Thoratec PVAD Research Articles

Pediatric Single Ventricle VADs: A Single Center Review

<h3>Purpose</h3> Single ventricular assist device (SVAD) support in with children with single ventricle (SV) physiology remains challenging. We hypothesized that an individualized approach to SV patients—particularly those with superior cavopulmonary connections (SCPCs)—including changing the "stage" of palliation at the time of VAD support would promote improved outcomes. <h3>Methods</h3> We performed a single-center retrospective chart review of all SVADs implanted 2006 to 2021. We evaluated implant strategy, outcomes, and adverse events (AEs, ACTION-defined). A successful VAD course was defined as still on support, 180 days on support, or transplanted. <h3>Results</h3> A total of 20 SV patients were supported on VAD (7 prior to 2017, 13 after). Devices have varied (Berlin 5, Thoratec PVAD 1, HVAD 1, PediMag 9, HM3 4). SV stage of palliation prior to VAD support included 2 stage 1, 12 SCPC, and 7 Fontan patients. Among the 12 patients with pre-VAD SCPC: 9 were supported as a SCPC, 2 following biventricular conversion, and 1 as a Fontan. Successful support occurred in 13/20 (65%) patients (9 transplanted, 2 180 days of support, 2 alive on support). AE rates were high and success rate lower among SCPC patients, but all patients with BiVAD or Fontan were successfully supported (Table). Among patients on durable devices, 2/5 (40%) were discharged to home on support. Patients with pre-VAD ECMO had a lower likelihood of success when supported as a SCPC (0/4, 0%) than when supported as a BiVAD (2/2, 100%). <h3>Conclusion</h3> Data compiled from our center shows SV patients can be supported successfully on VADs. Stage 1 and SCPC patients remain challenging, but conversion to biventricular circulation or Fontan completion improves outcomes

Timing Of RVAD Insertion and The Associated Outcomes in CF-LVAD Patients

Study Right ventricular assist devices (RVAD) are commonly used for severe right heart failure (RHF) after continuous flow left ventricular assist device (CF-LVAD) insertion. However, the timing of RVAD insertion and the associated outcomes in CF-LVAD patients remains unclear. This study evaluates the effect of timing of RVAD insertion on long-term outcomes of CF-LVAD patients. Methods We performed a retrospective review CF-LVAD implantations from Jan 2001 through Mar 2017 at our center. From this, we culled out patients who received an RVAD and divided this cohort into early insertion (≤24 hours after CF-LVAD placement) and delayed insertion (>24 hours and ≤30days after CF-LVAD placement) groups. We compared early and late outcomes in the two groups. Results Within the CF-LVAD placement cohort (n=692), 61 (8.82%) patients required RVAD for severe RHF, with 35 (57.4%) patients in the early insertion group and 26 (42.6%) in the delayed insertion group. The majority of patients received temporary-type RVADs (CentriMag=42, TandemHeart=3) while some received durable-type RVADs (HeartWare=5, HeartMateII=1, Abiomed5000=4, Jarvik2000=1, Thoratec PVAD=3, Biomedicus=1). The mean duration of RVAD support was 48.8 days. In the early group, 17 (48.6%) patients were successfully weaned vs. 10 (38.5%) in the delayed group (p=NS). Overall differences between the early and late group have been summarized in Table 1 . Thirty-day mortality was similar for early 19 (54.3%) vs. delayed group 15 (57.7%) (p=NS) (Figure 1). There was no significant difference between the two groups in successfully bridging to transplantation. The 12-month overall survival rate in early placement patients was 16.7% and 26.9% in the delayed placement patients (p=NS) (Figure 1). Conclusions In this cohort of patients, no significant differences were found between the early and delayed groups in length of stay or 30-day readmission rates. There is no effect of timing of RVAD insertion on long-term outcomes of CF-LVAD patients. Prospective randomized trials can be designed to answer this equipoise effectively.

