Current Status of Left Ventricular Assist Device Therapy

Impact of Frailty on Left Ventricular Assist Device Clinical Outcomes

Frailty is a clinical syndrome prevalent in older adults and carries poor outcomes in patients with heart failure. We investigated the impact of frailty on left ventricular assist device (LVAD) clinical outcomes. The Nationwide Readmission Database was used to retrospectively identify patients with a primary diagnosis of heart failure who underwent LVAD implantation during their hospitalization from 2014 to 2020. Patients were categorized into frail and nonfrail groups using the Hospital Frailty Risk Score. Cox and logistic regression were used to predict the impact of frailty on inpatient mortality, 30-day readmissions, length of stay, and discharge to a skilled nursing facility. LVADs were implanted in 11,465 patients who met the inclusion criteria. There was more LVAD use in patients who were identified as frail (81.6% vs 18.4%, p <0.001). The Cox regression analyses revealed that LVAD insertion was not associated with increased inpatient mortality in frail patients (hazard ratio 1.15, 95% confidence interval 0.81 to 1.65, p = 0.427). Frail patients also did not experience a higher likelihood of readmissions within 30 days (hazard ratio 1.15, 95% confidence interval 0.91 to 1.44, p = 0.239). LVAD implantation did not result in a significant increase in inpatient mortality or readmission rates in frail patients compared with nonfrail patients. These data support continued LVAD use in this high-risk patient population.

Pulmonary Capillary Recruitment Is Attenuated Post Left Ventricular Assist Device Implantation

There is limited knowledge of pulmonary physiology and pulmonary function after continuous flow-left ventricular assist device (CF-LVAD) implantation. Therefore, this study investigated whether CF-LVAD influenced pulmonary circulation by assessing pulmonary capillary blood volume and alveolar-capillary conductance in addition to pulmonary function in patients with heart failure. Seventeen patients with severe heart failure who were scheduled for CF-LVAD implantation (HeartMate II, III, Abbott, Abbott Park, IL or Heart Ware, Medtronic, Minneapolis, MN) participated in the study. They underwent pulmonary function testing (measures of lung volumes and flow rates) and unique measures of pulmonary physiology using a rebreathe technique that quantified the diffusing capacity of the lungs for carbon monoxide (DLCO) and diffusing capacity of the lungs for nitric oxide before and 3 months after CF-LVAD implantation. After CF-LVAD, pulmonary function was not significantly changed (p >0.05). For lung diffusing capacity, alveolar volume (VA) was not changed (p = 0.47), but DLCO was significantly reduced (p = 0.04). After correcting for VA, DLCO/VA showed a trend toward reduction (p = 0.08). For the alveolar-capillary component, capillary blood volume (Vc) was significantly reduced (p = 0.04), and alveolar-capillary membrane conductance trended toward a reduction (p = 0.06). However, alveolar-capillary membrane conductance/Vc was not altered (p = 0.92). In conclusion, soon after CF-LVAD implantation, Vc is reduced likely because of pulmonary capillary derecruitment, which contributes to the decrease in lung diffusing capacity.

Selection and management considerations to enhance outcomes in patients supported by left ventricular assist devices

PURPOSE OF REVIEW

Left ventricular assist devices (LVADs) are life-saving therapies for patients in end-stage heart failure (HF) with reduced ejection fraction regardless of candidacy for heart transplantation. Multiple clinical trials have demonstrated improved morbidity and mortality with LVADs when compared to medical therapy alone. However, the uptake of LVADs as a therapeutic option in a larger section of end-stage HF patients remains limited, partly due to associated adverse events and re-hospitalization.

RECENT FINDINGS

Accurate assessment and staging of HF patients is crucial to guide appropriate use of LVADs. Innovative methods to risk stratify patients and manage cardiac and noncardiac comorbidities can translate to improved outcomes in LVAD recipients. Inclusion of quality of life metrics and measurements of adverse events can better inform heart failure cardiologists to help identify ideal LVAD candidates. Addition of machine learning algorithms to this process may guide patient selection to improve outcomes.

SUMMARY

Patient selection and assessment of reversible medical comorbidities are critical to the postoperative success of LVAD implantation. Identifying patients most likely to benefit and least likely to experience adverse events should be a priority.

