Risk factors, mortality, and timing of ischemic and hemorrhagic stroke with left ventricular assist devices

An ISHLT consensus statement on strategies to prevent and manage hemocompatibility related adverse events in patients with a durable, continuous-flow ventricular assist device

Life expectancy of patients with a durable, continuous-flow left ventricular assist device (CF-LVAD) continues to increase. Despite significant improvements in the delivery of care for patients with these devices, hemocompatability-related adverse events (HRAEs) are still a concern and contribute to significant morbility and mortality when they occur. As such, dissemination of current best evidence and practices is of critical importance. This ISHLT Consensus Statement is a summative assessment of the current literature on prevention and management of HRAEs through optimal management of oral anticoagulant and antiplatelet medications, parenteral anticoagulant medications, management of patients at high risk for HRAEs and those experiencing thrombotic or bleeding events, and device management outside of antithrombotic medications. This document is intended to assist clinicians caring for patients with a CF-LVAD provide the best care possible with respect to prevention and management of these events.

The Double Barrel Impella Exchange: A Reliable Method for Uninterrupted Mechanical Circulatory Support

Classic Impella exchange interrupts flow when the old device is pulled into the aorta before advancing the new device across the aortic valve, threatening circulatory collapse and loss of left ventricular access. In "double barrel," uninterrupted Impella exchange, the new device is placed into the ventricle alongside the old, where flow is first transitioned completely. Of thirty-one consecutive patients undergoing this procedure, none experienced intraoperative cardiac arrest and 96.8% (30/31) had no new aortic insufficiency. One vascular complication ensued following known preoperative iliac injury. One patient suffered nonembolic stroke; another had subarachnoid hemorrhage. Fifty-five percent (17/31) of patients survived, with 22.6% (7/31) recovering, 25.8% (8/31) undergoing transplant, and 6.5% (2/31) transitioning to durable LVAD. Impella-only survival (83.3%, 10/12) was significantly higher than Impella-ECMO survival (36.8%, 7/19) (OR 14.46, 95% CI 1.74-119.93, p=0.01). We conclude "double barrel" technique is reliable in device-dependent cardiogenic shock patients, offering significant advantage and minimal risk.

Application of interpretable machine learning algorithms to predict acute kidney injury in patients with cerebral infarction in ICU

BACKGROUND

Acute kidney injury (AKI) is not only a complication but also a serious threat to patients with cerebral infarction (CI). This study aimed to explore the application of interpretable machine learning algorithms in predicting AKI in patients with cerebral infarction.

METHODS

The study included 3920 patients with CI admitted to the Intensive Care Unit and Emergency Medicine of the Central Hospital of Lishui City, Zhejiang Province. Nine machine learning techniques, including XGBoost, logistics, LightGBM, random forest (RF), AdaBoost, GaussianNB (GNB), Multi-Layer Perceptron (MLP), support vector machine (SVM), and k-nearest neighbors (KNN) classification, were used to develop a predictive model for AKI in these patients. SHapley Additive exPlanations (SHAP) analysis provided visual explanations for each patient. Finally, model effectiveness was assessed using metrics such as average precision (AP), sensitivity, specificity, accuracy, F1 score, precision-recall (PR) curve, calibration plot, and decision curve analysis (DCA).

RESULTS

The XGBoost model performed better in the internal validation set and the external validation set, with an AUC of 0.940 and 0.887, respectively. The five most important variables in the model were, in order, glomerular filtration rate, low-density lipoprotein, total cholesterol, hemiplegia and serum kalium.

CONCLUSION

This study demonstrates the potential of interpretable machine learning algorithms in predicting CI patients with AKI.

Atrial fibrillation increases thrombogenicity of LVAD therapy

BACKGROUND

This study investigates the hypothesis that presence of atrial fibrillation (AF) in LVAD patients increases thrombogenicity in the left ventricle (LV) and exacerbates stroke risk.

METHODS

Using an anatomical LV model implanted with an LVAD inflow cannula, we analyze thrombogenic risk and blood flow patterns in either AF or sinus rhythm (SR) using unsteady computational fluid dynamics (CFD). To analyze platelet activation and thrombogenesis in the LV, hundreds of thousands of platelets are individually tracked to quantify platelet residence time (RT) and shear stress accumulation history (SH).

RESULTS

The irregular and chaotic mitral inflow associated with AF results in markedly different intraventricular flow patterns, with profoundly negative impact on blood flow-induced stimuli experienced by platelets as they traverse the LV. Twice as many platelets accumulated very high SH in the LVAD + AF case, resulting in a 36% increase in thrombogenic potential score, relative to the LVAD + SR case.

CONCLUSIONS

This supports the hypothesis that AF results in unfavorable blood flow patterns in the LV adding to an increased stroke risk for LVAD + AF patients. Quantification of thrombogenic risk associated with AF for LVAD patients may help guide clinical decision-making on interventions to mitigate the increased risk of thromboembolic events.

Artificial Intelligence Approaches for Predicting the Risks of Durable Mechanical Circulatory Support Therapy and Cardiac Transplantation

Background: The use of AI-driven technologies in probing big data to generate better risk prediction models has been an ongoing and expanding area of investigation. The AI-driven models may perform better as compared to linear models; however, more investigations are needed in this area to refine their predictability and applicability to the field of durable MCS and cardiac transplantation. Methods: A literature review was carried out using Google Scholar/PubMed from 2000 to 2023. Results: This review defines the knowledge gaps and describes different AI-driven approaches that may be used to further our understanding. Conclusions: The limitations of current models are due to missing data, data imbalances, and the uneven distribution of variables in the datasets from which the models are derived. There is an urgent need for predictive models that can integrate a large number of clinical variables from multicenter data to account for the variability in patient characteristics that influence patient selection, outcomes, and survival for both durable MCS and HT; this may be fulfilled by AI-driven risk prediction models.

Developments and Challenges in Durable Ventricular Assist Device Technology: A Comprehensive Review with a Focus on Advancements in China

Heart transplantation is currently the most effective treatment for end-stage heart failure; however, the shortage in donor hearts constrains the undertaking of transplantation. Mechanical circulatory support (MCS) technology has made rapid progress in recent years, providing diverse therapeutic options and alleviating the dilemma of donor heart shortage. The ventricular assist device (VAD), as an important category of MCS, demonstrates promising applications in bridging heart transplantation, destination therapy, and bridge-to-decision. VADs can be categorized as durable VADs (dVADs) and temporary VADs (tVADs), according to the duration of assistance. With the technological advancement and clinical application experience accumulated, VADs have been developed in biocompatible, lightweight, bionic, and intelligent ways. In this review, we summarize the development history of VADs, focusing on the mechanism and application status of dVADs in detail, and further discuss the research progress and use of VADs in China.

