Ventricular Assist Devices

Microneedle patches: the next frontier in cardiovascular care

Myocardial infarction is a condition where the heart muscle is damaged due to clogged coronary arteries. There are limited treatment options for treating myocardial infarction. Microneedle patches have recently become popular as a possibly viable therapy for myocardial. By adhering to the surface of the heart, these microneedle patches provide mechanical support, regenerative medicines, or cells directly to the injured tissue allowing for targeted treatment. These microneedle patches resolve the drawbacks of systemic therapy by facilitating targeted administration and integration with the goal of restoring damaged heart function. Recent advances in fabrication methods and current perspectives on the therapeutic advantages of cardiac microneedles patches used in the treatment of myocardial infarction are summarized in this review. Although the data is less in this area this review provides an avenue for the formulation scientist working in biomedical science to develop such microneedle patches for clinical applications in cardiology.

Driveline dressings used in heartmate patients and local complications: A retrospective cohort

BACKGROUND

Patients with long-term ventricular assist devices (VAD) are predisposed to infection, bleeding, and pressure injuries at the insertion of the driveline. There is no consensus on a driveline dressing protocol. Chlorhexidine is often used to clean the driveline exit site and has been associated with lower rates of infection. For driveline coverage, bacteriostatic agents and transparent film have shown good results, but are costly. The same issue was associated with anchorage devices.

OBJECTIVES

The purpose of this study was to evaluate the types of dressings used in the driveline of patients using HeartMate (HM) and to describe the incidence density of local complications (infection, bleeding, and pressure injury) within 30 days postoperatively.

METHODS

A retrospective cohort study was conducted and included 22 patients admitted to the Intensive Care Unit after implantation of HM II and III in a Brazilian private hospital.

RESULTS

Several types of dressings were used in the drivelines. There were 22 different types of dressings. Dressing type 6 (Chlorhexidine, Excilon, Gauze and IV3000) were the most used (45.4%). Subjects using the Flexi-Trak anchoring device had a higher rate of local bleeding (50.0%) and those who used the Hollister device had more infection (61.1%) and pressure injury associated with a medical device (11.1%), compared to others. Infection was the primary complication (45.4%), followed by local bleeding (27.7%).

CONCLUSION

Despite the high variability of products used in the driveline of patients using HeartMate, the dressing made with chlorhexidine, silver-impregnated absorbent foam and transparent film, and the use of anchoring devices was the most frequently used. Infection was the most common complication.

Ambulatory short-term mechanical circulatory support: facilitates recovery and prepares patients for definitive therapy

Short-term mechanical circulatory support (ST-MCS) devices have been traditionally deployed in patients with cardiogenic shock, advanced heart failure, cardiovascular collapse, and cardiorespiratory failure. Limitations of the mechanical support devices are typically related to mobility of the patient since the access is frequently through femoral vasculature. This limits the time the patient can be supported by mechanical circulatory support (MCS). We describe deployment of ST-MCS using alternate access such as the subclavian/axillary artery that facilitates ambulation of the patient. These include the deployment of intra-aortic balloon pump (IABP) through the subclavian artery, Impella pump through the axillary/subclavian artery, and extracorporeal membrane oxygenation (ECMO) using the subclavian artery and jugular vein.

Relationship between muscle strength and rehospitalization in ventricular assist device patients

We examined the relationship between leg extensor muscle strength (LEMS) at discharge and rehospitalization within 1 year in patients with a newly implanted ventricular assist device (VAD). This study included 28 patients who had received a VAD at our institution between October 2013 and February 2019, all of whom had been discharged for 1 year. The patients were divided into two groups according to their LEMS at discharge (higher strength [group H] and lower strength [group L]), based on the median value of the 55.2 kg-force (kgf)/body weight (BW) equation. Exercise performance parameters (e.g., grip strength, 6-min walk distance, and peak VO₂) and laboratory data concerning nutritional status were also collected. Nine patients (64.3%) in group L were rehospitalized within 1 year after discharge. The rehospitalization rate was significantly higher in group L than group H (p = 0.020). Compared with discharge, patients exhibited higher grip strength (56.3 vs. 48.6 kg/BW, respectively; p = 0.011), 6-min walk distances (588 vs. 470 m, respectively; p = 0.002), and peak VO₂ (15.4 vs. 11.9 mL/min/kg, respectively; p < 0.001) at 1 year after discharge. However, the LEMS (57.4 vs. 58.0 kgf/BW, respectively; p = 0.798) did not increase after discharge in VAD patients who avoided rehospitalization. LEMS at discharge was associated with rehospitalization after VAD surgery; a high LEMS improves the likelihood of avoiding rehospitalization.

What is the lived experience of patients with left ventricular assist devices during the COVID-19 pandemic? A qualitative analysis

Background

During the COVID-19 outbreak, patients with left ventricular assist device (LVAD) faced several changes in their daily life. However, the effects of these changes on the patients’ lived experiences are not still investigated.

Aims

The current study explored the lived experience of people with left ventricular assist device (LVAD) during the COVID-19 pandemic. During the COVID-19 outbreak, people with LVADs faced several changes in their daily life. However, the effects of these changes on the patients’ lived experiences are not still investigated.