Safety and Effectiveness of Intravenous Iron Therapy in Patients Supported by Durable Left Ventricular Assist Devices

Aims: While it is common practice to use intravenous (IV) iron in patients with left ventricular assist devices (LVADs) and iron deficiency, there is insufficient evidence regarding outcomes in this patient population. We evaluated the safety and effectiveness of IV iron therapy in patients supported by LVADs with iron deficiency. Methods: We performed a retrospective analysis of iron deficient patients on continuous LVAD support at a large academic center between 2008 and 2019. Patients were divided into two cohorts based on IV iron sucrose treatment. The primary endpoint was hemoglobin at 12 weeks. Secondary endpoints were mean corpuscular volume (MCV) and New York Heart Association (NYHA) class at 12 weeks. Safety endpoints included hospitalization, infection, pump thrombosis, arrhythmia, and gastrointestinal bleed. Models were weighted by the inverse probability of receiving IV iron using a propensity score, and endpoints were adjusted for their corresponding baseline values. Results: Among 213 patients, 70 patients received IV iron and 143 patients did not. Hemoglobin at 12 weeks was significantly greater among those treated (intergroup difference: 0.6 g/dL; 95% CI, 0.1 to 1.1; p = 0.01), while MCV was similar in both groups (intergroup difference: 0.7 μm³; 95% CI, −1.3 to 2.7; p = 0.50). NYHA class distribution at 12 weeks was significantly different (odds ratio for improvement: 2.84; 95% CI, 1.42 to 4.68; p = 0.003). The hazards of adverse events in each group were similar. Conclusions: In patients with LVADs and iron deficiency, treatment with IV iron sucrose was safe and associated with improvements in functional status and hemoglobin.

Retrospective Review of Secondary Prevention Strategies for Gastrointestinal Bleeding and Associated Clinical Outcomes in Left Ventricular Assist Device Patients

BACKGROUND

Gastrointestinal bleeding (GIB) is one of the most common bleeding complications associated with Left Ventricular Assist Devices (LVAD). Currently, there is no strong evidence or clear guidance for which secondary GIB prophylaxis strategy should be implemented after the discontinuation of aspirin.

METHODS

Our single-center study describes the outcomes of 26 LVAD patients who experienced a total of 49 GIB events, these individuals were either in Group-1) lower INR target range or Group-2) lower INR target plus a hemostatic agent as the secondary prophylaxis strategy. Each GIB event was considered an independent event. Outcomes assessed were bleeding reoccurrence rates, time to next GIB, acute GIB strategies, GIB-free days, thromboembolic events, survival, coagulation, and hematologic parameters.

RESULTS

GIB reoccurrence rates were not statistically different, Group-1) 9 (40.9%) vs Group-2) 15 (55.6%), p = 0.308. Danazol was utilized 81.5% of the time as the designated hemostatic agent. Additionally, no significant differences were observed with all of our secondary outcome measures for bleeding, ischemic events, or survival.

CONCLUSION

While our study was not powered to assess the clinical outcomes related to survival and thromboembolic events, no discernable increased risk of ischemic events including pump thrombosis was observed. Our data suggest that a lower INR target range plus danazol does not confer any additional benefit over a lower INR target range only approach. The results of this report are hypothesis-generating and additional studies are warranted to elucidate the optimal antithrombotic strategy and role of hemostatic agents in reducing the risk of recurrent GIB events.

Characteristics and Outcomes of Candidemia in Patients with Durable Left Ventricular Assist Device Support

There are limited data on the characteristics and clinical course of fungal infections in patients on durable left ventricular assist device (LVAD) support. We sought to further characterize the epidemiology and outcomes of LVAD patients with fungemia. We performed a retrospective review of patients receiving LVAD support from January 2012 through June 2020 at a large academic institution. Among 336 patients on LVAD support, five (1.4%) were diagnosed with fungemia during the study period. Three patients had diabetes with mean hemoglobin A1c 7.1% (R 6.6, 7.4). Fever and leukocytosis (mean white blood count 17.0 thousand/µL [R 12.5, 29.9]) were the most common symptoms. Fungemia was diagnosed early after LVAD implantation (mean 14.4 support days [R 2, 19]). All patients were infected with Candida species, and four isolates were susceptible to fluconazole. Central nervous system outcomes included an ischemic stroke, subarachnoid hemorrhage, and malignant hemorrhagic stroke. Two patients were successfully transplanted, and two patients on destination therapy remain on suppressive fluconazole. In conclusion, fungemia is a rare and severe complication in LVAD patients occurring early postimplant.

Contemporary Trends of Clinical Outcomes in Primary Left Ventricular Assist Device Implantation and Postprocedure High-Risk Categories

OBJECTIVE

We aimed to analyze trends of 30-day readmission and find high-risk patients associated with increased risk of mortality, resource use, and readmission after primary left ventricular assist device (LVAD) implantation. Limited data exist on the contemporary trends of readmission rates and patients at a higher risk of worse outcomes after LVAD implantation.