Aortic arch branching variations and risk of cerebrovascular accidents in patients with a left ventricular assist device

AIMS

This retrospective study investigated the association between anatomical variations in the aortic arch branching and adverse events, including the risk of cerebrovascular accidents (CVAs), in patients with a left ventricular assist device (LVAD).

METHODS

Medical charts were reviewed for all patients with HeartMate 3 LVAD support at our center from 2016 to 2021. Computed tomography scans were evaluated to categorize the variations in the aortic arch branching based on seven different types, as described in the literature.

RESULTS

In total, 101 patients were included: 86 (85.1%) with a normal branching pattern and 15 (14.9%) with an anatomical variation. The following variations were observed: eight (7.9%) with a bovine arch and seven (6.9%) with a left vertebral arch. The median age was 57 years, 77.2% were men, and the median follow-up was 25 months. No difference was found in the rate of early (< 30 days) re-exploration due to bleeding after LVAD implantation. The rate of CVA and mortality did not differ significantly between patients with a normal arch or an anatomical variation during follow-up, with hazard ratios of 1.47 [95% confidence interval (CI): 0.48-4.48; P = 0.495] and 0.69 (95% CI: 0.24-1.98; P = 0.489), respectively.

CONCLUSION

This preliminary study showed no differences in early and long-term adverse events, including CVA, when comparing patients with a variation in the aortic arch branching to patients with a normal aortic arch. However, knowledge of the variations in aortic arch branching could be meaningful during cardiac surgery for potential differences in surgical events in the perioperative period.

Diagnostic value of coagulation index and serum inflammatory cytokines in hemorrhagic stroke patients with pulmonary infection in the sequelae stage

BACKGROUND

Stroke is the second reason for global deaths and a major reason for disabilities.

OBJECTIVE

To unravel the clinical value of the coagulation index and serum inflammatory cytokines in hemorrhagic stroke patients with pulmonary infection in the sequelae stage.

METHODS

Altogether, 130 hemorrhagic stroke patients who received treatment in Hebei General Hospital from April 2019 to December 2020 were selected. Patients were classified into the infection group (n= 65) and non-infection group (n= 65) according to whether they had a pulmonary infection in the sequelae stage of hemorrhagic stroke. Levels of coagulation index and serum inflammatory cytokines of patients in two groups were compared. Multiple linear regression analysis was used to analyze pulmonary infection-related factors of hemorrhagic stroke patients. The diagnostic value of the coagulation index and serum inflammatory cytokines in pulmonary infection was analyzed by the receiver operating characteristic (ROC) curve.

RESULTS

Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-dimer (D-D), platelet (PLT) related to coagulation function levels and interleukin 1β (IL-1β), interleukin 17 (IL-17) related to serum inflammatory cytokines levels of patients in the infection group were higher than those in non-infection groups (p< 0.05). Multiple linear regression analysis uncovered that FIB, D-D, PLT, and IL-17 were influencing factors of pulmonary infection in the sequelae of patients with hemorrhagic stroke (p< 0.05). Area under the curve (AUC) values of pulmonary infection in the sequelae stage of patients with hemorrhagic stroke diagnosed by FIB, D-D, PLT, and IL-17 were 0.823, 0.758, 0.660, and 0.755, respectively.

CONCLUSION

FIB, D-D, PLT, and IL-17 levels could be used for pulmonary infection diagnosis in the sequelae stage of hemorrhagic stroke patients.

Left Ventricular Assist Device Emergencies: Diagnosis and Management

Durable left ventricular assist devices (LVADs) are a virtually limitless advanced therapy option for an increasingly growing population of patients with end-stage advanced heart failure. As of 2019, 30% to 40% of all patients diagnosed with heart failure were categorized as New York Heart Association class III or IV. In 2018 more than 3.2 million office visits and 1.4 million emergency department visits carried a primary diagnosis of heart failure. Given the rapid growth of the LVAD population, facility in the diagnosis and management of common perioperative and outpatient LVAD emergencies has become of paramount importance in a variety of clinical settings.

Thrombotic and Hemorrhagic Complications Following Left Ventricular Assist Device Placement: An Emphasis on Gastrointestinal Bleeding, Stroke, and Pump Thrombosis

The left ventricular assist device (LVAD) is a mechanical circulatory support device that supports the heart failure patient as a bridge to transplant (BTT) or as a destination therapy for those who have other medical comorbidities or complications that disqualify them from meeting transplant criteria. In patients with severe heart failure, LVAD use has extended survival and improved signs and symptoms of cardiac congestion and low cardiac output, such as dyspnea, fatigue, and exercise intolerance. However, these devices are associated with specific hematologic and thrombotic complications. In this manuscript, we review the common hematologic complications of LVADs.

Stroke and Mechanical Circulatory Support in Adults

PURPOSE OF THE REVIEW

Short-term and durable mechanical circulatory support (MCS) devices represent life-saving interventions for patients with cardiogenic shock and end-stage heart failure. This review will cover the epidemiology, risk factors, and treatment of stroke in this patient population.

RECENT FINDINGS

Short-term devices such as intra-aortic balloon pump, Impella, TandemHeart, and Venoatrial Extracorporal Membrane Oxygenation, as well as durable continuous-flow left ventricular assist devices (LVADs), improve cardiac output and blood flow to the vital organs. However, MCS use is associated with high rates of complications, including ischemic and hemorrhagic strokes which carry a high risk for death and disability. Improvements in MCS technology have reduced but not eliminated the risk of stroke. Mitigation strategies focus on careful management of anti-thrombotic therapies. While data on therapeutic options for stroke are limited, several case series reported favorable outcomes with thrombectomy for ischemic stroke patients with large vessel occlusions, as well as with reversal of anticoagulation for those with hemorrhagic stroke. Stroke in patients treated with MCS is associated with high morbidity and mortality. Preventive strategies are targeted based on the specific form of MCS. Improvements in the design of the newest generation device have reduced the risk of ischemic stroke, though hemorrhagic stroke remains a serious complication.

