HeartMate XVE Research Articles

The Evolution and Complications of Long-Term Mechanical Circulatory Support Devices

Heart failure, a common clinical syndrome caused by functional and structural abnormalities of the heart, affects 64 million people worldwide. Long-term mechanical circulatory support can offer lifesaving treatment for end-stage systolic heart failure patients. However, this treatment is not without complications. This review covers the major complications associated with implantable mechanical circulatory support devices, including strokes, pump thrombosis and gastrointestinal bleeding. These complications were assessed in patients implanted with the following devices: Novacor, HeartMate XVE, CardioWest, Jarvik 2000, HeartMate II, EVAHEART, Incor, VentrAssist, HVAD and HeartMate 3. Complication rates vary among devices and remain despite the introduction of more advanced technology, highlighting the importance of device design and flow patterns. Beyond clinical implications, the cost of complications was explored, highlighting the difference in costs and the need for equitable healthcare, especially with the expected rise in the use of mechanical circulatory support. Future directions include continued improvement through advancements in design and technology to reduce blood stagnation and mitigate high levels of shear stress. Ultimately, these alterations can reduce complications and enhance cost-effectiveness, enhancing both the survival and quality of life for patients receiving mechanical circulatory support.

A clinical and cost-effectiveness analysis of the HeartMate 3 left ventricular assist device for transplant-ineligible patients: A United Kingdom perspective

The clinical and cost-effectiveness of left ventricular assist device (LVAD) therapy for patients with advanced heart failure (HF) who are ineligible for heart transplantation is debated in the UK. This study develops an indirect comparison between the fully magnetically levitated HeartMate 3 (HM 3) LVAD and medical therapy (MT) to evaluate expected clinical and cost-effectiveness in the UK National Health Service (NHS) context. We performed an economic analysis comparing the HM3 pump against the HeartMate II LVAD (MOMENTUM 3), and then another analysis comparing MT with the first- and second-generation HeartMate XVE pump LVAD and HeartMate II LVAD for the same patient population (REMATCH and ROADMAP, respectively). By bridging those 2 analyses, an indirect comparison between HM3 and MT in the form of a network meta-analysis was developed. A literature search was performed to select the most appropriate pair of studies for this purpose. Outcomes were adjusted to produce Kaplan-Meier curves for the cost-effectiveness evaluation by using a decision-analytic model. Data were extrapolated linearly over a 5-year time horizon. Uncertainty and additional scenarios were addressed by one-way and probabilistic sensitivity analysis. Local costs and health utility were used from England, thereby representing the UK context. The incremental cost-effectiveness ratio (ICER) for LVAD vs MT in transplant ineligible patients with advanced HF was estimated to be £47,361 per quality-adjusted life year gained, with a 97.1% probability of being cost-effective at £50,000. In a subgroup of patients who are inotropic therapy dependent (INTERMACS 1-3 severity profile), the ICER was £45,616, while for a population with less-ill ambulatory HF (INTERMACS profile 4-7) the ICER changed to £64,051. This study provides evidence that HM3 LVAD therapy in advanced HF patients ineligible for heart transplantation may be cost-effective compared to MT in the NHS UK-England context. The ICER is lowest for patients dependent on inotropic support, but exceeds the willingness to pay threshold of £50,000 in ambulatory noninotropic therapy dependent advanced HF patients.

Gastrointestinal Bleeding After HeartMate II or HVAD Implantation: Incidence, Location, Etiology, and Effect on Survival.