METHODS AND RESULTS

This is a retrospective study of adults from the Nationwide Readmission Database who underwent primary durable LVAD implantation from 2010 to 2018. The main outcomes were 30-day readmission rates and their trends in patients with primary durable LVAD implantation from 2010 to 2018. This study also sought to identify patients at the highest risk for readmission, in-hospital mortality, and resource use. A total of 31,002 adults with primary durable LVAD implantation were included in the present analysis. Overall, 3808 patients (12.3%) died and 27,168 (87.6%) were discharged alive. Of those discharged alive, 8303 patients (30.6%) were readmitted within 30 days. The trend of 30-day all-cause readmission among LVAD implantation patients remained similar from 2010 to 2018 (P = .809). The in-hospital mortality rate during the index hospitalization decreased significantly (P = .014), and the mean cost of an index hospitalization increased (P = .031) during the study period. The patients with post-LVAD in-hospital cardiac, vascular, and thromboembolic complications (ie, high-risk patients) had the highest mortality, resource use, and readmission rates compared with patients without major complications.

CONCLUSIONS

This study found that the readmission rates associated with LVAD implantation did not change from 2010 to 2018 and identified high-risk patients who may benefit from closer monitoring after primary LVAD implantation.

Uncommon obstacle: management of end-stage heart failure in thrombocytopenia with absent radii (TAR) syndrome

Thrombocytopenia with absent radii (TAR) syndrome is a rare genetic condition causing absent radial bones and thrombocytopenia. Management is generally supportive although there may be a role for platelet-stimulating agents such as romiplostim. In this case, we highlight the obstacles in managing end-stage heart failure in a patient with TAR syndrome.

Cost-effectiveness of using hepatitis C viremic hearts for transplantation into HCV-negative recipients

Outcomes following hepatitis C virus (HCV)-viremic heart transplantation into HCV-negative recipients with HCV treatment are good. We assessed cost-effectiveness between cohorts of transplant recipients willing and unwilling to receive HCV-viremic hearts. Markov model simulated long-term outcomes among HCV-negative patients on the transplant waitlist. We compared costs (2018 USD) and health outcomes (quality-adjusted life-years, QALYs) between cohorts willing to accept any heart and those willing to accept only HCV-negative hearts. We assumed 4.9% HCV-viremic donor prevalence. Patients receiving HCV-viremic hearts were treated, assuming $39 600/treatment with 95% cure. Incremental cost-effectiveness ratios (ICERs) were compared to a $100 000/QALY gained willingness-to-pay threshold. Sensitivity analyses included stratification by blood type or region and potential negative consequences of receipt of HCV-viremic hearts. Compared to accepting only HCV-negative hearts, accepting any heart gained 0.14 life-years and 0.11 QALYs, while increasing costs by $9418/patient. Accepting any heart was cost effective (ICER $85 602/QALY gained). Results were robust to all transplant regions and blood types, except type AB. Accepting any heart remained cost effective provided posttransplant mortality and costs among those receiving HCV-viremic hearts were not >7% higher compared to HCV-negative hearts. Willingness to accept HCV-viremic hearts for transplantation into HCV-negative recipients is cost effective and improves clinical outcomes.

Impact of distance from implant center on mechanical circulatory device patient outcomes

OBJECTIVES

Patients on left ventricular assist device (LVAD) support receive extensive care and education before discharge home. We investigated the impact of patient's residential distance from LVAD implantation center on outcomes and survival.

METHODS

A total of 214 patients received a LVAD between 2006 and 2018 at our institution. Patient's residential distance from the LVAD implantation center, LVAD complications, hospitalization, and death were recorded. Patients were divided into two groups: patients living less than or equal to 100 miles (Group 1), patients living more than 100 (Group 2).

RESULTS

A total of 106 patients were assigned to Group 1 and 108 patients were assigned to Group 2. Destination therapy was intended in 20% of patients in Group 1 and 34% in Group 2 (p = .023). Mean length of stay was 13 ± 9 days for Group 1 and 21 ± 12 for Group 2 (p < .001). Major postoperative complications were unplanned readmissions due to infections (9% and 12%), gastrointenstinal bleeding (15% and 14%), cerebrovascular accidents (6% and 7.4%), and acute kidney injury (5% and 2%), respectively for Group 1 and Group 2. There was no difference in major complications (all p > .05) and survival between patients in both groups (p > .05).

CONCLUSIONS

Distance from implanting center had no impact on adverse outcomes after LVAD implantation. There was a significant increase in hospital stay for patients who live far from the implanting center, suggesting that distance should not be a contraindication when considering patients for LVAD therapy, but plans should be made for prolonged hospital stay or extended local stay near the hospital for close follow-up.

Reduction of Postoperative Infections Through Routine Preoperative Universal Decolonization of Advanced Heart Failure Patients With Chlorhexidine and Mupirocin Before Left Ventricular Assist Device Implantation: A Single-Center Observational Study

BACKGROUND

Left ventricular assist devices (LVADs) are increasingly being used in patients with advanced heart failure as bridge to transplant, bridge to decision, or destination therapy. Infections are a major complication associated with LVADs. Staphylococcus aureus is one of the common causative organisms associated with LVAD infections. Methicillin resistant staphylococcus aureus (MRSA)-colonized patients are at an increased risk for developing MRSA-associated infections. Various studies have demonstrated decolonization of skin with topical chlorhexidine and nares with 2% intranasal mupirocin ointment is effective in reducing MRSA-associated infections.

