemocompatibility of the HeartWare HVAD based on no observable differences being detected for routine biomarkers, and (ii) the time-course for increased RBC-NOS activity observed during continuous flow mayhave improved RBC deformability.

Durable Biventricular Support Using Right Atrial Placement of the HeartWare HVAD.

Patients with Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) levels 1-2 who either have or are at risk for right ventricular failure face significant morbidity and mortality after continuous flow left ventricular assist device (CF-LVAD) implantation. Currently, the options for biventricular support are limited the Total Artificial Heart (TAH; CardioWest, Syncardia, Tuscon, AZ) or biventricular assist device (BiVAD), which uses bulky extracorporeal or implantable displacement pumps. We describe a successful series based on an innovative approach for biventricular support in consecutive INTERMACS levels 1-2 patients utilizing a HeartWare Ventricular Assist Device (HVAD; HeartWare, Framingham, MA) in a left ventricular (LV-HVAD) and a right atrial (RA-HVAD) configuration. From June 2014 through May 2016, 11 consecutive INTERMACS levels 1-2 patients with evidence of biventricular failure underwent implantation of a CF LVAD (10 LV-HVAD and 1 HeartMate II LVAD, Thoratec, Pleasanton, CA) and RA-HVAD pumps. A total of 4,314 BiVAD support days were accumulated in our case series. Seven patients have undergone orthotopic heart transplant, whereas 3 are ambulatory and are either waiting transplant or reconsideration for transplantation. There is one mortality in this case series, which was due to an intracranial bleed from supratherapeutic anticoagulation. Two other patients experienced hemorrhagic strokes, but without neurologic sequelae, whereas no patients have experienced ischemic strokes. There were two episodes of gastrointestinal bleeding. This is the largest series to date involving this approach with outcomes superior to those previously described in patients receiving biventricular support. We conclude this novel therapy is a viable alternative to current practices in the management of biventricular failure.

Model of End-Stage Liver Disease-eXcluding International Normalized Ratio (MELD-XI) Scoring System to Predict Outcomes in Patients Who Undergo Left Ventricular Assist Device Implantation

The use of continuous-flow left ventricular assist devices (CF-LVADs) to treat advanced heart failure is increasing. Although risk scores, such as Model for End-Stage Liver Disease and the HeartMate II Risk Score, require the use of the international normalized ratio, many patients are on anticoagulation before CF-LVAD implantation. This study evaluated the ability of the Model of End-Stage Liver Disease-eXcluding International Normalized Ratio (MELD-XI) scoring system to predict clinical outcomes in patients with advanced heart failure who undergo CF-LVAD implantation. A single-center retrospective review was performed of 524 patients who were implanted with the HeartMate II LVAD (Thoratec Corporation, Pleasanton, CA) or the HeartWare HVAD (HeartWare International Inc, Framingham, MA) between 2004 and 2016. Patients were stratified into two cohorts: those with a MELD-XI score of less than 14 (n= 301) and 14 or higher (n= 223). Patients with the higher-risk MELD-XI score of 14 or higher demonstrated lower survival rates at 1, 3, 6, 12, and 24 months (p < 0.001 for all) and increased risk of early right heart failure and infections compared with patients with MELD-XI score of less than 14. MELD-XI was not significantly inferior at predicting 90-day mortality compared with the HeartMate II Risk Score (p=0.92). Patients with elevated MELD-XI scores at follow-up demonstrated higher rates of mortality. These findings suggest that a MELD-XI score of 14 or higher was associated with a higher postoperative mortality rate than that seen in patients with a lower MELD-XI score. The MELD-XI scoring system can be used to predict outcomes in patients with advanced heart failure who undergo CF-LVAD implantation.

Is Low-rpm a Risk Factor for Pump Thrombosis in Pediatric Patients with HeartWare HVAD?

Is Low-rpm a Risk Factor for Pump Thrombosis in Pediatric Patients with HeartWare HVAD?

Evidence for Subclinical, Progressive Outflow Graft Stenosis in Patients With Heartware HVAD

Evidence for Subclinical, Progressive Outflow Graft Stenosis in Patients With Heartware HVAD

HeartWare HVAD Log Files Provide Insight into Patient Behavior and Predicts Adverse Events

HeartWare HVAD Log Files Provide Insight into Patient Behavior and Predicts Adverse Events

Evaluation of HeartWare HVAD Appearance on Serial Chest Radiographs: Pump Position and Migration Influence Adverse Outcomes

Evaluation of HeartWare HVAD Appearance on Serial Chest Radiographs: Pump Position and Migration Influence Adverse Outcomes

HVAD Thrombosis - Searching for the Source

Today sintering of inflow cannulae in left ventricular assist devices (LVAD) is accepted as standard to ensure good myocardial ingrowth, preventing thrombus formation at the apical penetration site. Various studies like the ADVANCE trial compared the formerly polished pump of the HeartWare HVAD and the sintered version commercialized since 2012, investigating the incidence of pump thrombosis and thromboembolic complications. Though this is of essential clinical importance, it is only a surrogate for inflow cannula thrombus development.