Clinical management of continuous-flow left ventricular assist devices in advanced heart failure

Vascular procedures in patients with left ventricular assist devices: single-center experience

Objective

A growing number of patients suffering from heart failure is living with a left ventricular assist device (LVAD) and is in the need for non-cardiac surgery. Vascular procedures due to ischemia, bleeding, or other device-related complications may be required and pose a challenge to the caregivers in terms of monitoring and management of these patients. Therefore, we reviewed our experience with LVAD patients undergoing vascular surgery.

Methods

From January 2010 until March 2017, a total of 54 vascular procedures were performed on 41 LVAD patients at our institution. Patient records were reviewed retrospectively in terms of incidence of LVAD-related complications, including thrombosis, stroke, bleeding, wound healing, and survival associated with vascular surgery. The type of surgery was recorded, as well as various clinical demographic variables.

Results

Vascular procedures were performed in 35 men (85.4%) and 6 women (14.6%) with LVADs. There were no perioperative strokes, device thromboses, or device malfunctions. Thirty-day mortality overall was 26.8% (eleven patients), with most patients dying within 30 days after LVAD implantation due to multi-organ failure. In 25 procedures (46.3%), a blood transfusion was necessary.

Conclusion

Patients on LVAD support are a complex cohort with a high risk for perioperative complications. In a setting where device function and anticoagulation are monitored closely, vascular surgery in these patients is feasible with an acceptable perioperative risk.

Correlation between Myocardial Function and Electric Current Pulsatility of the Sputnik Left Ventricular Assist Device: In-Vitro Study

This study assesses the electric current parameters and reports on the analysis of the associated degree of myocardial function during left ventricular assist device (LVAD) support. An assumption is made that there is a correlation between cardiac output and the pulsatility index of the pump electric current. The experimental study is carried out using the ViVitro Pulse Duplicator System with Sputnik LVAD connected. Cardiac output and cardiac power output are used as a measure of myocardial function. Different heart rates (59, 73, 86 bpm) and pump speeds (7600–8400 rpm in 200 rpm steps) are investigated. In our methodology, ventricular stroke volumes in the range of 30–80 mL for each heart rate at a certain pump speed were used to simulate different levels of contractility. The correlation of the two measures of myocardial function and proposed pulsatility index was confirmed using different correlation coefficients (values ≥ 0.91). Linear and quadratic models for cardiac output and cardiac power output versus pulsatility index were obtained using regression analysis of measured data. Coefficients of determination for CO and CPO models were in the ranges of 0.914–0.982 and 0.817–0.993, respectively. Study findings suggest that appropriate interpretation of parameters could potentially serve as a valuable clinical tool to assess myocardial therapy using LVAD infrastructure.

Considerations for Referral: What Happens to Patients After Being Turned Down for Left Ventricular Assist Device Therapy

BACKGROUND

Left ventricular assist device (LVAD) therapy has revolutionized the treatment options for patients with advanced heart failure. Patient selection is essential for obtaining successful results. However, few data exist concerning the outcomes of patients evaluated for LVAD therapy but subsequently rejected or deferred.

METHODS AND RESULTS

This is a retrospective review of all patients referred for LVAD therapy at our institution between January 2009 and December 2016. Baseline demographics and Interagency Registry for Mechanically Assisted Circulatory Support profiles were collected, and reasons for rejection or deferral for LVAD placement were investigated. A total of 669 patients were referred for LVAD therapy, and 228 patients (34%) were turned down. The yearly acceptance rate ranged between 57% and 75%. The average age of the turned-down cohort was 60.8 ± 12.5 years; 83% were men. Reasons for rejection included: patient being too sick (34%); psychosocial concerns (25%); patient declined (16%); decision was deferred for medical optimization (15%); or patient being too well (10%). The percentage of patients who were rejected due to psychosocial concerns has increased over time (P = 0.02), whereas the rate of deferral for medical optimization has remained stable (P = 0.10). One-year survival after initial LVAD consultation was 42% in those who were too sick, 64% in those with psychosocial concerns, 68% in patients who declined, 86% in those deferred for medical optimization; and 100% in those too well (P < 0.01).

