Implantation of the permanent Jarvik-2000 left ventricular assist device: a single-center experience

Longest reported support (7.5 years) with postauricular type of Jarvik 2000 axial-flow left ventricular assist device

Mechanical circulatory supports with left ventricular assist devices (LVAD) are nowadays an established treatment in end-stage heart failure for those patients who are waiting for an organ donation or are unsuitable for transplantation. The duration of LVAD support is variable, depending on the device, the intention to treat and the issues occurring during treatment, which can change the purpose treatment or accelerate the transplantation. Moreover, length of reported supports in the literature is heterogenous. In here, we present the clinical and surgical case of the longest LVAD support reported in the literature, as a bridge to transplantation, with axial pump Jarvik 2000 (Jarvik Heart, Inc, New York, NY).

Imaging of Cardiac Support Devices

Patients hospitalized in the intensive care unit (ICU) often have multiple support lines and devices that need routine imaging evaluation by radiologists. In patients with cardiogenic shock or depressed cardiac function, mechanical circulation support devices are used in combination with medical therapies to improve patient outcomes and sometimes can stabilize patients for surgical intervention. This article discusses some of the more commonly encountered mechanical circulation devices seen in ICU patients, including intra-aortic balloon pumps, Impella devices, extracorporeal membrane oxygenation cannulas, and ventricular assist devices. Normal appearance and commonly encountered device-related complications that can be diagnosed on imaging are reviewed.

Anaesthesia for Implantation of the Jarvik 2000 Flowmaker® LVAD

The Jarvik 2000 Flowmaker® is an intraventricular continuous axial flow left ventricular assist device. We describe the anaesthetic management and considerations for five patients with end-stage heart failure who underwent implantation of the Jarvik 2000 Flowmaker® as a bridge to transplantation or as destination therapy.

Transthyretin Cardiac Amyloidosis

PURPOSE OF REVIEW

Transthyretin (TTR)-related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive, hypertrophic heart disease and may go undiagnosed. Transthyretin-derived amyloidosis accounts for 18% of all cases of cardiac amyloidosis. Thus, the study's purpose is to provide a comprehensive review of transthyretin cardiac amyloidosis.

RECENT FINDINGS

Wild-type transthyretin (ATTRwt) protein causes cardiac amyloidosis sporadically, with 25 to 36% of the population older than 80 years of age are at risk to develop a slowly progressive, infiltrative amyloid cardiomyopathy secondary to ATTRwt. In contrast, hereditary amyloidosis (ATTRm) is an autosomal dominant inherited disease associated with more than 100 point mutations in the transthyretin gene and has a tendency to affect the heart and nervous system. Up to 4% of African-Americans carry the Val122Ile mutation in the transthyretin gene, the most prevalent cause of hereditary cardiac amyloidosis in the USA. Identifying transthyretin cardiac amyloidosis requires increased awareness of the prevalence, signs and symptoms, and diagnostic tools available for discrimination of this progressive form of cardiomyopathy associated with left ventricular hypertrophy. While there are no FDA-approved medical treatments, investigation is underway on agents to reduce circulating mutated transthyretin.

Comparison of intraplatelet reactive oxygen species, mitochondrial damage, and platelet apoptosis after implantation of three continuous flow left ventricular assist devices: HeartMate II, Jarvik 2000, and HeartWare

Differences in device design may have an effect on platelet damage and associated clinical complications. We aimed to compare device-specific platelet functionality in 26 heart failure patients supported with three continuous-flow left ventricular assist devices: HeartMate II (n = 8), Jarvik 2000 (n = 9), and HeartWare (n = 9). Intraplatelet reactive oxygen species (ROS) generation, mitochondrial damage, and platelet apoptosis were compared between device types before and after the implantation at every week up to 1 month. Overall, the baseline characteristics, demographics, routine laboratory values were comparable between the three device groups. Intraplatelet ROS, mitochondrial damage, and platelet apoptosis significantly elevated in the HeartWare group in comparison with the other two device groups after implantation. The major bleeding, infections, systemic inflammatory response syndrome, and right ventricular failure were found to be more common among the HeartWare group than others. Intraplatelet ROS and platelet damage levels were returned to baseline in both the HeartMate II and the Jarvik groups, whereas in HeartWare group they remained elevated. The patients with the Jarvik and the HeartMate II experienced less clinical complications and the platelet functionality is not compromised by these devices. Data from this study suggests that the continuous-flow left ventricular assist devices design may exert different effects on platelet function.

Minimally invasive surgical Jarvik 2000 off-pump implantation

Therapy with mechanical ventricular assist devices (VADs) in severe heart failure, open to discussion decades ago, is now well established for temporary or long-term support. The typical VAD candidate is very compromised and may not have sufficient resources to tolerate major surgical insults and trauma. Therefore, device implantation through smaller, less traumatic incisions is a desirable goal. The median sternotomy decreases lung volumes and reduces thoracic motion with a significant decrease in functional residual capacity and total lung capacity months later. Minimally invasive cardiac surgery was devised to reduce morbidity because of its potentially less inflammatory response, reduced transfusion requirements and minimal scarring with consequent rapid rehabilitation to normal life activity. Additionally, avoiding cardiopulmonary circulatory support (CPB) even for a short period might reduce the release of inflammatory cytokines and their consequences, as most CPB-related damage happens within the first few minutes. We describe the tricks and traps of minimally invasive approach during VAD implantation, by associating mini-anterior left thoracotomy in the fifth intercostal space with a mini-anterior right thoracotomy in the second intercostal space, without the aid of CPB in paravertebral block regional analgesia combined with mild general anasthesia.

