Myocardial Recovery Strategy with Decommissioning for the HeartWare Left Ventricular Assist Device

Deactivation of LVAD support for myocardial recovery-surgical perspectives

Left ventricular assist devices (LVADs) are excellent therapies for advanced heart failure patients either bridged to transplant or for lifetime use. LVADs also allow for reverse remodeling of the failing heart that is often associated with functional improvement. Indeed, growing enthusiasm exists to better understand this population of patients, whereby the LVAD is used as an adjunct to mediate myocardial recovery. When patients achieve benchmarks suggesting that they no longer need LVAD support, questions related to the discontinuation of LVAD therapy become front and center. The purpose of this review is to provide a surgical perspective on the practical and technical issues surrounding LVAD deactivation.

Advanced Heart Failure: Therapeutic Options and Challenges in the Evolving Field of Left Ventricular Assist Devices

Heart Failure is a chronic and progressively deteriorating syndrome that has reached epidemic proportions worldwide. Improved outcomes have been achieved with novel drugs and devices. However, the number of patients refractory to conventional medical therapy is growing. These advanced heart failure patients suffer from severe symptoms and frequent hospitalizations and have a dismal prognosis, with a significant socioeconomic burden in health care systems. Patients in this group may be eligible for advanced heart failure therapies, including heart transplantation and chronic mechanical circulatory support with left ventricular assist devices (LVADs). Heart transplantation remains the treatment of choice for eligible candidates, but the number of transplants worldwide has reached a plateau and is limited by the shortage of donor organs and prolonged wait times. Therefore, LVADs have emerged as an effective and durable form of therapy, and they are currently being used as a bridge to heart transplant, destination lifetime therapy, and cardiac recovery in selected patients. Although this field is evolving rapidly, LVADs are not free of complications, making appropriate patient selection and management by experienced centers imperative for successful therapy. Here, we review current LVAD technology, indications for durable MCS therapy, and strategies for timely referral to advanced heart failure centers before irreversible end-organ abnormalities.

A Peek at LVADs Pumping to Recovery

Left ventricular assist devices (LVADs) have revolutionized the management of patients with advanced heart failure refractory to medical therapy. Current indications of LVADs include Bridge to Transplantation (BTT), Destination Therapy (DT) for long-term use, Bridge to the Decision (BTD) used as a temporary measure, and lastly Bridge to Recovery (BTR). Here, we briefly review the clinical evidence and the molecular mechanisms behind myocardial recovery following LVAD placement. We also share institutional protocols used at 2 major medical centers in the USA.

Clinical myocardial recovery in advanced heart failure with long term left ventricular assist device support

Left ventricular assist-device (LVAD) implantation is a life-saving therapy for patients with advanced heart failure (HF). With chronic unloading and circulatory support, LVAD-supported hearts often show significant reverse remodeling at the structural, cellular and molecular level. However, translation of these changes into meaningful cardiac recovery allowing LVAD explant is lagging. Part of the reason for this discrepancy is lack of anticipation and hence promotion and evaluation for recovery post LVAD implant. There is additional uncertainty about the long-term course of HF following LVAD explant. In selected patients, however, guided by the etiology of HF, duration of disease and other clinical factors, significant functional improvement and LVAD explantation with long-term freedom from recurrent HF events has been demonstrated to be feasible in a reproducible manner. The identified predictors of myocardial recovery suggest that the elective therapeutic use of potentially less invasive VADs for reversal of HF earlier in the disease process is a future goal that warrants further investigation. Hence, it is prudent to develop and implement tools to predict HF reversibility prior to LVAD implant, optimize unloading-promoted recovery with guideline directed medical therapy and monitor for myocardial improvement. This review article summarizes the clinical aspects of myocardial recovery and together with its companion review article focused on the biological aspects of recovery, they aim to provide a useful framework for clinicians and investigators.