Methods and results

Qualitative data analysis was conducted employing the interpretative phenomenological analysis approach. We followed the Standards for Reporting Qualitative Research guidelines. Eight male participants with LVAD aged from 65 to 82 were interviewed. Overall, two main themes (‘Worsening of psychological distress’ and ‘Moving forward’) and eight sub-themes emerged from the qualitative analysis.

Conclusions

People with LVADs experienced feelings of worry and solitude related to the risk of being infected or not receiving adequate treatment due to changes in the healthcare system during the pandemic; however, they managed to move forward with their lives using different strategies for dealing with the difficult situation.

The role of renin-angiotensin system in patients with left ventricular assist devices

End-stage heart failure is a condition in which the up-regulation of the systemic and local renin-angiotensin-aldosterone system (RAAS) leads to end-organ damage and is largely irreversible despite optimal medication. Left ventricular assist devices (LVADs) can downregulate RAAS activation by unloading the left ventricle and increasing the cardiac output translating into a better end-organ perfusion improving survival. However, the absence of pulsatility brought about by continuous-flow devices may variably trigger RAAS activation depending on left ventricular (LV) intrinsic contractility, the design and speed of the pump device. Moreover, the concept of myocardial recovery is being tested in clinical trials and in this setting LVAD support combined with intense RAAS inhibition can promote recovery and ensure maintenance of LV function after explantation. Blood pressure control on LVAD recipients is key to avoiding complications as gastrointestinal bleeding, pump thrombosis and stroke. Furthermore, emerging data highlight the role of RAAS antagonists as prevention of arteriovenous malformations that lead to gastrointestinal bleeds. Future studies should focus on the role of angiotensin receptor inhibitors in preventing myocardial fibrosis in patients with LVADs and examine in greater details the target blood pressure for these patients.

Self-management with the therapeutic regimen in patients with ventricular assist device (VAD) support - a scoping review

BACKGROUND

Ventricular assist device (VAD) implantation has become an established treatment strategy for the increasing number of patients with advanced heart failure. Adequate patient self-management becomes essential to prevent adverse events, which could diminish expected outcomes and survival for patients on VAD support.

OBJECTIVES

The aim of this study was to provide an overview of the current state of evidence concerning self-management in VAD patients through a systematized search and mapping of the literature.

METHODS

Following the scoping review process, a comprehensive literature search (PubMed, PsychInfo), tabular synthesis of included articles, and data analysis of synthesized findings were performed.

RESULTS

Overall, twenty articles were included. Results describe the complexity of regular self-management tasks and give direction for specific self-management training.

CONCLUSIONS

This article represents the first comprehensive overview of available evidence suggesting the need for development and implementation of evidence-based, patient self-management curricula with therapeutic regimen for VAD patients.

Prothrombin Complex Concentrate for Warfarin Reversal in Patients with Continuous-Flow Left Ventricular Assist Devices: A Narrative Review

Durable left ventricular assist device (LVAD) recipients require long-term anticoagulation to prevent thromboembolic complications. Their management is complicated by the risk of bleeding, which may require rapid anticoagulation reversal. We conducted a narrative review of data published from January 2007 to September 2018, analyzing anticoagulation reversal strategies in patients with durable, continuous-flow LVADs. The aim of this review is to provide guidance for reversal strategies in patients with LVADs experiencing bleeding complications or needing urgent surgical procedures, incorporating four-factor prothrombin complex concentrate (4F-PCC). Most data were from small, retrospective studies. Data for 4F-PCC use were more robust for heart transplant than for other surgical procedures or bleeding management. In patients undergoing heart transplant, 4F-PCC reversed warfarin more rapidly and reduced total blood product use versus other reversal strategies. Most surgical procedures were conducted without excess bleeding when utilizing 4F-PCCs. Time to warfarin reversal was shorter when managing intracranial hemorrhage with 4F-PCC. No differences in thromboembolic rates between 4F-PCC and control groups were observed. Overall, the use of 4F-PCC resulted in more rapid and predictable warfarin reversal in LVAD patients with no apparent risk of thromboembolism. Well-designed, larger prospective trials are required to better define 4F-PCC use in patients with LVADs.

Computational characterization of flow and blood damage potential of the new maglev CH-VAD pump versus the HVAD and HeartMate II pumps

Left ventricular assist devices are routinely used to treat patients with advanced heart failure as a bridge to transplant or a destination therapy. However, non-physiological shear stress generated by left ventricular assist devices damages blood cells. The continued development of novel left ventricular assist devices is essential to improve the left ventricular assist device therapy for heart failure patients. The CH-VAD is a new maglev centrifugal left ventricular assist device. In this study, the CH-VAD pump was numerically analyzed and compared with the HVAD and HeartMate II pumps under two clinically relevant conditions (flow: 4.5 L/min, pressure head: normal ~80 and hypertension ~120 mmHg). The velocity and shear stress fields, washout, and hemolysis index of the three pumps were assessed with computational fluid dynamics analysis. Under the same condition, the CH-VAD hemolysis index was two times lower than the HVAD and HeartMate II pumps; the CH-VAD had the least percentage volume with shear stress larger than 100 Pa (i.e. normal condition: 0.4% vs HVAD 1.0%, and HeartMate II 2.9%). Under the normal condition, more than 98% was washed out of the three pumps within 0.4 s. The washout times were slightly shorter under the hypertension condition for the three pumps. No regions inside the CH-VAD or HVAD had extremely long residential time, while areas near the straightener of the HeartMate II pump had long residential time (>4 s) indicating elevated risks of thrombosis. The computational fluid dynamics results suggested that the CH-VAD pump has a better hemolytic biocompatibility than the HVAD and HeartMate II pumps under the normal and hypertension conditions.

