Impact of Extended Microaxial Flow Pump Use: Do Complications Increase with Prolonged Support?

Background: Microaxial flow pumps (mAFP) are frequently implanted in patients with cardiogenic shock (CS) as a bridge to recovery, durable left ventricular assist device (LVAD) implantation, or, in rare cases, heart transplantation (HTx). Prolonged use of mAFP may be necessary to enable end-organ recovery, to allow for eligibility VAD assessment in case weaning is not possible, or to keep a patient alive until a suitable donor organ becomes available. In CS, full support mAFP is CE-approved for either 10-day or 30-day use. This study aimed to evaluate the impact of prolonged mAFP use on complication rates and clinical outcomes.

Methods: A retrospective, single-center study of 81 patients who underwent surgical implantation of mAFP between January 1, 2020 and May 1, 2023 was conducted. Patients with a history of recent cardiac surgery or mAFP support duration of less than 24 hours were excluded. The remaining patients were divided into two groups: those with support up to 10 days (≤10 days group, n = 47) and those with support over 10 days (>10 days group, n = 32). Complications were compared using Chi-square and Mann-Whitney U test (p ≤ 0.05).

Results: Baseline characteristics, including gender, age, BMI, LVEF, and SCAI stage, were similar between groups. The median support time was 6 days (2–10 days) for the ≤10 days group and 18 days (11–118 days) for the >10 days group. There were no significant differences in pump malfunction requiring exchange (4.3% versus 3.1%, p = 0.80), stroke during mAFP (6.4% versus 3.1%, p = 0.52), limb ischemia (0.0% versus 3.1%, p = 0.22), device thrombosis necessitating lysis therapy or exchange (4.3% versus 12.5%, p = 0.17), or septic shock (44.3% versus 15.6%, p = 0.08). However, prolonged mAFP use was associated with significantly increased rates of bleeding complications (defined as bleeding ≥ BARC 3b or multiple bleeding < BARC 3b; 10.6% versus 31.1%, p = 0.02), lower minimum hemoglobin levels (8.6 versus 7.5 mg/dL, p = 0.001) or platelet counts (103 versus 79/nL, p = 0.02), higher transfusion rates (RBC: mean 2.9 versus 10.0 U, p = 0.003; platelets: mean 0.7 versus 1.8 U, p = 0.03), and higher peak plasma-free hemoglobin levels (median 21.7 versus 34.5 mg/dL, p < 0.001). Most patients were bridged to LVAD (68.1% versus 53.1%, p = 0.18), less to recovery (mAFP weaning and hospital discharge; 12.8% versus 3.1%, p = 0.14) or HTx (0.0% versus 3.1%, p = 0.22).

Conclusion: Although prolonged mAFP use is associated with increased bleeding, anemia, and transfusion needs, it does not lead to higher device exchange rates.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
11 February 2025