Percutaneous Decommissioning of a Left Ventricular Assist Device in a Patient With Myocardial Recovery

A 37-year-old man was referred for consideration of percutaneous decommissioning of a left ventricular assist device (LVAD). Following careful hemodynamic monitoring during pump turn-down and temporary outflow graft occlusion, the LVAD was permanently decommissioned by using a vascular plug to induce thrombosis of the outflow graft. (Level of Difficulty: Advanced.)

LVAD decommissioning for myocardial recovery: Long-term ventricular remodeling and adverse events

BACKGROUND

Left ventricular assist devices (LVADs) mechanically unload the heart and coupled with neurohormonal therapy can promote reverse cardiac remodeling and myocardial recovery. Minimally invasive LVAD decommissioning with the device left in place has been reported to be safe over short-term follow-up. Whether device retention reduces long-term safety, or sustainability of recovery is unknown.

METHODS

This is a dual-center retrospective analysis of patients who had achieved responder status (left ventricular ejection fraction, LVEF ≥40% and left ventricular internal diastolic diameter, LVIDd ≤6.0 cm) and underwent elective LVAD decommissioning for myocardial recovery from May 2010 to January 2020. All patients had outflow graft closure and driveline resection with the LVAD left in place. Emergent LVAD decommissioning for an infection or device thrombosis was excluded. Patients were followed with serial echocardiography for up to 3-years. The primary clinical outcome was survival free of heart failure hospitalization, LVAD reimplantation, or transplant.

RESULTS

During the study period 515 patients received an LVAD and 29 (5.6%) achieved myocardial recovery, 12 patients underwent total device explantation or urgent device decommissioning, 17 patients underwent elective LVAD decommissioning, and were included in the analysis. Median age of patients at LVAD implantation was 42 years (interquartile range, IQR: 25-54 years), all had a nonischemic cardiomyopathy, and 5 (29%) were female. At LVAD implantation, median LVEF was 10% (IQR: 5%-15%), and LVIDd 6.6 cm (IQR: 5.8-7.1 cm). There were 11 hydrodynamically levitated centrifugal-flow (65%), and 6 axial-flow LVADs (35%). The median duration of LVAD support before decommissioning was 28.7 months (range 13.5-36.2 months). As compared to the turndown study parameters, 1-month post-decommissioning, median LVEF decreased from 55% to 48% (p = 0.03), and LVIDd increased from 4.8 cm to 5.2 cm (p = 0.10). There was gradual remodeling until 6 months, after which there was no statistical difference on follow-up through 3-years (LVEF 42%, LVIDd 5.6 cm). Recurrent infections affected 41% of patients leading to 3 deaths and 1 complete device explant. Recurrent HF occurred in 1 patient who required a transplant. Probability of survival free of HF, LVAD, or transplant was 94% at 1-year, and 78% at 3-years.

CONCLUSIONS

LVAD decommissioning for myocardial recovery was associated with excellent long-term survival free from recurrent heart failure and preservation of ventricular size and function up to 3-years. Reducing the risk of recurrent infections, remains an important therapeutic goal for this management strategy.

Antiplatelet and Anticoagulant Strategies Following Left Ventricular Assist Device (LVAD) Explantation or Decommissioning: A Scoping Review of the Literature

Mechanical circulatory support using left ventricular assist devices (LVADs) has transformed management of patients with end-stage heart failure with more patients on LVAD therapy surviving long enough to necessitate either device explantation or decommissioning. Usually, there is foreign material retained following these procedures that requires maintaining antiplatelet and/or anticoagulant therapy. However, there is no consensus on optimal management of antiplatelet and anticoagulant therapy following LVAD explantation or decommissioning. We conducted a scoping review of antiplatelet and anticoagulation strategies, searching EMBASE, PubMed and CENTRAL. A total of 15 case reports and series encompassing 38 patient cases were found that met inclusion criteria. There was a heterogeneity of LVAD types and techniques used for explantation and decommissioning. Most reports identified in our review maintained patients on a vitamin K antagonist for at least 3 months post-explantation or decommissioning with or without concomitant antiplatelet therapy with low-dose aspirin. However, there was no single agreed-upon optimal strategy for antiplatelet and anticoagulant use post-procedure. Factors such as the degree of foreign material retained following device explantation or decommissioning and whether there is another indication for anticoagulation or antiplatelet use must be considered. A lack of overall consensus indicates that more studies are needed in this area to establish definitive guidelines around antiplatelet and anticoagulant therapy following LVAD explantation or decommissioning.