Anti-inflammatory loaded poly-lactic glycolic acid nanoparticle formulations to enhance myocardial gene transfer: an in-vitro assessment of a drug/gene combination therapeutic approach for direct injection

Background

Cardiac gene therapy for heart disease is a major translational research area with potential, yet problems with safe and efficient gene transfer into cardiac muscle remain unresolved. Existing methodology to increase vector uptake include modifying the viral vector, non-viral particle encapsulation and or delivery with device systems. These advanced methods have made improvements, however fail to address the key problem of inflammation in the myocardium, which is known to reduce vector uptake and contribute to immunogenic adverse events. Here we propose an alternative method to co-deliver anti-inflammatory drugs in a controlled release polymer with gene product to improve therapeutic effects.

Methods

A robust, double emulsion production process was developed to encapsulate drugs into nanoparticles. Briefly in this proof of concept study, aspirin and prednisolone anti-inflammatory drugs were encapsulated in various poly-lactic glycolic acid polymer (PLGA) formulations. The resultant particle systems were characterized, co-delivered with GFP plasmid, and evaluated in harvested myocytes in culture for uptake.

Results

High quality nanoparticles were harvested from multiple production runs, with an average 64 ± 10 mg yield. Four distinct particle drug system combinations were characterized and evaluated in vitro: PLGA(50:50) Aspirin, PLGA(65:35) Prednisolone, PLGA(65:35) Aspirin and PLGA(50:50) Prednisolone Particles consisted of spherical shape with a narrow size distribution 265 ± 104 nm as found in scanning electron microscopy imaging. Prednisolone particles regardless of PLGA type were found on average ≈ 100 nm smaller than the aspirin types. All four groups demonstrated high zeta potential stability and re-constitution testing prior to in vitro. In vitro results demonstrated co uptake of GFP plasmid (green) and drug loaded particles (red) in culture with no incidence of toxicity.

Conclusions

Nano formulated anti-inflammatories in combination with standalone gene product therapy may offer a clinical solution to maximize cardiac gene therapy product effects while minimizing the risk of the host response in the inflammatory myocardial environment.

Currently available ventricular-assist devices: capabilities, limitations and future perspectives

The continuous progress in ventricular-assist device (VAD) technology and the management of patients with VADs has broadened the treatment options for end-stage heart failure patients. The available line-up of clinical devices provides the current optimal therapies to meet the specific needs of each patient. The extended durability, safety, efficacy and improved quality of life of the patients provides sufficient proof for the VAD to be a likely alternative therapy to heart transplantation. The sequential progress from the first-, to the second- and to the third-generation VAD technology is expected to bring increasing benefits to clinical outcomes. This article reviews the current status, capabilities, limitations and future perspectives of currently available VADs by generally classifying them via support duration, alignment of pump devices and via pulsatile or nonpulsatile mode of perfusion. Furthermore, the future direction of research and development for next-generation VADs is presented based on the lessons learned from currently available VADs.

Predictors of survival to orthotopic heart transplant in patients with light chain amyloidosis

BACKGROUND

Orthotopic heart transplant (OHT), followed by myeloablative chemotherapy and autologous stem cell transplant (ASCT), has been successful in the treatment of amyloid light-chain (AL) cardiac amyloidosis. The purpose of this study was to identify predictors of survival to OHT in patients with end-stage heart failure due to AL amyloidosis and compare post-OHT survival of cardiac amyloid patients with survival of other cardiomyopathy patients undergoing OHT.

METHODS

From January 2000 to June 2011, 31 patients with end-stage heart failure secondary to AL amyloidosis were listed for OHT at Massachusetts General Hospital. Univariate and multivariate regression analyses identified predictors of survival to OHT. Kaplan-Meier analysis compared survival between the Massachusetts General Hospital amyloidosis patients and non-amyloid cardiomyopathy patients from the Scientific Registry of Transplant Recipients (SRTR).

RESULTS

Low body mass index was the only predictor of survival to OHT in patients with end-stage heart failure caused by cardiac amyloidosis. Survival of cardiac amyloid patients who died before receiving a donor heart was only 63 ± 45 days after listing. Patients who survived to OHT received a donor organ at 53 ± 48 days after listing. Survival of AL amyloidosis patients on the waiting list was less than patients on the waiting list for all other non-amyloid diagnoses. The long-term survival of amyloid patients who underwent OHT was no different than the survival of non-amyloid, restrictive (p = 0.34), non-amyloid dilated (p = 0.34), or all non-amyloid cardiomyopathy patients (p = 0.22) in the SRTR database.

CONCLUSIONS

Amyloid patients who survive to OHT, followed by ASCT, have a survival rate similar to other cardiomyopathy patients undergoing OHT; however, 35% of the patients died awaiting OHT. The only predictor of survival to OHT in AL amyloidosis patients was a low body mass index, which correlated with a shorter time on the waiting list. To optimize the survival of these patients, access to donor organs must be improved.