Noninvasive measurement of arterial blood pressure in patients with continuous-flow left ventricular assist devices: a systematic review

Accurate mean blood pressure determination is essential to prevent adverse events in patients with continuous-flow left ventricular assist devices (CFLVAD). We sought to evaluate the accuracy of noninvasive methods of blood pressure measurement compared with invasive intra-arterial recordings in patients with CFLVAD. Systematic electronic search was performed on four online databases (PubMed, Scopus, Embase, and Web of Knowledge) for the terms "Blood Pressure" AND ("Heart-Assist Devices" OR "Left ventricular Assist Devices"). Only studies that compared an intra-arterial and noninvasive blood pressure measurement were included. Electronic search of scientific literature identified 5968 articles. After deduplication, screening of titles and abstracts, full-text review, and excluding incorrect populations and comparator, a total of 12 studies with 502 participants were included, of those 402 participants who had intra-arterial blood pressure measurement. Doppler mean arterial blood pressure showed a very high correlation with mean intra-arterial blood pressure (r = 0.97, r = 0.87) in low pulsatility situations. When the pulsatility was not evaluated, the correlation was high moderate (r = 0.63, r = 0.741). In low pulsatility situations, the correlation was moderate to high moderate (r = 0.42 to r = 0.65). Oscillometer automatic blood pressure cuff showed a moderate to very high correlation with intra-arterial mean arterial blood pressure (r = 0.42, r = 0.86) but also could be low in the context of low pulsatility associated with inconsistent success in noninvasive measurement (r = 0.25). Studies correlating intra-arterial with noninvasive techniques were performed in the context of routine clinical care using fluid-filled catheters. The degree of correlation between both methods is at least moderate.

Longitudinal Effects of Left Ventricular Assist Device Implantation on Global and Domain-Specific Cognitive Function

BACKGROUND

Left ventricular assist devices (LVADs) are a common treatment of advanced heart failure, but cognitive dysfunction, which is common in heart failure, could limit the ability to perform postimplantation LVAD care. Implantation of an LVAD has been associated with improved cerebral perfusion and may improve cognitive function post implantation.

OBJECTIVE

The aim of this study was to quantify longitudinal change in cognitive function after LVAD implantation.

METHODS

A secondary analysis of data on 101 adults was completed to evaluate cognitive function before implantation and again at 1, 3, and 6 months post implantation of an LVAD. Latent growth curve modeling was conducted to characterize change over time. Serial versions of the Montreal Cognitive Assessment were used to measure overall (total) cognitive function and function in 6 cognitive domains.

RESULT

There was moderate, nonlinear improvement from preimplantation to 6 months post implantation in Montreal Cognitive Assessment total score (Hedges' g = 0.50) and in short-term memory (Hedges' g = 0.64). There also were small, nonlinear improvements in visuospatial ability, executive function, and attention from preimplantation to 6 months post implantation (Hedges' g = 0.20-0.28). The greatest improvements were observed in the first 3 months after implantation and were followed by smaller, sustained improvements or no additional significant change.

CONCLUSIONS

Implantation of an LVAD is associated with significant, nonlinear improvement in short-term memory and global cognitive function, with the most significant improvements occurring in the first 3 months after implantation. Clinicians should anticipate improvements in cognitive function after LVAD implantation and modify postimplantation education to maximize effectiveness of LVAD self-care.

Insight into Atrial Fibrillation in LVAD Patients: From Clinical Implications to Prognosis

The use of left ventricular assist devices (LVADs), whether for destination therapy or bridge to transplantation, has gained increasing validation in recent years in patients with advanced heart failure. Arrhythmias can be the most challenging variables in the management of such patients but the main attention has always been focused on ventricular arrhythmias given the detrimental impact on mortality. Nevertheless, atrial fibrillation (AF) is the most common rhythm disorder associated with advanced heart failure and may therefore characterize the LVADs' pre- and postimplantation periods. Indeed, the consequences of AF in the population suffering from standard heart failure may require a more comprehensive evaluation in the presence of or in sight of an LVAD, making the AF clinical management in these patients potentially complex. Several studies have been based on this subject with different and often conflicting results, leaving many questions unresolved. The purpose of this review is to summarize the main pieces of evidence about the clinical impact of AF in LVAD patients, underlining the main implications in terms of hemodynamics, thromboembolic risk, bleeding and prognosis. Therapeutic considerations about the clinical management of these patients are also made according to the latest evidence.