OBJECTIVE

The objective of this observational study was to examine the impact of a universal decolonization protocol using topical chlorhexidine and intranasal mupirocin ointment for 5 days before LVAD implantation on postoperative infections (30, 60, and 90 days) and 30-day infection-related rehospitalization.

METHODS

A preoperative universal decolonization with 4% chlorhexidine daily whole-body bath and 2% intranasal mupirocin ointment twice a day for 5 days was implemented for patients undergoing elective LVAD implantation. Using an observational study design, we included a convenience sample of 84 subjects who were established patients in an accredited advanced heart failure program. Thirty-seven patients served in the standard protocol group, and 47 in the universal decolonization protocol group participated in the observational study.

RESULTS

In the standard protocol group, there were 4 MRSA infections with none in the universal decolonization group (χ = 5.34, P = .03). In total, there were 8 surgical site infections in the standard protocol group and 1 in the universal decolonization group (χ = 5.95, P = .01).

CONCLUSION

A 5-day universal decolonization protocol before LVAD implantation was effective in reducing total infections as well as MRSA-specific infections.

An unusual case of Scedosporium apiospermum fungaemia in an immunocompetent patient with a left ventricular assist device and an implantable cardiac device

Left ventricular assist device (LVAD)-related infections are a leading cause of morbidity and mortality, with fungal infections being particularly difficult to manage. We report a case of an immunocompetent 39-year-old male with an LVAD and an implantable cardiac device (ICD) who developed fatal Scedosporium apiospermum fungaemia. To the best of our knowledge, this is the first reported case of LVAD-related S. apiospermum fungaemia.

[Features of the clinical picture and outcomes in patients from a heart transplantation waiting list with different causes of heart failure]

Aim To identify clinical differences between patients on the heart transplant waiting list (HTWL) in the origin of chronic heart failure (CHF).Materials and methods From January 2010 through September 2019, 235 patients (age, 47+13 years (from 10 to 67 years); men, 79% (n=186)) were included in the HTWL. The patients were divided into two groups; group 1 (n=104, 44 %) consisted of patients with ischemic heart disease (IHD); group 2 (n=131, 56 %) included patients with noncoronarogenic CHF. Clinical and instrumental data and frequency of the mechanical circulatory support (MCS) as a "bridge" to heart transplantation (HT) were retrospectively evaluated.Results Group 1 included more male patients than group 2 [97 % (n=101) and 82 % (n=85), р&lt;0.0001]; patients were older (54±8 and 42±14 years, р=0.0001). On inclusion into the HTWL, the CHF functional class was comparable in the groups, III [III;IV]; there were more patients of the UNOS 2 class in group 1 than in group 2 [75 % (n=78) and 57 % (n=75), р=0.005]. Patient distribution in UNOS 1B and 1A classes was comparable in the groups: 21% (n=22) and 3% (n=4) in group 1 and 33 % (n=43) and 10 % (n=13) in group 2. According to echocardiography patients of group 1 compared to group 2 showed a tendency towards higher values of left ventricular ejection fraction (Simpson method) [22 [18;26] % and 19 [15;24] %, р=0.37] and stroke volume [59 [44;72] % and 50 [36;67] %, р=0.07]. Numbers of patients with a cardioverter defibrillator or a cardiac resynchronization device with a defibrillator function were comparable in the groups [35 % (n=36) and 34 % (n=45)]. Comparison of comorbidities in groups 1 and 2 showed higher incidences of pulmonary hypertension [55 % (n=57) and 36 % (n=47), р=0.005], obesity [20 % (n=21) and 10 % (n=13), р=0.03], and type 2 diabetes mellitus [29 % (n=30) and 10 % (n=13), р=0.0004]. Rates of chronic obstructive lung disease, stroke, chronic kidney disease and other diseases were comparable. Duration of staying on the HTWL was comparable (104 [34; 179] and 108 [37; 229] days). During staying on the HTWL, patients of group 1 less frequently required MCS implantation [3 % (n=3) and 28 % (n=21), р=0.0009]. HT was performed for 59 % patients (n=61) in group 2 and 52 % (n=69) patients in group 2. Death rate in the HTWL was lower in group 1 [13 % (n=14) and 27 % (n=35), р&lt;0.01].Conclusion On inclusion into the HTWL, patients with noncoronarogenic CHF had more pronounced CHF manifestations and a more severe UNOS class but fewer comorbidities than patients with CHF of ischemic origin. With a comparable duration of waiting for HT, patients with noncoronarogenic CHD more frequently required MCS implantation and had a higher death rate.

