De Novo Aortic Insufficiency and Its Progression in Patients on Microaxial Flow Pump Support Before Durable Left Ventricular Assist Device

Aortic insufficiency (AI) is associated with worse outcomes in patients with left ventricular assist device (LVAD). Microaxial flow pumps (mAFP) are increasingly used to stabilize cardiogenic shock pre-LVAD, but their transvalvular nature raises concerns for valvular damage. We studied AI incidence and outcomes in HeartMate 3 (HM3) recipients supported by mAFP. A single-center retrospective analysis (2014-2023) compared HM3 recipients bridged with mAFP to those supported by inotropes or other mechanical circulatory support. A secondary analysis used a propensity-matched cohort. The primary outcome was the incidence of significant (≥ moderate) AI at 6 and 12 months. Secondary outcomes were hemocompatibility-related adverse events, late right heart failure, aortic valve intervention (AVI), and mortality. A total of 170 HM3 patients were included: 27 with pre-LVAD mAFP and 143 without. Median age 58.9 years; 83.5% male; 37.6% White. More patients with pre-LVAD mAFP underwent AVI at implantation (22.9% vs. 13.2%, p = 0.130). At 1 year, significant AI was more prevalent in the mAFP group (22.2% vs. 4.2%, p = 0.003). In the propensity-matched cohort, 12 month significant AI was numerically higher with mAFP (20.8% vs. 5%, p = 0.198). Secondary outcomes did not differ. Pre-HM3 mAFP support is associated with higher rates of post-HM3 AI. Further large-scale studies are needed to validate these findings.