Sudden Cardiac Arrest Survivorship: A Scientific Statement From the American Heart Association

Cardiac arrest systems of care are successfully coordinating community, emergency medical services, and hospital efforts to improve the process of care for patients who have had a cardiac arrest. As a result, the number of people surviving sudden cardiac arrest is increasing. However, physical, cognitive, and emotional effects of surviving cardiac arrest may linger for months or years. Systematic recommendations stop short of addressing partnerships needed to care for patients and caregivers after medical stabilization. This document expands the cardiac arrest resuscitation system of care to include patients, caregivers, and rehabilitative healthcare partnerships, which are central to cardiac arrest survivorship.

Anesthesia at the Edge of Life: Mechanical Circulatory Support

Mechanical circulatory support devices are increasingly being used for patients presenting with heart failure. The primary goal of these devices is to maintain perfusion to all organs. Intra-aortic balloon pump and extracorporeal membrane oxygenators are temporary devices that are usually reserved for patients presenting with acute heart failure. A left ventricular assist device may be implanted either as a bridge to heart transplant or to cardiac recovery, or for destination therapy in refractory heart failure. Familiarization with these devices is key to patient management in the perioperative period, especially for patients presenting for noncardiac surgeries.

Medical Management of Left Ventricular Assist Device Patients: A Practical Guide for the Nonexpert Clinician

Left ventricular assist devices (LVADs) provide short- or long-term circulatory support to improve survival and reduce morbidity in selected patients with advanced heart failure. LVADs are being used increasingly and now have expanded indications. Health care providers across specialties will therefore not only encounter LVAD patients but play an integral role in their care. To accomplish that, they need to understand the elements of LVAD function, physiology and clinical use. This article provides a concise overview of the medical management of LVAD patients for nonexpert clinicians. Our presentation includes the basics of LVAD physiology, design, and operation, patient selection and assessment, medical management, adverse event identification and management, multidisciplinary care, and management of special circumstances, such as noncardiac surgery, cardiac arrest, and end-of-life care. The clinical examination of LVAD patients is unique in terms of blood pressure and heart rate assessment, LVAD "hum" auscultation, driveline and insertion site inspection, and device parameter recording. Important potential device-related adverse events include stroke, gastrointestinal bleeding, hematologic disorders, device infection, LVAD dysfunction, arrhythmias, and heart failure. Special considerations include the approach to the unconscious or pulseless patient, noncardiac surgery, and palliative care. An understanding of the principles presented in this paper will enable the nonexpert clinician to be effective in collaborating with an LVAD center in the assessment, medical management, and follow-up of LVAD patients. Future opportunities and challenges include the improvement of device designs, greater application of minimally invasive surgical implantation techniques, and management of health economics in cost-constrained systems like those of Canada and many other jurisdictions.

Application of Bioengineered Materials in the Surgical Management of Heart Failure

The epicardial surface of the heart is readily accessible during cardiac surgery and presents an opportunity for therapeutic intervention for cardiac repair and regeneration. As an important anatomic niche for endogenous mechanisms of repair, targeting the epicardium using decellularized extracellular matrix (ECM) bioscaffold therapy may provide the necessary environmental cues to promote functional recovery. Following ischemic injury to the heart caused by myocardial infarction (MI), epicardium derived progenitor cells (EPDCs) become activated and migrate to the site of injury. EPDC differentiation has been shown to contribute to endothelial cell, cardiac fibroblast, cardiomyocyte, and vascular smooth muscle cell populations. Post-MI, it is largely the activation of cardiac fibroblasts and the resultant dysregulation of ECM turnover which leads to maladaptive structural cardiac remodeling and loss of cardiac function. Decellularized ECM bioscaffolds not only provide structural support, but have also been shown to act as a bioactive reservoir for growth factors, cytokines, and matricellular proteins capable of attenuating maladaptive cardiac remodeling. Targeting the epicardium post-MI using decellularized ECM bioscaffold therapy may provide the necessary bioinductive cues to promote differentiation toward a pro-regenerative phenotype and attenuate cardiac fibroblast activation. There is an opportunity to leverage the clinical benefits of this innovative technology with an aim to improve the prognosis of patients suffering from progressive heart failure. An enhanced understanding of the utility of decellularized ECM bioscaffolds in epicardial repair will facilitate their growth and transition into clinical practice. This review will provide a summary of decellularized ECM bioscaffolds being developed for epicardial infarct repair in coronary artery bypass graft (CABG) surgery.

Mobile Geolocation Technology to Improve Multidisciplinary Care of Patients With Ventricular Assist Devices: A Feasibility Study

We evaluated the feasibility of a mobile phone-based geolocation technology in patients with ventricular assist devices (VAD). We prospectively enrolled VAD patients with a smartphone for 6 months. A proprietary mobile technology platform (Position Health, Reading, MA) was downloaded onto Apple or Android smartphones. When a patient entered an emergency department, the app was activated and a "ping" with patient location and contact information was sent to our VAD team pager. Fifty-four patients were approached, and 21 were enrolled. The primary reason for nonenrollment was lack of smartphone (46%). The technology was active for 3780 patient-days and activated on 4 occasions, all cases in which patients were inside a hospital but not seeking emergency care. When surveyed at 3 and 6 months, 90% and 100% of patients, respectively, reported the app remained active on their phones; 14 of 18 (78%) reported the app was helpful and gave them additional reassurance. Implementing this technology for VAD patients was feasible and accepted by patients and providers, but a larger study is needed to demonstrate an impact on care delivery.

