Left ventricular assist device exchange for the treatment of HeartMate II pump thrombosis

Nine Years of Continuous Flow LVAD (HeartMate 3): Survival and LVAD-Related Complications before and after Hospital Discharge

BACKGROUND

End-stage heart failure is associated with high mortality. Recent developments such as the left ventricular assist device (LVAD) have improved patient outcomes. The HeartMate 3 LVAD is a novel centrifugal pump that was developed to provide hemodynamic support in heart failure patients, either as a bridge-to-transplant (BTT), myocardial recovery, or destination therapy (DT). Our objective was to evaluate the survival rates and LVAD-related complications of the HeartMate 3 LVAD before and after hospital discharge in our center.

METHODS

We retrospectively reviewed all patients implanted with the HeartMate 3 LVAD in our institute between September 2015 and June 2024. Patients who received a Heart Ware Ventricular Assist Device (HVAD) and HeartMate 2 LVAD devices were excluded. The primary endpoint was survival before and after hospital discharge. The secondary endpoints included an incidence of serious LVAD adverse events (bleeding, major infection, hemolysis, device thrombosis and malfunction, and neurological dysfunction) and the causes of re-admission along the follow-up period.

RESULTS

A total of 48 consecutive HeartMate 3 LVAD patients were enrolled in this study. The mean age was 56.1 ± 10.6 years. A total of 72.9% of patients received LVAD therapy as a BTT, 14.6% as DT, 10.4% as a bridge-to-decision, and 2.1% as a bridge-to-recovery. A total of 85.4% of patients were discharged after implantation. The main cause for in-hospital mortality was right ventricular failure (8.3%), followed by stroke, abdominal bleeding, and multi-organ failure (2.1% each). One patient (2.1%) had successful heart transplantation, 26 patients (63.4%) are still on LVAD support, and 11 (26.8%) patients have died during follow-up. The main cause of mortality after hospital discharge was sepsis, which occurred in 9.8% of patients, followed by right ventricular failure, non-LVAD-related causes, unknown causes with two (4.9%) cases each, and one case of fatal stroke (2.4%). During the follow-up, there was no need for LVAD replacement.

CONCLUSIONS

HeartMate 3 LVAD is associated with excellent in-hospital survival rates in patients with end-stage heart failure. Right ventricular failure was the main cause of death before hospital discharge, whereas sepsis was the main cause of death after hospital discharge.

Repeat left ventricular-assisted device exchange and upgrade from second- to third-generation devices in a high-volume single center

BACKGROUND

Pump exchange is an established strategy to treat LVAD-related complications such as thrombosis, infection, and driveline failure. Pump upgrades with an exchange to newer generation devices are being performed to the advantage of the patient on long-term support. The safety and efficacy of a repeat LVAD exchange with a concomitant upgrade to a third-generation pump have not been reported.

METHODS

We performed a retrospective analysis of all consecutive patients who underwent a repeat LVAD device exchange and upgrade to HeartMate III (HMIII) at Houston Methodist Hospital between December 2018 and December 2020.

RESULTS

Five patients underwent exchange and upgrade to HMIII within the specified timeframe. Four patients had already had two prior exchanges (all HMII to HMII), and one patient had one prior exchange (HVAD to HVAD). In all cases, implantation was performed as destination therapy. The surgical exchange was performed via redo median sternotomy on full cardiopulmonary bypass. No unplanned redo surgery of the device component was required. In-hospital mortality was 20% in this very high-risk population. At 1-, 3-, and 6-month follow-up, all discharged patients were on HMIII support, with no major LVAD-related adverse events reported.

CONCLUSION

We report the feasibility and safety of a repeat pump exchange with an upgrade to HMIII in a high-volume center. The decision for medical therapy versus surgical exchange has to be tailored to individual cases based on risk factors and clinical stability but in expert hands, even a re-redo surgical approach grants options for good medium-term outcomes.

Decommission of a Heartmate 3 LVAD in a patient with left ventricular recovery

BACKGROUND

Left ventricular assist devices (LVADs) have been a significant development in the treatment of patients with advanced heart failure supporting circulation as a bridge to transplant, recovery, or long-term destination therapy. When ventricular recovery occurs, there are multiple described ways of proceeding. HM2 decommissions are well described with varying degrees of explant operations, less so in HM3 due to the novelty of the device. In certain situations, invasive surgery can carry high risk and so a minimally invasive decommission, leaving the LVAD essentially intact in situ can be considered.

