Age-associated outcomes in cardiogenic shock supported with microaxial flow pumps

Background: Age represents a critical prognostic factor in cardiogenic shock (CS), yet older patients are underrepresented in randomized trials evaluating temporary mechanical circulatory support (tMCS). We aimed to assess the impact of age on outcomes in CS patients supported with micro-Axial Flow Pump (mAFP) across the age spectrum. Methods: We analyzed patients with CS treated with mAFP (Impella CP, 5.0 and 5.5) across 11 European centers between 2010 and 2023. Patients were stratified into quartiles by age: Q1 ≤ 52.0 years, Q2 > 52.0-60.0 years, Q3 > 60.0-69.0 years, and Q4 ≥ 69.0 years. The association between age and mortality was assessed using a Fine-Gray competing risks model and restricted cubic spline analysis. The primary endpoint was all-cause mortality at 30 days. Results: Among 1,043 patients supported with mAFP, the oldest quartile (Q4) was more frequently female, had higher comorbidity burden, and received less intensive support compared to Q1. In the Fine-Gray competing risks model, Q3 and Q4 patients had significantly higher 30-day and 1-year mortality risks (30-day: adjusted sHR 1.66 [95% CI: 1.19-2.34] and 1.87 [1.34-2.62]; 1-year: sHR 1.78 [1.31-2.41] and 2.08 [1.54-2.80]; Ptrend < 0.01 for all), with each additional year of age conferring a 3.2% increase in 30-day mortality risk (adjusted sHR 1.032 [1.017-1.047]). Major left ventricular ejection fraction (LVEF) recovery (≥10 percentage points) declined progressively with age, from 74.5% in Q1 to 41.9% in Q4 (p < 0.01), with each year associated with a 0.40 percentage-point reduction in LVEF improvement. Conclusions: In this European registry, increasing age was associated with higher mortality and lower observed myocardial recovery among patients with cardiogenic shock supported with mAFP.