Corrugated diaphragm shape design study for hemocompatible pulsatile ventricular assist devices

We aim to maximize the pumping volume of a pulsatile ventricular assist device, where the diaphragm is covered with an endothelial cell layer. These cells are estimated to survive a cyclic strain up to fifteen percent. To increase the pumping volume under this strain constraint we use an approach based on corrugation of the diaphragm in its reference configuration. The paper explains the parametrization scheme for finding corrugation shapes, addresses modeling and evaluation schemes and reports on the results of a parameter study. The results show that corrugated diaphragm shapes are effective for increasing pumping volumes under a strain constraint.

Anticoagulation Control in Patients With Ventricular Assist Devices

Anticoagulation control has been associated with risk of thromboembolism and hemorrhage. Herein, we explore the relationship between anticoagulation control achieved in left ventricular assist device (LVAD) patients and evaluate the association with risk of thromboembolism and hemorrhage. Patients (19 years old or older) with a continuous flow LVAD placed from 2006 to 2012. Percent time spent in target range (PTTR) for international normalized ratio (INR) was estimated with target range of 2.0-3.0. Proportion of time spent in target range was categorized into PTTR > 60%, PTTR ≥ 50 < 60%, and PTTR < 50%. The relationship between PTTR and thromboembolism and hemorrhage was assessed. One hundred fifteen participants contributed 624.5 months of follow-up time. Only 20% of patients achieved anticoagulation control (PTTR > 60% for INR range of 2-3). After adjusting for chronic kidney disease, history of diabetes, history of atrial fibrillation, and age at implant, compared with patients with PTTR < 50%, the relative risk of thromboembolism in patients with PTTR ≥ 60% (hazard ratio [HR]: 0.37; 95% confidence interval [CI]: 0.14-0.96; p = 0.042) was significantly lower, but not for patients with a PTTR of ≥ 50 < 60% (HR: 0.21; 95% CI: 0.02-1.82; p = 0.16). The relative risk for hemorrhage was also significantly lower among patients with a PTTR ≥ 60% (HR: 0.45; 95% CI: 0.21-0.98; p = 0.045), but not among those with PTTR of ≥ 50 < 60% (HR: 0.47; 95% CI: 0.14-1.56; p = 0.22). This current study demonstrates that LVAD patients remain in the INR target range an average of 42.9% of the time. To our knowledge, this is the first report with regard to anticoagulation control as assessed by PTTR and its association with thromboembolism, hemorrhage, or death among patients with ventricular assist devices (VADs).

The use of soft robotics in cardiovascular therapy

INTRODUCTION

Robots have been employed in cardiovascular therapy as surgical tools and for automation of hospital systems. Soft robots are a new kind of robot made of soft deformable materials, that are uniquely suited for biomedical applications because they are inherently less likely to injure body tissues and more likely to adapt to biological environments. Awareness of the soft robotic systems under development will help promote clinician involvement in their successful clinical translation. Areas covered: The most advanced soft robotic systems, across the size scale from nano to macro, that have shown the most promise for clinical application in cardiovascular therapy because they offer solutions where a clear therapeutic need still exists. We discuss nano and micro scale technology that could help improve targeted therapy for cardiac regeneration in ischemic heart disease, and soft robots for mechanical circulatory support. Additionally, we suggest where the gaps in the technology currently lie. Expert commentary: Soft robotic technology has now matured from the proof-of-concept phase to successful animal testing. With further refinement in materials and clinician guided application, they will be a useful complement for cardiovascular therapy.

Ventricular Assist Devices: Current State and Challenges

Cardiovascular disease (CVD), as the most prevalent human disease, incorporates a broad spectrum of cardiovascular system malfunctions/disorders. While cardiac transplantation is widely acknowledged as the optional treatment for patients suffering from end-stage heart failure (HF), due to its related drawbacks, such as the unavailability of heart donors, alternative treatments, i.e., implanting a ventricular assist device (VAD), it has been extensively utilized in recent years to recover heart function. However, this solution is thought problematic as it fails to satisfactorily provide lifelong support for patients at the end-stage of HF, nor does is solve the problem of their extensive postsurgery complications. In recent years, the huge technological advancements have enabled the manufacturing of a wide variety of reliable VAD devices, which provides a promising avenue for utilizing VAD implantation as the destination therapy (DT) in the future. Along with typical VAD systems, other innovative mechanical devices for cardiac support, as well as cell therapy and bioartificial cardiac tissue, have resulted in researchers proposing a new HF therapy. This paper aims to concisely review the current state of VAD technology, summarize recent advancements, discuss related complications, and argue for the development of the envisioned alternatives of HF therapy.

Complications, Risk Factors, and Staffing Patterns for Noncardiac Surgery in Patients with Left Ventricular Assist Devices

BACKGROUND

Patients with left ventricular assist devices presenting for noncardiac surgery are increasingly commonplace; however, little is known about their outcomes. Accordingly, the authors sought to determine the frequency of complications, risk factors, and staffing patterns.