CASE REPORT

In this report, we describe the case of a 35-year-old male diagnosed with an idiopathic dilated cardiomyopathy requiring an LVAD with subsequent identification of cardiac recovery with the asymptomatic thrombosis of the second HM3 device. Investigations demonstrated absent flow through the pump whilst the patient-reported NYHA I functional class symptoms. The Driveline was cut with the remaining internal pump components decommissioned and left in situ. At 1 year, the patient continues to do well with continued features of cardiac recovery with an LVEF of over 40%.

CONCLUSION

LV recovery is well recognized with typical management being LVAD explant surgeries performed. Each case should be analyzed for risks and benefits to the patient and future research showed be directed towards levels of decommissioning surgery and management post-LVAD decommission patient care.

Infection following CF-LVAD exchange for non-infectious indications: A systematic review and meta-analysis

Introduction:

Patients on continuous flow left ventricular assist devices (CF-LVADs) often require CF-LVAD exchange. The purpose of this study was to investigate the incidence of infection following CF-LVAD exchange performed for non-infectious indications.

Methods:

An electronic literature search was performed to identify all studies of patients undergoing CF-LVAD exchange for pump thrombosis or device malfunction. Of 2,698 articles identified, 6 studies with 81 total patients met the inclusion criteria. Cohort-level data were pooled for meta-analysis.

Results:

Mean patient age was 60 years (95% CI: 41–78), and 74% were male (95% CI: 61–84). Pump thrombosis was the most common indication for exchange in 70% of patients (95% CI: 47–86). Other indications were driveline fracture and electrical malfunction in 21% (95% CI: 5–56) and 12% (95% CI: 4–33) of patients, respectively. Prior to exchange, 95% of patients were on HeartMate II (HM2) LVADs (95% CI: 86–98) and average duration of support for these patients was 27.1 months (95% CI: 9.3–44.8). The majority were placed on a HM2 following exchange (88% (95% CI: 45–98)) versus HM3 (12% (95% CI: 2–55)). Follow-up was an average of 16.4 months (95% CI: 6.8–26.0). Following exchange, 16 of 81 patients developed infection, with pooled mean incidence of 24% (95% CI: 14–38). 30-day mortality was 14% (95% CI: 7–26). Survival at follow-up was 65% (95% CI: 52–76).

Conclusions:

Infection following CF-LVAD exchange can occur at rates higher than those observed with primary implantation; therefore, effective strategies need to implemented early and consistently to help lower infections rates and help improve outcomes following exchange.

Interventional Microbubble Enhanced Sonothrombolysis on Left Ventricular Assist Devices

The left ventricular assist device (LVAD) is often used in the treatment of heart failure. However, 4% to 9% implanted LVAD will have thrombosis problem in one year, which is fatal to the patient's life. In this work, an interventional sonothrombolysis (IST) method is developed to realize the thrombolysis on LVAD. A pair of ultrasound transducer rings is installed on the shell of LVAD, and drug-loaded microbubbles are injected into the LVAD through the interventional method. The microbubbles are adhere on the thrombus with the coated thrombus-targeted drugs, and the thrombolytic drugs carried by the bubbles are brought into the thrombus by the cavitation of bubbles under the ultrasound. In a proof-of-concept experiment in a live sheep model, the thrombus on LVAD is dissolved in 30 min, without damages on LVADs and organs. This IST exhibits to be more efficient and safer compared with other thrombolysis methods on LVAD.

Diagnostic and surgical management of HeartMate 3 outflow graft obstruction due to two different mechanisms

Outflow graft obstruction is a potentially catastrophic complication of left ventricular assist devices that may occur secondary to different mechanisms. Two cases of Heartmate 3 outflow graft obstruction associated with two different pathophysiological mechanisms are presented. The first one was a 70-year-old man who developed outflow graft obstruction secondary to kinking. The second case was a 72-year-old man who presented with signs and symptoms of heart failure due to outflow graft extrinsic obstruction. Both cases were diagnosed with 3D-CT scan and successfully surgically treated.

Six-month outcomes in postapproval HeartMate3 patients: A single-center US experience

BACKGROUND

The European CE Mark approval study and the MOMENTUM 3 trial demonstrated safety and a reduction in hemocompatibility-related adverse events with the use of HeartMate 3 (HM3) device. This single-center study investigated the real-world experience in HM3 patients since FDA approval.