Application of a likelihood ratio test based method for safety signal detection to left ventricular assist devices

Effective post-market safety surveillance of medical devices is critical for public health. However, many current statistical methods for safety signal detection do not control for type I error when assessing multiple device and adverse event (AE) combinations. This can result in increased false signals, underscoring the need for more robust statistical methods. Moreover, the duration of medical device use can be an important factor to consider in safety surveillance. In this study, we adapted a likelihood ratio test (LRT) based method, which was initially developed and applied to drugs, to identify safety signals for left ventricular assist devices (LVAD). Among patients with chronic, advanced left ventricular failure, we analyzed AE data for HeartWare and HeartMate II patients during a two-year period and further incorporated person-years (henceforth exposure-time). The novel modified LRT and conventional Z-test with p-values adjusted by the Benjamini-Hochberg (BH) procedure were used to explore safety signals by comparing HeartWare and HeartMate II patients in the presence of multiple adverse events. Both methods identified greater incidence of stroke among HeartWare as compared to HeartMate II patients without exposure-time (p = .025 for LRT and p = .027 for Z-test with BH) and with exposure-time (p = .002 for LRT and p = .005 for Z-test with BH). By using improved statistical methods for safety signal detection, potential safety issues can be identified and addressed in a more timely manner to enhance public safety.

Left ventricle assist device pulsatility index at the time of implantation is associated with follow-up pulmonary hemodynamics

HeartMate II left ventricular assist device controllers provide data including pulsatility index, reflecting the relationship between pump function and hemodynamics. We propose that a higher pulsatility index at hospital discharge following implant may be associated with less vascular congestion and improved clinical outcomes. A retrospective analysis of 40 patients (age 59.2 ± 10.3 years) supported with the HeartMate II devices was conducted. Data revealed moderate Pearson correlations between pulsatility index at discharge and right atrial pressure, pulmonary artery systolic pressure, pulmonary artery diastolic pressure, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure, respectively, post-surgery (median of 377 days), demonstrating a stronger relationship when analyzed for the EPC controller (n = 28) only (r = -.57, p < .01; r = -.38, p < .05; r = -.59, p < .01; r = -.47, p = .01 and r = -.53, p < .01, respectively). The pulsatility index derived from the EPC controller was associated with the significant risk of re-hospitalization within 1 and 2 years after the implantation of left ventricular assist device; hazard ratio = 0.557 with 95% confidence interval (0.315-0.983), p = .04 and hazard ratio = .579 (0.341-0.984), p = .04. A higher pulsatility index at discharge was associated with greater volume unloading, lower pulmonary pressures, and lower risk of all-cause re-hospitalizations within 1 and 2 years post-surgery. As such, pump-derived data may provide additional value in predicting left ventricular assist device hemodynamics.

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.

ESTABLISHMENT OF OVINE MODEL FOR CH-VAD IMPLANTABLE VENTRICULAR ASSIST DEVICE

The objective of this study was to establish an ovine model for CH-VAD (CH Biomedical Inc., JiangSu, China) implantable ventricular assist device (IVAD) to evaluate experimental protocols, including anesthesia management, surgical process, autopsy criteria and a validated anticoagulation procedure. Method: IVAD was implanted into the chest of sheep without stopping the beating heart through a left thoracotomy, and the inflow cannula was connected to the left ventricular apex and the outflow cannula was anastomosed to the descending aorta. Results: Totally 23 cases were established: 6 died of an anaesthetic or surgical reasons, one died of lung infection, the other 16 cases survived for more than 15 days, among which four cases were terminated because of decrease of pump flow and the other 12 cases survived for more than 30 days. Conclusions: Sheep models suitable for implantation of CH-VAD implantable LVAD were successfully established and the appropriate safety evaluation indicators of this model were validated in the course of the animal experiments, and the survival rate of the experiments were improved gradually over time.

Non-invasive assessment of arterial pulsatility in patients with continuous-flow left ventricular assist devices

INTRODUCTION

Long-term use of continuous-flow left ventricular assist devices may have negative consequences for autonomic, cardiovascular and gastrointestinal function. It has thus been suggested that non-invasive monitoring of arterial pulsatility in patients with a left ventricular assist device is highly important for ensuring patient safety and longevity. We have developed a novel, semi-automated frequency-domain-based index of arterial pulsatility that is obtained during suprasystolic occlusions of the upper arm: the 'cuff pulsatility index'.

PURPOSE

The purpose of this study was to evaluate the relationship between the cuff pulsatility index and invasively determined arterial pulsatility in patients with a left ventricular assist device.

