Hemolysis during short-term mechanical circulatory support: from pathophysiology to diagnosis and treatment

INTRODUCTION

Despite advances in heart failure therapies and percutaneous coronary interventions, survival for cardiogenic shock remains poor. Percutaneous ventricular assist devices (pVAD) are increasingly used, but current evidence remains conflicting. The Impella is an example of such a device, based on a catheter mounted micro-axial continuous flow pump, that has been rapidly adopted in routine practice. An important aspect in the post implantation care is the prevention of complications. Hemolysis is one of the more frequent complications seen with this device.

AREAS COVERED

In this review we discuss the pathophysiology, diagnosis and treatment of hemolysis in patients supported with a pVAD. A practical algorithm for rapid identification of hemolysis and the underlying cause is presented, allowing for early treatment and prevention of further complications.

EXPERT OPINION

Hemolysis remains a threat to patients supported with any mechanical circulatory support device. Prevention as well as treatment demands for sufficient knowledge about the device, the optimal position and hemodynamics. Future studies should try to clarify some of the elements that are still unclear such as optimal anticoagulation, the place of pentoxyfilline or extracorporeal removal of free hemoglobin. This could help to optimize outcomes in clinical practice as well as future studies.

Antithrombotic and anticoagulation therapies in cardiogenic shock: a critical review of the published literature

Cardiogenic shock (CS) is a complex multifactorial clinical syndrome, developing as a continuum, and progressing from the initial insult (underlying cause) to the subsequent occurrence of organ failure and death. There is a large phenotypic variability in CS, as a result of the diverse aetiologies, pathogenetic mechanisms, haemodynamics, and stages of severity. Although early revascularization remains the most important intervention for CS in settings of acute myocardial infarction, the administration of timely and effective antithrombotic therapy is critical to improving outcomes in these patients. In addition, other clinical settings or non-acute myocardial infarction aetiologies, associated with high thrombotic risk, may require specific regimens of short-term or long-term antithrombotic therapy. In CS, altered tissue perfusion, inflammation, and multi-organ dysfunction induce unpredictable alterations to antithrombotic drugs' pharmacokinetics and pharmacodynamics. Other interventions used in the management of CS, such as mechanical circulatory support, renal replacement therapies, or targeted temperature management, influence both thrombotic and bleeding risks and may require specific antithrombotic strategies. In order to optimize safety and efficacy of these therapies in CS, antithrombotic management should be more adapted to CS clinical scenario or specific device, with individualized antithrombotic regimens in terms of type of treatment, dose, and duration. In addition, patients with CS require a close and appropriate monitoring of antithrombotic therapies to safely balance the increased risk of bleeding and thrombosis.