Hemodynamics Indicates Differences Between Patients With And Without A Stroke Outcome After Left Ventricular Assist Device Implantation

Stroke remains a leading cause of complications and mortality in heart failure patients treated with LVAD circulatory support. Hemodynamics plays a central role in affecting risk and etiology of stroke during LVAD support. Yet, detailed quantitative assessment of hemodynamic variables and their relation to stroke outcomes in patients with an implanted LVAD remains a challenge. We present an in silico hemodynamics analysis in a set of 12 patients on LVAD support; 6 with reported stroke outcomes and 6 without. We conducted patient-specific hemodynamics simulations for models with the LVAD outflow graft reconstructed from cardiac-gated CT images. A pre-implantation baseline flow model was virtually generated for each case by removing the LVAD outflow graft and driving flow from the aortic root. Hemodynamics was characterized using quantitative descriptors for helical flow, vortex generation, and wall shear stress. Our analysis showed higher average values for descriptors of positive helical flow, vortex generation, and wall shear stress, across the 6 cases with stroke outcomes on LVAD support, when compared with cases without stroke. When the descriptors for LVAD-driven flow were compared against estimated baseline flow pre-implantation, extent of positive helicity was higher, and vorticity and wall shear were lower in cases with stroke compared to those without. The study suggests that quantitative analysis of hemodynamics after LVAD implantation; and hemodynamic alterations from a pre-implant flow scenario, can potentially reveal hidden information linked to stroke outcomes during LVAD support. This has broad implications on understanding stroke etiology, LVAD treatment planning, surgical optimization, and efficacy assessment.

Mortality following durable left ventricular assist device implantation by timing and type of first infection

OBJECTIVE

Although infections are common after left ventricular assist device implantation, the relationship between timing and type of first infection with regard to mortality is less well understood.

METHODS

The Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support patients receiving a primary left ventricular assist device from April 2012 to May 2017 were included. The primary exposure was defined 3 ways: any infection, timing of first infection (early: ≤90 days; intermediate: 91-180 days; late: >180 days), and type (ventricular assist device specific, ventricular assist device related, non-ventricular assist device). The association between first infection and all-cause mortality was estimated using Cox regression.

RESULTS

The cohort included 12,957 patients at 166 centers (destination therapy: 47.4%, bridge-to-transplant: 41.2%). First infections were most often non-ventricular assist device (54.2%). Rates of first infection were highest in the early interval (10.7/100 person-months). Patients with any infection had a significantly higher adjusted hazard of death (hazard ratio, 2.63; 2.46-2.86). First infection in the intermediate interval was associated with the largest increase in adjusted hazard of death (hazard ratio, 3.26; 2.82-3.78), followed by late (hazard ratio, 3.13; 2.77-3.53) and early intervals (hazard ratio, 2.37; 2.16-2.60). Ventricular assist device-related infections were associated with the largest increase in hazard of death (hazard ratio, 3.02; 2.69-3.40), followed by ventricular assist device specific (hazard ratio, 2.92; 2.57-3.32) and non-ventricular assist device (hazard ratio, 2.42; 2.20-2.65).

CONCLUSIONS

Relative to those without infection, patients with any postimplantation infection had an increased risk of death. Ventricular assist device-related infections and infections occurring in the intermediate interval were associated with the largest increase in risk of death. After left ventricular assist device implantation, infection prevention strategies should target non-ventricular assist device infections in the first 90 days, then shift to surveillance/prevention of driveline infections after 90 days.

Outcomes of heart transplant recipients with prior left ventricular assist device associated stroke

BACKGROUND

Left ventricular assist devices (LVADs) improve survival in patients with end-stage heart failure but are associated with ischemic stroke and intracranial hemorrhage (ICH). The impact of LVAD-associated stroke on transplant candidacy and outcomes has not been characterized.

METHODS

Adult patients undergoing LVAD implantation at Cleveland Clinic between 2004 to 2021 were reviewed and patients who developed ischemic stroke or ICH were identified. Post-transplant survival analysis was performed between patients with LVAD-associated stroke vs. without.

RESULTS

917 patients had an LVAD implantation of whom 244 (median age 57, 79% male) underwent subsequent transplant including 25 with prior LVAD-associated stroke. The 1- and 2-year survival after transplant in patients with LVAD-associated stroke were 100% and 95% respectively, compared with 92% and 90% in patients without stroke (p=0.156; p=0.323) Similarly, there was no difference in stroke incidence at 1- and 2 years after transplant between patients with LVAD-associated stroke (4% and 5%) and those without prior stroke (5% and 6%, p = 0.884; p=0.744).

CONCLUSIONS

In this single-center retrospective study, patients with LVAD-associated stroke were significantly less likely to undergo heart transplant, but those who underwent heart transplant had similar post-transplant outcomes as patients without history of LVAD-associated stroke. Given the similar outcomes seen in this population, history of LVAD-associated stroke should not be viewed as an absolute contraindication to subsequent heart transplant.

Depression among Patients with an Implanted Left Ventricular Assist Device: Uncovering Pathophysiological Mechanisms and Implications for Patient Care

Depression is a common and devastating mental illness associated with increased morbidity and mortality, partially due to elevated rates of suicidal attempts and death. Select patients with end-stage heart failure on a waiting-list for a donor heart undergo left ventricular assist device (LVAD) implantation. The LVAD provides a circulatory flow of oxygenated blood to the body, mimicking heart functionality by operating on a mechanical technique. LVAD improves functional capacity and survivability among patients with end-stage heart failure. However, accumulating data suggests that LVAD recipients suffer from an increased incidence of depression and suicide attempts. There is scarce knowledge regarding the pathological mechanism and appropriate treatment approach for depressed LVAD patients. This article summarizes the current evidence on the association between LVAD implantation and occurrence of depression, suggesting possible pathological mechanisms underlying the device-associated depression and reviewing the current treatment strategies. The summarized data underscores the need for a rigorous pre-(LVAD)-implantation psychiatric evaluation, continued post-implantation mental health assessment, and administration of antidepressant treatment as necessary.

Management of hypertension in patients supported with continuous flow left ventricular assist devices

PURPOSE OF REVIEW

Hypertension remains one of the most common clinical problems leading to devastating postleft ventricular assist device (LVAD) implant complications. This study reviews the pathophysiology of hypertension in the setting of continuous flow LVAD support and provides an update on currently available antihypertensive therapies for LVAD patients.

RECENT FINDINGS

The true prevalence of hypertension in the LVAD population remains unknown. Effective blood pressure (BP) control and standardization of BP measurement are key to prevent suboptimal left ventricular unloading, pump malfunction and worsening aortic regurgitation. Angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB), beta blockers and mineralocorticoid receptor antagonists (MRA) are the preferred antihypertensive agents because of their additional potential benefits, including optimization of haemodynamics, prevention of stroke, gastrointestinal bleed and in some patients myocardial recovery. Angiotensin receptor-neprilysin inhibition (ARNI) may be a well tolerated and effective therapy for BP control especially among CF-LVAD patients with resistant hypertension. Similarly, sodium glucose co-transporter 2 inhibitors (SGLT2i) should be considered in the absence of contraindications.

SUMMARY

Hypertension is very common post-LVAD implant. Heart failure guideline directed medical therapies, including ACEI, ARB, beta blockers and MRA, are the preferred antihypertensive agents to improve post-LVAD outcomes.

