Underwent Ventricular Assist Devices Implantation Research Articles

674 Acute Renal Failure Does Not Predict Long-Term Outcome after Heart Transplantation

associated hypoxemia, different types of MS are considered. We evaluate the outcomes in this population and the influence of the type of MS used. Methods and Materials: 101 patients presented PGD requiring MS, between 01/2000-07/2011. Intra-aortic Balloon Pump (IABP) was used in 40 cases with mild-moderate ventricular dysfunction. Extracorporeal Membrane Oxygenation (ECMO) was used in 30 cases with severe ventricular dysfunction not infrequently with associated hypoxemia. Ventricular Assist Device (VAD) was used in 19 cases (18 RVAD,1 BiVAD). Combination of ECMO after VAD (or vice-versa) was used in 12 cases (combined MS). Results: No significant donor or recipients differences were noted among the groups, except for higher age and pre-transplant pacemaker/ICD in the VAD group (p 0.04 and 0.04). 30-day and 1-year survival were 98%, 79%, 50%, 25% and 90%, 53%, 43%, 8% in the IABP, VAD, ECMO and combined MS groups respectively. Patients undergoing VAD implantation requiring also ECMO support had higher risk of mortality than those not requiring ECMO pre or post VAD implant (p 0.002). Multivariate analysis showed ECMO (alone or with VAD) (HR:11.95,95%CI:4.3532.85,p 0.0001), preoperative cardiac surgery (HR:2.46,95%CI:1.135.36,p 0.023), and diabetes (HR:2.21,95%CI:0.99-5.01,p 0.050) as risk factors of 30-day mortality.

Ethical Considerations for Ventricular Assist Device Support: A 10-Point Model

The potential for long-term support on a ventricular assist device (VAD) in the bridge-to-transplant (BTT) and destination therapy (DT) settings has created unprecedented ethical challenges for patients and caregivers. Concerns include the patient's adaptation to life on a device and the ethical, clinical, and practical issues associated with living on mechanical support. On the basis of our experience treating 175 consecutive VAD patients, we have developed a model to address the ethical and psychosocial needs of patients undergoing VAD implantation. Patient preparation for VAD implantation encompasses three phases: 1) initial information regarding the physical events involved in implantation, risks and benefits of current device technology, and the use of VAD as a rescue device; 2) preimplant preparation including completion of advance directives specific to BTT/DT, competency determination, and identifying a patient spokesperson, multidisciplinary consultants, and cultural preferences regarding device withdrawal; and 3) VAD-specific end-of-life issues including plans for device replacement and palliative care with hospice or device withdrawal. This three-phase 10-point model addresses the ethical and psychosocial issues that should be discussed with patients undergoing VAD support.

Mitochondrial disease is a common cause of severe cardiomyopathy in children

AimsRespiratory chain abnormalities have been documented in children with idiopathic cardiomyopathy undergoing diagnostic endomyocardial biopsy.1 Mitochondrial disease can present with isolated cardiomyopathy or prominent cardiac involvement in multisystem disease, but...

655 A New Bowel Management Strategy Reduces Gastrointestinal Complications and Improves Patient Outcomes after Ventricular Assist Device Implantation

Purpose: Post-cardiotomy cardiogenic shock carries a substantial morbidity and mortality. Short term ventricular assist devices (VADs) are frequently used in patients with cardiogenic shock refractory to conventional therapy. Here we report the outcome of our experience. Methods and Materials: Retrospective analysis was performed for patients who received either left, right, or bi-ventricular assist device for postcardiotomy shock between 1/2001 to 5/2010. Results: During the study period, 37 patients required short term VAD (11 LVADs, 9 RVADs, and 17 BIVADs) support. 18 patients received Centrimag, 8 received Abiomed BVS, and 11 received other devices. Initial cardiac surgery were CABG (15 patients), CABG/Valve (15 patients), Valve (4 patients) and other procedures (3 patients). The overall one-year-survival was 25.4% by Kaplan-Meier survival function. VAD specific 1-year survival was 36.4% for LVAD, 33.3% for RVAD, 10.1% for BIVAD, and was not significantly different by log-rank test (p 0.69). Median interval to device implantation was 3 days (range 0 25 days). Patients that underwent VAD implantation on postoperative day 2 to 6 had better survival (6 of 15 survived) than those who underwent implantation within the first day (2 of 11 survived) or 7 days following the initial cardiotomy (1 of 11 survived). There was no improvement of survival over the study period from 2001 to 2010. Conclusions: The outcome of VAD support for postcardiotomy shock remains poor. Requirement of VAD support in early postoperative period, but not immediately after the cardiotomy, seems to be associated with better overall survival. 655