METHODS

This retrospective, observational study included patients implanted with the HM3 LVAD as a primary implant between October 2017 and March 2020. Patients were divided into trial group and postapproval group. The primary endpoint was survival at 6 months. Secondary endpoints were adverse events including pump thrombosis (requiring pump exchange), stroke, renal failure, acute limb ischemia, re-exploratory for bleeding, gastrointestinal bleeding, right ventricular failure, and driveline infection.

RESULTS

A total of 189 patients were implanted with HM3 device during the study period. 174 patients met the inclusion criteria: 82 patients in the trial group and 92 patients in the postapproval group. The postapproval group had younger patients, higher preoperative mean international normalized ratio, and greater numbers of patients with bridge to transplant (BTT) indications, IINTERMACS profile 1, and use of mechanical assist devices (other than IABP) than the trial group. Other characteristics between the two groups were comparable. Overall survival at 6 months in the postapproval group was 93.3% versus 93.8% (p = .88). The postapproval group demonstrated a statistically significant lower incidence of re-explorative surgery for bleeding (10.9% vs. 46.3, p = .01) than the trial group.

CONCLUSION

In this single-center study, the real-world 6-month survival in the postapproval group was comparable to the trial results. Further studies are needed to monitor long-term outcomes.

Continuous-flow left ventricular assist device: Current knowledge, complications, and future directions

Long-term continuous-flow left ventricular assist devices have become a real alternative to heart transplantation in patients with advanced heart failure, achieving a promising 2-year event-free survival rate with new-generation devices. Currently, this technology has spread throughout the world, and any cardiologist or cardiac surgeon should be familiar with its fundamentals and its possible complications as well as the advances made in recent years. The aim of this review is to describe current knowledge, management of complications, and future directions of this novel heart-failure therapy.

Shear-Mediated Platelet Activation is Accompanied by Unique Alterations in Platelet Release of Lipids

INTRODUCTION

Platelet activation by mechanical means such as shear stress exposure, is a vital driver of thrombotic risk in implantable blood-contacting devices used in the treatment of heart failure. Lipids are essential in platelets activation and have been studied following biochemical activation. However, little is known regarding lipid alterations occurring with mechanical shear-mediated platelet activation.

METHODS

Here, we determined if shear-activation of platelets induced lipidome changes that differ from those associated with biochemically-mediated platelet activation. We performed high-resolution lipidomic analysis on purified platelets from four healthy human donors. For each donor, we compared the lipidome of platelets that were non-activated or activated by shear, ADP, or thrombin treatment.

RESULTS

We found that shear activation altered cell-associated lipids and led to the release of lipids into the extracellular environment. Shear-activated platelets released 21 phospholipids and sphingomyelins at levels statistically higher than platelets activated by biochemical stimulation.

CONCLUSIONS

We conclude that shear-mediated activation of platelets alters the basal platelet lipidome. Further, these alterations differ and are unique in comparison to the lipidome of biochemically activated platelets. Many of the released phospholipids contained an arachidonic acid tail or were phosphatidylserine lipids, which have known procoagulant properties. Our findings suggest that lipids released by shear-activated platelets may contribute to altered thrombosis in patients with implanted cardiovascular therapeutic devices.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12195-021-00692-x.

Three year follow-up after less-invasive Left Ventricular Assist Device exchange to HeartMate 3

BACKGROUND

Device exchange to a newer generation left ventricular assist device (LVAD) offers the opportunity to benefit from improved adverse events profiles. We present the three year results of a patient cohort undergoing VAD upgrades to a new generation device focusing on outcomes and adverse events.

METHODS

We present the first series of patients who underwent LVAD upgrade to HeartMate 3. All operations were performed less invasively. Follow-up time was three years after LVAD exchange.

RESULTS

Overall four HeartMate II and two HVAD patients underwent LVAD upgrade. In five cases severe infection of the VAD led to device exchange (83%, 5/6). Three year survival after LVAD exchange was 100% (6/6). In the follow-up examinations one patient showed a single syncope and several low flow alarms (1/6). The remaining five patients showed no technical malfunctions of the LVAD or hemodynamic adverse events (5/6). Four out of five patients whose devices had to be changed due to an infection suffered a local re-infection (4/5), which, however, did not require any further surgical intervention. Four patients were successfully transplanted and two patients were still on device support at three years after LVAD exchange.