Molecular- and Organelle-Based Predictive Paradigm Underlying Recovery by Left Ventricular Assist Device Support

Advanced heart failure (HF) is a major cause of morbidity and mortality in the United States, and heart transplantation remains as the gold standard therapy. Because of scarcity of donor organs, the application of mechanical circulatory support devices has become a crucial approach in HF therapy as a bridge to transplantation. Therefore, mechanical circulatory support devices have existed both conceptually and experimentally for >40 years, along which an exponential evolution of mechanical circulatory support device technology has occurred. To mimic human physiology, the first generation of left ventricular assist devices (LVADs) were pulsatile volume displacement pumps (HeartMate XVE LVAS, Thoratec PVAD, and Novacor, etc). Insights demonstrating the inessentiality of the pulsatile nature of LVADs for survival from a physiological standpoint propelled the design of second-generation continuous flow devices (HeartMate II [Thoratec Inc], the Micromed DeBakey VAD, Berlin Heart Incor [Berlin Heart AG], and the Jarvik 2000 [Jarvik Heart Inc]), which emerged with superior safety and durability. Consequently, the HeartMate II was approved for bridge to transplantation and destination therapy in the United States.1 Recent reports2,3 have demonstrated a 2-year survival rate of 87% in destination therapy patients under intense surveillance, comparable with open heart transplantation survival statistics. In parallel, these promising outcomes of LVADs in HF therapy have spawned the translational research field of LV reverse remodeling, which has already shown great promise for elucidating underlying molecular and cellular mechanisms. HF is a highly complex clinical syndrome marked by a multitude of derangements, both in adult and pediatric populations.4 The clinical phenotype of HF begins with an injury or supranormal stressor on the heart and, through prolonged dyshomeostasis, eventuates in cellular and organ failure. The compensatory adaptive mechanisms including neurohormonal activation (eg, the …

Bacteraemia in Ventricular Assist Devices: A Common Complication that Need Not Affect Clinical Outcomes

Ventricular assist device (VAD) implantation has become an effective option for patients with severe heart failure. However, device-related infections remain a significant problem. The aim of this study was to describe the incidence and microbiological aetiology of bacteraemia in patients with VADs, and to assess the impact of bacteraemia on clinical outcomes. A retrospective study was conducted of patients having VAD implantation at the Alfred Hospital (Melbourne, Australia) from October 1990 to July 2009. Medical records and microbiology databases were reviewed. Patients who were supported with a VAD for 72h or more were evaluated for demographic data, VAD type, the occurrence of bacteraemia and clinical outcomes. During the 19-year period, 135 VAD patients (89 Thoratec PVAD, 10 Novacor, and 36 Ventrassist) supported for a total duration of 17,304 (median 74) support days were included. Sixty-one patients (45%) developed VAD-associated bacteraemia, an incidence of 5.6 episodes per 1000 support days. The incidence of bacteraemia per 1000 days of support was similar for the three devices used: Thoratec PVAD, Novacor and Ventrassist VADs (7.8±0.8, 5.2±1.5 and 3.4±0.5, respectively, p=0.74). Staphylococcus aureus was the most common pathogen (25%). The rates of death on device, survival to transplant, recovery with explant and outcomes after transplantation, including 30-day mortality, median survival time and incidence of cerebrovascular accidents were not significantly impacted upon by bacteraemia. Bacteraemia is common in VAD patients. However, the incidence of VAD-associated bacteraemia is independent of device type and with aggressive antimicrobial therapy; clinical outcomes need not be affected by the bacteraemia.

