Patients Supported with Impella 5.5 Percutaneous LVAD may have higher hemolysis and need for blood products: Study

Recent study evaluated hemolysis in patients supported with the Impella 5.5 percutaneous left ventricular assist device in a single-center experience. The research aimed to characterize the hemolytic sequelae in the largest series of Impella 5.5-supported patients to date. A total of 123 patients with recorded plasma free hemoglobin (PfHb) levels were included in the retrospective analysis, with 26 patients classified as high hemolysis (HH) and 25 as low hemolysis (LH) based on PfHb levels. The study found that HH patients had higher admission SCAI stages, longer Impella 5.5 support days, more additional mechanical circulatory support (MCS), and required more blood product transfusions compared to LH patients.

Risk Factors and Prognosis

Logistic regression identified additional MCS and more Impella days as risk factors for hemolysis. Survival analysis showed no significant differences in postoperative complications between HH and LH patients. However, HH patients who survived had fewer platelet transfusions and fewer days of elevated PfHb compared to those who died. The study highlighted the poor prognosis associated with hemolysis in this high-risk cohort. Further analysis of factors associated with survival in the HH group revealed that survivors required fewer platelet transfusions, had lower bilirubin levels, and fewer days of elevated PfHb. The study emphasized the importance of identifying and minimizing hemolysis, given its association with adverse outcomes.

Study Limitations

Limitations of the study included its retrospective nature, a relatively small sample size, and the lack of a consistent hemolysis definition in MCS. The authors recommended larger studies with standardized hemolysis sampling protocols to better understand percutaneous LVAD-associated hemolysis.

Conclusion and Future Research

Overall, the research shed light on the hemolytic complications in Impella 5.5-supported patients and underscored the need for aggressive monitoring and management of hemolysis to improve outcomes in this patient population. Further research is warranted to elucidate the factors contributing to hemolysis and its implications in patients receiving mechanical circulatory support.

Key Points

- The study assessed hemolysis in patients supported with the Impella 5.5 percutaneous left ventricular assist device, focusing on characterizing hemolytic sequelae in a large series of patients.

- 123 patients with recorded plasma free hemoglobin (PfHb) levels were analyzed, with 26 classified as high hemolysis (HH) and 25 as low hemolysis (LH) based on PfHb levels.

- Patients with high hemolysis had higher admission SCAI stages, longer Impella 5.5 support days, more additional mechanical circulatory support (MCS), and required more blood product transfusions compared to low hemolysis patients.

- Logistic regression identified additional MCS and longer Impella days as risk factors for hemolysis, with survival analysis showing no significant differences in postoperative complications between high and low hemolysis patients.

- Survivors in the high hemolysis group required fewer platelet transfusions, had lower bilirubin levels, and fewer days of elevated PfHb, emphasizing the importance of identifying and minimizing hemolysis for better outcomes.

- Study limitations included its retrospective nature, small sample size, and inconsistent hemolysis definition in MCS, recommending larger studies with standardized hemolysis sampling protocols for better understanding of percutaneous LVAD-associated hemolysis.

Reference –

Clothier, J.S., Kobsa, S., Lester, L. et al. Evaluation of hemolysis in patients supported with Impella 5.5: a single center experience. J Cardiothorac Surg 20, 143 (2025). https://doi.org/10.1186/s13019-025-03352-7