CONCLUSIONS

Three-year outcomes and adverse events after LVAD exchange to HeartMate 3 show excellent results. The superior hemocompatibility in terms of pump thrombosis makes the HM3 a favored choice in case of LVAD exchange due previous pump thrombosis. However, in cases of exchange due to device infection the risk of reinfection remains high.

Continuous-flow LVAD exchange to a different pump model: Systematic review and meta-analysis of the outcomes

Despite improved outcomes of modern continuous-flow left ventricular assist devices (CF-LVADs), device exchange is still needed for various indications. While the majority of CF-LVADs are exchanged to the same model, exchange to a different pump model is occasionally warranted. In this meta-analysis, we sought to consolidate the existing evidence to better elucidate the indications and outcomes in these cases. A comprehensive systematic search of adult patient cohorts who underwent CF-LVAD exchange to a different CF-LVAD model was performed. Study-level data from 10 studies comprising 98 patients were extracted and pooled for analysis. Mean patient age was 58 (95% CI: 48-65) and 81% were male. Indication for initial CF-LVAD was ischemic cardiomyopathy in 45% (34-57). Initial device was HeartMate II LVAD (HMII) in 93 (94.9%) and HeartWare HVAD (HW) in 5 (5.1%) patients. After mean CF-LVAD support time of 18.8 (15.2-22.4) months, exchange indications included thrombosis in 71% (43-89), infection in 21% (8-47) and device malfunction in 12% (7-21). HMII to HW exchange occurred in 53 (54.1%) patients, HMII to HeartMate III (HM3) in 32 (32.7%), and HM II to either HW or HM3 in 13 (13.2%) patients. Postoperatively, right ventricular assist device was required in 16% (8-32). Overall, 20% (8-40) of patients experienced a stroke, while HW patients had a significantly higher stroke incidence than HM3 patients (HW: 21% (8-47) vs. HM3: 5% (1-24), P < .01). Overall 30-day mortality was 10% (6-17), while HW had a significantly worse 30-day mortality than HM3 (HW: 13% (7-24) vs. HM3: 5% (1-24), P = .03). Following device exchange from a different CF-LVAD model, HM3 is associated with lower stroke and higher survival when compared to HW.

Minimally invasive left ventricular assist device implantation: optimizing device design for this approach

Introduction: The global heart failure (HF) burden is expected to increase due to aging populations, increasing number of end-stage HF patients and adverse lifestyle changes. Mechanical circulatory support (MCS) devices such as left ventricular assist devices (LVADs) have become a promising treatment option for short-term and long-term circulatory support of end-stage HF patients.Areas covered: Recent developments in MCS technology have been focused on miniaturization leading to the development of minimally invasive surgical procedures for LVAD implantation. This helps overcome possible postoperative complications such as major incisions and poor outcomes due to infections, right heart failure, and bleeding. This article discusses clinical and technological developments in the field of minimally invasive procedures for LVAD implantation.Expert opinion: Most patients might benefit from minimally invasive LVAD implantation performed through a limited left lateral thoracotomy associated with an upper hemisternotomy or a right anterior thoracotomy. The thoracotomy approach can also be considered in case of pump exchange or pump explant. The success of these techniques is mainly based on the optimization of LVAD pump design, inflow cannula insertion, and outflow graft as well as driveline exit sites. The future direction of the LVAD field is likely to include less-invasive approaches and smartificial technologies.

HeartMate 3 pump exchange via sternal-sparing bilateral minithoracotomies

As median survival for left ventricular assist device (LVAD) patients increases, the incidence of adverse events requiring device exchange is likely to increase as well. Less invasive surgical approaches for device exchange of older generation pumps have demonstrated multiple potential benefits compared with median sternotomy. However, there remains a paucity of data in regard to less invasive surgical techniques for the exchange of the newest generation intrapericardial devices. In this report we describe a complete sternal-sparing technique for the LVAD exchange of a HeartMate 3 via bilateral minithoracotomies.

Early outcomes with durable left ventricular assist device replacement using the HeartMate 3

BACKGROUND

The HeartMate 3 (HM3) left ventricular assist device (LVAD) (Abbott, Inc, Chicago, Ill) is a fully magnetically levitated centrifugal implantable pump used to treat patients with chronic heart failure. The MOMENTUM (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) trial demonstrated that patients treated with the HM3 experienced reduced need for reoperation for LVAD replacement compared with a control group receiving an axial flow design, Heartmate II (Abbott, Inc). However, there are few reports of using HM3 as the replacement pump in patients who already are supported by a durable LVAD and experience a device-related complication necessitating replacement.