Surgical Therapy of End-Stage Heart Failure in Pediatric Patients

Objective We herein review our experience with ventricular assist device (VAD) implantation and heart transplantation in children with end-stage heart failure. Methods We performed a retrospective nonrandomized review of all patients who underwent insertion of a Berlin Heart Excor VAD or heart transplantation in our clinic. The study spans from July 2005 to July 2010. We transplanted 11 patients of mean age 11.8 ± 4.49 years, 3 of whom with critical hemodynamic situations were bridged to heart transplantation by VAD implantation. Despite the poor right ventricular systolic functions, they did not require right rVAD. In addition, 2 patients who underwent VAD implantation are still awaiting a donor heart. The mean follow-up was 825.27 ± 630.23 days (range, 21–1,888 days). Results There was no serious complication during VAD support. The overall heart transplantation mortality rate was 9.1% (1/11). In all patients, impaired end-organ functions were improved by VAD implantation before the heart transplantation. Cardiac biopsies revealed 4 grade 2R rejection episodes, which were successfully controlled in 3 patients. Conclusion Heart transplantation is highly effective therapy for pediatric patients with end-stage heart failure. Pediatric VAD implantation provided satisfactory safe circulatory support for small children in poor condition on the waiting list. This option should be considered for all pediatric candidates who show a poor hemodynamic status.

Ventricular Assist Device in Patients With Prosthetic Heart Valves

Ventricular assist device (VAD) support inpatients with a prosthetic heart valve had previously been considered a relative contraindication due to an increased risk of thromboembolic complications. We report our clinical experience of VAD implantation in patients with prosthetic heart valves, including both mechanical and bioprosthetic valves. The clinical records of 133 consecutive patients who underwent VAD implantation at a single institution from January 2002 through June 2009 were retrospectively reviewed. Six of these patients had a prosthetic valve in place at the time of device implantation. Patient demographics,operative characteristics, and postoperative complications were reviewed.Of the six patients,four were male.The mean age was 57.8 years (range 35–66 years). The various prosthetic cardiac valves included a mechanical aortic valve (n = 2), a bioprosthetic aortic valve (n = 3), and a mechanical mitral valve (n = 1).The indications for VAD support included bridge to transplantation (n = 2), bridge to recovery (n = 1), and postcardiotomy ventricular failure(n = 3). Three patients underwent left ventricular assist device placement and three received a right ventricular assist device. Postoperatively, standard anticoagulation management began with a heparin infusion (if possible)followed by oral anticoagulation.The 30-day mortality was50% (3/6). The mean duration of support among survivors was 194.3 days (range 7–369 days) compared with 16.0 days(range 4–29 days) for nonsurvivors. Of the three survivors,two were successfully bridged to heart transplantation and one recovered native ventricular function.Among the three nonsurvivors,acute renal failure developed in each case, and two developed heparin-induced thrombocytopenia. This study suggests that VAD placement in patients with a prosthethic heart valve, either mechanical or bioprosthetic,appears to be a reasonable option.

Ventricular Assist Device Implantation Corrects Myocardial Lipotoxicity, Reverses Insulin Resistance and Normalizes Cardiac Metabolism in Advanced Heart Failure