The number of patients on destination therapy is increasing as long-term survival on continuous-flow left ventricular assist device (CF-LVAD) therapy has improved. Gastrointestinal bleeding (GIB) is a common complication after CF-LVAD implantation, and its risk correlates with longer support time, emphasizing the importance of GIB management. The lower pulsatility of CF-LVADs may promote arteriovenous malformations, which amplify the bleeding risk. Here, we retrospectively analyzed the location, incidence, and survival effect of GIB events in HeartMate II (HM-II) and HeartWare Ventricular Assist Device (HVAD) recipients to provide specific details regarding these complications. From November 2003 to March 2016, 526 patients with chronic heart failure underwent primary implantation of an HM-II (n = 403) or HVAD (n = 123) CF-LVAD at our center. Of the 526 patients, 140 (26.6%) had a GIB event (HM-II: n = 100; HVAD: n = 40), 92 (17.5%) had a single GIB event, and 48 (9.1%) had multiple GIB events (range: 2-9 events). HVAD recipients had a higher incidence of both upper and lower GIB events (p < 0.001 and P = 0.002, respectively) than HM-II recipients. Arteriovenous malformation was the most common etiology for GIB (50 patients/72 events); for this group, the average time-to-event was 300.4 days, the recurrence rate was 34%, and the 90-day and 1-year survival rates were 88.3% and 66.7%, respectively. Age at implantation was the only predictor of GIB. In conclusion, our study provides detailed information about GIB events associated with current CF-LVADs. Additional studies are required to evaluate strategies to reduce the incidence of GIB morbidity.

Third-Generation LVADs: Has Anything Changed?

The field of durable left ventricular assist devices has advanced dramatically since its introduction into the clinical realm. From the first-generation pulsatile HeartMate XVE device to the second-generation continuous axial flow HeartMate-2 to the current third-generation centrifugal flow devices, the left ventricular assist device has undergone significant evolution. This review describes the technology and its changes over the course of time, with a focus on the fundamental question: Has anything changed?

Experience with the HeartMate II Left Ventricular Assist Device in Patients Older than 60 Years.

Advanced age is a relative contraindication for heart transplantation, but no age cutoff has been defined for patients receiving mechanical circulatory support. Between November 1, 2003 and November 1, 2012, we implanted the HeartMate II (HMII) left ventricular assist device (LVAD) in 319 patients. One hundred seven patients (89 men, 18 women) were over 60 years old (mean, 66 ± 4 years, range, 61-78 years) and received the HMII as a bridge to transplantation (n = 45) or as destination therapy (n = 62). We evaluated their experience by performing a retrospective analysis. Seventy-two patients had ischemic cardiomyopathy, and 34 had idiopathic cardiomyopathy. Three patients (2.8%) already had a HeartMate XVE LVAD, 54 (50.5%) were receiving intra-aortic balloon pump support, 52 (48.6%) had undergone a previous cardiac procedure, and 9 (8.4%) had received renal replacement therapy (RRT) (continuous venovenous hemofiltration, hemodialysis, or both) before HMII implantation. The median duration of HMII support was 313 days (range, 1-3339 days). After device implantation, 36 patients (33.6%) had gastrointestinal bleeding, 24 (23%) required RRT, 18 (17.5%) had ventricular arrhythmias, and 24 (22.4%) had LVAD-related infections, and 9 (8.4%) had right ventricular failure requiring mechanical support, and 28 (26.2%) had neurologic complications. The actual survival rate was 69% at 6 months, 63% at 1 year, and 54% at 2 years. Eighty-one patients died, 9 are still receiving HMII support, and 17 are alive after heart transplantation. Older patients can benefit from LVAD therapy, and advanced age should not preclude LVAD implantation.

Acquired Von Willebrand Syndrome and Blood Pump Design.

The existence of acquired von Willebrand syndrome (AVWS) in patients with continuous flow left ventricular assist devices (LVADs) is well documented and has been verified by numerous investigators. AVWS has not been observed to occur in pulsatile devices such as the SynCardia total artificial heart (TAH), the HeartMate XVE, and the Thoratec pulsatile ventricular assist device (PVAD) used as a single pump. AVWS can also occur in patients with aortic stenosis, ventricular septal defect, mitral stenosis, and patent ductus arteriosus. It has been experimentally verified that supraphysiologic shear stress that occurs under these conditions can cleave the von Willebrand molecule, but the critical magnitude of stress and duration is unclear. Limited experimental results demonstrate that shear stresses as low as 5 Pa (50 dyne/cm2 ) can cause cleavage. Stresses in current centrifugal pumps can be as high as two orders of magnitude greater than this value. Pulsatile LVADs have stresses almost two orders of magnitude less than continuous flow LVADs. In order to improve continuous flow LVADs, the challenge for designers is to first determine the magnitude and duration of stress that is causing AVWS and then, if possible, design a pump below these stresses.