Axial and centrifugal continuous-flow rotary pumps: a translation from pump mechanics to clinical practice

The recent success of continuous-flow circulatory support devices has led to the growing acceptance of these devices as a viable therapeutic option for end-stage heart failure patients who are not responsive to current pharmacologic and electrophysiologic therapies. This article defines and clarifies the major classification of these pumps as axial or centrifugal continuous-flow devices by discussing the difference in their inherent mechanics and describing how these features translate clinically to pump selection and patient management issues. Axial vs centrifugal pump and bearing design, theory of operation, hydrodynamic performance, and current vs flow relationships are discussed. A review of axial vs centrifugal physiology, pre-load and after-load sensitivity, flow pulsatility, and issues related to automatic physiologic control and suction prevention algorithms is offered. Reliability and biocompatibility of the two types of pumps are reviewed from the perspectives of mechanical wear, implant life, hemolysis, and pump deposition. Finally, a glimpse into the future of continuous-flow technologies is presented.

The spectrum of complications following left ventricular assist device placement

INTRODUCTION

Left ventricular assist device (LVAD) support is associated with many complications, but relatively few studies have examined the full spectrum of complications beyond infectious and bleeding events.

METHODS

We conducted a retrospective review of patients receiving either a pulsatile-flow Heartmate XVE (HM1; Thoratec Corp., Pleasanton, CA, USA) or continuous-flow Heartmate II (HM2; Thoratec Corp.) LVAD at our institution (June 2000 to March 2012). Frequency and date of onset of nonbleeding, noninfectious complications were examined.

RESULTS

One hundred eighty-two LVADs were implanted, 49 HM1, and 133 HM2. Support duration was longer for HM2s (median 358 vs. 112 days; p = 0.0003). Overall, the most frequent complications were respiratory failure, ventricular arrhythmia, atrial arrhythmia, right heart failure, and renal failure. Respiratory failure, arrhythmias, severe psychiatric events, and renal failure all occurred with median date of onset ≤ seven days postprocedure. Right heart failure, hepatic failure, thromboembolism, and transient ischemic attacks had a median date of onset 8 to 30 days postprocedure. Stroke, hemolysis, and device failure occurred mostly more than a month postoperatively. Right heart failure, hepatic failure, and device failure were more frequent in HM1 patients than in HM2 patients. Several events, including stroke, had much later onset in HM2 patients.

CONCLUSION

In this 10-year review of complications following LVAD implantation, the most common adverse events tended to occur early after implantation. As pulsatile-flow HM1s showed greater frequency and earlier onset of some adverse events, our data suggest better overall outcomes with the continuous-flow HM2s.

Cerebrovascular complications of left ventricular assist devices

Left ventricular assist devices (LVADs) are increasingly being used as a bridge to heart transplantation or destination therapy. It is unclear which antithrombotic regimen should be used to reduce the risk of stroke. We systematically reviewed the literature on all types of antithrombotic regimens and stroke in patients with any type of LVADs. Our primary outcome measure was the mean incidence of any type of stroke. Twenty-six articles were selected as relevant, comprehending 1989 patients with a mean LVAD support of 200 days (range 30-621). The mean proportion of patients affected with stroke was 20% (range 0-55%), with a mean incidence of 0.74 (range 0-6.91) events/patient-year. Support with HeartMate II and a regimen of postoperative heparin converted to coumarins, acetylsalicylic acid (ASA) and dipyridamole resulted in 0.17 (mean; range 0.06-0.29) strokes/patient-year. HeartMate II support and the same regime without heparin was associated with 0.07 (mean; range 0.03-0.11) strokes/patient-year. A Novacor device with heparin, converted to coumarins, was associated with 3.82 (mean; range 1.03-6.91) strokes/patient-year, while ASA added to this regime resulted in 0.97 ischaemic strokes/patient-year (mean; range 0.53-1.48). Other combinations of assist devices and antithrombotic regimes were investigated in one or two studies only. This systematic review provides risk estimates for stroke for various LVADs and antithrombotic regimes. Our findings indicate that the postoperative use of heparin in HeartMate II patients is doubtful, and suggest an important role for antiplatelet drugs to prevent stroke in patients supported with a Novacor device.

The use of computational fluid dynamics in the development of ventricular assist devices

Progress in the field of prosthetic cardiovascular devices has significantly contributed to the rapid advancements in cardiac therapy during the last four decades. The concept of mechanical circulatory assistance was established with the first successful clinical use of heart-lung machines for cardiopulmonary bypass. Since then a variety of devices have been developed to replace or assist diseased components of the cardiovascular system. Ventricular assist devices (VADs) are basically mechanical pumps designed to augment or replace the function of one or more chambers of the failing heart. Computational Fluid Dynamics (CFD) is an attractive tool in the development process of VADs, allowing numerous different designs to be characterized for their functional performance virtually, for a wide range of operating conditions, without the physical device being fabricated. However, VADs operate in a flow regime which is traditionally difficult to simulate; the transitional region at the boundary of laminar and turbulent flow. Hence different methods have been used and the best approach is debatable. In addition to these fundamental fluid dynamic issues, blood consists of biological cells. Device-induced biological complications are a serious consequence of VAD use. The complications include blood damage (haemolysis, blood cell activation), thrombosis and emboli. Patients are required to take anticoagulation medication constantly which may cause bleeding. Despite many efforts blood damage models have still not been implemented satisfactorily into numerical analysis of VADs, which severely undermines the full potential of CFD. This paper reviews the current state of the art CFD for analysis of blood pumps, including a practical critical review of the studies to date, which should help device designers choose the most appropriate methods; a summary of blood damage models and the difficulties in implementing them into CFD; and current gaps in knowledge and areas for future work.