Stroke and pump thrombosis following left ventricular assist device implantation: The impact of the implantation technique

Objectives

Several studies have shown the potential advantage of less-invasive surgery (LIS) for left ventricular assist device (LVAD) implantation. This study aims to determine the impact of LIS on stroke and pump thrombosis events after LVAD implantation.

Methods

Between January 2015 and March 2021, 335 consecutive patients underwent LVAD implantation using either conventional sternotomy (CS) or the LIS technique. Patient characteristics was prospectively collected. All patients were followed up until October 2021. Logistic multivariate regression and propensity-matched analyses were performed to account for confounding factors.

Results

A total of 242 patients (F = 32; 13.0%) underwent LVAD implantation with CS and 93 patients (F = 8; 8.6%) with the LIS approach. Propensity matching generated two groups, including 98 patients in the CS group and 67 in the LIS group. Intensive care unit stay for the LIS group patients was significantly shorter than that for the CS group patients [2 (IQR: 2-5) days vs. 4 (IQR: 2-12) days, p < 0.01]. There were no significant differences in the incidence of stroke events (14% in CS vs. 16% in the LIS group; p = 0.6) or in pump thrombosis (6.1% in CS vs. 7.5% in the LIS group; p = 0.8) between the groups. The hospital mortality rate in the matched cohort was significantly lower in the LIS group (7.5% vs. 19%; p = 0.03). However, the 1-year mortality rate showed no significant difference between both groups (24.5% in CS and 17.9% in LIS; p = 0.35).

Conclusions

The LIS approach for LVAD implantation is a safe procedure with potential advantage in the early postoperative period. However, the LIS approach remains comparable to the sternotomy approach in terms of postoperative stroke, pump thrombosis, and outcome.

Continuous-Flow Ventricular Assist Device Support in Adult Congenital Heart Disease: A 15-Year, Multicenter Experience of Temporary and Durable Support

Heart failure (HF) is common in adult congenital heart disease (ACHD) patients; however, use of continuous-flow ventricular assist devices (CF-VADs) remains rare. We reviewed outcomes of patients with congenital heart disease greater than or equal to 18 years of age at the time of CF-VAD implant at the affiliated pediatric and adult institutions between 2006 and 2020. In total, 18 ACHD patients (15 with great anatomical complexity) received 21 CF-VADs. Six patients (median age 34 years) received seven percutaneous CF-VADs with a median duration of support of 20 days (3-44 days) with all patients survived to hospital discharge and two patients were bridged to durable CF-VADs. Fourteen patients (median age 38 years) received durable CF-VADs. Thirteen patients (93%) survived to hospital discharge and the median duration of support was 25.8 months (6.4-52.1 months). Estimated survival on durable CF-VAD at 1, 3, and 5 years was 84%, 72%, and 36%, respectively. Three patients were successfully bridged to transplantation. Device-related complications include cerebrovascular accident (n = 5), driveline infection (n = 3), device infection requiring chronic antibiotic therapy (n = 4), gastrointestinal bleeding (n = 6), and presumed pump thrombosis (n = 5). These results show percutaneous and durable CF-VADs can support ACHD patients with advanced HF.

Vascular Function in Continuous Flow LVADs: Implications for Clinical Practice

Left ventricular assist devices (LVADs) have been increasingly used in patients with advanced heart failure, either as a destination therapy or as a bridge to heart transplant. Continuous flow (CF) LVADs have revolutionized advanced heart failure treatment. However, significant vascular pathology and complications have been linked to their use. While the newer CF-LVAD generations have led to a reduction in some vascular complications such as stroke, no major improvement was noticed in the rate of other vascular complications such as gastrointestinal bleeding. This review attempts to provide a comprehensive summary of the effects of CF-LVAD on vasculature, including pathophysiology, clinical implications, and future directions.

Sex disparities in left ventricular assist device implantation outcomes: A systematic review and meta-analysis of over 50 000 patients

BACKGROUND

Left ventricular assist devices (LVAD) represent an important therapeutic option for patients progressing to end-stage heart failure. Women have been historically underrepresented in LVAD studies, and have been reported to have worse outcomes despite technological optimisation. We aimed to systematically explore the evidence on sex disparities in the use and outcomes of LVAD implantation.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles of men versus women undergoing LVAD implantation, in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to July 2022. Primary outcomes were stroke (haemorrhagic and ischaemic) and early/overall mortality. Secondary outcomes were LVAD thrombosis, right VAD implantation, major bleeding, kidney dysfunction, and device/driveline infection.

RESULTS

Our search yielded 137 relevant studies, including 22 meeting the inclusion criteria with a total of 53 227 patients (24.2% women). Overall mortality was higher in women (odds ratio [OR] 1.35, 95% confidence interval [CI] 1.05-1.62, p = 0.02), as was overall stroke (OR 1.32, 95%CI 1.06-1.66, p = 0.01), including ischemic (OR 1.80, 95%CI 1.22-2.64, p = 0.003) and haemorrhagic (OR 1.72, 95%CI 1.09-2.70, p = 0.02). Women had more frequent right VAD implantation (OR 2.11, 95%CI 1.24-3.57, p = 0.006) and major bleeding (OR 1.40, 95%CI 1.06-1.85, p = 0.02). Kidney dysfunction, LVAD thrombosis, and device/driveline infections were comparable between sexes.

CONCLUSIONS

Our analysis suggests that women face a greater risk of adverse events and mortality post-LVAD implantation. Although the mechanisms remain unclear, the difference in outcomes is thought to be multifactorial. Further research, that includes comprehensive pre-operative characteristics and post-operative outcomes, is encouraged.

Neurologic Complications in Patients With Left Ventricular Assist Devices

Left ventricular assist device (LVAD) use has revolutionised the care of patients with advanced heart failure, allowing more patients to survive until heart transplantation and providing improved quality for patients unable to undergo transplantation. Despite these benefits, improvements in device technology, and better clinical care and experience, LVADs are associated with neurologic complications. This review provides information on the incidence, risk factors, and management of neurologic complications among LVAD patients. Although scant guidelines exist for the evaluation and management of neurologic complications in LVAD patients, a high index of suspicion can prompt early detection of neurologic complications which may improve overall neurologic outcomes. A better understanding of the implications of continuous circulatory flow on systemic and cerebral vasculature is necessary to reduce the common occurrence of neurologic complications in this population.

Controversies and challenges of coil embolization for intracranial aneurysm in a continuous-flow LVAD implanted patient: A case report

Background

Continuous-flow left ventricular assist device (CF-LVAD) technology has rapidly developed to support the failing heart refractory to standard medical treatments. Although the expected prognosis has improved dramatically, ischemic and hemorrhagic strokes are possible complications and the leading causes of death in the CF-LVAD population.