Echocardiographic Assessment of Left Ventricular Assist Device Outflow Velocity During Percutaneous Decommissioning

Left ventricular assist devices (LVADs) have been used as an effective therapeutic option in patients with advanced heart failure, either as a bridge to transplantation or, in some patients, as a bridge to recovery. LVAD withdrawal with ventricular recovery represents the optimal outcome for patients previously implanted with an LVAD. In this E-Challenge, the authors present a case of percutaneous decommissioning of an LVAD, in which TEE provided critical, real-time perioperative evaluation. The authors also review the current perspectives on LVAD decommissioning in terms of patient selection and surgical techniques.

HeartWare Explant After Recovery 6 Years After Implant in a 3-Year-Old Child: Has the Game Changed?

The use of continuous-flow mechanical circulatory support in preschool children remains anecdotal. This case report describes the sequel to the implantation with a HeartWare HVAD system (Medtronic, Minneapolis, MN) in a 3-year old child. A 3-year-old boy with myocarditis-related cardiomyopathy underwent implantation with a HeartWare device. After an uncomplicated postoperative course, the patient was discharged home. Serial echocardiography showed progressive left ventricular recovery. After 6 months, the device was decommissioned, and the outflow graft was tied off. Six years after insertion, the device was explanted uneventfully. The HeartWare ventricular assist device offers viable long-term mechanical circulatory support in selected children that results in sustainable care and good quality of life.

A Minimally Invasive Approach to Left Ventricular Assist Device Insertion Facilitates Subsequent Explant

A minimally invasive approach to left ventricular assist device (LVAD) insertion may benefit patients at the time of implant, but whether the approach to LVAD insertion influences the outcome of subsequent cardiovascular reoperations is unknown. Here we present the case of a 50-year-old male who underwent LVAD insertion through a minimally invasive approach and subsequently had left ventricular recovery. LVAD explant was performed without the use of any blood products or inotropic support. This case demonstrates that a minimally invasive approach to LVAD insertion may also facilitate subsequent device explant.

Initial conservative management strategy of HeartWare left ventricular assist device thrombosis with intravenous heparin or bivalirudin

Introduction and objectives:

Pump thrombosis is a serious left ventricular assist device complication, though there are no guidelines regarding its treatment. The main aim of this study was to describe a strategy of intravenous anticoagulation as the initial treatment in these patients and then to compare intravenous heparin with bivalirudin.

Methods:

All consecutive patients who received a HeartWare left ventricular assist device from July 2009 to March 2019 were retrospectively analysed. Patients developing a pump thrombosis were selected, and treatment, outcomes and complications were recorded.

Results:

During this period of time (116 months), 220 patients underwent HeartWare left ventricular assist device implantation and 57 developed pump thrombosis, with an incidence rate of first pump thrombosis of 0.17 events per patient-year of support (incidence rate of all episodes of pump thrombosis: 0.30 events per patient-year of support). All the patients were initially treated medically, predominantly with either intravenous heparin (n = 26) or bivalirudin (n = 16). Patients treated with bivalirudin during the first pump thrombosis episode had less subsequent re-thrombosis episodes (18.7% vs 57.7%, p < 0.05). In addition, percentage time in therapeutic range was greater for bivalirudin compared with heparin (68.5% ± 16.9% vs 37.4% ± 31.0%, p < 0.01). During the first pump thrombosis episode, 26.3% of the patients needed surgery (left ventricular assist device exchange (n = 8), transplant (n = 6) or decommissioning (n = 1)). The overall survival at 1 year was 61.4%, and there was no significant difference in survival.