Emergency repair of a broken Jarvik 2000 power connector using a paper-clip

The power connectors of assist devices that link the controller to the driveline are exposed to extreme mechanical stress, especially if they are implanted for permanent use. We report the case of a successful emergency repair of a power connector of a Jarvik 2000 left ventricular assist device by using a paper-clip in a patient who was supported with the device for >7 years at our institution.

Evaluation of platelet activation in patients supported by the Jarvik 2000* high-rotational speed impeller ventricular assist device

OBJECTIVE

The Jarvik 2000 (Jarvik Heart, Inc, New York, NY) is a thumb-sized high-speed impeller pump that is used as a ventricular assist device in patients with terminal heart failure. Because the Jarvik 2000 is designed for long-term use, it is a central question whether the mechanical forces inside the pump affect blood components. This study evaluated the potential association of the high rotational speed of the Jarvik 2000 with platelet activation, which may result in thromboembolic events.

METHODS

The study group comprised patients with terminal heart failure who were supported with the Jarvik 2000. All were men and received 100 mg aspirin daily. In 8 patients, soluble platelet activation markers (P-selectin and sCD40L), platelet counts, and hemolysis markers (haptoglobin and lactate dehydrogenase levels) were determined. In 5 patients, P-selectin expression and platelet receptor glycoprotein IIb/IIIa activation were determined with flow cytometry and compared with a control group of 5 healthy men. Platelet activation was measured at various rotational device speeds.

RESULTS

After Jarvik 2000 implantation, increased hemolysis was observed, but platelet activation markers and platelet counts were not affected. Increased rotational speed (8000 to 12,000 rpm) of the device also did not result in increased platelet activation.

CONCLUSION

The Jarvik 2000 was not associated with detectable platelet activation, despite high rotational impeller speeds.

Three-dimensional magnetic resonance flow analysis in a ventricular assist device

OBJECTIVE

The assessment of flow characteristics inside ventricular assist devices by magnetic resonance imaging techniques may provide insight into the mechanisms underlying the high rate of thromboembolic events after implantation of a ventricular assist device. Furthermore, these investigations may form the basis to optimize the device's design and its need for anticoagulation. The purpose of this study was to integrate a clinical routine ventricular assist device into a flow circuit with realistic geometric and pulsatile inflow conditions. Combination with flow-sensitive magnetic resonance imaging at 3 T permitted the detailed analysis of local and global 3-dimensional flow dynamics in a realistic environment.

METHODS

A commercially available ventricular assist device was integrated into a magnetic resonance-compatible flow circuit. Flow-sensitive 3-dimensional magnetic resonance imaging was performed to measure time-resolved 3-directional flow velocities in the entire device. Advanced computer-aided 3-dimensional flow visualization methods were used to derive a comprehensive picture of flow dynamics within the ventricular assist device system.

RESULTS

On the basis of the ventricular assist device model system, magnetic resonance imaging, and flow visualization, the first 4-dimensional functional magnetic resonance imaging analysis of flow characteristics inside an operating clinical routine ventricular assist device chamber system is reported. Detailed visualization of flow patterns and local changes in flow characteristics were successfully performed and revealed locally accelerated, vortical, and helical flow regions inside the geometry of the device.

CONCLUSIONS

Complex flow patterns such as vortex formation and locally accelerated flow demonstrate the potential of the presented method to further deepen the understanding of complex and regionally different flow characteristics inside ventricular assist devices.

Successful treatment of ventricular assist device associated ventricular thrombus with systemic tenecteplase

We report a case of intracardiac thrombus in a patient supported by the Jarvik 2000 Flowmaker successfully treated with a single dose of peripherally administered TNK-tissue plasminogen activator (Tenecteplase, Metalyse, Boehringer Ingelheim). This strategy may be considered in the case of life-threatening VAD associated thrombosis to avoid the need for intracardiac drug delivery or VAD replacement. We also discuss the apparent increased thrombotic risk in patients receiving a VAD for chemotherapy induced cardiomyopathy and the implications this may have for the choice of VAD.

Aortic valve surgery: what is the future?

Modern surgical treatment for aortic valve disease has undergone significant improvements in all areas of this procedure. Successful treatment strategies for cardiovascular diseases have often been initiated and driven by surgeons. Radical excision of diseased tissue, repair and replacement strategies lead to long-term successful treatment of the underlying diseases and clearly improved patient outcome. In highly developed nations, valve surgery will be increasing applied in older people, with more co-morbidities and a higher incidence of concomitant coronary artery disease. Cardiovascular surgeons will be facing increased competition from the catheter-based procedures; these are already applied clinically, and their numbers will rise in near future. Right now interventional cardiologists supported by some cardiac surgeons are on their way to transform some conventional open surgical procedures into catheter-based less invasive interventions, such as valve repair and replacement. Cardiovascular surgery is undergoing a rapid transformation; socio-economic factors and recent advances in medical technology contribute to these changes. Further developments will come, and surgeons with all their expertise in the treatment of valvular heart disease need to be part of it. Cardiovascular surgeons have to adapt the exciting new approaches of transapical and transfemoral transcatheter valve implantation techniques.

Does total implantability reduce infection with the use of a left ventricular assist device? The LionHeart experience in Europe

BACKGROUND

Infection is the leading cause of death for left ventricular assist device (LVAD) patients with end-stage heart failure. Decreased infection may be possible with fully implantable LVADs such as the LionHeart, which lacks percutaneous conduits (PCs), a common source of device-related infection (DRI). This sub-study reports infections with the LionHeart and compares these results with historic data from the REMATCH trial, bridge to recovery (BTR) and bridge-to-transplantation (BTT) studies.