METHODS

Twenty-three patients with a left ventricular assist device with end-stage heart failure (six females: age = 65 ± 9 years; body mass index = 30.5 ± 3.7 kg m^-2) were recruited for this study. Suprasystolic occlusions were performed on the upper arm of the patient's dominant side, from which the cuff pressure waveform was obtained. Arterial blood pressure was obtained from the radial artery on the contralateral arm. Measurements were obtained in triplicate. The relationship between the cuff pressure and arterial blood pressure waveforms was assessed in the frequency-domain using coherence analysis. A mixed-effects approach was used to assess the relationship between cuff pulsatility index and invasively determined arterial pulsatility (i.e. pulse pressure).

RESULTS

The cuff pressure and arterial blood pressure waveforms demonstrated a high coherence up to the fifth harmonic of the cardiac frequency (heart rate). The cuff pulsatility index accurately tracked changes in arterial pulse pressure within a given patient across repeated measurements.

CONCLUSIONS

The cuff pulsatility index shows promise as a non-invasive index for monitoring residual arterial pulsatility in patients with a left ventricular assist device across time.

Low immunogenic endothelial cells endothelialize the Left Ventricular Assist Device

Low haemocompatibility of left ventricular assist devices (LVAD) surfaces necessitates anticoagulative therapy. Endothelial cell (EC) seeding can support haemocompatibility, however, the availability of autologous ECs is limited. In contrast, allogeneic ECs are readily available in sufficient quantity, but HLA disparities induce harmful immune responses causing EC loss. In this study, we investigated the feasibility of using allogeneic low immunogenic ECs to endothelialize LVAD sintered inflow cannulas (SIC). To reduce the immunogenicity of ECs, we applied an inducible lentiviral vector to deliver short-hairpins RNA to silence HLA class I expression. HLA class I expression on ECs was conditionally silenced by up to 70%. Sufficient and comparable endothelialization rates were achieved with HLA-expressing or HLA-silenced ECs. Cell proliferation was not impaired by cell-to-Sintered Inflow Cannulas (SIC) contact or by silencing HLA expression. The levels of endothelial phenotypic and thrombogenic markers or cytokine secretion profiles remained unaffected. HLA-silenced ECs-coated SIC exhibited reduced thrombogenicity. In contrast to native ECs, HLA-silenced ECs showed lower cell lysis rates when exposed to allogeneic T cells or specific anti-HLA antibodies. Allogeneic HLA-silenced ECs could potentially become a valuable source for LVAD endothelialization to reduce immunogenicity and correspondingly the need for anticoagulative therapy which can entail severe side effects.

Defibrillator-Heart Pump: An Implantable Ventricular Assist Device With Integrated Defibrillator Component-The First In Vitro Testing

Left ventricular assist devices (LVADs) are an important therapeutic option for patients with end-stage heart failure waiting for heart transplantation or in older patients as definite therapy for heart failure. Interestingly, about 62% of patients receiving LVADs do not have an automatic implantable cardioverter-defibrillator (AICD) at the time of implantation, although these patients have increased risk of being confronted with dangerous arrhythmia. Therefore, an LVAD system including AICD function is a reasonable alternative for such heart failure patients thereby avoiding a second surgical intervention for AICD implantation. In this article, a newly developed system including LVAD and AICD function is introduced, and we also report its first in vitro testing.

Chronic Heart Failure Treatment With the Left Ventricular Assist Device

The prevalence of chronic heart failure is increasing in the United States due to the increase in the number of older adults and because many people are surviving acute cardiac events and living longer with chronic heart disease. In end-stage heart failure, heart transplant was once the gold standard of treatment and patients had to wait for a matching heart donor. In the past, the left ventricular assist device (LVAD) was a mechanical circulatory support treatment used temporarily for those awaiting heart transplant. However, the LVAD is increasingly becoming the chosen treatment of patients in lieu of heart transplant. Home healthcare nurses and clinicians need to be familiar with LVADs in order to care for patients in end-stage heart failure who are using these devices. This article explains the mechanism, potential complications, and nursing implications of caring for the patient who is using an LVAD.

A novel model for minimally invasive left ventricular assist device implantation training

Background: Significant advances in minimally invasive implantation of mechanical circulatory support devices have been made. These approaches are technically challenging and associated with a learning curve. Simulation and training opportunities in these techniques are limited. We developed a high-fidelity novel model for minimally invasive left ventricular assist device implantation.Material and methods: Using a modified inanimate simulator (LSI SOLUTIONS^®) and an animal tissue model, a hybrid simulator was created, with a porcine ex vivo heart secured within the inanimate simulator in the normal anatomic position. Key components of the minimally invasive left ventricular assist device implantation were performed, including left ventricular apical coring, attachment of the apical ring, attachment of the assist device, and creation of the aortic-outflow graft anastomosis.Results: A novel composite inanimate and tissue model for minimally invasive left ventricular assist device implantation was successfully developed. These simulation techniques were reproducible, and the model demonstrated ability to successfully simulate key components of the procedure.Conclusions: This high-fidelity, reproducible hybrid model allows for crucial components of minimally invasive LVAD implantation to be performed. This model has the potential to be used as an adjunct to surgical training, providing a safe and controlled learning environment for trainees to acquire skills in minimally invasive LVAD implantation.

