Ventricular Assist Devices as Destination Therapy: Psychosocial and Ethical Implications

One of the candidate evaluation challenges is determining when and how psychosocial domains influence short- and long-term destination therapy ventricular assist device (DT-VAD) outcomes. There are very few DT-VAD studies and no validated instruments to identify psychosocial risk factors. General practice is to borrow from the transplant literature, which may not be applicable to this unique device application. We question the relevance of using transplant psychosocial evaluation for patients who are candidates for DT-VAD only, particularly because these patients require a certain level of cognitive, psychological, and behavioral functioning to ensure proper long-term self-care with the VAD. We may be missing important psychological characteristics in our pre-evaluations by “borrowing” from the transplant literature, thereby underplaying significant factors that are especially relevant for DT-VAD candidates. Conversely, we may be screening out candidates who may benefit greatly from DT-VAD by using transplant criteria as part of the screening process. We use a case study to illustrate some of the challenges of weighing psychosocial risk factors in the DT-VAD population and to emphasize the need for developing distinct psychosocial assessment criteria for DT-VAD patients.     

Antithrombotic Therapy for Stroke in Young Adults

Stroke in young adults is a markedly heterogeneous disease, and remains an understudied phenomenon. While advances are being made in our understanding of the pathophysiology of its underlying conditions, treatment concerns are controversial, and clinical trials are sorely lacking. This review presents an overview of some of the relevant management issues in hypercoagulable states, migraine, patent foramen ovale, vascular dissection and venous sinus thrombosis.     

Arrhythmias after left ventricular assist device implantation: Incidence and management

The use of mechanical circulatory support has become an increasingly common practice in patients with heart failure, whether used as bridge to transplantation or as destination therapy. The last couple of decades has seen a drastic change in the functioning of the left ventricular assist devices (LVAD), changing from the first generation devices running on pulsatile flow to the current continuous flow devices. Atrial and ventricular arrhythmias are common among heart failure patients, and though the systematic circulation is well supported in patients on mechanical circulatory support, these arrhythmias can still be the cause of detrimental symptoms and lead to potentially fatal outcomes. Several studies have shown that mortality rates in LVAD recipients secondary to lethal arrhythmias are uncommon, and newer generation continuous flow devices particularly seem to support hemodynamic support well. While it is common practice to implant ICDs in patients with LVADs and a history of ventricular arrhythmias, the efficacy behind this practice at preventing sudden death in this population is unknown. In this review, we highlight what is already known about the complications, management and treatment of atrial and ventricular arrhythmias in patients with LVAD devices.     

The future of adult cardiac assist devices: novel systems and mechanical circulatory support strategies

The recent, widespread success of mechanical circulatory support has prompted the development of numerous implantable devices to treat advanced heart failure. It is important to raise awareness of novel device systems, the mechanisms by which they function, and implications for patient management. This article discusses devices that are being developed or are in clinical trials. Devices are categorized as standard full support, less-invasive full support, partial support: rotary pumps, partial support: counterpulsation devices, right ventricular assist device, and total artificial heart. Implantation strategy, mechanism of action, durability, efficacy, hemocompatibility, and human factors are considered. The feasibility of novel strategies for unloading the failing heart is examined.     

Right ventricular failure following placement of a percutaneous left ventricular assist device

Right ventricular (RV) dysfunction following surgical implantation of a left ventricular assist device (LVAD) is a well-documented phenomenon, and it is associated with poor outcomes. We are reporting a 25-year-old male patient who presented to the hospital with flu-like symptoms, hypotension and acute hypoxic respiratory failure. The patient's Laboratory data was significant for elevated troponin, and his Chest X-ray showed acute pulmonary edema. Echocardiogram revealed reduced left ventricular (LV) ejection fraction and normal RV function. Coronary angiography was normal, and the cardiac index was 1.3?L/min/m². Impella 5.0 (Abiomed, MA) was placed through the left axillary artery graft and 4.5?L/min flow was achieved with an improvement in blood pressure. Thirty minutes later, he developed hypotension, the device flow dropped to 3.0?L/min, and right atrial pressure increased. The Pulmonary artery pulsatility index was consistent with RV failure. Possible causes of RV failure include unmasking of RV dysfunction with high LVAD flow and altered RV geometry due to ventricular septum shift. Impella RP (Abiomed, MA) was placed for RV support achieving a flow of 3.8?L/min with a significant improvement in impella LV flow, cardiac output and blood pressure (mean 90?mmHg). Ventricular support devices were weaned off on day 9. The patient was discharged on day 15. Conclusion: our case highlights the risk of RV failure following percutaneous LVAD placement. Early identification and appropriate mechanical support is imperative.     