METHODS

Twenty-three patients were implanted with the LionHeart LVAD and followed until death or heart transplant during a non-randomized, multicenter, European trial from October 1999 to April 2004. The nature and incidence of infection were analyzed and adjudicated to definitions similar to, or the same as, the REMATCH definitions.

RESULTS

The combined number of implant days was 7,980, with a mean of 347 days (median 112, range 17 to 1,259 days). Survival at 1 year was 39%, with 2-year survival at 22%. Seventy-four percent of patients developed one or more infections, with 30% developing sepsis, and 35% developing pump-pocket infections (PSIs). No patients developed pump-housing or inflow- or outflow-tract infections (PI). For comparison, the prevalence rates of sepsis, PSI and PI in REMATCH were 51%, 35% and 19%, respectively.

CONCLUSIONS

The patients in the European LionHeart Clinical Utility Baseline Study (CUBS) trial had less sepsis and less overall DRI compared with the REMATCH LVAD group. Therefore, the fully implanted device may cause less infection than PC devices during destination therapy (DT). Although lower for DT, these rates are still higher than for some BTT experiences. Areas for future improvement include miniaturization of controller/battery components to reduce wound complications related to pocket size, and installation of more modern lithium-ion batteries to decrease the need for re-operations due to battery end-of-life.

Clinical and cost-effectiveness of left ventricular assist devices as destination therapy for people with end-stage heart failure: A systematic review and economic evaluation

Objectives: The clinical and cost-effectiveness of left ventricular assist devices as destination therapy for people with end-stage heart failure is assessed through a systematic review and economic evaluation.

Methods: Systematic review was performed of randomized controlled trials, quasiexperimental studies, case series, and case studies identified through searching eighteen electronic databases, bibliographies, and consultation with experts and manufacturers. Studies assessed survival, functional capacity, and quality of life. Cost-effectiveness was assessed through a 5-year decision analytic model to estimate the incremental cost-effectiveness ratio for using left ventricular assist devices compared with usual care.

Results: Six studies met the inclusion criteria, showing that left ventricular assist devices appear beneficial, improving survival and quality of life. Adverse events are a serious concern. The economic evaluation showed that left ventricular assist devices had a cost per quality adjusted life year of £170,616. Sensitivity analysis showed that the cost-effectiveness was not sensitive to changes in costs or utility.

Conclusions: Although left ventricular assist devices appear clinically effective as destination therapy, it is unlikely they will be cost-effective unless costs decrease or the benefits of their use increase.

Post-transplant survival after lowering fixed pulmonary hypertension using left ventricular assist devices

OBJECTIVE

We have previously shown that fixed pulmonary hypertension in cardiac transplant candidates can be lowered using left ventricular assist devices (LVADs). The post-transplant survival of these patients is uncertain as pulmonary hypertension may reappear, possibly affecting post-transplant survival.

MATERIALS AND METHODS

Between 01/2000 and 01/2005 a total of 26 cardiac transplant candidates (92% male; mean age 56.2 years) in whom fixed pulmonary hypertension was lowered by LVAD implantation (pulmonary vascular resistance (PVR) before implantation: 5.1+/-2.8wood units (WU); PVR before cardiac transplantation: 2.0+/-.9WU) underwent cardiac transplantation at our institution. These patients were age and sex matched with 52 cardiac transplant candidates without pulmonary hypertension undergoing cardiac transplantation during the same time period. Study endpoints were peri-transplant complications and long-term survival. Mean follow-up was 36+/-14 months.

RESULTS

Peri-transplant mortality was 5% in patients after LVAD therapy and 7% in patients without prior LVAD therapy (p=.089). We observed 2 cases (4%) of acute right heart failure requiring mechanical support in patients without prior LVAD therapy. None of the patients with LVAD therapy developed peri-transplant right heart failure requiring mechanical support. Incidence of other peri-transplant complications was comparable between the two groups. Log-rank (p=.124) revealed comparable long-term survival between patients with (1 year: 85%, 2 year: 85%, 3 year: 85%) and without (1 year: 90%, 2 year 82%, 3 year prior 79%) prior LVAD therapy.

CONCLUSION

LVAD therapy lowers fixed pulmonary hypertension in cardiac transplant candidates with fixed pulmonary hypertension. Thereafter, long-term post-transplant survival is comparable to cardiac transplant recipients without pulmonary hypertension.

Left ventricular assist devices decrease fixed pulmonary hypertension in cardiac transplant candidates

OBJECTIVE

Fixed pulmonary hypertension is a contraindication for cardiac transplantation because of the increased risk of donor heart failure. We sought to determine whether left ventricular assist devices improve fixed pulmonary hypertension in cardiac transplant candidates to enable safe cardiac transplantation.

METHODS

Thirty-five consecutive cardiac transplant candidates (age 56 +/- 6 years, 88.5% were men) with fixed pulmonary hypertension (5.1 +/- 2.6 Wood units) resistant to medical treatment received a left ventricular assist device as a bridge to transplantation. Three left ventricular assist device systems were used (pulsatile blood flow: Novacor [World Heart Inc, Oakland, Calif] n = 8; continuous blood flow: MicroMed DeBakey [MicroMed Technology Inc, Houston, Tex] n = 24, DuraHeart [Terumo Heart Inc, Ann Arbor, Mich] n = 3). Right-sided heart catheter data were obtained before left ventricular assist device implantation at 3-day and 6-week follow-ups. Clinical data and complications were recorded.

