Incidence of Hemolysis in Patients with Cardiogenic Shock Treated with Impella Percutaneous Left Ventricular Assist Device

Impella assist devices have been increasingly used in cardiogenic shock (CS). This study aims to assess the incidence of hemolysis when Impella support is used longer than 6 hours in CS. We retrospectively studied all patients who required Impella between April 2009 and September 2013. Demographic data and hemolysis indicators were sampled and analyzed using paired t-test. A total of 118 devices were placed and 40 used longer than 6 hours. The average time of support was 86.63 hours, and the 30 and 90 days of survival were 65% and 60%, respectively. After 24 hours of support, the hemoglobin (Hb) decreased significantly despite 17% of patients receiving blood transfusion (p = 0.0001). By the time of removal, 65% of patients were transfused to maintain a Hb of 10 mg/dl (p = 0.0014). The lactate dehydrogenase (LDH) increased to 5,201 U/L (n = 22; p = 0.0096), the bilirubin to 5.6 mg/dl (p = 0.008), and the haptoglobin level was 15.4 mg/dl (n = 25). The cumulative incidence of hemolysis was 62.5%. Hemolysis is a common occurrence in patients with long-term Impella support for CS, evaluated by the persistent decline in Hb and haptoglobin as well as increase in LDH and bilirubin. Strict monitoring of hemolysis parameters at baseline and at frequent intervals is crucial.