Case Description

We encountered a case of an unruptured large internal carotid aneurysm in a patient with a CF-LVAD. Following a detailed discussion of his expected prognosis, the risk of aneurysm rupture, and the inherited risk of aneurysm treatment, coil embolization was performed without adverse events. The patient remained recurrence-free for 2-year postoperatively.

Conclusion

This report illustrates the feasibility of coil embolization in a CF-LVAD recipient and emphasizes the necessity of vigilant consideration of whether to intervene in an intracranial aneurysm after CF-LVAD implantation. We confronted several challenges during the treatment: optimal endovascular technique, management of antithrombotic drugs, safe arterial access, desirable perioperative imaging modalities, and prevention of ischemic complications. This study aimed to share this experience.

Sex differences in patients undergoing heart transplantation and LVAD therapy

INTRODUCTION

Left ventricular assist device (LVAD) and heart transplantation (HT) are the two life-sustaining therapies that have revolutionized the management of end-stage heart failure (HF). Yet, significant sex differences exist with respect to their use and effects.

AREAS COVERED

This review summarizes sex differences in the utilization, outcomes, and complications of LVAD and HT. Particular emphasis is placed on leading clinical trials in the field, historical and recent large registries-based analyses, as well as contemporary technological and policy changes affecting these differences.

EXPERT OPINION

Women with advanced HF remain under-treated with guideline-directed medical therapy and are less likely to be referred for consideration for LVAD and HT. This remains true despite newer LVAD technology and the new heart transplant allocation system. Community outreach, education, as well as increased representation of women in clinical research may reduce inequities.

Implications of Causes of Intracranial Hemorrhage During Left Ventricular Assist Device Support

BACKGROUND

Intracranial hemorrhage (ICH) is a frequent complication in patients with an implanted left ventricular assist device (LVAD) for advanced heart failure. Bloodstream infection is known to be associated with ICH in patients with LVAD, but its effects on ICH-associated mortality are unknown. We compared characteristics and mortality of infection-associated, traumatic, and spontaneous hemorrhages.

METHODS

Patients in an LVAD registry at a tertiary care center were reviewed for this cohort study. ICH included intraparenchymal hemorrhage, subarachnoid hemorrhage, and subdural hemorrhage. Hemorrhages were categorized into infectious, traumatic, and spontaneous by the presence or absence of concurrent device-associated infection or antecedent trauma.

RESULTS

Of 683 patients with an LVAD, 73 experienced ICH (10.7%). Intraparenchymal hemorrhage was the most prevalent (72%), followed by subarachnoid hemorrhage (27%) and subdural hemorrhage (23%), with multiple concurrent hemorrhage subtypes in 16 patients (22%). Median time from implantation to ICH was shorter in spontaneous ICH than in infection-associated ICH (100 days vs. 252 days, p = 0.048). The prevalence of the different subtypes of ICH were similar between spontaneous and infection-associated ICH, and no differences were seen in mortality between the different causes of ICH.

CONCLUSIONS

Although spontaneous ICH occurred earlier after LVAD implantation than infection-associated ICH, no difference in mortality was seen between the different causes of ICH.

Surgical left atrial appendage occlusion in patients with left ventricular assist device

BACKGROUND

Thromboembolic (TE) events are among the most common and devastating adverse events in patients with continuous-flow left ventricular assist device (cf-LVAD). Given the high burden of AF among cf-LVAD patients, we sought to evaluate the effect of concomitant surgical LAAO in patients receiving cf-LVAD.

METHODS

A systematic search using electronic databases was performed using the keywords: "left atrial appendage occlusion" and "left ventricular assist device." Statistical analysis was performed using meta-package for R version 4.0 and Rstudio version 1.2. Mantel-Haenszel risk ratio (RR) random-effects model was used to summarize data between two groups. The primary outcomes included: (a) stroke; (b) LVAD pump thrombosis; (c) all-cause mortality RESULTS: : Three studies with a total of 305 patients (LAAO=68 and No-LAAO=237) were included in the analysis. HeartMate II (39%) and Heartware (27.5%) were the two most common cf-LVADs utilized, while only 5% received HeartMate III. At a mean follow up of 1.47 years, LAAO group had a lower risk of stroke (8.8% vs 15.2%, RR 0.64; 95% CI 0.28 - 1.49), LVAD pump thrombosis (1.5% vs 3.8%, RR 0.28; 95% CI 0.05 - 1.55) and all-cause mortality (5.9% vs 20.2%, RR 0.69; 95% CI 0.19 - 2.52) when compared with no-LAAO group, but the difference did not reach statistical significance.

CONCLUSION

Concomitant surgical LAAO at the time of cf-LVAD implantation demonstrated a trend towards positive outcomes and was not associated with adverse outcomes during the follow-up period, though the results were not statistically significant This article is protected by copyright. All rights reserved.

Intracranial Mycotic Aneurysm after Left Ventricular Assist Device Implantation Treated with Trans-arterial Embolization via the Brachial Artery: A Case Report

Implantation of left ventricular assist device (LVAD) is widely performed in patients with end-stage chronic heart failure. Infection and stroke are major complications after LVAD implantation. However, the incidence of intracranial mycotic aneurysm after LVAD implantation is rare, and with no standard of care. In this study, we describe a case of an intracranial mycotic aneurysm after LVAD implantation that was successfully treated with trans-arterial embolization (TAE) with N-butyl 2-cyanoacrylate (NBCA) via the brachial artery. A 49-year-old man with a history of implantation of LVAD for ischemic cardiomyopathy was admitted to our institution. He had infectious endocarditis and was administered systemic antibiotics. At 3 weeks after admission, intracranial mycotic aneurysm of the left posterior parietal artery was detected during a diagnostic examination for asymptomatic intracranial hemorrhage. Anticoagulant therapy was administered to prevent thromboembolic complications of LVAD implantation. Under local anesthesia, TAE with NBCA was performed via the brachial artery because of the tortuous anatomy of the origin of the innominate artery and implant of the aortic arch. The aneurysm was completely obliterated. The patient was discharged without neurological deficits. TAE using NBCA could be an effective modality for the treatment of intracranial mycotic aneurysm after LVAD implantation.