Left ventricular assist devices in the treatment of advanced heart failure

The left ventricular assist device (LVAD) is becoming the standard of care in treating patients with advanced heart failure. This article describes available LVADs, their clinical indications, and important caveats when caring for this complex patient population.

Sex-Specific Outcome Disparities in Patients Receiving Continuous-Flow Left Ventricular Assist Devices: A Systematic Review and Meta-analysis

Continuous-flow left ventricular assist devices (CF-LVADs) decrease mortality and improve quality of life in patients with advanced heart failure (HF). Their widespread utilization has led to concerns regarding increased adverse effects, especially in women. Nevertheless, sex-specific data remain limited. We searched Medline, Embase, Scopus, and the Cochrane Library for publications reporting sex-specific outcomes after CF-LVADs from January 2008 through January 2017. Outcomes were compared under the random-effects model and heterogeneity examined via χ test and I statistics. A total of 10 studies including 4,493 CF-LVAD recipients were included in the analysis (23.5% women). The overall rate of stroke was significantly higher in women (odds ratio [OR] 1.94; 95% confidence interval [CI] 1.32-2.84; p = 0.0007). This was true for ischemic strokes (OR 2.03; 95% CI 1.21-3.42; p = 0.008) and hemorrhagic strokes (OR 2.03; 95% CI 1.21-3.42; p = 0.008). Women were also more likely to develop right HF necessitating right ventricular assist device (RVAD) implantation (OR 2.12; 95% CI 1.08-4.15; p = 0.03). Other adverse events including renal failure, bleeding, and device-related infection were comparable for both genders. The overall mortality while on CF-LVAD was similar in both groups (OR 1.05; 95% CI 0.81-1.36; p = 0.71). Our analysis suggests that women are at greater risk of significant complications such as cerebrovascular events and right HF necessitating RVAD after CF-LVAD implantation. Further research is needed to better understand the mechanisms underlying these sex-specific outcome disparities.

Pulmonary function assessment post-left ventricular assist device implantation

Aim

The lungs—and particularly the alveolar‐capillary membrane—may be sensitive to continuous flow (CF) and pulmonary pressure alterations in heart failure (HF). We aimed to investigate long‐term effects of CF pumps on respiratory function.

Methods and results

We conducted a retrospective study of patients with end‐stage HF at our institution. We analysed pulmonary function tests [e.g. forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁)] and diffusing capacity of the lung for carbon monoxide (D_LCO) from before and after left ventricular assist device (LVAD) implantation and compared them with invasive haemodynamic studies. Of the 274 patients screened, final study analysis involved 44 patients with end‐stage HF who had CF LVAD implantation between 1 February 2007 and 31 December 2015 at our institution. These patients [mean (standard deviation, SD) age, 50 (9) years; male sex, n = 33, 75%] received either the HeartMate II (Thoratec Corp.) pump (77%) or the HeartWare (HeartWare International Inc.) pump. The mean (SD) left ventricular ejection fraction was 21% (13%). At a median of 237 days post‐LVAD implantation, we observed significant D_LCO decrease (−23%) since pre‐implantation (P < 0.001). ΔD_LCO had an inverse relationship with changes in pulmonary capillary wedge pressure (PCWP) and right atrial pressure (RAP) from pre‐LVAD to post‐LVAD implantation: ΔD_LCO to ΔPCWP (r = 0.50, P < 0.01) and ΔD_LCO to ΔRAP (r = 0.39, P < 0.05). We observed other reductions in FEV₁, FVC, and FEV₁/FVC between pre‐LVAD and post‐LVAD implantation. In mean (SD) values, FEV₁ changed from 2.3 (0.7) to 2.1 (0.7) (P = 0.005); FVC decreased from 3.2 (0.8) to 2.9 (0.9) (P = 0.01); and FEV₁/FVC went from 0.72 (0.1) to 0.72 (0.1) (P = 0.50). Landmark survival analysis revealed that ΔD_LCO from 6 months after LVAD implantation was predictive of death for HF patients [hazard ratio (95% confidence interval), 0.60 (0.28–0.98); P = 0.03].

Conclusions

Pulmonary function did not improve after LVAD implantation. The degree of D_LCO deterioration is related to haemodynamic status post‐LVAD implantation. The ΔD_LCO within 6 months post‐operative was associated with survival.