RESULTS

Before left ventricular assist device implantation, the pulmonary vascular resistance was 5.1 +/- 2.8 Wood units. Values were comparable in patients receiving pulsatile (5.1 +/- 3.4 Wood units) or continuous blood flow left ventricular assist devices (5.1 +/- 2.7 Wood units, P = .976). Left ventricular assist device implantation decreased pulmonary vascular resistance at 3-day (2.9 +/- 1.3 Wood units, P < .0001) and 6-week (2.0 +/- 0.8 Wood units, P < .0001) follow-ups compared with before implantation. This effect was independent of the type of left ventricular assist device system used (3-day follow-up: pulsatile flow: 3.2 +/- 1.3 Wood units vs continuous flow: 2.7 +/- 1.2 Wood units; P = .310 and 6-week follow-up: pulsatile flow: 1.9 +/- 0.9 Wood units vs continuous flow: 2.1 +/- 0.8 Wood units; P = .905). Twenty-four patients had successful bridges to transplantation (69%, mean time on left ventricular assist device 210 +/- 83 days), and 11 patients died before transplantation (31%, mean time on left ventricular assist device 67 +/- 30 days). The 1-year survival after transplantation was 95%.

CONCLUSION

Left ventricular assist devices decrease fixed pulmonary hypertension in cardiac transplant candidates and allow patients to overcome a contraindication for cardiac transplantation. Therefore, left ventricular assist devices should be considered in all cardiac transplant candidates with fixed pulmonary hypertension.

Cardiac failure: Mechanical support strategies

OBJECTIVE

Mechanical support of the circulation is necessary when heart failure becomes refractory to medical support and is typically applied when organ dysfunction occurs as a result of hypoperfusion. However, in timing the intervention, it is important to apply mechanical support before multiple organ failure occurs. The objective of this work is to review the current strategies for mechanical circulatory support in patients with refractory cardiac failure.

DESIGN

A review of the use of mechanical circulatory support is presented for patients with refractory cardiac failure.

PATIENTS

Data are taken from human studies that were selected to best exemplify the results that may be obtained from various forms of mechanical circulatory support.

INTERVENTIONS

Commonly applied forms of mechanical support include mechanical ventilatory support, intraaortic balloon counterpulsation, and hemodialysis or ultrafiltration. If these measures fail, mechanical support of the circulation with ventricular assist devices is possible in specialized centers with expertise in the implantation and management of these devices. The decision to pursue mechanical circulatory support in the critically ill patient is based on the cause of acute decompensation, the potential reversibility of the condition, and the possibility for other treatments to improve the underlying condition or, in highly selected cases, heart transplantation. Newer forms of ventricular assistance that require less surgery are becoming available and may allow use in a broader range of critically ill patients.

MAIN RESULTS

There is a range of means to mechanically support the circulation in patients with advanced heart failure.

CONCLUSIONS

A variety of means to support the circulation have found application in the treatment of patients with refractory heart failure. More work is required to best identify populations who will benefit from the therapy and to refine the therapy to reduce associated risks.

Clinical and cost-effectiveness of left ventricular assist devices as a bridge to heart transplantation for people with end-stage heart failure: a systematic review and economic evaluation

AIMS

To evaluate the clinical and cost-effectiveness of left ventricular (LV) assist devices (LVADs) as a bridge to transplant (BTT) for people with end-stage heart failure (ESHF) through a systematic review and economic evaluation.

METHODS AND RESULTS

The systematic review and economic evaluation was conducted according to internationally recognized methods. The search strategy identified systematic reviews, randomized controlled trials, quasi-experimental studies, and observational studies evaluating the effects of LVADs on survival, functional capacity, and quality of life. Cost-effectiveness was assessed through a 5-year decision analytic model to estimate the incremental cost-effectiveness ratio of LVADs compared with usual care. Despite the poor methodological quality of the 18 studies included, LVADs appear beneficial improving survival, functional status, and quality of life. Adverse events are a serious concern. The economic evaluation showed that LVADs had a cost per quality adjusted life year of pound 65,242 (95% confidence interval pound 34,194-364,564). Sensitivity analysis showed that post-heart transplant survival gains, pre-heart transplant patient utility, and one-off costs associated with implantation determine cost-effectiveness.

CONCLUSION

Although LVADs appear clinically effective as a BTT for people with ESHF, it is unlikely that they will be cost-effective unless costs decrease or the benefits of their use increase.

Anterior Approach to Implant the Jarvik 2000 With Retroauricular Power Supply

The retroauricular power supply of the Jarvik 2000 (Jarvik Heart Inc, New York, NY) left ventricular assist device is suitable for permanent support, as it is associated with fewer infections than conventional drivelines. Implantation through a left-lateral thoracotomy limits the performance of additional cardiac procedures. We describe a technique that used a sternotomy for the implantation of the Jarvik 2000 with retroauricular power supply in two patients. The retroauricular power supply of the Jarvik 2000 can be provided with an anterior approach, allowing full surgical access to the heart. If the outflow graft to the ascending aorta indeed reduces aortic stasis and thromboembolic events, the anterior approach with retroauricular power delivery might evolve into a standard procedure.