Risk of Stroke with Impella Placement Is Not Associated with Access Vessel

Objective: The Impella heart pump is an intravascular microaxial device that provides short-term mechanical circulatory support and can be placed through the femoral, axillary, or central vessels. One of the most feared complications is stroke. It is unclear if patient stroke risk varies based on access vessel. Methods: A retrospective review of consecutive patients who underwent Impella placement at an academic institution from January 1, 2007, through September 15, 2018, was performed. Four groups were compared: (1) minimally invasive Impella (femoral or axillary access), (2) minimally invasive Impella upgraded to another minimally invasive Impella, (3) minimally invasive Impella upgraded to a central Impella (ascending aorta), and (4) central Impella. Patient charts were reviewed to identify baseline characteristics. Outcome measures included length of stay, stroke, and mortality. Results: A total of 349 patients (or 407 Impellas) were identified, and the majority of the devices were inserted through a minimally invasive approach (n = 248, 60.9%), while the remainder were implanted via central access (n = 159, 39.1%). Minimally invasive Impellas were upgraded in 44 patients. The risk of stroke for the entire cohort was 10.3% (n = 36), with no difference observed in any particular group. Overall mortality was 44.4% (n = 155). Of the patients who initially received a minimally invasive Impella, those who were upgraded had higher rates of mortality (56.8% vs 39.4%, P = 0.03), postoperative dialysis (50.0% vs 27.4%, P < 0.01), and sepsis (43.2% vs 20.0%, P < 0.01). Conclusions: This study found no statistically significant difference in rates of postoperative stroke based on initial access vessel.

Stroke epidemiology and outcomes in the modern era of left ventricular assist devices

The care for the patients with end-stage heart failure has been revolutionized by the introduction of durable left ventricular assist devices, providing a substantial improvement in patient survival and quality of life and an alternative to heart transplantation. The newest devices have lower instances of mechanical dysfunction and associated pump thrombosis. Despite these improvements in complications, the use of continuous flow assist devices is still associated with high rates of thrombotic and hemorrhagic complications, most notably stroke in approximately 10% of continuous flow assist devices patients per year. With the newest HeartMate 3 devices, there have been lower observed rates of stroke, which has in part been achieved by both improvements in pump technology and knowledge of the risk factors for stroke and neurological complications. The therapeutic options available to clinicians to reduce the risk of stroke, including management of hypertension and antithrombotics, will be reviewed in this manuscript.

Clinical considerations for the evaluation of patients with left ventricular assist devices

ABSTRACT

A left ventricular assist device (LVAD) provides mechanical circulatory support for patients with end-stage heart failure. As these devices become more prevalent, clinicians must be familiar with the device's function, common complications, and management strategies when evaluating this patient population.

Physiology of Continuous-Flow Left Ventricular Assist Device Therapy

The expanding use of continuous-flow left ventricular assist devices (CF-LVADs) for end-stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure-flow (H-Q) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF-LVAD therapy on right ventricular filling and function, through right-sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF-LVAD therapy has physiologic consequences for end-organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device-circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.

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.

Driveline Features as Risk Factor for Infection in Left Ventricular Assist Devices: Meta-Analysis and Experimental Tests

Background: Risk factors for driveline infection (DLI) in patients with left ventricular assist devices are multifactorial. The aim of this study was to analyze the correlation between mechanical driveline features and DLI occurrence.

Methods: A meta-analysis was conducted that included studies reporting DLI rates at 6 months after implantation of any of three contemporary devices (HVAD with Pellethane or Carbothane driveline, HeartMate II, and HeartMate 3). Further, outer driveline diameter measurements and ex-vivo experimental three-point bending and torsion tests were performed to compare the stiffness of the four different driveline types.

Results: 21 studies with 5,393 patients were included in the meta-analysis. The mean weighted DLI rates ranged from 7.2% (HeartMate II) to 11.9% (HeartMate 3). The HeartMate II driveline had a significantly lower maximal bending force (Load_max) (4.52 ± 0.19 N) compared to the Carbothane HVAD (8.50 ± 0.08 N), the HeartMate 3 (11.08 ± 0.3 N), and the Pellethane HVAD driveline (15.55 ± 0.14 N) (p < 0.001). The maximal torque (Torque_max) of the HeartMate II [41.44 (12.61) mNm] and the Carbothane HVAD driveline [46.06 (3.78) mNm] were significantly lower than Torque_max of the Pellethane HVAD [46.06 (3.78) mNm] and the HeartMate 3 [95.63 (26.60) mNm] driveline (p < 0.001). The driveline of the HeartMate 3 had the largest outer diameter [6.60 (0.58) mm]. A relationship between the mean weighted DLI rate and mechanical driveline features (Torque_max) was found, as the the HeartMate II driveline had the lowest Torque_max and lowest DLI rate, whereas the HeartMate 3 driveline had the highest Torque_max and highest DLI rate.

Conclusions: Device-specific mechanical driveline features are an additional modifiable risk factor for DLI and may influence clinical outcomes of LVAD patients.

Alarms and Their Outcomes in Left Ventricular Assist Device Patients

Low flow and suction alarms are provided to alert caregivers of changes in left ventricular assist device pump function but may be reset in clinical practice. We investigated the incidence and underlying causes of these alarms as well as their prognostic significance. HeartWare ventricular assist device patients (n = 113) were divided into quartiles based on their frequency of low flow and suction alarms. Survival and adverse events (thrombus, stroke, bleeding, and right heart failure) were compared between quartiles. Low flow alarms peaked in the first few months of pump support before dropping down to near negligible levels. Suction alarm frequency remained relatively constant throughout pump support. Although pump speeds (p < 0.001) and flow (p = 0.01) decreased over time, there was an increase in suction alarm frequency (p = 0.018), with no changes in low flow alarms. Patients with smaller body size (p = 0.016) and lower pump flows (p = 0.008) had higher frequencies of low flow alarms on multiple regression (p < 0.001). Patients with the highest low flow alarm frequency demonstrated poorer survival (p = 0.026). There was no relationship between suction alarm frequency and survival. There was also no relationship between either low flow or suction alarm frequency with strokes, gastrointestinal bleeds, pump thrombus, or right ventricular failure. Duration of alarm and intervention in response to the alarm was not assessed in this study. Further studies examining alarm duration and responses may inform future pump alarm algorithms.

Long-Term Neurocognitive Outcome in Patients With Continuous Flow Left Ventricular Assist Device

OBJECTIVES

The authors sought to examine the long-term cognitive outcome of patients with continuous flow left ventricular assist device (CF-LVAD).

BACKGROUND

Data on long-term neurocognitive outcome in LVAD are limited. We examined the neurocognitive outcome of patients who received a CF-LVAD as destination therapy.

METHODS

Patients with HeartWare (HVAD) and HeartMate II who were enrolled in the ENDURANCE and ENDURANCE Supplemental trials were eligible. Cognition was evaluated with neuropsychological testing preoperatively and at 6, 12, and 24 months after implantation. General linear models identified demographic, disease, and treatment factors that predicted decline on each neurocognitive measure.