Abciximab/Heparin Therapy for Left Ventricular Assist Device Implantation in Patients With Heparin-Induced Thrombocytopenia

Optimal anticoagulation strategy remains uncertain in patients with heparin-induced thrombocytopenia (HIT) and undergoing left ventricular assist device (LVAD) implantation. We describe our protocol of abciximab and heparin in these patients. Our protocol is to administer abciximab, 0.25 mg/kg loading dose, followed by continuous infusion of 0.125 μg · kg-1 · min-1 throughout cardiopulmonary bypass. Full-dose heparin is then given with subsequent additional doses to maintain an activated clotting time of 400 seconds or longer. The abciximab infusion is stopped 15 minutes after heparin reversal with protamine, and platelets are transfused. Six patients underwent LVAD implantation with this protocol in our program. HIT was confirmed in 4 patients was suspected in 2, which was negative after the operation. One patient received a HeartMate XVE (Thoratec Corp, Pleasanton, CA) and the others received HeartMate II (Thoratec Corp). There were no thromboembolic complications. One patient required chest reexploration for bleeding and temporary right VAD support. Postoperative anticoagulation with argatroban was restarted on median postoperative day 3 (range, days 1 to 6) and warfarin was started on day 5 (range, days 3 to 12). Median postoperative intensive care unit stay was 9 days (range, 5 to 76 days), and hospital stay was 22 days (range, 18 to 132 days). After the initial LVAD implantation, 1 patient required HeartMate XVE LVAD exchange to HeartMate II and subsequent heart transplant, both of which were performed with the abciximab/heparin protocol. A HeartMate II device was explanted in another patient after myocardial recovery. The remaining 4 patients are alive on device support. This is the first report of a novel abciximab/heparin protocol for LVAD implantation in patients with HIT. The preliminary results suggest the feasibility and safety of this protocol.

Anchoring in Destination-Therapy Left Ventricular Assist Device Decision Making: A Mechanical Turk Survey

BackgroundPeople with end-stage heart failure may have to decide about destination-therapy left ventricular assist device (DT-LVAD). Individuals facing difficult decisions often rely on heuristics, such as anchoring, which predictably bias decision outcomes. We aimed to investigate whether showing a larger historical Heartmate XVE creates an anchoring effect, making the smaller Heartmate II (HMII) appear more favorable. MethodsWith the use of Amazon Mechanical Turk, participants watched videos asking them to imagine themselves dying of end-stage heart failure, then were presented the option of LVAD as potentially life-prolonging therapy. Participants were randomized to a control group who were only shown the HMII device, and the intervention group who saw the XVE device before the HMII. Participants then completed surveys. ResultsA total of 487 participants completed the survey (control = 252; intervention = 235); 79% were <40 years of age, 84% were white, and 55% were male. The intervention group was not more likely to accept the LVAD therapy (68% vs 61%; P = .37). However, participants in the intervention group were more likely (51% vs 17%; P < .01) to agree or strongly agree with the statement that the HMII was “smaller than expected.” Participants in the intervention group were also more likely to rate the size of the device as “important” or “very important” in their decision (61% vs 46%; P < .01). ConclusionsAlthough the XVE anchor did not affect likelihood of accepting the LVAD, it did affect device perception. This article highlights an important point with clinical implications: factors such as anchoring have the potential to inappropriately influence perceptions and decisions and should be carefully considered in research and practice.