Device Therapy in the Management of Congestive Heart Failure

Despite significant advancements in the treatment of heart failure over the past 2 decades, this patient population is still subject to considerably high morbidity and mortality rates. In recent years, the field of device therapy as adjunctive treatment to the medical management of congestive heart failure has grown in the wake of the large number of randomized trials that have demonstrated the safety and efficacy of these devices. The implantable defibrillator currently represents the standard of care in certain segments of the heart failure population, even in those without a prior arrhythmic event. Biventricular pacing systems appear to have a role in heart failure patients with prolongation of their QRS duration in improving ventricular performance and symptoms, if not mortality. Last, the shortage of organs available for orthotopic transplant has heightened interest in using ventricular-assist devices as destination therapy, and although there is evidence for the feasibility for this approach at the current time, there is a next generation of devices that appear even more promising.

Advanced heart failure: feasibility study of long-term continuous axial flow pump support

AIMS

A lack of donor hearts has stimulated interest in using blood pumps to treat severe heart failure. We tested the hypothesis that a new continuous flow circulatory assist device could be employed safely to relieve symptoms of heart failure and evaluated the potential to prolong life.

METHODS AND RESULTS

An intracardiac axial flow pump was implanted in 17 heart failure patients [idiopathic dilated (12), ischaemic (4), or amyloid cardiomyopathy (1)]. All were deemed ineligible for transplantation. Implantation of the device was by left thoracotomy (15) or median sternotomy (2). Power delivery was by a skull-mounted titanium pedestal. All patients survived surgery. None needed right ventricular support. There were three hospital deaths, two early from subdural haematoma and aortic thrombosis, one late after switching to transplantation. A total of 14 patients left hospital with a cumulative support-time of 15.9 years (median: 293 days, interquartile range: 286 days, 1-44 months). Actuarial 1-, 2-, and 3-year survivals were 56, 47, and 24%, respectively. There was no pump failure. Quality of life scores improved. Two superficial pedestal infections were successfully treated. Four patients had cerebral thrombo-embolism: two early events attributed to inadequate anticoagulation and two late with near-complete resolution. An improved anticoagulant regime addressed this problem. Late death occurred in five patients from battery disconnection, subdural haematoma, bowel ischaemia, respiratory failure, and after cardiac transplantation.

CONCLUSION

Continuous flow blood pumps provided symptomatic relief of severe heart failure with high quality of life. Event-free survival reached 4 years. Analysis of adverse events led to improved management strategies. There is potential for widespread use of blood pumps in the community. A controlled trial is required.

Quality of Life in Bridge-to-Transplant Patients With Chronic Heart Failure After Implantation of an Axial Flow Ventricular Assist Device

Research suggests that ventricular assist devices improve quality of life for congestive heart failure patients awaiting heart transplantation. Axial flow ventricular assist devices like the Jarvik 2000 (Jarvik Heart, Inc., New York, NY) represent the newest type of ventricular assist device technology, but their effects on quality of life are not well understood. Therefore, the authors administered the Minnesota Living with Heart Failure Questionnaire to patients who had the Jarvik 2000 implanted as a bridge to heart transplantation. Patients completed the Minnesota Living with Heart Failure Questionnaire immediately before device implantation, 1 month after implantation, immediately before heart transplantation, and 1 month after transplantation. One month after implantation of the device, the nine patients who completed the study showed significant improvements in physical (p<0.008), emotional (p<0.02), and overall (p<0.008) quality of life. These improvements were maintained until the device was explanted. The authors conclude that implantation of the Jarvik 2000 ventricular assist device can substantially improve quality of life for patients awaiting heart transplantation.

Clinical experience with an implantable, intracardiac, continuous flow circulatory support device: physiologic implications and their relationship to patient selection

BACKGROUND

We have been investigating continuous-flow circulatory support devices for 20 years. Unlike pulsatile assist devices, continuous-flow pumps have a simplified pumping mechanism and they do not require compliance chambers or valves. In the 1980s, clinical experience with the Hemopump proved a high-speed, intravascular, continuous-flow pump could safely augment the circulation. Subsequently, a decade of animal experiments with a larger, longer-term continuous-flow pump (the Jarvik 2000) confirmed the safety and efficacy of intraventricular placement, leading to its clinical application.

METHODS

We analyzed the physiologic and anatomic effect of using the Jarvik 2000 pump for cardiac support in 23 patients in whom the device was applied as a bridge to transplant under the protocol approved by the Food and Drug Administration Investigational Device Exemption. The device was used as a bridge to transplantation in 20 patients and as destination therapy in 3 patients.

RESULTS

In the bridge-to-transplant group, 14 patients underwent transplantation, 5 died during the circulatory support period and 1 is in an ongoing study. The support period lasted an average of 90 days. For the survivors, the follow-up period has averaged 16 months. Within the first 48 postoperative hours, the average cardiac index increased by 65% (from 1.77 +/- 0.24 to 2.92 +/- 0.60 L. min(-1). m(-2), p = 0.00000002), the systemic vascular resistance decreased by 42% (from 1604 +/- 427 to 930 +/- 330 dynes/sec per cm(2), p = 0.00001), and the pulmonary capillary wedge pressure (PCWP) decreased by 41.8% (from 23 +/- 5.1 to 13.4 +/- 6.6 mm Hg, p = 0.00009). Similar results were seen for the patients undergoing destination therapy. Cardiac index increased 89.5% (from 1.9 +/- 0.1 to 3.6 +/- 0.6, p = 0.046) and PCWP decreased by 52.2% (from 23 +/- 10 to 11 +/- 2, p = 0.22). In that group, 1 patient died unexpectedly from an accident 382 days after device implantation. The 2 survivors remain in New York Heart Association (NYHA) functional class I at 700 to 952 days after implantation.

