Neurologic Events in Continuous-Flow Left Ventricular Assist Devices

Management of Hypertension in Patients With Ventricular Assist Devices: A Scientific Statement From the American Heart Association

Mechanical circulatory support with durable continuous-flow ventricular assist devices has become an important therapeutic management strategy for patients with advanced heart failure. As more patients have received these devices and the duration of support per patient has increased, the postimplantation complications have become more apparent, and the need for approaches to manage these complications has become more compelling. Continuous-flow ventricular assist devices, including axial-flow and centrifugal-flow pumps, are the most commonly used mechanical circulatory support devices. Continuous-flow ventricular assist devices and the native heart have a constant physiological interplay dependent on pump speed that affects pressure-flow relationships and patient hemodynamics. A major postimplantation complication is cerebrovascular vascular accidents. The causes of cerebrovascular vascular accidents in ventricular assist device recipients may be related to hypertension, thromboembolic events, bleeding from anticoagulation, or some combination of these. The most readily identifiable and preventable cause is hypertension. Hypertension management in these patients has been hampered by the fact that it is difficult to accurately measure blood pressure because these ventricular assist devices have continuous flow and are often not pulsatile. Mean arterial pressures have to be identified by Doppler or oscillometric cuff and treated. Although guidelines for hypertension management after ventricular assist device implantation are based largely on expert consensus and conventional wisdom, the mainstay of treatment for hypertension includes guideline-directed medical therapy for heart failure with reduced ejection fraction because this may reduce adverse effects associated with hypertension and increase the likelihood of favorable ventricular remodeling. The use of systemic anticoagulation in ventricular assist device recipients may at a given blood pressure increase the risk of stroke.

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.

Continuous-flow left ventricular assist device: Current knowledge, complications, and future directions

Long-term continuous-flow left ventricular assist devices have become a real alternative to heart transplantation in patients with advanced heart failure, achieving a promising 2-year event-free survival rate with new-generation devices. Currently, this technology has spread throughout the world, and any cardiologist or cardiac surgeon should be familiar with its fundamentals and its possible complications as well as the advances made in recent years. The aim of this review is to describe current knowledge, management of complications, and future directions of this novel heart-failure therapy.

A Comprehensive Review of Risk Factor, Mechanism, and Management of Left Ventricular Assist Device-Associated Stroke

The use of left ventricular assist devices (LVADs) has been increasing in the last decade, along with the number of patients with advanced heart failure refractory to medical therapy. Ischemic stroke and intracranial hemorrhage remain the leading causes of morbidity and mortality in LVAD patients. Despite the common occurrence and the significant outcome impact, underlying mechanisms and management strategies of stroke in LVAD patients are controversial. In this article, we review our current knowledge on pathophysiology and risk factors of LVAD-associated stroke, outline the diagnostic approach, and discuss treatment strategies.

Mechanical Circulatory Support Prior to Heart Transplantation Predicts Early Post-Operative Stroke

BACKGROUND

Mechanical circulatory support (MCS) devices are often deployed to treat patients with refractory cardiogenic shock, rapid deterioration of heart failure, and inotrope-dependent patients. Stroke is a common complication of MCS therapy. This study assesses the risk of stroke during the early post-heart transplantation (HT) period (days from successful HT to discharge or death) in patients who received MCS therapy leading to HT.

METHODS

Data were derived from the United Organ Sharing (UNOS) database. MCS modalities studied include left ventricular assist devices (LVAD), right ventricular assist devices (RVAD), biventricular ventricular assist devices (BiVAD), and extra-corporeal membrane oxygenation (ECMO). A multiple logistic regression model was used to determine the risk of stroke during the early post-HT period associated in patients treated with MCS leading to HT.

RESULTS

Between 1988 and 2014, 10,258 patients received MCS therapy leading to HT. Of these, 160 patients (1.96%) developed stroke during the early post-HT period. Multiple regression analysis showed that MCS modalities and associated odds ratios for early post-HT stroke and associated 95% confidence intervals were as follows: LVAD (1.44, 0.70-2.94), RVAD (2.89, 1.03-8.05, BiVAD (3.24, 1.15-9.10), ECMO (2.27 (1.17-4.40), and any MCS (1.60 (1.20-2.12).

CONCLUSIONS

With the exception of left ventricular assist devices, use of MCS modalities leading to HT is significantly and independently associated with stroke during the early post-HT period.

Mechanical circulatory support in children: past, present and future

Rapid advances in the field of mechanical circulatory support (MCS) have dramatically changed the management of pediatric patients with heart failure. There is now emphasis on timely implantation of ventricular assist devices (VADs) to preserve or recover end-organ function, and increased focus on post-implant management to improve the stroke rate. Transplant waitlist mortality has significantly decreased in the era of VAD use. Devices approved for adults are being used off-label in children with excellent outcomes, allowing chronic therapy and discharge home to become part of pediatric VAD therapy.

Left ventricular assist devices and their complications: A review for emergency clinicians

INTRODUCTION

End stage heart failure is associated with high mortality. However, recent developments such as the ventricular assist device (VAD) have improved patient outcomes, with left ventricular assist devices (LVAD) most commonly implanted.

OBJECTIVE

This narrative review evaluates LVAD epidemiology, indications, normal function and components, and the assessment and management of complications in the emergency department (ED).

DISCUSSION

The LVAD is a life-saving device in patients with severe heart failure. While first generation devices provided pulsatile flow, current LVAD devices produce continuous flow. Normal components include the pump, inflow and outflow cannulas, driveline, and external controller. Complications related to the LVAD can be divided into those that are LVAD-specific and LVAD-associated, and many of these complications can result in severe patient morbidity and mortality. LVAD-specific complications include device malfunction/failure, pump thrombosis, and suction event, while LVAD-associated complications include bleeding, cerebrovascular event, infection, right ventricular failure, dysrhythmia, and aortic regurgitation. Assessment of LVAD function, patient perfusion, and mean arterial pressure is needed upon presentation. Electrocardiogram and bedside ultrasound are key evaluations in the ED. LVAD evaluation and management require a team-based approach, and consultation with the LVAD specialist is recommended.

CONCLUSION

Emergency clinician knowledge of LVAD function, components, and complications is integral in optimizing care of these patients.