Impact of Continuous and Pulsatile-Flow Left Ventricular Assist Devices on Post-Transplant Rejection

Purpose LVADs have become an established treatment for end stage heart failure patients. The use of mechanical support systems has been associated with overproduction of antibodies with potential donor reactivity. The aim of our study was to assess the impact of different LVAD types on sensitization, post transplantation rejection and survival. Methods and Materials This was a retrospective cohort study of 81 heart transplant recipients who were bridged with either pulsatile (Thoratec PVAD) or continuous-flow (Heart Mate II) devices. Results There were no differences in baseline demographic and clinical characteristics between the groups.[table1]Early mortality was 10.8% in Thoratec PVAD and 2.3% in Heart Mate II group (p = 0.173). Six patients (16.2%) supported with Thoratec PVAD became sensitized versus 17 patients (38.6%) supported with Heart Mate II (p = 0.026). Significantly more patients in Thoratec PVAD group than Heart Mate II group experienced post-transplant rejection.[table2]Survival at 5 years was 59% ± 8% in Thoratec PVAD and 95% ± 3% in Heart Mate II patients. Conclusions Our data suggest that despite higher rates of sensitization in patients supported by Heart Mate II they experience less rejections. Several explanations for the lack of impact of sensitization on post-transplantation rejection have been proposed. Further research is needed into the exact nature, specificities and titers of antibodies associated with continuous-flow LVADs. Table 1 Thoratec PVAD (N = 37) Heart Mate II (N = 44) p Age, years 47 ± 13 48 ± 13 0.688 Male gender 30 (81.1%) 39 (88.6%) 0.340 BSA, m² 1.94 ± 0.2 1.99 ± 0.3 0.327 COPD 6 (16.2%) 6 (13.6%) 0.745 Diabetes Mellitus 9 (24.3%) 9 (20.5%) 0.676 Hypertension 7 (19.9%) 13 (29.5%) 0.239 Non-ischemic etiology of heart failure 20 (54.1%) 22 (50%) 0.7 Donor age, years 32 ± 11 38 ± 11 0.026 Male donor 32 (86.5%) 35 (79.5%) 0.411 Ischemic time, min 151 ± 42 142 ± 62 0.444 Table 2 Thoratec PVAD (N = 37) Heart Mate II (N = 44) p Right heart failure 2 (5.4%) 1 (2.3%) 0.590 Renal failure 4 (10.8%) 5 (11%) NS Rejection 15 (40.5%) 2 (4.5%)

A Novel Scoring System for Recovery after VAD Implantation in Children: Initial Feasibility

Purpose Use of MCS in children has increased rapidly in the past decade. Initial reporting has focused on survival and major morbidities. We describe a novel scoring system to measure clinical status after implantation, which we apply to a test series of 25 children. Methods and Materials The scoring system was developed based upon clinical expertise and literature review to capture heart failure severity in a hospitalized cohort. The score is based upon multiple aspects of heart failure care. The components of the scoring system and the score ranges are shown in the table, with examples. Higher scores represent higher levels of care. Final scores are normalized to 100 points. We applied the score to a retrospective test set of 25 children with MCS. Results We evaluated 24 children with 25 MCS implantations as a bridge to transplant between 2009 and 2011. There were 14 males. Mean (SD) age was 6.7 (6.2) yrs. Support duration was 59 (49) days. Outcomes included: transplant (58%), death (29%), and explantation (13%). Devices include EXCOR (12), Thoratec PVAD (9), and other (4). Support was LVAD (17), RVAD (1), and BIVAD (7). Scores at day -3 (pre-implant), and days 7, 21 and 60 are shown in the figure. [ figure 1 ] Conclusions The Stanford VAD score summarizes overall patient recovery after MCS implantation in children. It can be readily obtained from chart review. Validation with other clinical data is needed. Components of Stanford VAD Score Category Point Range Sample Item Nutrition 0–4 Effective enteral support: 1 pt Respiratory Support 0–3 Mechanical ventilation: 3 pts Physical Activity (if > 5 yrs) 0–4 Bed rest: 4 pts Heart Failure Medications 0–7 IV vasoconstrictors: 2 pts Care Setting 0–3 ICU care: 3 pts Total 0–21 (0–17 if

US Trends in Pediatric VAD Utilization: Analysis of Organ Procurement and Transplant Network Data

