Comprehensive review of hemolysis in ventricular assist devices

Abstract

Ventricular assist devices (VADs) have played an important role in altering the natural history of end-stage heart failure. Low-grade hemolysis has been traditionally described in patients with VADs, indicating effective device functionality. However, clinically significant hemolysis could be crucial in terms of prognosis, calling for prompt therapeutic actions. The absence of solid and widely approved diagnostic criteria for clinically significant hemolysis, render the utilization of hemolysis laboratory markers challenging. Hemolysis incidence varies (5%-18%) depending on definition and among different VAD generations, being slightly higher in continuous-flow devices than in pulsatile devices. Increased shear stress of red blood cells and underlying device thrombosis appear to be the main pathogenetic pathways. No certain algorithm is available for the management of hemolysis in patients with VADs, while close clinical and laboratory monitoring remains the cornerstone of management. Imaging examinations such as echocardiography ramp test or computed tomography scan could play a role in revealing the underlying cause. Treatment should be strictly personalized, including either pharmacological (antithrombotic treatment) or surgical interventions.

Extracorporeal membrane oxygenation‐assisted emergency percutaneous treatment of left ventricular assist device graft occlusion

“…Laboratory tests (LDH (lactate dehydrogenase) levels, haematocrit/haemoglobin, haptoglobin, total bilirubin, and INR (International Normalized Ratio)) ruled out clinically significant haemolysis, usually associated with pump thrombosis. 7 Computed tomography (CT) excluded the external compression of the LVAD outflow graft. We immediately started with a pharmacological therapy with a high dose of furosemide, that is, and sodium nitroprusside, which brought to a mild clinical improvement, as well as to a reduction of the LV chamber dimensions.…”

“…LVAD parameters showed a normal estimated flow with normal pump‐power and pulsatility index, while the haemodynamic ramp tests failed to reduce left ventricular end‐diastolic diameter. Laboratory tests (LDH (lactate dehydrogenase) levels, haematocrit/haemoglobin, haptoglobin, total bilirubin, and INR (International Normalized Ratio)) ruled out clinically significant haemolysis, usually associated with pump thrombosis 7 . Computed tomography (CT) excluded the external compression of the LVAD outflow graft.…”

Comparison of the Hemocompatibility of an Axial and a Centrifugal Left Ventricular Assist Device in an In Vitro Test Circuit

“…The extent of shear stress caused by LVADs is dependent on its design type [ 6 ]. High shear stress regions are more prominent in continuous-flow rotary LVADs compared to pulsatile hydraulic LVADs, even though their overall number of adverse events is lower [ 7 , 8 , 9 ]. Hemolysis causes the intracellular hemoglobin of RBCs to be released into the blood plasma.…”

“…Furthermore, axial-flow LVADs are typically associated with higher pump-induced hemolysis compared to centrifugal LVADs in in vitro experiments [ 3 , 5 , 7 ]. This hypothesis was further investigated in this study as well.…”

Computational Fluid–Structure Interaction Study of a New Wave Membrane Blood Pump

“…3,49 LVADs have to meet many requirements in terms of device implantability, 11,15,32 durability, 17,53 hydraulic power 29,36 and hemocompatibility. 6,39 All currently available LVADs are rotary blood pumps. They are small and reliable devices equipped with an internal impeller, which propels blood by rotating at elevated velocities, exerting high stresses on blood cells.…”