Abstract 20: Dying With a Left Ventricular Assist Device as Destination Therapy

Background: Left ventricular assist devices as destination therapy (DT-LVAD) have been shown to decrease mortality compared with medical management, and can improve quality of life for many patients with advanced heart failure. However, while most patients live longer with DT-LVAD than they would have with medical therapy, deaths still occur. We sought to systematically examine the end-of-life care of patients who died with a DT-LVAD at a single center. Methods: All patients undergoing DT-LVAD at the Mayo Clinic in Rochester, Minnesota from January 1, 2007 through September 30, 2014 who subsequently died prior to July 1, 2015 were included. The cause of death was determined based on review of documentation in the electronic medical record, including autopsy reports, death certificates and clinical notes. Details about palliative care consultations, hospice enrollment, hospitalizations, and device deactivation at the end-of-life were obtained from the electronic medical record. Results: Of 89 patients that died with a DT-LVAD (84 HeartMate II, 3 HeartWare, 2 Heartmate XVE, mean age at death 66.1 years), the mean (standard deviation) time from LVAD implantation to death was 2.0 (1.9) years. The most common causes of death were multiorgan failure (25.9%), hemorrhagic stroke (24.7%), and progressive heart failure (20.0%). Nearly half (45.6%) of patients saw palliative care in consultation within a month prior to death. However, only 13 (15.5%) patients enrolled in hospice a median of 11 (range 1-315) days prior to death, including 4 patients with concurrent cancer, 2 with stroke, and 7 with multiorgan failure. The vast majority of patients (78.6%) died in the hospital, and of those hospitalized at death, 87.7% died in the intensive care unit. Most patients hospitalized at death transitioned to a comfort-directed approach to care within 24 hours of dying. In total, 43 (48.3%) patients had their LVAD deactivated prior to death, with all but 3 undergoing deactivation in the hospital. The vast majority of patients died within an hour of LVAD deactivation, and all within 26 hours. Conclusions: In contrast to the general heart failure population, most patients with DT-LVAD die in the hospital and very few enroll in hospice. A significant body of research has demonstrated that patients who die in the intensive care unit and the hospital, as opposed to home or with hospice assistance, experience worse quality of life, quality of death and caregiver outcomes. Potential reasons that patients with DT-LVAD may experience different end-of-life care than other patients with heart failure exist, including that they often experience sudden changes in health status prior to death from acute events such as hemorrhagic stroke. However, further work is needed to understand these differences and to determine whether patients with DT-LVAD are receiving optimal end-of-life care.

A Decade of Experience With Continuous-Flow Left Ventricular Assist Devices

The use of continuous-flow left ventricular assist devices (CF-LVADs) has revolutionized the landscape of mechanical circulatory support for patients with heart failure. Clinical trials are already testing the next generation of CF-LVADs. In this study, our objective was to review our long-term experience with the current generation of CF-LVADs, specifically, the HeartMate (HM) II (Thoratec Corp, Pleasanton, CA). In this single-center retrospective analysis, we evaluated the records of 278 consecutive patients who underwent a total of 302 HM II placements from June 2005 through June 2014. We excluded 11 patients from our final study group, who had previously undergone placement of a HM XVE that failed. We divided the remaining 267 patients into 3 equal groups of 89 patients each, by time period: group 1, June 2005 through May 2009; group 2, June 2009 through January 2012; and group 3, February 2012 through June 2014. To examine differences in survival between our 3 groups, we used time-to-event analysis, including the Kaplan-Meier method. To examine secondary outcomes (including stroke, hemolysis, gastrointestinal bleeding, pump thrombus, and transplant), we used one-way analysis of variance. For our final study group of 267 patients, the total follow-up time was 479.01 patient-years (median, 469 days). The mean age of patients was 57 years; 81.4% were male. In all, 209 (78.9%) patients underwent HM II placement as a bridge to transplant; 58 (21.1%), as destination therapy (DT). The overall survival rate was 94% at 30 days, 77% at 1 year, 65% at 2 years, 60% at 3 years, 50% at 4 years, and 48% at 5 years. In bridge to transplant patients, the survival rate was 78% at 1 year and 66% at 2 years; in DT patients, 70% and 60%. In group 1 patients, the survival rate was 94% at 30 days, 64% at 1 year, and 48% at 2 years; in group 2, 93%, 88%, and 76%; and in group 3, 94%, 77%, and 73% (P = 0.003). In the later years of our study period, from June 2009 onwards (ie, in groups 2 and 3), we noted a statistically significant increase in HM II placement as DT, a reduction of driveline infections, increasing pump exchange, increasing hemolysis, a reduced frequency of transplants, and an improved survival rate (as compared with the earlier group 1). The HM II has favorably influenced the outcomes of patients with end-stage heart failure, yet major complications still limit their survival. Improving compatibility between the pump and the individual host patient, enhancing anticoagulation strategies, and developing a totally implantable pump might further reduce complications thereby improving survival times and allowing CF-LVAD placement to be a true long-term alternative to a heart transplant.