Purpose Pediatric ventricular assist device (VAD) utilization has purportedly surged in the US in recent years. Accurate information regarding the type and frequency of devices currently used in children is limited. We sought to describe overall trends in pediatric VAD utilization as a bridge to heart transplant (HT) in the current era. Methods and Materials All children Results Since July 2004, a total of 450 children (14% of children at HT) received a VAD in the US as a bridge-to-transplant. The percent of children supported with a VAD at HT increased from 2% in 2004 to 17% in 2010. The median age of VAD recipients was 9 years (IQR, 1, 14), the median weight was 29 kg (IQR 11, 55). Cardiomyopathy (CMP) was the primary indication for support in 62% (N=277), CHD in 17% (N=76), myocarditis in 15% (N=74) and re-transplant in 2% (N=9). LVADs were used in 62% (N=278) of children, BIVADs in 35% (N=158) and RVADs alone in 3% (N=14). Overall, the most commonly used LVADs included the Berlin Heart EXCOR Pediatric (48%), the Heartmate II (13%), Thoratec XVE (13%), Thoratec IVAD (5%), Toyobo (4%) and heartware (1%). For those receiving BIVAD support, the most commonly used VADs were the Berlin Heart (56%), Thoratec XVE (23%, Thoratec PVAD or IVAD (9%), Abiomed 5000 (5%) and mixed devices. Conclusions Use of pediatric ventricular assist devices has increased dramatically in recent years, and has emerged as a widely accepted therapy for children with end stage heart failure who fail medical therapy. Nearly two-thirds of pediatric VADs are used for cardiomyopathy. While a broad range of VADs are used, a few devices account for the majority of pediatric implants in the current era.

Complete Aortic Valve Fusion After HeartMate II Left Ventricular Assist Device Support

HEART FAILURE affects millions of people, costs billions of dollars, and at the end-stage level is curative only through heart transplant and only for those who meet the criteria. By paralleling the function of the heart, mechanical support devices provide another tool in the management of heart failure.1 The first generation of ventricular assist devices included the Thoratec PVAD (Thoratec Corp, Pleasanton, CA) and the Heartmate I (Thoratec Corp); they provided a new avenue for the treatment of heart failure but left much to be desired.

547 An Aggressive Policy of Pump Exchange Can Salvage Most Patients with Pump Malfunction

Purpose: Advances have been made in the biocompatibility and durability of ventricular assist devices. Be it rare, device failure is a significant source of morbidity and can be a fatal event if not promptly managed. We sought to describe the management of device malfunction in our institution. Methods and Materials: A single center retrospective study of 165 mechanical assist devices, placed from 7/05-11/11 in 138 patients, (77 Heartmate II; 36 Heartware; 17 Heartmate XVE, 6 Novocor; 19 Thoratec PVAD; 6 Ventracor Ventrassist; 4 Thoratec IVAD) was conducted. Cases of device malfunction were examined. Results: 14 pump malfunctions occurred in 13 patients. 12 patients underwent 13 successfull device exchanges. (3/3) HeartMate XVE to Heartmate II; (1/1)Thoratec PVAD to a second PVAD; (4/5) HeartMate II with thrombus, (3/3) with electrical failure, and (1/1) with bend relief obstruction, to a second HeartMate II. In 1 patient with a thrombosed HeartMate II, care was withdrawn. 3 HeartWare HVADs developed thrombus in 2 patients, and were exchanged to a second and and a subsequent second and third HVAD. 6 patients underwent heart transplantation (3 HeartMate II, 2 HVAD, 1 PVAD). 1 patient was explanted for recovery (HeartMate II). 2 patients expired (Heartmate II), and 3 patients are ongoing (Heartmate II). Conclusions: Device malfunction occurred in 8.5% (14/165) of all pumps placed and in 8.5% (10/118) of continuous flow pumps. For continous flow pumps, pump thrombus 60% (6/10) and electrical failure 30% (3/10) were the most common causes for pump malfunction. An aggressive policy of pump exchange results in successful outcomes in the majority of patients. Device manufacturers should be encouraged to enhance the biocompatability and durability of devices.

