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Updated: Oct 10, 2026
A Pre-Clinical Porcine Model of Orthotopic Heart Transplantation
Published on: April 27, 2019
Functional Recovery Patterns and Baseline Cardiac Power Output During Impella 5.5 Support in Heart Transplant
Background:
The Impella 5.5 microaxial pump facilitates ambulatory mechanical circulatory support via axillary implantation, providing a model for active prehabilitation in critically ill heart transplant candidates. Whether patients with severely reduced baseline cardiac power output (CPO) can achieve meaningful ambulation during Impella 5.5 support remains uncertain.
Methods:
This is a retrospective descriptive study of consecutive adults with cardiogenic shock (SCAI stages C-E) who received an Impella 5.5 as a bridge to heart transplantation between April 2022 and September 2024. Cardiac Power Output was calculated via pre-implantation right heart catheterization, defined as low (≤0.60 W) or higher (>0.60 W). Measures of functional recovery include maximum walking distance per day, cumulative walking distance during Impella 5.5 support, time to first walk, and percentage of patients who walked at least once. The LOWESS method is used to illustrate overall walking distance trajectories.
Results:
The final analytic cohort included 80 patients: 37 (46.3%) with baseline CPO ≤0.60 W and 43 (53.8%) with baseline CPO >0.60 W. Overall, 75 of 80 patients (93.8%) ambulated at least once before transplantation, including 89.2% in the low-CPO group and 97.7% in the higher-CPO group (p = 0.176). The time to first walking day was 5 days (IQR 3-7) in the low-CPO group vs. 3 days (IQR 2-7) in the higher-CPO group (p = 0.27). Maximum daily walking distance was 5,200 ft (IQR 2,000-10,400 ft) vs. 4,000 ft (IQR 2,400-8,000 ft) (p = 0.26), while cumulative distance was 15,400 ft vs. 11,000 ft (p = 0.81).
Conclusions:
Prehabilitation is feasible in patients undergoing Impella 5.5 support across the spectrum of hemodynamic status. Patients with severely compromised baseline cardiac performance achieved early, substantial ambulation. Thus, Impella 5.5 appears feasible as a platform for both hemodynamic support and prehabilitation of patients awaiting heart transplantation, though larger, non-selected cohorts are needed to confirm these findings.