RESULTS

Of 668 patients who completed baseline testing and at least 1 follow-up evaluation, 552 were impaired at baseline on at least 1 cognitive measure. At each follow-up, approximately 23% of tested patients declined and 20% improved relative to baseline on at least 1 cognitive measure. Of those who were intact at baseline, only 10%-12% declined in delayed memory and 11%-16% declined in executive function at all 3 follow-ups. For patients impaired at baseline, delayed memory decline was associated with the HVAD device and male sex, whereas executive function decline was associated with the HVAD device and stroke during CF-LVAD support. For patients intact at baseline, male sex and history of hypertension were associated with decline in immediate memory and executive function, respectively.

CONCLUSIONS

Neurocognitive function remained stable or improved for most patients (∼80%) with CF-LVAD at 6, 12, and 24 months after implantation. Male sex, hypertension, HVAD, and stroke were associated with cognitive decline.

Stroke in Patients with Left Ventricular Assist Devices

BACKGROUND

Left ventricular assist devices (LVADs) are artificial pumps used in end-stage heart failure to support the circulatory system. These cardiac assist devices work in parallel to the heart, diverting blood from the left ventricle through an outflow graft and into the ascending aorta. LVADs have allowed patients with end-stage heart failure to live longer and with improved quality of life compared to best medical therapy alone. However, they are associated with significant risks related to both thrombosis and bleeding in this medically complex patient population. As LVADs continue to be used more widely, stroke neurologists need to become familiar with the unique physical exam and vascular imaging findings associated with this population.

SUMMARY

Reported rates of LVAD-associated stroke at 2 years post-implantation range from 10 to 30%, which is significantly higher than in age-matched controls. There are approximately equal rates of ischemic and hemorrhagic strokes, and rates are highest during the peri-implantation period and in the first year of therapy. Risk factors associated with ischemic and hemorrhagic stroke in this cohort can be grouped into treatment-related factors, including specific devices and antithrombotic/anticoagulation strategy, and patient-related factors. Evidence for reperfusion therapy for acute stroke in this population is limited. Intravenous tissue plasminogen activator (IV-tPA) is often contraindicated as events may occur in the perioperative setting, or in the context of therapeutic anticoagulation. Endovascular therapy with successful recanalization is reported, but there is little experience documented in the published literature. Key messages: LVAD use is increasingly common. Given the high associated risks of stroke, neurologists will need to become increasingly familiar with an approach to assessment and therapy for LVAD patients with cerebrovascular issues.

Cerebrovascular Events in Patients With Centrifugal-Flow Left Ventricular Assist Devices: Propensity Score-Matched Analysis From the Intermacs Registry

BACKGROUND

Ischemic and hemorrhagic cerebrovascular accidents remain common among patients with centrifugal-flow left ventricular assist devices, despite improvements in survival and device longevity. We compared the incidence of neurologic adverse events (NAEs) associated with 2 contemporary centrifugal-flow left ventricular assist devices: the Abbott HeartMate3 (HM3) and the Medtronic HeartWare HVAD (HVAD).

METHODS

Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a centrifugal-flow left ventricular assist device as a primary isolated implant between January 1, 2017, and September 30, 2019. Major NAEs were defined as transient ischemic attack, ischemic cerebrovascular accident, or hemorrhagic cerebrovascular accident. The association of HVAD with risk of NAE in the first year after implant was evaluated using propensity score matching to balance for preimplant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data-driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase.

RESULTS

Of 6205 included patients, 3129 (50.4%) received the HM3 and 3076 (49.6%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD, respectively). Patients receiving HVAD had more major NAEs (16.4% versus 6.4%, P<0.001) as well as each subtype (transient ischemic attack: 3.3% versus 1.0%, P<0.001; ischemic cerebrovascular accident: 7.7% versus 3.4%, P<0.001; hemorrhagic cerebrovascular accident: 7.2% versus 2.0%, P<0.001) than did patients receiving HM3. A propensity-matched cohort balanced for preimplant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE 82% versus 92%, P<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio, 5.71 [CI, 3.90-8.36]).

CONCLUSIONS

HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early postimplantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Medical and Surgical Management of Left Ventricular Assist Device-Associated Intracranial Hemorrhage

OBJECTIVES

Management of left ventricular assist device (LVAD)-associated intracranial hemorrhage (ICH) is complicated by the competing concerns of hematoma expansion and the risk of thrombosis. Strategies include reversal or withholding of anticoagulation (AC) and neurosurgical (NSG) interventions. The consequences of these decisions can significantly impact both short- and long-term survival. Currently no guidelines exist. We reviewed medical and NSG practices following LVAD-associated ICH and analyzed outcomes.

MATERIALS AND METHODS

Retrospective analysis of data collected between 2012-2018 was performed. Survival probability following ICH was calculated using the Kaplan-Meier method.

RESULTS

Out of 283 patients, 32 (11%) had 34 ICHs: 16 intraparenchymal (IPH, 47%), 4 subdural (SDH, 12%), and 14 subarachnoid (SAH, 41%). IPH tended to occur sooner (median 138 [IQR 48 - 258] days post-LVAD placement) and be more neurologically devastating (mean GCS 11.4 [4.4]). Antithrombotics were reversed in 27 (79%); 1 thrombotic event occurred while off AC. Following resumption, re-hemorrhage occurred in 7 (25%), a median of 13 days (IQR 8-30) post-ICH. Five underwent NSG intervention and 6 (18%) went on to receive heart transplant. Overall, 30-day mortality was 26% (38% in IPH, 0% in SDH, and 29% in SAH), but rose to 44% at 6 months.

CONCLUSION

ICH is a common post-LVAD complication with high short- and long-term mortality, though ICH subtypes may not be equally devastating. Despite this, some may benefit from neurosurgical intervention and do well following cardiac transplant. Anticoagulation is frequently reversed after ICH. Resumption however should be approached cautiously in patients with LVADs given their possible baseline coagulopathy.