METHODS

The authors performed a retrospective study at their academic tertiary care center, investigating all adult left ventricular assist device patients undergoing noncardiac surgery from 2006 to 2015. The authors described perioperative profiles of noncardiac surgery cases, including patient, left ventricular assist device, surgical case, and anesthetic characteristics, as well as staffing by cardiac/noncardiac anesthesiologists. Through univariate and multivariable analyses, the authors studied acute kidney injury as a primary outcome; secondary outcomes included elevated serum lactate dehydrogenase suggestive of left ventricular assist device thrombosis, intraoperative bleeding complication, and intraoperative hypotension. The authors additionally studied major perioperative complications and mortality.

RESULTS

Two hundred and forty-six patients underwent 702 procedures. Of 607 index cases, 110 (18%) experienced postoperative acute kidney injury, and 16 (2.6%) had elevated lactate dehydrogenase. Of cases with complete blood pressure data, 176 (27%) experienced intraoperative hypotension. Bleeding complications occurred in 45 cases (6.4%). Thirteen (5.3%) patients died within 30 days of surgery. Independent risk factors associated with acute kidney injury included major surgical procedures (adjusted odds ratio, 4.4; 95% CI, 1.1 to 17.3; P = 0.03) and cases prompting invasive arterial line monitoring (adjusted odds ratio, 3.6; 95% CI, 1.3 to 10.3; P = 0.02) or preoperative fresh frozen plasma transfusion (adjusted odds ratio, 1.7; 95% CI, 1.1 to 2.8; P = 0.02).

CONCLUSIONS

Intraoperative hypotension and acute kidney injury were the most common complications in left ventricular assist device patients presenting for noncardiac surgery; perioperative management remains a challenge.

International coordinator survey results on the outpatient management of patients with the HeartWare® ventricular assist system

PURPOSE

While the HeartWare® Ventricular Assist System (HVAS) is a successful therapy for end-stage heart failure, outpatient management methods can vary significantly and require further investigation.

METHODS

A survey to assess the long-term HVAS patient management and monitoring strategies was completed by 36 international heart centers that currently have over 1,450 patients on VAD support either at home or in the hospital. Multiple choice questions examined VAD program characteristics, anticoagulation management, driveline exit-site dressing and showering recommendations, blood pressure and pump parameter monitoring, and patient discharge protocols.

RESULTS

Outpatient international normalized ratio (INR) was most frequently measured every 3-4 days (28.6%), and the most frequent schedule for changing driveline exit site dressings was 3 times per week (30.6%). Only 25.7% of centers required their patients to measure blood pressure at home. A subgroup analysis was performed to assess the influence of center experience and larger centers generally had more frequent monitoring compared to smaller centers.

CONCLUSIONS

This survey showed specific differences in outpatient management strategies that were previously unreported. However, further studies with correlations to patient outcomes are necessary to determine optimal patient management recommendations.

Mechanical Circulatory Support for Advanced Heart Failure: Are We about to Witness a New "Gold Standard"?

The impact of left ventricular assist devices (LVADs) for the treatment of advanced heart failure has played a significant role as a bridge to transplant and more recently as a long-term solution for non-eligible candidates. Continuous flow left ventricular assist devices (CF-LVADs), based on axial and centrifugal design, are currently the most popular devices in view of their smaller size, increased reliability and higher durability compared to pulsatile flow left ventricular assist devices (PF-LVADs). The trend towards their use is increasing. Therefore, it has become mandatory to understand the physics and the mathematics behind their mode of operation for appropriate device selection and simulation set up. For this purpose, this review covers some of these aspects. Although very successful and technologically advanced, they have been associated with complications such as pump thrombosis, haemolysis, aortic regurgitation, gastro-intestinal bleeding and arterio-venous malformations. There is perception that the reduced arterial pulsatility may be responsible for these complications. A flow modulation control approach is currently being investigated in order to generate pulsatility in rotary blood pumps. Thrombus formation remains the most feared complication that can affect clinical outcome. The development of a preoperative strategy aimed at the reduction of complications and patient-device suitability may be appropriate. Patient-specific modelling based on 3D reconstruction from CT-scan combined with computational fluid dynamic studies is an attractive solution in order to identify potential areas of stagnation or challenging anatomy that could be addressed to achieve the desired outcome. The HeartMate II (axial) and the HeartWare HVAD (centrifugal) rotary blood pumps have been now used worldwide with proven outcome. The HeartMate III (centrifugal) is now emerging as the new promising device with encouraging preliminary results. There are now enough pumps on the market: it is time to focus on the complications in order to achieve the full potential and selling-point of this type of technology for the treatment of the increasing heart failure patient population.

Successful Hemodialysis Arteriovenous Fistula Creation in a Patient With Continuous-Flow Left Ventricular Assist Device Support

Heart failure necessitating left ventricular assist device (LVAD) support can lead to kidney failure requiring dialysis. Some of these patients may require long-term hemodialysis (HD). Optimal vascular access for a patient on long-term HD therapy with an LVAD remains a complex issue. The majority of LVADs are of the continuous-flow type, and it has been theorized that native arteriovenous fistula maturation may be impaired in a setting of decreased pulsatile arterial flow. We describe a case of successful creation and use of an arteriovenous fistula in an HD-dependent patient with a continuous-flow LVAD.