CONCLUSIONS

The Jarvik 2000 can offer effective long-term support for patients with chronic heart failure and NYHA class IV status. However, the new physiology produced by continuous offloading of the heart throughout the cardiac cycle has introduced unique clinical problems. The understanding of the problems generated by this biotechnological interface is essential for obtaining optimal clinical outcomes.

Anesthetic Management for Implantation of the Jarvik 2000??? Left Ventricular Assist System

The Jarvik 2000 Heart(TM) is a left ventricular assist device that produces continuous nonpulsatile axial flow by means of a single, rotating, vaned impeller. Anesthetic and perioperative considerations of the Jarvik 2000 Heart(TM) differ from those of conventional assist devices. The Jarvik 2000 is implanted within the left ventricle through a left thoracotomy, which is aided by left lung isolation. A brief period of cardiopulmonary bypass and induced ventricular fibrillation facilitate implantation. Transesophageal echocardiography is essential to assure proper intraventricular positioning of the device and aortic outflow, confirmed by observation of aortic valve opening in the presence of adequate left ventricular volume. Because continuous flow devices function best in the presence of lower systemic and pulmonary vascular resistance, milrinone was preferentially used as an inotropic drug. In the first group of 10 patients to receive the Jarvik 2000, the pump provided a cardiac output of up to 8 L/min, depending on preload, afterload, and pump speed. There were no early perioperative deaths. The average support duration was 81.2 days; the range was 13-214 days. Seven of the 10 patients survived to transplantation. Survivors underwent complete physical rehabilitation during pump support.

IMPLICATIONS

The Jarvik 2000 is a left ventricular assist device that produces continuous nonpulsatile axial flow by means of a rotating, vaned impeller. Because the anesthetic considerations differ from those of conventional left ventricular assist devices, we report the perioperative management of the first 10 patients who participated in a bridge-to-transplantation feasibility study of the Jarvik 2000.

Biventricular Support with the Jarvik 2000 Axial Flow Pump: A Feasibility Study

Patients with congestive heart failure who are supported with a left ventricular assist device (LVAD) may experience right ventricular dysfunction or failure that requires support with a right ventricular assist device (RVAD). To determine the feasibility of using a clinically available axial flow ventricular assist device as an RVAD, we implanted Jarvik 2000 pumps in the left ventricle and right atrium of two Corriente crossbred calves (approximately 100 kg each) by way of a left thoracotomy and then analyzed the hemodynamic effects in the mechanically fibrillated heart at various LVAD and RVAD speeds. Right atrial implantation of the device required no modification of either the device or the surgical technique used for left ventricular implantation. Satisfactory biventricular support was achieved during fibrillation as evidenced by an increase in mean aortic pressure from 34 mm Hg with the pumps off to 78 mm Hg with the pumps generating a flow rate of 4.8 L/min. These results indicate that the Jarvik 2000 pump, which can provide chronic circulatory support and can be powered by external batteries, is a feasible option for right ventricular support after LVAD implantation and is capable of completely supporting the circulation in patients with global heart failure.

Use of the Jarvik 2000 left ventricular assist system as a bridge to heart transplantation or as destination therapy for patients with chronic heart failure

OBJECTIVE

To evaluate the Jarvik 2000 axial flow left ventricular assist system (LVAS) as a bridge to transplant and as destination therapy.

SUMMARY BACKGROUND DATA

The Jarvik 2000 LVAS was implanted in 22 patients (16 men, 6 women; mean age 53 years) as a bridge to transplant (in the United States) and in 4 patients (all men; mean age 62.8 years) as destination therapy (in the United Kingdom). All patients in both of these initial feasibility studies were in NYHA class 4.

METHODS

The pump was implanted through a thoracotomy or median sternotomy incision with the aid of partial cardiopulmonary bypass in bridge-to-transplant patients. A skull-mounted percutaneous power delivery was used for the patients who received the pump as destination therapy.

RESULTS

Of the 22 bridge-to-transplant patients, 13 underwent transplant; 7 died during support; and 2 studies are ongoing. The surviving patients have an average follow-up of 15 months; one died at 2.6 months after transplant, and the remaining patients are all in NYHA class 1. Support averaged 67.1 days. Deaths were due to acute myocardial infarction in two patients and multiorgan failure in five patients. Hemodynamic function improved with LVAS support. The average cardiac index increased 70.6% by 48 hours after implant, pulmonary capillary wedge pressure decreased 44%, systemic vascular resistance decreased significantly, and inotropic support became unnecessary. Similar results have been seen in the patients who received the device as destination therapy. In that series, one patient died of subdural hematoma 380 days after implant. The other two patients are in NYHA class 1, 642 and 889 days after implant. The average cardiac index increased 89.5%, and pulmonary capillary wedge decreased 52.2%.

CONCLUSIONS

The Jarvik 2000 axial-flow LVAS can be used safely in selected patients to provide support until transplant or as destination therapy. In this series, the patients who most benefited from this device were those who required true left ventricular assistance rather than total capture of left ventricular output. Current experience indicates that continuous offloading of the ventricle is most effective when there is enough residual myocardial function to maintain pulsatility and aortic root ejection and to maintain, with nonpulsatile pump support, a normal cardiac index as well as reinstitution of the Frank-Starling response to the native ventricle.