Analysis of Patients with Ventricular Assist Devices Presenting to an Urban Emergency Department

Introduction

Left ventricular assist device (LVAD) insertion is an increasingly common intervention for patients with advanced heart failure; however, published literature on the emergency department (ED) presentation of this population is limited. The objective of this study was to characterize ED presentations of patients with LVADs with a focus on device-specific complications to inform provider education and preparation initiatives.

Methods

This was a retrospective chart review of all patients with LVADs followed at an urban academic medical center presenting to the ED over a five-year period (July 1, 2009, to June 30, 2014). Two abstractors reviewed 45 randomly selected charts to standardize the abstraction process and establish a priori categories for reason for presentation to the ED. Remaining charts were then divided evenly for review by one of the two abstractors. Primary outcomes for this study were (1) frequency of and (2) reason for presentation to the ED by patients with LVADs.

Results

Of 349 patients with LVADs identified, 143 (41.0%) had ED encounters during the study period. There were 620 total ED encounters, (range 1 to 32 encounters per patient, median=3, standard deviation=5.3). Among the encounters, 431 (69.5%) resulted in admission. The most common reasons for presentation were bleeding (e.g., gastrointestinal, epistaxis) (182, 29.4%); infection (127, 20.5%); heart failure exacerbation (68, 11.0%); pain (56, 9.0%); other (45, 7.3%); and arrhythmias (40, 6.5%). Fifty-two encounters (8.4%) were device-specific; these patients frequently presented with abnormal device readings (37, 6.0%). Interventions for device-specific presentations included anticoagulation regimen adjustment (16/52, 30.8%), pump exchange (9, 17.3%), and hardware repair (6, 11.5%). Pump thrombosis occurred in 23 cases (3.7% of all encounters). No patients required cardiopulmonary resuscitation or died in the ED.

Conclusion

This is the largest study known to the investigators to report the rate of ED presentations of patients with LVADs and provide analysis of device-specific presentations. In patients who do have device-specific ED presentations, pump thrombosis is a common diagnosis and can present without device alarms. Specialized LVAD education and preparation initiatives for ED providers should emphasize the recognition and management of the most common and critical conditions for this patient population, which have been identified in this study as bleeding, infection, heart failure, and pump thrombosis.

Thirty-Day Readmissions After Left Ventricular Assist Device Implantation in the United States

Background:

Early readmissions contribute significantly to heart failure–related morbidity and negatively affect quality of life. Data on left ventricular assist device (LVAD)–related 30-day readmissions are scarce and limited to small studies.

Methods and Results:

Patients undergoing LVAD implantation between January 2013 and November 2014 who survived the index hospitalization were identified in the Nationwide Readmissions Database. We analyzed the incidence, predictors, causes, and costs of 30-day readmissions. Of 2510 LVAD recipients, 788 (31%) were readmitted within 30 days. Length of index hospitalization ≥31 days (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.07–1.50) and female sex (HR, 1.19; 95% CI, 1.01–1.42) were associated with a higher risk of 30-day readmission, whereas private insurance (HR, 0.83; 95% CI, 0.70–0.99), pre-LVAD use of short-term mechanical circulatory support (HR, 0.53; 95% CI, 0.29–0.98), and discharge to a short-term hospital facility (HR, 0.41; CI, 0.21–0.78) were associated with a lower risk. Cardiac causes accounted for 23.8% of readmissions: heart failure (13.4%) and arrhythmias (8.1%). Noncardiovascular causes accounted for 76.2% of readmissions: infection (30.2%), bleeding (17.6%), and device-related causes (8.2%). Mean length of stay for readmission was 10.7 days (median, 6 days), and average hospital cost per readmission was $34 948±2457.

Conclusions:

Early readmissions are frequent after LVAD implantation even in contemporary times. Preimplant identification of high-risk patients, and a protocol-driven follow-up using a multidisciplinary approach will be needed to reduce readmissions and improve outcomes.

Restrictive Cardiomyopathy

Restrictive cardiomyopathy (RCM) is characterized by nondilated left or right ventricle with diastolic dysfunction. The restrictive cardiomyopathies are a heterogenous group of myocardial diseases that vary according to pathogenesis, clinical presentation, diagnostic evaluation and criteria, treatment, and prognosis. In this review, an overview of RCMs will be presented followed by a detailed discussion on 3 major causes of RCM, for which tailored interventions are available: cardiac amyloidosis, cardiac sarcoidosis, and cardiac hemochromatosis. Each of these 3 RCMs is challenging to diagnose, and recognition of each disease entity is frequently delayed. Clinical clues to promote recognition of cardiac amyloidosis, cardiac sarcoidosis, and cardiac hemochromatosis and imaging techniques used to facilitate diagnosis are discussed. Disease-specific therapies are reviewed. Early recognition remains a key barrier to improving survival in all RCMs.