756 Can Right Ventricular Failure Associated with LVAD Insertion Be Avoided?

Background: Acute right ventricular failure (ARVF) can occur as a result of myocardial infarction, myocarditis, or postcardiotomy. Devices including implantable right ventricular assist devices (RVAD) and short-term microaxial devices offer improved hemodynamic support in this syndrome. Although the prognosis of ARVF has historically been grim, few studies have examined outcomes in the era of mechanical circulatory support. In this study, we describe our experience with mechanical right ventricular support in patients with ARVF. Methods: We performed a retrospective review of our institutional database. Sixteen consecutive patients underwent implantation of right-sided assist devices for ARVF between November 2005 and November 2010. Data were collected on the ARVF patients, including 30-day mortality, duration of support, and successful weaning rate. Results: Ten recipients were male and the mean age was 50.5 years (14 to 68 years). Etiology of ARVF included RV infarction (n56), myocarditis (n52), post-LVAD (n52), postheart transplant (n55), and post-cardiotomy (n51). Devices implanted included Thoratec IVAD and PVAD (n55), Impella RD 5.0 (n510), and Impella RP (n51). The mean duration of support ranged from 1 to 107 days (mean 24 days). Ten patients (62.5%) were successfully weaned, while six (37.5%) died during device therapy. No patients went on to transplantation. The 30-day mortality rate was 44% overall, with no difference between different etiologies of ARVF. Conclusions: ARVF continues to be associated with a high mortality rate, regardless of underlying etiology. Mechanical support with RVAD and microaxial devices can offer temporary support during acute hemodynamic compromise, allowing the RV to recover in many cases. Most patients who are successfully weaned will survive to hospital discharge. Our experience supports ongoing use of mechanical circulatory support in ARVF.

Mechanical Circulatory Support for Right Heart Failure: Current Technology and Future Outlook

The increasing global prevalence of congestive heart failure is a major healthcare concern, accounting for a high morbidity rate worldwide. In particular, isolated right heart dysfunction after cardiotomy has a poor prognosis and is associated with a high mortality rate. The occurrence of postoperative right heart failure may develop in more than 40% of patients undergoing implantation of a left ventricular assist device (LVAD) and cardiac transplantation. To date, mechanical cardiac assistance in the form of VADs has become accepted as a therapeutic solution for end-stage patients when a donor heart is not available. However, right ventricular (RV) assistance is still in the early phase of development when compared with LVAD technology. State-of-the-art RVADs, both in clinical use and under development, are reviewed in this manuscript. Clinical RVADs include the extracorporeal pulsatile Abiomed BVS 5000 and AB5000, Thoratec PVAD, MEDOS VAD, BerlinHeart Excor, the percutaneous continuous flow CentriMag and TandemHeart systems, and the implantable Thoratec IVAD. Devices on the horizon, including the wear-free implantable DexAide and the minimally invasive Impella RD, are additionally reviewed. In addition to the current status of RV assistance, as well as the device categorization, the outlook and considerations for successful development of future RVADs were discussed.

Single-centre experience with the Thoratec ® paracorporeal ventricular assist device for patients with primary cardiac failure