Postoperative Management for Patients With Durable Mechanical Circulatory Support Devices

Mechanical circulatory support devices have been approved as bridge to transplantation, as bridge to recovery, or as destination therapy to treat end-stage heart failure. The perioperative challenges for the anesthesiologist and the intensivist caring for these patients include device-related complications, hemodynamic instability, arrhythmias, right ventricular failure, and coagulopathy. Perioperative management in this high-risk population has a significant impact on patient outcomes. This review focuses immediate postoperative intensive care unit management of device-related complications.

Ventricular assist devices and sleep-disordered breathing

Congestive heart failure is one of the leading causes of morbidity and mortality in the United States, and left ventricular assist devices have revolutionized treatment of end-stage heart failure. Given that sleep apnea results in significant morbidity in these patients with advanced heart failure, practicing sleep physicians need to have an understanding of left ventricular assist devices. In this review, we summarize what is known about ventricular assist devices as they relate to sleep medicine.

Periprocedural Management of 172 Gastrointestinal Endoscopies in Patients with Left Ventricular Assist Devices

The number of patients with left ventricular assist devices (LVADs) continues to increase, and gastrointestinal (GI) endoscopy is commonly required in this patient population. We retrospectively reviewed the experience of a single tertiary care center in managing patients with LVADs undergoing GI endoscopy between 2006 and 2013. After hospital dismissal from the LVAD placement, 53 patients underwent 172 GI endoscopic procedures. Gastrointestinal bleeding was the indication for endoscopy in 73.8% of patients. Median age at endoscopy was 66 years, and median time from LVAD implantation to initial endoscopy was 271 days (range, 31-1681 days). Anticoagulation or antiplatelet therapy was present within 1 week before 120 of 172 endoscopies (70%) and was withheld or actively reversed in 91 of 120 cases (76%). For sedation/anesthesia during endoscopy, 63 involved care by an anesthesiology team and 109 were performed with nursing sedation protocols. Noninvasive blood pressure techniques (conventional automated cuffs or Doppler pulses) were used for hemodynamic monitoring in 84%, arterial lines in 10%, and no blood pressure recordings documented/charted as inaccurate in 6%. Six patients died within 30 days of endoscopy with one death because of aspiration of blood and multiorgan failure. Patients with LVADs may safely undergo GI endoscopy with various individualized anesthetic/sedation models. Complications after endoscopy likely represent the acuity of this patient population.

In Vitro PET Imaging of a Miniature Ventricular Assist Device

Interactions between the life-sustaining ventricular assist devices and diagnostic therapies must be carefully considered to decrease the risk of inaccurate diagnostic imaging or pump failure.

METHODS

The MVAD(®) pump, currently under investigational use, was tested for interaction with radiotracers in an in vitro flow-loop study. The radiotracers (18)F-sodium fluoride and (18)F-FDG were injected into a closed loop to determine the feasibility of direct imaging of the MVAD(®) pump in a PET scanner.

RESULTS

No real-time changes were observed in pump operation, and there were no statistical differences in pump parameters (power consumption, speed, and estimated flow rate) between the baseline and circulation conditions. In addition, no effect was observed on any external components, including the permissive-action-link controller and the batteries powering the device. Imaging of the internal pump components was possible, with obscuration observed only in the portion of the pump where the spinning impeller is located. Retention of radiotracer in the pump components after circulation was minimal (<1%).

CONCLUSION

PET imaging is an attractive diagnostic tool for patients with a ventricular assist device and may have additional utility outside its current use, detection of infection.

Mechanical circulatory assist devices: a primer for critical care and emergency physicians

Mechanical circulatory assist devices are now commonly used in the treatment of severe heart failure as bridges to cardiac transplant, as destination therapy for patients who are not transplant candidates, and as bridges to recovery and “decision-making”. These devices, which can be used to support the left or right ventricles or both, restore circulation to the tissues, thereby improving organ function. Left ventricular assist devices (LVADs) are the most common support devices. To care for patients with these devices, health care providers in emergency departments (EDs) and intensive care units (ICUs) need to understand the physiology of the devices, the vocabulary of mechanical support, the types of complications patients may have, diagnostic techniques, and decision-making regarding treatment. Patients with LVADs who come to the ED or are admitted to the ICU usually have nonspecific clinical symptoms, most commonly shortness of breath, hypotension, anemia, chest pain, syncope, hemoptysis, gastrointestinal bleeding, jaundice, fever, oliguria and hematuria, altered mental status, headache, seizure, and back pain. Other patients are seen for cardiac arrest, psychiatric issues, sequelae of noncardiac surgery, and trauma. Although most patients have LVADs, some may have biventricular support devices or total artificial hearts. Involving a team of cardiac surgeons, perfusion experts, and heart-failure physicians, as well as ED and ICU physicians and nurses, is critical for managing treatment for these patients and for successful outcomes. This review is designed for critical care providers who may be the first to see these patients in the ED or ICU.

A Cloud-Based Home Management System for Patients with a left Ventricular Assist Device: A Case Report

Since implantable left ventricular assist devices (LVAD) with smaller configurations became available for bridge-to-transplant or even destination therapy in patients with end-stage heart failure, an increasing number of patients with these devices are receiving home medical management. However, these patients may be anxious about potential complications such as pump failure, thromboembolism, and infections that may occur during home management. To provide a sense of security during home management of patients with LVAD and to establish an ideal shared-care system, we developed a patient-centered cloud-based home management system for patients with LVAD. In this case report, we describe this system and report a trial of it in a 64-year-old patient with an LVAD.