Continuous-flow left ventricular assist device support in patients with advanced heart failure: points of interest for the daily management

Today, continuous-flow left ventricular assist devices (cf-LVADs) are implanted more often in patients with end-stage heart failure. Because of greater durability they can be implanted for an extended period of time. As a result of increased numbers of patients on cf-LVAD support, healthcare professionals should be aware of the potential complications inherent to this therapy. Both bleeding and thrombosis may occur, and also complications related either to the device itself or to the ensuing altered haemodynamics, valvular pathology, and rhythm disturbances such as ventricular tachycardias and fibrillation. Accurate clinical evaluation, together with an electrocardiogram and, if necessary, combined with an echocardiogram, is obligatory in these situations. This review summarizes common complications complemented by a few clinical cases.     

Patient selection for left ventricular assist devices

Heart transplantation (HTx) improves symptoms and prolongs life in advanced heart failure (HF), but organ supply is limited. In recent years, mechanical circulatory support and specifically implantable left ventricular assist devices (LVADs) have undergone technical improvements, and outcomes have improved dramatically. Left ventricular assist devices are now viable options for patients with severe HF as bridge to transplantation, destination therapy, or as bridge to recovery. Many believe that LVADs may soon provide outcomes similar to, or better than, HTx, launching a new era of end‐stage HF management. The key to improving outcomes is patient selection, but the field is changing rapidly and guidelines and consensus are limited. This review summarizes recent reports of predictors of poor outcomes and provides an overview of selection for LVAD therapy.     

Percutaneous bi‐atrial extracorporeal membrane oxygenation for acute circulatory support in advanced heart failure

Veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) may improve survival after cardiac arrest by providing cardiopulmonary support. However, VA‐ECMO increases left ventricular (LV) afterload, which can promote progressive LV distension and often requires a secondary approach to reduce LV pressure and volume in patients with left heart failure. We report a case of biventricular unloading via biatrial cannulation in the presence of LV thrombus using a TandemHeart percutaneous trans‐septal cannula for VA‐ECMO in an adult patient with refractory ventricular fibrillation. © 2014 Wiley Periodicals, Inc.     

Sudden Cardiac Death Unresponsive to Implantable Defibrillator Therapy: An Urgent Target for Clinicians,Industry and Government

A major expansion in utilization of implantable cardioverter-defibrillators (ICDs) is anticipated based on the results of randomized clinical trials (RCT) that demonstrate increased survival in a sizable population of patients with reduced left ventricular function. However, if RCT accurately reflect clinical practice, then a substantial proportion of patients will die suddenly despite ICD implantation. ICD-unresponsive sudden cardiac death (SCD) has been recognized since the initial ICD experience. Yet, despite 25 years of technical advances, the frequency of ICD-unresponsive SCD has not declined. Pooled analysis of RCT indicates a crude rate of ICD-unresponsive SCD of 5%. This may not cause alarm in an average practice, but it comprises about 30% of cardiac deaths. Meta-analyses of RCT show that ICD therapy is associated with a relative risk reduction of SCD of approximately 60%, far less than the greater than 90% efficacy that many expect. The suboptimal performance of ICD therapy accounts for the failure of some RCT to achieve statistically significant effects on survival. The number of patients with ICD-unresponsive SCD is highly correlated with the number of cardiac deaths among control patients as well as ICD recipients. Otherwise, no definite patterns have emerged that clearly distinguish this mode of demise from other modes of cardiac death. Retrospective post-hoc analyses have not revealed distinguishing characteristics of patients with ICD-unresponsive SCD with respect to clinical variables, pre-terminal symptoms or to the setting of the terminal event. Despite advanced storage capabilities of implanted devices, almost no information has become available from RCT regarding the terminal rhythm or the response of the ICD. These observations have implications for clinical management and research. Candidates for ICD implantation based on RCT should be accurately informed about the residual risk of SCD. Investigators seeking to identify populations likely to benefit from ICD therapy based on SCD incidence should recognize that a significant fraction may not respond to ICD therapy. Reducing the incidence of ICD-unresponsive SCD would substantially improve survival and cost-effectiveness related to ICD therapy. Close cooperation between clinicians, investigators and representatives of industry and government is urgently needed to develop strategies to identify patients prone to ICD-unresponsive SCD, to determine its mechanisms and to develop methods of prevention and treatment.