Off-label use of microaxial left ventricular assist devices is associated with higher mortality despite use in younger patients with fewer comorbidities.

BACKGROUND: Microaxial left ventricular assist devices (Impella CP, Johnson & Johnson) are FDA-approved for cardiogenic shock, COVID-19 requiring extracorporeal membrane oxygenation (ECMO), and high-risk percutaneous coronary intervention (HRPCI). Clinicians may also use Impella CP devices off-label, but real-world outcomes data on off-label use is limited. We examined national trends and comparative outcomes associated with off-label versus on-label Impella CP device use. METHODS: The Healthcare Cost and Utilization Project National Inpatient Sample was analyzed for adult hospitalizations containing ICD-10 codes for Impella CP from October 1, 2015 to December 31, 2022. Admissions with ICD-10 codes for cardiogenic shock, COVID-19 with ECMO, or HRPCI were classified as on-label; all others were classified as off-label. The primary outcome was in-hospital mortality. Secondary outcomes were limb revascularization, access site bleeding, hospital length of stay (LOS), and discharge home. RESULTS: Among 31,263 hospitalizations with Impella CP, 1988 (6.4%) were classified as off-label. While on-label use increased over time, off-label use remained stable. Hospitalizations with off-label Impella use represented younger patients (61.0 vs 65.6 years; p < 0.0001) who were more often female (33.7% vs 27.8%; p < 0.001) and Black (15.2% vs 12.5%; p < 0.0001) and had fewer comorbidities (Elixhauser score 4.2 vs 4.9; p < 0.0001) and more elective admissions (30.3% vs 18.6%; p < 0.0001). Hospitalizations with off-label Impella use were associated with higher in-hospital mortality (37.5% vs 27.9%, p < 0.0001), similar access site complications (15.1% vs 13.8%, p = 0.12), longer hospital LOS (median 15.8 vs 14.4 days, p < 0.001), and lower rates of discharge home (25.5% vs 31.3%, p < 0.001). CONCLUSIONS: In a large contemporary national cohort, 1 in 15 Impella CP placements occurred off-label. These hospitalizations involved younger, electively admitted patients with fewer comorbidities but were associated with higher mortality and longer LOS.