Team-based Palliative and End-of-life Care for Heart Failure

Clinical practice guidelines endorse the use of palliative care in patients with symptomatic heart failure. Palliative care is conceptualized as supportive care afforded to most patients with chronic, life-limiting illness. However, the optimal content and delivery of palliative care interventions remains unknown and its integration into existing heart failure disease management continues to be a challenge. Therefore, this article comments on the current state of multidisciplinary care for such patients, explores evidence supporting a team-based approach to palliative and end-of-life care for patients with heart failure, and identifies high-priority areas for research.

A simple education tool for ventricular assist device patients and their caregivers

BACKGROUND

Ventricular assist devices (VADs) have become an important therapy in the management of patients with end-stage heart failure. Driveline infection is the most common late-onset complication in this group of patients. Patients and their caregivers require education regarding management of the driveline to reduce the risk of infection when they are discharged home with a VAD.

PURPOSE

The aim of this study was to develop an educational booklet on VAD driveline care for patients and their caregivers. A literature review was undertaken to explore the availability of patient education material pertaining to driveline management and to update evidence-informed knowledge that could potentially reduce infection rates in these patients. This information was evaluated by peers, patients, and caregivers to produce the final colored booklet.

CONCLUSIONS

Driveline care is not comprehensively discussed in the literature and lacks detail in the particulars of wound care, patient education, and the adaptation of driveline care to the patient's home environment. An educational booklet was designed to convey what is currently known about preventing driveline infections to those who are responsible for providing the required daily care. Evaluation of patient education material by those using the material is essential. As with all written material, the information will require updating as new evidence becomes available.

CLINICAL IMPLICATIONS

Managing driveline infection risk for patients at home with extended therapy is a critical nursing issue in improving morbidity and mortality. After VAD implantation, patients and caregivers must be educated about the ongoing care of the driveline exit site to minimize the risk of infection. A rigorously developed and patient-evaluated educational booklet on driveline exit site care can be a valuable reference tool for patients and caregivers after hospital discharge.

[Rehabilitation standards for follow-up treatment and rehabilitation of patients with ventricular assist device (VAD)]

The increasing use of ventricular assist devices (VADs) in terminal heart failure patients provides new challenges to cardiac rehabilitation physicians. Structured cardiac rehabilitation strategies are still poorly implemented for this special patient group. Clear guidance and more evidence for optimal modalities are needed. Thereby, attention has to be paid to specific aspects, such as psychological and social support and education (e.g., device management, INR self-management, drive-line care, and medication).In Germany, the post-implant treatment and rehabilitation of VAD Patients working group was founded in 2012. This working group has developed clear recommendations for the rehabilitation of VAD patients according to the available literature. All facets of VAD patients' rehabilitation are covered. The present paper is unique in Europe and represents a milestone to overcome the heterogeneity of VAD patient rehabilitation.

Blood pressure management in mechanical circulatory support

Durable mechanical support has become widely available for end stage heart failure as destination therapy and as bridge to transplantation. The accurate measurement of blood pressure (BP) as well as the recognition and management of hypertension in patients with continuous flow left ventricular assist devices (CF-VADs) is an essential component of optimal clinical care. Strategies for the control of BP in CF-VAD patients are increasingly important as there is an evolving understanding of the connection between hypertension, pump output, and adverse outcomes. As clinical experience grows, optimal BP targets, as well as methods to measure BP in CF-VAD patients have been further defined.

Hypertension: an unstudied potential risk factor for adverse outcomes during continuous flow ventricular assist device support

In end-stage heart failure, left ventricular assist devices (LVADs) represent an exciting new frontier in which post-device implantation survival approaches that of heart transplant. However, expansion of this technology is still limited by complications that impact morbidity and mortality. Thus, it is essential to identify and optimize modifiable predictors of poor outcomes. One such predictor may be hypertension (HTN). Not only may chronic HTN as a traditional cardiovascular risk factor be present during long-term LVAD support, but HTN may also contribute to device malfunction or device-associated complications. Although current guidelines identify blood pressure (BP) control as important to outpatient continuous flow (CF) LVAD management, there is no evidence base to support these guidelines. Indeed, our comprehensive literature search did not identify any studies that evaluated post-device implantation HTN as a potential predictor of adverse CF-LVAD outcomes. HTN among CF-LVAD patients is likely a relatively unstudied factor because of difficulties using standard noninvasive techniques to measure BP in the setting of reduced pulsatile flow. Fortunately, recent research has elucidated the meaning of Doppler BP measurements and validated a slow-cuff deflation system for BP measurements in the setting of CF-LVAD support. Therefore, CF-LVAD researchers and clinicians may (1) consider potential mechanisms relating HTN to poor outcomes, (2) realize that HTN management is a stated goal despite scarce evidence, and (3) utilize the new reliable and valid methods for outpatient BP measurement that make research and management possible. It is critical and now feasible that research on HTN in the CF-LVAD patient population move forward.