Left Ventricular Assist Device in Patients With Body Mass Index Greater Than 30 as Bridge to Weight Loss and Heart Transplant Candidacy

IntroductionIn obese patients with heart failure, weight reduction may be difficult due to physical restrictions, but may be necessary to achieve heart transplant candidacy. We report the outcomes of obese patients who underwent implantation of a left ventricular assist device (LVAD) using a pulsatile (HeartMate XVE [XVE]) or continuous flow (HeartMate II [HMII]) design and the effect on body mass index (BMI). MethodsOf 37 patients with BMI >30 kg/m2 who underwent LVAD implantation, 29 survived at least 30 days and were followed for weight change. In the 30-day survivors, end points of the study were continued LVAD support, heart transplant, or death. One patient underwent gastric bypass surgery and was excluded. ResultsIn the 28 patients who met inclusion criteria, BMI was 35.6 ± 4.4 kg/m2 at baseline, and at follow-up was 33.1 ± 5.5 kg/m2 (mean BMI change −2.5 kg/m2; P = .063), with a mean follow-up time of 301.6 ± 255.5 days. The XVE group showed a significant BMI reduction of 3.9 kg/m2 (P = .016 vs baseline); however, the HMII group showed 0.1 kg/m2 increase in BMI. BMI <30 kg/m2 at follow-up was achieved in 6 patients (21%), 5 of 19 (26%) in XVE group, and 1 of 9 (11%) in HMII group. In the 14 patients (12 XVE, 2 HMII) or 50% who received a heart transplant, the mean decrease in BMI was 4.6 kg/m2 (P = .003). ConclusionsLVAD placement in patients with BMI >30 kg/m2 provided significant weight loss in the pulsatile XVE group, but not in recipients of the continuous flow HMII. In patients successfully bridged to a heart transplant after LVAD insertion, mean reduction in BMI was 4.6 kg/m2 (P = .003). LVAD implantation provides a period of hemodynamic support for obese patients with advanced heart failure, during which time opportunity may be available for weight loss. Pulsatile devices appear to be associated with greater weight loss than nonpulsatile continuous flow devices. Additional therapies may be necessary to achieve significant weight loss in recipients of the continuous flow LVAD.

Institutional volume of heart transplantation with left ventricular assist device explantation influences graft survival

There are increasing numbers of patients undergoing orthotopic heart transplantation (OHT) with left ventricular assist device (LVAD) explantation (LVAD explant-OHT). We hypothesized that LVAD explant-OHT is a more challenging surgical procedure compared to OHT without LVAD explantation and that institutional LVAD explant-OHT procedural volume would be associated with post-transplant graft survival. We sought to assess the impact of institutional volume of LVAD explant-OHT on post-transplant graft survival. This is a retrospective analysis of the Scientific Registry of Transplant Recipients for adult OHTs with long-term LVAD explantation. LVAD explant-OHT volume was characterized on the basis of the center's year-specific total OHT volume (OHTvol) and year-specific LVAD explant-OHT volume quartile (LVADvolQ). The effect of LVADvolQ on graft survival (death or re-transplantation) was analyzed. From 2004 to 2011, 2,681 patients underwent OHT with LVAD explantation (740 with HeartMate XVE, 1,877 with HeartMate II and 64 with HeartWare devices). LVAD explant-OHT at centers falling in the lowest LVADvolQ was associated with reduced post-transplant graft survival (p = 0.022). After adjusting for annualized OHTvol (HR = 0.998, 95% CI 0.993 to 1.003, p = 0.515 and pulsatile XVE (HR = 0.842, 95% CI 0.688 to 1.032, p = 0.098), multivariate analysis confirmed a significantly (approximately 37%) increased risk of post-transplant graft failure among explant-OHT procedures occurring at centers in the lowest volume quartile (HR = 1.371, 95% CI 1.030 to 1.825, p = 0.030). Graft survival is decreased when performed at centers falling in the lowest quartile of LVAD explant-OHT for a given year. This volume-survival relationship should be considered in the context of limited donor organ availability and the rapidly growing number of LVAD centers.