Introduction: In advanced heart failure (HF), impaired myocardial substrate metabolism results in a substrate shift from fatty acid to glucose utilization for generation of ATP. Impaired fatty acid oxidation potentially leads to accumulation of toxic lipid intermediates, impaired insulin signaling and progression of cardiac dysfunction. Hypothesis: Mechanical unloading through implantation of a ventricular assist device (VAD) will reverse metabolic derangements in patients with HF. Methods: Myocardial tissue was obtained from 36 patients with HF undergoing VAD implantation and explantation. Clinical data were obtained from institutional medical records. mRNA expression was analyzed by RT-PCR and protein levels analyzed by western blot. Triglyceride content was assessed using the Folch method. Serum insulin levels were measured by ELISA and insulin resistance calculated using the HOMA-IR method. Results: The cohort had a mean BMI of 27.1 ± 5.1 kg/m2, age of 51 ± 12.0 years and VAD duration of 185 ± 156.2 days. There was a history of diabetes mellitus in 31%, hypertension in 22%, hyperlipidemia in 50%, and smoking in 44% of the cases. VAD implantation reduced fasting glucose (144 ± 47.1 to 112 ± 43.8 mg/dL), HbA1c (7.5 ± 2.4 to 6.3 ± 1.5), and HOMA-IR (4.5 ± 0.56 to 3.2 ± 0.45) (all p < 0.05). Expression of lipid metabolism genes CD36, CPT1 and ACO increased and levels of cardiac triglycerides decreased (5.1 ± 1.09 to 3.6 ± 0.67 mg/g) after VAD implantation. Expression of the glucose uptake gene, GLUT4, decreased; PDK4 also decreased suggesting more glucose oxidation. Improved insulin signaling was noted by increased protein levels of phospho-IRS, total Akt, phospho-Akt, and phospho-FoxO after VAD. Membrane localization of protein kinase C (PKC) isoforms, known inhibitors of insulin signaling, also decreased after VAD implantation. Conclusion: In conclusion, hemodynamic improvement and mechanical unloading after VAD implantation leads to correction of systemic and local metabolic derangements in patients with advanced HF as evidenced by increased fatty acid oxidation, reduced toxic intracellular signaling events and subsequent improvement in markers of insulin sensitivity.

Impact of fixed pulmonary hypertension on post–heart transplant outcomes in bridge-to-transplant patients

Fixed pulmonary hypertension (FPH) is considered a contraindication to cardiac transplantation. Ventricular assist device (VAD) therapy through prolonged left ventricular unloading may reverse FPH. Our aim was to assess post-transplant outcomes and survival in patients with and without FPH undergoing VAD implantation as bridge to transplant. Fifty-four patients received an intracorporeal left VAD (LVAD) as a bridge to transplant from 2000 to 2008 at two institutions (Rigshospitalet, Denmark, and the Toronto General Hospital, Canada). Twenty-two (41%) patients had fixed FPH (defined as pulmonary vascular resistance [PVR] >3 Wood units and resistant to pulmonary vasodilators) prior to VAD implant (FPH group) and were compared with 32 patients without FPH (NoFPH group). Baseline characteristics, pre- and post-transplant pulmonary pressures, incidence of complications and post-transplant survival were analyzed. Baseline characteristics were similar except that patients in the FPH group were older (46 ± 11 years vs 39 ± 13 years in the NoFPH group, p < 0.05). The mean pre-VAD PVR was 4.3 ± 1.7 Wood units in the FPH group and 1.7 ± 0.5 Wood units in the NoFPH group (p < 0.001). Pulmonary pressures were higher in the FPH group immediately prior to VAD implant, but they were comparable immediately pre-transplant and during the first year post-transplant. The incidence of post-transplant RV failure was not significantly different between groups. Post-transplant survival was similar between groups. VAD therapy successfully decreases pulmonary hypertension, even in patients with "fixed" FPH, allowing candidacy for heart transplantation. Among bridge-to-transplant candidates, the presence of FPH does not reduce post-transplant survival.

Pediatric Heart Transplant Candidates With Failed Donor Heart Allocation After Eurotransplant Urgency Listing Profit From Pretransplant Mechanical Circulatory Support Bridging

Due to the Eurotransplant organ allocation policy, urgency listing for heart transplantation (HTx) remains in force until ventricular assist device (VAD) implantation in Germany. We studied the prognosis of HTx candidates after failed donor heart allocation in urgent status. We studied all adult and pediatric (<18 years) HTx candidates who underwent primary HTx after Eurotransplant urgency listing between January 2001 and December 2006 (Group A-uHTx [A-"u"rgent status "HTx"], n = 99; Group P-uHTx [P-"u"rgent status "HTx"], n = 24) and those to whom donor heart was not urgently allocated before VAD implantation or death in the same period (Group A-fHA [A-"f"ailed "H"eart "A"llocation], n = 21, Group P-fHA [P-"f"ailed "H"eart "A"llocation], n = 10). Mortality rate after urgency listing or primary VAD implantation was studied in each group. In adult patients, 1-year mortality rate after urgency listing in Group A-fHA was 56.8% and significantly higher than in Group A-uHTx (30.6%, P < 0.001, log-rank test). After failed urgent heart allocation, 15 out of 21 patients in Group A-fHA had VAD implantation and two patients (9.5%) underwent HTx after VAD implantation. In pediatric patients, 1-year mortality rate in Group P-fHA was 40.0% and significantly higher than in Group P-uHTx (8.5%, P < 0.05). In Group P-fHA, all 10 patients underwent VAD implantation after failed urgent heart allocation and six patients (60.0%, P < 0.01 vs. Group A-fHA, Fisher's exact test) underwent HTx after VAD implantation. After failed urgent donor heart allocation, pediatric HTx candidates seem to profit more from mechanical circulatory support than adults.