Cerebrovascular Events in Patients with Centrifugal-Flow Left Ventricular Assist Devices: A Propensity Score Matched Analysis from the Intermacs Registry

Background: Ischemic and hemorrhagic cerebrovascular accidents (ICVA and HCVA, respectively) remain common among patients with centrifugal-flow left ventricular assist devices (CF-LVADs), despite improvements in survival and device longevity. Therefore, the incidence of neurological adverse events (NAEs) associated with two contemporary CF-LVADs, the Abbott HeartMate3^® (HM3) and the Medtronic HeartWare^™ HVAD^® (HVAD), were compared. Methods: Using the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs), we collected data on adult patients who received a CF-LVAD as a primary isolated implant between 1/1/2017 and 9/30/2019. Major NAEs were defined as transient ischemic attack (TIA), ICVA, and HCVA. The association of HVAD with risk of NAE in the first year post implant was evaluated using propensity score matching to balance for pre-implant risk factors. After matching, freedom from first major NAE in the HM3 and HVAD cohorts was compared with Kaplan-Meier curves. A secondary analysis using multivariable multiphase hazard models was used to identify predictors of NAE, which uses a data driven parametric fit of the early declining and constant phase hazards and the associations of risk factor with either phase. Results: Of 6,205 included patients, 3,076 (49.6%) received the HM3 and 3,129 (50.4%) received the HVAD. Median follow-up was 9 and 12 months (HM3 and HVAD). HVAD patients had more major NAEs (16.4% vs. 6.4%, p<0.001), as well as each subtype (TIA: 3.3% vs. 1.0%, p<0.001; ICVA: 7.7% vs. 3.4%, p<0.001; and HCVA: 7.2% vs. 2.0%, p<0.001), than did HM3 patients. A propensity-matched cohort balanced for pre-implant risk factors showed that HVAD was associated with higher probabilities of major NAEs (% freedom from NAE: 82% vs. 92%, p<0.001). Device type was not significantly associated with NAEs in the early hazard phase, but HVAD was associated with higher incidence of major NAEs during the constant hazard phase (hazard ratio: 5.71, confidence interval: 3.90-8.36). Conclusions: HM3 is associated with lower hazard of major NAEs than is HVAD beyond the early post-implantation period and during the constant hazard phase. Defining the explanation for this observation will inform device selection for individual patients.

Total Artificial Heart as Bridge to Cardiac Retransplantation

Mechanical circulatory support has been performed as a bridge to cardiac retransplantation in selected patients with graft failure. However, there is limited published experience on the use and potential benefit of the total artificial heart (TAH) as a bridge to cardiac retransplantation. We report on our institutional experience with 3 patients that received TAH as a bridge to retransplant, with 1 patient surviving post-retransplantation. This case series demonstrates the high-risk nature of this undertaking in cardiac retransplant candidates and highlights the issue of sensitization portending greater risk for poor outcomes after TAH as bridge to retransplantation.

Alternatives for Vitamin K Antagonists as Thromboprophylaxis for Mechanical Heart Valves and Mechanical Circulatory Support Devices: A Systematic Review

The holy grail of anticoagulation in patients with intracardiac devices, such as mechanical heart valves (MHVs) and left ventricular assist devices (LVADs), comprises safe prevention of thrombosis without interrupting normal hemostasis. Device-induced thrombosis and anticoagulant-related bleeding problems are dreaded complications that may cause a significantly reduced quality of life and increased morbidity and mortality. Vitamin K antagonists are the current standard for oral anticoagulation therapy in patients with MHVs and LVADs. Even within the therapeutic range, hemorrhage is the primary complication of these drugs, which emphasizes the need for safer anticoagulants for the prevention of device-induced thrombosis. Device-induced thrombosis is a complex multifactorial phenomenon that likely requires anticoagulant therapy targeting multiple pathways. Here, we review the preclinical and clinical data describing the efficacy of a variety of anticoagulants as thromboprophylaxis after implantation of intracardiac devices.

How Are We Monitoring Brain Injuries in Patients With Left Ventricular Assist Device? A Systematic Review of Literature

Despite the common occurrence of brain injury in patients with left ventricular assist device (LVAD), optimal neuromonitoring methods are unknown. A systematic review of PubMed and six electronic databases from inception was conducted until June 5, 2019. Studies reporting methods of neuromonitoring while on LVAD were extracted. Of 5,190 records screened, 37 studies met the inclusion criteria. The neuromonitoring methods include Transcranial Doppler ultrasound for emboli monitoring (TCD-e) (n = 13) and cerebral autoregulation (n = 3), computed tomography and magnetic resonance imaging (n = 9), serum biomarkers (n = 7), carotid ultrasound (n = 3), and near-infrared spectroscopy (n = 2). Of 421 patients with TCD-e, thromboembolic events (TEs) were reported in 79 patients (20%) and microembolic signals (MES) were detected in 105 patients (27%). Ischemic stroke was more prevalent in patients with MES compared to patients without MES (43% vs.13%, p < 0.001). Carotid ultrasound for assessing carotid stenosis was unreliable after LVAD implantation. Elevated lactate dehydrogenase (LDH) levels were associated with TEs. Significant heterogeneity exists in timing, frequency, and types of neuromonitoring tools. TCD-e and serial LDH levels appeared to have potential for assessing the risk of ischemic stroke. Future prospective research incorporating protocolized TCD-e and LDH may assist in monitoring adverse events in patients with LVAD.

The Use of Factor Eight Inhibitor Bypass Activity (FEIBA) for the Treatment of Perioperative Hemorrhage in Left Ventricular Assist Device Implantation

OBJECTIVE

To test the hypothesis that factor eight inhibitor bypassing activity (FEIBA) can be used to control bleeding following left ventricular assist device (LVAD) implantation without increasing the 14-day composite thrombotic outcome of pump thrombus, ischemic cerebrovascular accidents, pulmonary embolism, and deep venous thrombosis.

DESIGN

Retrospective cohort study.

SETTING

Academic hospital.

PARTICIPANTS

Three hundred nineteen consecutive patients who underwent LVAD implantation (December 1, 2009 to December 30, 2018).

INTERVENTION

FEIBA administered to control perioperative hemorrhage.

MEASUREMENTS AND MAIN RESULTS

The 82 patients (25.7%) in the FEIBA cohort had more risk factors for perioperative hemorrhage, such as lower preoperative platelet count (169 ± 66 v 194 ± 68 × 10³/mL, p = 0.004), prior cardiac surgery (36.6% v 21.9%, p = 0.008), and longer cardiopulmonary bypass (CPB) time (100.3 v 75.2 minutes, p = 0.001) than the 237 controls. After 16.6 units (95% CI: 14.3-18.9) of blood products were given, 992 units (95% CI: 821-1163) of FEIBA were required to control bleeding in the FEIBA cohort. Compared to the controls, there were no differences in the 14-day composite thrombotic outcome (11.0% v 7.6%, p = 0.343) or mortality rate (3.7% v 1.3%, p = 0.179). Multivariate logistical regression identified preoperative international normalized ratio (odds ratio [OR]: 1.30, 95% CI: 1.04-1.62) and CPB time (OR: 1.11, 95% CI: 1.02-1.20) as risk factors for 14-day thrombotic events, but FEIBA usage was not associated with an increased risk.

CONCLUSIONS

In this retrospective cohort study, the use of FEIBA (∼1,000 units, ∼13 units/kg) to control perioperative hemorrhage following LVAD implantation was not associated with increases in mortality or composite thrombotic outcome.