Assessment and Management of Heart Failure After Left Ventricular Assist Device Implantation

Case Presentation: A 56-year-old man with a history of ischemic cardiomyopathy and New York Heart Association functional class IV heart failure (HF) requiring intravenous inotropic therapy underwent uncomplicated implantation of a continuous-flow left ventricular assist device (LVAD) as bridge to heart transplantation (HT). The patient was weaned off inotropic support during the first week after surgery and had progressive improvement in functional status. He was discharged home on maintenance antithrombotic therapy with aspirin 325 mg once daily and warfarin targeted to an international normalized ratio of 2.0 to 3.0. Eight weeks after LVAD implantation, he developed progressive dyspnea on exertion, recurrent pedal edema, and a 7-pound weight gain. Physical examination revealed conjunctival pallor, a palpable carotid pulse, jugular venous pressure of 14 cm H2O, and 2+ pitting edema bilaterally. A rapid and targeted assessment of recurrent HF is essential in this LVAD patient because of multiple, potentially life-threatening causes that necessitate divergent treatments. The US Food and Drug Administration first approved implantable LVADs as a bridge to transplantation in 1994.1 Although HT remains the gold standard therapy for selected patients with end-stage HF, the stable donor base of <2500 hearts per year in North America limits its widespread applicability.2 The landmark Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure (REMATCH) trial established the first-generation, pulsatile-flow HeartMate (HM) XVE LVAD as a viable, life-prolonging treatment in patients who were not candidates for HT, a strategy known as destination therapy (DT). However, survival 2 years after implantation was still only 23%, in part because of the high rates of mechanical pump failure. The advent of continuous-flow LVADs has provided a more durable long-term treatment that improves quality of life and survival.3 The continuous-flow HM II LVAD has a markedly lower rate of device …

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 …

General and Acute Care Surgical Procedures in Patients with Left Ventricular Assist Devices

Left ventricular assist devices (LVADs) have become common as a bridge to heart transplant as well as destination therapy. Acute care surgical (ACS) problems in this population are prevalent but remain ill-defined. Therefore, we reviewed our experience with ACS interventions in LVAD patients. A total of 173 patients who received HeartMate(®) XVE or HeartMate(®) II (HMII) LVADs between December 2001 and March 2010 were studied. Patient demographics, presentation of ACS problem, operative intervention, co-morbidities, transplantation, complications, and survival were analyzed. A total of 47 (27 %) patients underwent 67 ACS procedures at a median of 38 days after device implant (interquartile range 15-110), with a peri-operative mortality rate of 5 % (N = 3). Demographics, device type, and acuity were comparable between the ACS and non-ACS groups. A total of 21 ACS procedures were performed emergently, eight were urgent, and 38 were elective. Of 29 urgent and emergent procedures, 28 were for abdominal pathology. In eight patients, the cause of the ACS problem was related to LVADs or anticoagulation. Cumulative survival estimates revealed no survival differences if patients underwent ACS procedures (p = 0.17). Among HMII patients, transplantation rates were unaffected by an ACS intervention (p = 0.2). ACS problems occur frequently in LVAD patients and are not associated with adverse outcomes in HMII patients. The acute care surgeon is an integral member of a comprehensive approach to effective LVAD management.

Implantable cardioverter-defibrillator shocks in patients with ventricular assist devices