Temporary mechanical circulatory support may be indicated in some patients with cardiac failure refractory to conventional therapy, as a bridge to myocardial recovery or transplantation. To evaluate outcomes in cardiogenic shock patients managed by the primary use of a paracorporeal ventricular assist device (p-VAD). We did a retrospective analysis of demographics, clinical characteristics and survival of patients assisted with a Thoratec p-VAD. p-VADs were used in 84 patients with cardiogenic shock secondary to acute myocardial infarction (35%), idiopathic (31%) or ischaemic (12%) cardiomyopathy, myocarditis or other causes (23%). Before implantation, 23% had cardiac arrest, 38% were on a ventilator and 31% were on an intra-aortic balloon pump. Cardiac index was 1.6+/-0.5 L/min/m(2) and total bilirubin levels were 39+/-59 micromol/L. During support, 29 patients (35%) died in the intensive care unit and seven (10%) died after leaving. Forty-seven patients (56%) were weaned or transplanted, with one still under support. Despite significantly more advanced preoperative end-organ dysfunction, survival rates were similar in patients with biventricular devices (74%) and those undergoing isolated left ventricular support (24%) (63% versus 45%, respectively; p=0.2). Actuarial survival estimates after transplantation were 78.7+/-6.3%, 73.4+/-6.9% and 62.6+/-8.3% at 1, 3 and 5 years, respectively. Our experience validates the use of p-VAD as a primary device to support patients with cardiogenic shock. In contrast to short-term devices, p-VADs provide immediate ventricular unloading and pulsatile perfusion in a single procedure. Biventricular support should be used liberally in patients with end-organ dysfunction.

Improvement in Early Oxygen Uptake Kinetics With Left Ventricular Assist Device Support

Sustained myocardial recovery and reversal of heart failure has been reported with the use of left ventricular assist devices (LVADs). However, clinical predictors of sustained recovery have not been clearly defined, and little information exists regarding exercise improvement in LVAD patients. Therefore, we sought to determine whether peripheral oxygen delivery and utilization were improved with LVAD support. Eleven patients with available pre- and post-LVAD cardiopulmonary exercise (CPX) data were studied retrospectively. Five patients received a HeartMate XVE for destination therapy (DT) and six patients received a Thoratec PVAD pneumatic LVAD for bridge-to-recovery (BTR). Oxygen uptake kinetics was assessed by fitting a single exponential function to the VO2 response. There was a significant improvement in several key parameters of cardiac performance including peak VO2, VO2 at anaerobic threshold (AT), oxygen kinetics as measured by mean response time (MRT), and oxygen deficit during LVAD support. Oxygen deficiency improved from 0.29 +/- 0.16 ml/kg to 0.16 +/- 0.06 ml/kg (p = 0.023), as did MRT 68 +/- 47.7 seconds to 35.8 +/- 13.3 seconds (p = 0.046) with LVAD support. Improved oxygen kinetics suggests improved peripheral utilization of oxygen, and may offer an additional clinical parameter to predict the likelihood of sustained recovery.

274: Cumulative Incidence and Pattern of Adverse Events in the First 60 Days Post Ventricular Assist Device Implantation

this might guide VAD selection in bridge-to-transplant (BTT) patients. Methods and Materials: Thirty-four patients implanted between 2001 and 2007 had both preand post-VAD PRA data available. We compared sensitization rates between pulsatile and CF devices. Sensitization was defined as either an absolute PRA or an increase in PRA 10% by cytotoxicity or class I or II flow cytometry. One Heartmate II, four VentrAssist, and fifteen Jarvik 2000 patients comprised the CF group. The pulsatile group included two Heartmate XVE, seven Novacor, and five Thoratec pVAD patients. Groups were compared using the Mann-Whitney U test. Results: Patients in each group had similar rates of pre-VAD sensitization. Sensitization rates post-VAD did not differ significantly between pulsatile and CF VADs. Gender did not impact preor post-VAD sensitization. In BTT patients, the average time to cardiac transplant was significantly shorter for the CF VADs (mean 81 61d, n 16) as compared to the pulsatile VADs (mean 205 119d, n 8, p 0.007). Conclusions: Sensitization rates were similar in patients with pulsatile and CF VADs. Despite this, CF VADs were associated with a significantly shorter average time to cardiac transplant. Our data suggest that sensitization should not be a deciding factor in selecting a pulsatile or a CF device. Factors other than sensitization may contribute to decreased time to transplant in CF VAD patients, which may improve post-transplant outcomes.