Understanding Left Ventricular Assist Devices.

Background/aims: Long-term mechanical assist devices are now commonly used in the treatment of severe heart failure to unload the failing ventricle, maintain sufficient end-organ perfusion and improve functional capacity. Depending on the assisted ventricles, 3 categories of long-term assist devices are available: left ventricular assist device (LVAD), biventricular assist device and total artificial heart. Improvements in technology, especially the advent of smaller, durable continuous flow pumps, have led to the use of LVADs in a much broader population of patients in the last 10 years. Both the number of patients living with LVADs and the life expectancy of these patients are increasing. Regarding this growing number of patients with LVAD, intensivists need to understand the physiology of the devices, their functioning, potential complications and their management.

Methods: We performed a narrative review of relevant medical literature regarding the physiology of patients with LVAD and management of common complications relevant to the critical care physicians.

Results: The most frequent complications occurring in the LVAD patients after the post-operative period are bleeding, driveline infections, thrombosis, device malfunction, right ventricular failure and arrhythmias. Bleeding is the most frequent adverse event in LVAD due to a combination of anticoagulation and acquired von Willebrand disease secondary to shear stress produced within the pump. Their management includes antiplatelet therapy arrest, reduction of the anticoagulation regimen and specific therapy if feasible. Infection is the second most common cause of death after cardiac failure in LVAD patients. All infections must be aggressively treated to avoid seeding the device. Device thrombosis can develop even when patients are adequately anticoagulated and taking antiplatelet therapy because the LVAD is responsible for a chronic hypercoagulable state.

Conclusion: Management of these unique patients in the ICU is best accomplished with a multidisciplinary team that includes specialists in advanced heart failure, LVAD nurse coordinators and intensivists.