Purpose: Ventricular assist device (VAD) use is becoming increasingly common for patients with end-stage heart failure (HF). The majority of events seem to occur in the early post-operative period.We sought to confirm the efficacy of ICDs in a single center cohort of VAD-supported HF patients. Methods: All adult subjects who underwent VAD support since 2003 as a bridge to transplantation (BTT) were reviewed and included in the study.All subjects in the cohort received one of the following VAD systems: HeartMate XVE,Novacor LVAS,LVAD INCOR Berlin Heart,HeartWare LVAS and Berlin Heart (LVAD and BiVAD).All patients had the ICD turned off for VAD implantation, and only LVAD recipients had the ICD turned on post-operatively (routinely within 12 – 48hours).BIVAD recipients had the ICD set to monitor only. Appropriate ICD shocks for Ventricular Tachycardia (VT) and Ventricular Fibrillation (VF) were recorded.The primary outcome was survival to transplantation. Results: A total of 87 VADs were implanted for the indication of bridge to transplantation.Of these,34 were left ventricular assist devices (LVAD) and 53 were biventricular assist devices (BIVAD).57 patients had an ICD (23 LVAD, 34 BIVAD).Mean age 40±12 years,78% male,LVEF 18±9%,54% dilated.Mean length of support was 365 days (range 1–1280). Overall, 48 (56%) patients survived to transplantation.More patients with an ICD were treated with amiodarone reflecting a higher incidence of arrhythmias.Of the 23 LVAD patients with an ICD,10 received at least one ICD shock.Appropriate shocks were delivered to 7 patients after LVAD implantation (5 VT, 1 VF, 1VT and VF). The mean time to first shock after LVAD implant was 129±109 days.In the LVAD cohort, more patients had an appropriate ICD shock for VT or VF before LVAD implant than afterwards.Of great interest was the analysis of the arrhythmias detected in the BiVAD group (15 patients out of 53 had at least one event VT or VF and one of them suffered an electrical storm).In BiVAD patients detection of those arrhythmias were of great importance because a decrease in cardiac outpout was observed. Arrhythmias detected in both groups were of prognostic significance,especially in the LVAD Group (RV failure and aortic regurgitation) In addition, two patients without an ICD had ventricular arrhythmias requiring placement of an ICD after VAD placement. Conclusion: ICD shocks are common after implantation of VADs.Shock frequency decreases after VAD implantation, likely due to ventricular unloading, but appropriate ICD shocks still occur in VAD supported patients.

Mechanical Circulatory Support and Heart Transplantation: Donor and Recipient Factors Influencing Graft Survival

Mechanical circulatory support is an accepted strategy to bridge patients to heart transplantation (HTx). Among mechanical circulatory support patients who go on to HTx, factors associated with improved graft survival have not been fully elucidated. Using the Scientific Registry for Transplant Recipients, we identified adults who were treated with a left ventricular assist device (LVAD) or total artificial heart (TAH) before HTx. Kaplan-Meier and multivariate Cox regression models were used to identify patient, donor, and device characteristics associated with graft survival. Between January 1997 and February 2012, 2,785 adults underwent HTx. Before HTx, 2,674 patients were treated with a LVAD (HeartMate XVE, 724; HeartMate II, 1,882; HeartWare, 68), and 111 were treated with a TAH. Follow-up averaged 25 ± 24 months. Gender mismatch occurred in 23%. Graft survival did not differ between LVAD groups (all p > 0.168), but TAH was associated with reduced graft survival compared with LVADs (p < 0.001). After controlling for device type (LVAD vs TAH), lower recipient pulmonary vascular resistance, shorter ischemic time, younger donor age, donor-to-recipient gender match, and higher donor-to-recipient body mass index ratio were independent predictors of longer graft survival (all p < 0.05). TAH was associated with reduced graft survival after transplant, and survival did not differ between the LVAD device groups. Additional variables that were independently associated with graft survival were donor age, recipient peripheral vascular resistance, ischemic time, gender match, and donor-to-recipient body mass index ratio. Recognition of these factors may inform decisions regarding device support and donor suitability.

Open Chest Epicardial Ablation of Ventricular Tachycardia Early after Left Ventricular Assist Device Implantation