METHODS

An institutional LVAD database was used to identify 19 consecutive patients who underwent pump replacement to HM3 (group 1) versus 85 consecutive control patients who underwent pump replacement to either Heartmate II or HeartWare Ventricular Assist Device (Medtronic Inc, Minneapolis, Minn) (group 2), at a single institution from January 2010 to August 2018. Patient baseline characteristic and outcomes were obtained from a prospectively maintained database. The primary endpoint was a composite of freedom from death or need for another replacement surgery.

RESULTS

There was no difference between the groups in heart failure etiology, indication for replacement, as well as the average days on the previous pump or the type of previous pump. The HM3 group did have a significantly greater body mass index (37 vs 31.6 P = .01), a greater number of previous LVAD implants (36.8% vs 5.9%, had 2 previous LVADs, P < .001), and a greater number of previous sternotomies (31.6% vs 7.1%, had 3 previous sternotomies, P = .001). No difference was found between the groups in terms of postoperative adverse event rates. With regards to the primary endpoint, the patients with HM3 replacements (group 1) versus group 2 experienced significantly greater freedom from either death or need for another replacement during the follow-up period (P = .039). During follow-up, there were no thrombosis events for the patients who received replacement with HM3.

CONCLUSIONS

LVAD replacement with HM3 can be performed safely and may be considered as the pump of choice in patients requiring LVAD replacement.

Recurrent pump thrombosis is common after axial continuous-flow left ventricular assist device exchange

In selected patients with left ventricular assist device-associated infection or malfunction, pump exchange may become necessary after conservative treatment options fail and heart transplantation is not readily available. We examined the survival and complication rate in patients (⩾19 years of age) who underwent HeartMate II to HeartMate II exchange at our institution from 1 January 2010 to 28 February 2018. Clinical outcomes were analyzed and compared for patients who underwent exchange for pump thrombosis (14 patients), breach of driveline integrity (5 patients), and device-associated infection (2 patients). There were no differences in 30-day mortality (p = 0.58), need for temporary renal replacement therapy (p = 0.58), right ventricular mechanical support (p = 0.11), and postoperative stroke (p = 0.80) among groups. Survival at 1 year was 90% ± 7% for the whole cohort and 85% ± 10% for those who underwent exchange for pump thrombosis. In patients exchanged for device thrombosis, freedom from re-thrombosis and survival free from pump re-thrombosis at 1 year were 49% ± 16% and 42% ± 15%, respectively. No association of demographic and clinical variables with the risk of recurrent pump thrombosis after the first exchange was identified. Survival after left ventricular assist device exchange compares well with published results after primary left ventricular assist device implantation. However, recurrence of thrombosis was common among patients who required a left ventricular assist device exchange due to pump thrombosis. In this sub-group, consideration should be given to alternative strategies to improve the outcomes.

Device exchange from Heartmate II to HeartWare HVAD

BACKGROUND

Despite technological advancements, pump durability and pump-related complications continue to affect and adversely impact the lives of patients with end-stage heart failure on left ventricular assist device (LVAD) support. In an attempt to avoid recurrent LVAD-related complications, there may be circumstances where it is clinically advantageous to exchange a patient's device from HeartMate II to HeartWare HVAD. However, there is a paucity of data that describes the safety and feasibility of such an approach.

OBJECTIVE

We present the largest single-center series of HeartMate II (HMII) to HeartWare (HVAD) device exchanges.

METHODS

A retrospective review of 11 patients who underwent HMII to HVAD exchange from 2012 to 2017 was conducted to evaluate patient characteristics, incidence of postoperative complications, and survival.

RESULTS

Eleven male patients (mean age 55 ± 14.4 years) underwent HMII to HVAD device exchange. One patient expired on postoperative day 7 secondary to sepsis. One patient was lost-to-follow-up after 23 months. An additional three patients died at 5, 7, and 24 months. Mean follow-up after device exchange was 1555 ± 311 days for the remaining six patients. None of the 11 study patients underwent LVAD explant, further device exchange, or heart transplant.

CONCLUSION

Exchange of an HMII LVAD to an HVAD can be performed safely with acceptable perioperative morbidity and mortality.