High profile transvalvular microaxial flow pump as a bridge to heart transplantation for amyloid cardiomyopathy: A case series.

Background: The definitive treatment for end-stage heart failure (ESHF) due to amyloid cardiomyopathy (ACM) is an orthotopic heart transplant (OHT). However, associated pulmonary hypertension (PH) can present as a contraindication to OHT and be challenging to manage with conventional therapies. We herein reported the successful use of Impella 5.5 in a series of patients with ACM to improve PH and successfully bridge to OHT.

Methods: Five patients with ACM associated ESHF were analyzed. All patients had moderate to severe PH on admission. As a bridge to transplant, Impella 5.5 was inserted through the axillary artery, and continued until OHT.

Results: All patients were male, and mean age was 62.2 ± 1.3 years. One patient had light chain associated amyloid cardiomyopathy (AL-CM), 2 had wild-type transthyretin associated amyloid cardiomyopathy (ATTRwt-CM), and 2 had variant transthyretin amyloid cardiomyopathy (ATTRv-CM). Indication for Impella 5.5 was to support acute on chronic heart failure and improve elevated PA pressures. Mean support time was 34.4 ± 11.97 days. Mean PA pressures decreased from 38.2 ± 4.43 mm Hg to 27 ± 4.24 mm Hg, and cardiac index increased from 1.58 ± 0.44 liter/min/m to 2.46 ± 0.43 liter/min/m. No major adverse events related to Impella insertion occurred. All patients were successfully transplanted and doing well after OHT with no mortality after a mean follow-up of 13 ± 10.88 months.

Conclusion: Bridging patients with ACM to OHT remains challenging due to small left ventricular cavity and associated PH. Temporary mechanical circulatory support with Impella 5.5 helps reduce PA pressures and improve cardiac index. Impella 5.5 can be safe and feasible option to bridge patients with ACM to OHT.