Conclusion:

Left ventricular assist device thrombosis is a serious life-threatening complication; hence, we propose an initial conservative management of pump thrombosis with enhanced intravenous anticoagulation with either intravenous heparin or bivalirudin, with surgery reserved for refractory cases.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Chest radiographs of cardiac devices (Part 2): Ventricular assist devices

Heart failure is considered a worldwide pandemic affecting 26 million people globally. Patients who are unfit or waiting for cardiac transplantation may benefit from alternate mechanical support therapies using ventricular assist devices. It is not uncommon for radiologists, especially those working in institutions with a high volume of cardiac transplantations, to be presented with radiographs containing these devices. The role of the radiologist is not only to accurately identify these devices, but also to evaluate for any complications.

Outcomes from a recovery protocol for patients with continuous-flow left ventricular assist devices

BACKGROUND

In this retrospective analysis we evaluated a standardized echocardiographic assessment and an invasive technique for patient selection for successful continuous-flow left ventricular assist device (CF-LVAD) explantation.

METHODS

Inclusion criteria for LVAD recovery assessment were: clinically stable condition; LVAD support for >6 months; physical activity; normal echocardiography findings; and no more than mild valvular disease and aortic valve opening. In a second step, echocardiography was performed under CF-LVAD reduction and stop conditions (PStopE). In the third step, patients who presented with stable parameters underwent right heart catheterization under CF-LVAD stoppage and occlusion of the outflow graft with a balloon catheter. Criteria for explantation were normal pulmonary artery pressure and pulmonary capillary wedge pressure <16 mmHg.

RESULTS

Thirty-three of 424 patients entered the second step of evaluation and 20 entered the third step. Fourteen presented positive results and the pump was successfully explanted. The PCWP at baseline was 8.5 (2.8) mmHg in the explantation group and 10.6 (2.8) mmHg in the non-explantation group (p = 0.105). It increased to 10.9 (3.0) mmHg vs 20.8 (4.9) mmHg under outflow graft occlusion. The wedge pressure was significantly higher in the non-explantation group (p < 0.001). Median duration of follow-up after explantation was 9.74 (interquartile range 4.3 to 20.60) months, with survival of 93%.

CONCLUSIONS

The protocol presented is feasible and safe. The criteria applied provide good patient selection for sustained mid-term myocardial recovery after LVAD explantation.

Left ventricular assist device for ventricular recovery of anabolic steroid-induced cardiomyopathy

Herein we report a case of a 26-year-old gentleman with severe cardiomyopathy likely secondary to anabolic-androgenic steroid (AAS) abuse who received a HeartMate II (Abbott Laboratories, Abbott Park, IL) left ventricular assist device (LVAD) for rapidly deteriorating heart failure with hemodynamic compromise. Following 18 months on LVAD support, excellent recovery of ventricular function was achieved to allow for LVAD discontinuation. Given that active substance abuse is a contraindication to heart transplantation, few options remain for patients with AAS induced heart failure. Our case demonstrates that LVAD therapy can be an important intervention for bridging to candidacy, recovery or destination therapy.

Construction of an Apical Plug for Explantation of HeartWare HVAD Left Ventricular Assist Device

Utilization of a left ventricular assist device as a bridge to myocardial recovery is an established therapy for acute systolic heart failure. However, device removal can present a technical challenge, with no clear consensus on preferred method. In this case report, we describe a complex patient who underwent successful explantation of a left ventricular assist device using an intraoperatively constructed apical plug. This method utilizes inexpensive and easily accessible materials, minimizes ventricular distortion during device removal, and preserves the ventricular sewing ring for future reimplantation.