CONCLUSIONS

One-year survival is reduced among patients who were initially turned down for LVAD therapy, except for those in whom this decision was deferred for medical optimization or because the patient was too well. Psychosocial concerns have become a significant barrier to LVAD therapy.

The Role of Computed Tomography in Predicting Left Ventricular Assist Device Infectious Complications

Objective:

The purpose of this study is to identify early computed tomography findings around the driveline which would predict mediastinal or left ventricular assist device (LVAD) pocket abscess formation.

Materials and Methods:

A retrospective analysis was performed on 128 LVAD recipients between January 2007 and December 2011. Infectious complications were subdivided into those affecting the driveline and those resulting in abscess formation either around the LVAD pump or mediastinum. The size and location of infiltrative changes surrounding the driveline were used to predict infection propagation resulting in abscess.

Results:

Of the 128 patients, 49 (38.3%) patients developed driveline infections and 24 (18.8%) patients developed abscess. 87.5% patients who developed abscess had a preceding driveline infection. The mean time from driveline infection to the development of pump pocket abscess was approximately 7 months. In addition, patients with abscess in the pump pocket or mediastinum had preceding infiltrative changes surrounding the driveline ≥14 mm (P = 0.0001). A preperitoneal location and size of infiltrative changes ≥14 mm were correlated with a higher likelihood of abscess formation (P = 0.0002).

Conclusion:

Our study demonstrates the predictive value of infection/infiltrative changes around the driveline, which increases the risk for abscess formation in the LVAD pump pocket and/or in the mediastinum.

Late Complications Following Continuous-Flow Left Ventricular Assist Device Implantation

Left ventricular assist devices have become standard therapy for patients with end-stage heart failure. They represent potential long-term solutions for a growing public health problem. However, initial enthusiasm for this technology has been tempered by challenges posed by long-term support. This review examines these challenges and out current understanding of their etiologies.

Preparedness planning before mechanical circulatory support: a "how-to" guide for palliative medicine clinicians

The role of palliative medicine in the care of patients with advanced heart failure, including those who receive mechanical circulatory support, has grown dramatically in the last decade. Previous literature has suggested that palliative medicine providers are well poised to assist cardiologists, cardiothoracic surgeons, and the multidisciplinary cardiovascular team with promotion of informed consent and initial and iterative discussions regarding goals of care. Although preparedness planning has been described previously, the actual methods that can be used to complete a preparedness plan have not been well defined. Herein, we outline several key aspects of this approach and detail strategies for engaging patients who are receiving mechanical circulatory support in preparedness planning.

Ethical dilemmas surrounding the use of ventricular assist devices in supporting patients with end-stage organ dysfunction

Successful practice of cardiovascular medicine requires familiarity with the complex ethical issues that accompany therapeutic innovation and diffusion. Even as technologies transition from experimental to standard care, challenges remain. Mechanical circulatory support devices, for instance, are increasingly conceptualized as conventional therapies. Despite this, or perhaps because of it, the ethical issues surrounding the use of these devices in patients with end-stage organ dysfunction are becoming increasingly apparent. In this paper, we provide an introduction to ethical considerations related to the use of ventricular assist devices (VADs) in end-stage organ failure, focusing on three stages or decision points: initiation, continued use, and deactivation. Our goal is not to exhaustively resolve these dilemmas but to illustrate how ethical considerations relate to decision making.

Ventricular assist devices: is destination therapy a viable alternative in the non-transplant candidate?

The topic of this article, stated a more familiar way, is whether left ventricular assist devices (LVADs) are ready for 'Primetime' as a therapeutic option in and of themselves. In order to provide an update and insight on this question, we briefly review from where the field has come, and in more detail describe its current state and where we are heading. We believe the short answer to this question is 'Yes', but like many things, a short answer is not adequate. Here we attempt to deliver a more comprehensive answer, providing some historical context, outlining the great achievements that have been made, as well as the many challenges that still remain before LVADs become a truly mainstream therapy.