Costs Associated With Ventricular Assist Device Use in Children

Ventricular assist devices (VADs) allow children with severe heart failure to be bridged to successful heart transplantation. Ventricular assist devices are being used with increasing frequency in the pediatric population, and newer devices allow even young infants to be supported. Ventricular assist device implantation and maintenance, however, is quite expensive, and the cost-effectiveness of VAD use in adults has been questioned. To date, an economic analysis of VAD support in children has not been undertaken. We used Pediatric Health Information System, an administrative database of the Child Health Corporation of America (a consortium of Children's Hospitals in North America), to determine the outcomes and costs related to VAD use in children. Data on patients younger than 18 years of age from 2002 to 2007 were reviewed. Hospital charges were converted to costs based on cost-to-charge ratios. Projected survival for subjects who were successfully bridged to heart transplant was derived from published data. The model assumed that if a VAD strategy were not used, the majority of subjects would have required extracorporeal membrane oxygenation support as a bridge to transplantation. Cost-utility was expressed as cost per quality-adjusted life years saved. All future costs and benefits were discounted at 3%. There were 145 children who underwent VAD implantation at 19 centers in North America. The median age at admission was 8.5 years; the range was newborn to 17.7 years. The median duration of VAD support was 43 days (range, 1 to 465 days). Ninety-four patients (65%) survived to heart transplantation. Thirty-nine (27%) patients died during hospitalization. There were 12 patients (8%) who had VAD explantation and survival to hospital discharge. The mean hospital cost was $624,798. When compared with a strategy of extracorporeal membrane oxygenation support, the calculated cost-utility for VAD as a bridge to transplantation was $119,937 per quality-adjusted life year saved. When key assumptions were changed, the cost-utility varied from $88,304 to $282,320 per quality-adjusted life year saved. Ventricular assist devices allow an effective bridge to heart transplantation in children. Under base-case assumptions, the cost-effectiveness ratios exceed the threshold of $100,000 per quality-adjusted life year saved. The cost-utility of this strategy, however, is comparable to a number of other life-saving technologies.

Ventricular Assist Device Implantation in the Pediatric Population: Does Pump Size Selection and Associated Hemodynamics Impact Outcomes?

The use of pediatric ventricular assist devices (VADs) continues to evolve with the availability of smaller blood pumps. We examine the correlation of implanting appropriate sized blood pumps with a lower incidence of VAD related complications (VADRC). A 7-year retrospective review was undertaken for all pediatric VAD patients. Optimal VAD hemodynamics were defined as cardiac index of 2.7 L/m2 and rate of 80 beats per minute (bpm) with complete fill/empty of the blood pump. Patient/blood pump size match, VAD rate and fill/empty ratios were calculated (optimum = 1.0) and then correlated with incidence of VADRC. The study included 22 patients, mean age 9.77 years (6 mo-18 yrs) and mean body surface area (BSA) of 1.14 m2 (0.14 m2-2.32 m2), who underwent VAD implantation. VADRC included death while on support (n = 5), bleeding requiring reoperation (n = 8), hemolysis (n = 2), neurologic events (n = 2), thrombus formation (n = 3), and infection (n = 3). Six patients were bridged to transplant without any VADRC. This subset of patients had a mean blood pump size match ratio of 0.98, VAD rate ratio of 0.92 and fill/empty ratio of 1.00. Patients with VADRC (n = 16) were found to have a mean blood pump size match ratio of 0.72, VAD rate ratio of 0.72 and fill/empty ratio of 0.78. We report a series of pediatric patients with wide ranging BSA receiving VAD implantation. Selection of appropriate sized blood pumps can be correlated with decreased VADRC.

167: Impact of Age on Outcomes of Ventricular Assist Devices Utilized as Bridge to Cardiac Transplantation

Ventricular assist devices (VAD) are an accepted treatment modality to bridge select patients with end stage heart failure to cardiac transplantation. Age is an independent risk factor for increased morbidity and mortality in this patient population. The purpose of this study is to compare outcomes in patients 60 years of age or older with their younger counterparts who underwent VAD implantation intended as bridge to cardiac transplantation (BTT) at UCLA Medical Center.