Purpose Patients with advanced heart failure who require left ventricular assist device (LVAD) implant are also susceptible to ventricular tachycardia (VT). Recurrent VT can compromise the hemodynamic support provided with LVADs and if not managed can cause RV failure and ultimately refractory shock. Methods and Materials Between March of 2009 and June of 2012, 5 patients underwent open chest hybrid epicardial mapping and ablation of recurrent VT early after placement of an LVAD. Patients had the VT ablation at the time of mediastinal washout or chest closure (median post-op day #3, range day #1-12). Results Five patients (4 males, median age 57, range 52-73, 3 ischemic cardiomyopathy) had received LVAD. Two patients had HeartMate II, one patient had HeartMate XVE, one patient had HeartMate XVE and right ventricular assist device (RVAD) and one patient had Levitronix for post-cardiotomy shock following coronary bypass surgery requiring placement of an ECMO. All patients had failed medical therapy for VT with at least 1 (median 3) antiarrhythmic agents. Two patients had had endocardial ablation of VT prior to LVAD. Four patients had acute success with VT ablation. The termination of VT allowed removal of the RVAD in one patient. In all patients, VT was either eliminated or significantly reduced with epicardial ablation. No procedure-related complications occurred. Three patients died in the index hospitalization due to other causes (intracranial hemorrhage, sepsis or refractory cardiogenic shock). Conclusions Open-chest hybrid epicardial ablation for recurrent or incessant VT is feasible in selected patients early after LVAD implant although the overall prognosis remains guarded.

Institutional Volume of Heart Transplantation with Left Ventricular Assist Device Explantation Influences Graft Survival

<h3>Purpose</h3> There are increasing numbers of patients undergoing orthotopic heart transplantation (OHT) with left ventricular assist device (LVAD) explantation. We sought to assess the impact of institutional volume of LVAD explant-OHT on post-transplant graft survival. <h3>Methods and Materials</h3> This is a retrospective analysis of the Scientific Registry of Transplant Recipients for adult OHTs with long-term LVAD explantation. LVAD explant-OHT volume was characterized on the basis of the center's year-specific total OHT volume (OHTvol) and year-specific LVAD explant-OHT volume quartile (LVADvolQ). The effect of LVADvolQ on graft survival (death or re-transplantation) was analyzed. <h3>Results</h3> From 2004 to 2011, 2681 patients underwent OHT with LVAD explantation (740 HeartMate XVE, 1877 HeartMate II, 64 HeartWare). LVAD explant-OHT at centers falling in the lowest LVADvolQ (Q1) was associated with reduced post-transplant graft survival (p=0.022). After controlling for annualized OHTvol, which was not significant in this sample (HR=0.998, 95%CI=0.993-1.003, p=0.545), multivariate analysis confirmed a significantly (approximately 35%) increased risk of post-transplant graft failure among explant-OHT procedures occurring in centers in the lowest volume quartile (HR=1.352, 95%CI=1.012-1.798, p=0.038). <h3>Conclusions</h3> Graft survival is decreased when performed at centers falling in the lowest quartile of LVAD explant-OHT for a given year. This volume-survival relationship should be considered in the context of limited donor organ availability and rapidly proliferating LVAD centers. [figure 1]

Clinical outcomes after ventricular assist device implantation in adults with complex congenital heart disease

There are minimal data regarding ventricular assist device (VAD) implantation in adult patients with complex congenital heart disease (CHD). The medical records of 6 adult patients with complex CHD who underwent VAD implantation were retrospectively analyzed to characterize pre-operative clinical status, implantation techniques and challenges, post-operative management, and post-operative outcomes. All patients had a systemic right ventricle, including 2 with single-ventricle physiology. The average age at VAD implantation was 41 years. The implanted VADs included 1 HeartMate XVE, 3 HeartMate II (Thoratec Corp, Pleasanton, CA), 1 Jarvik 2000 (Jarvik Heart, New York, NY), and 1 HeartWare HVAD (HeartWare Inc, Framingham, MA). In-hospital outcomes included no sub-pulmonic ventricular failure, no VAD thrombosis or mechanical failure, 30-day mortality in 1 patient, non-fatal sub-arachnoid hemorrhage in 1 patient, and sustained ventricular tachycardia requiring unsynchronized direct current cardioversion in 1 patient. Of the 5 patients who survived to discharge, 1 patient received 171 days of VAD support before cardiac transplantation and survived for 1,484 days after transplantation; 1 patient received 262 days of VAD support before out-of-hospital death of unknown etiology; 1 patient had received VAD support for 988 days as of December 1, 2012, while awaiting a transplant; and 2 patients who received VADs as destination therapy had received 577 and 493 days of VAD support, respectively, and were still alive as of December 1, 2012. This case series characterizes important post-operative management challenges and clinical outcomes associated with VAD implantation as a bridge-to-transplant or as destination therapy in adult patients with complex CHD.