The Impact of Hypogammaglobulinemia on Infection Outcome in Patients Undergoing Ventricular Assist Device Implantation

Infection is a major comorbidity after ventricular assist device (VAD) placement. Defects in cellular immunity have been reported after VAD placement. However, to our knowledge, quantitative immunoglobulin G (IgG) level determination and the impact of hypogammaglobulinemia (HGG) on infections after VAD implantation have not been evaluated before. A total of 76 patients (mean age, 53 years) underwent VAD implantation as a bridge to transplantation and had IgG levels determined as a baseline before transplantation. Patients were divided into 2 groups according to IgG level: Control Group (n = 56, IgG > or = 700 mg/dl) and HGG Group (n = 20, IgG < 700 mg/dl). Infection outcome during the VAD course and after transplantation was analyzed in relation to the IgG level. Baseline characteristics were similar in both groups. The incidence of bacteremia (14/20 [70%] vs 18/56 [32%], p = 0.0032) and major infection (19/20 [95%] vs 31/56 [56%], p = 0.0009) were significantly increased in the HGG Group compared with the Control Group. After transplantation, the episodes of rejection were similar in both groups and survival was similar. The HGG Group experienced more cytomegalovirus infections compared with the Control Group (9/20 [45%] vs 9/56 [16%], p = 0.009). VAD patients with HGG are at increased risk of infections. After transplantation, these patients also experience increased cytomegalovirus infections. A randomized preemptive IgG replacement trial may be warranted in the future to determine if this intervention will alleviate the risk of infection.

EFFECTS OF SURFACE MODIFICATIONS ON IN VIVO BIOCOMPAT-BILITY IN ROTARY BLOOD PUMPS

Biocompatibility remains a limitation to widespread adoption of ventricular assist device (VAD) technology. To assess potential enhancement of device compatibility by surface modification, we applied several flow cytometric assays to 46 bovines undergoing VAD implantation. Calves received either an Evaheart (EH) with diamond-like carbon (DLC; n=4) or 2-methacryloyloxyethyl phosphorylcholine (MPC; n=12) coating or a Heartmate II (HM) with Ti beads sintered to the inflow cannula, inflow and outflow elbows, pump housing not adjacent to the impeller, and inflow and outflow stators(n=22); or with the Ti beads only sintered onto the inflow cannula, inflow and outflow elbows (n=8). Calves received typical heparin/coumadin therapy to maintain INRs of 2.5–3.5. PLT and LEU activation and aggregate formation was measured by flow cytometry on samples collected pre-operatively and twice weekly post-operatively (post-op). All assays showed a similar pattern of low pre-operative levels followed by dramatic increased after pump implantation. The levels generally declined reaching a plateau after 2 to 3 weeks, which remained significantly elevated compared to pre-op levels. PLT activation was significantly decreased in the EH with MPC vs. the DLC coating as reflected by CD62P and annexin V being lower after 24 and 21 days post-op, respectively. No significant differences were found in the assays in the 2 versions of the HM. The application of sensitive flow cytometric assays may aid in the evaluation of the effects of device modification on biocompatibility during pre-clinical testing.

Relapsing bacteremia in patients with ventricular assist device: an emergent complication of extended circulatory support

Background. Ventricular assist devices (VAD) are currently approved for use as a bridge for transplantation. Although reports have suggested acceptable rates of survival of patients with VAD, there is little information regarding the mechanism and etiology of bacteremia in these patients. Methods. We prospectively followed patients who underwent VAD implantation and developed bacteremia during VAD support at the University of Pittsburgh Medical Center. Relapsing bacteremia was defined as at least two episodes of positive blood cultures with a genetically related organism on 2 different days. Species identification and susceptibility testing were performed on all isolates. Pulse field gel electrophoresis was performed on selected blood and VAD isolates. Results. Between January 1998 and August 1999, 3 patients with VAD developed relapsing bacteremia, which was treated with full courses of antibiotic agents, 2 of whom also developed VAD endocarditis. All 3 patients had documented driveline or device pocket infections with these isolates. Consecutive blood and VAD isolates were found to be genetically related within each patient. Conclusions. These patients with bacteremia after VAD implantation had relapse due to the same strain, which may have originated from indolent driveline infection. Endovascular infection in this setting is difficult to eradicate with antibiotic agents and carries a high mortality. These patients should be considered to have priority for orthotopic heart transplantation.