The Efficacy and Safety of Cardiopulmonary Exercise Testing in Advanced Heart Failure Receiving Intravenous Inotropes

Background: Cardiopulmonary exercise testing (CPET) is widely used for prognostic assessment and risk stratification in patients with heart failure (HF). However, its feasibility and clinical utility in patients with advanced HF requiring intravenous inotropic support remain unclear. Methods: This observational study included hospitalized patients with HF who received intravenous inotropic therapy and underwent CPET during index hospitalization. The primary outcome was a composite of HF rehospitalization or cardiovascular death. Results: A total of 528 patients hospitalized for HF required intravenous inotropic therapy; 50 patients were included. CPET was safely completed in all patients without exercise-related adverse events. The median peak VO2 was 12.5 mL/kg/min, and the median VE/VCO2 slope was 38.3. During a median follow-up of 762 days, 12 primary events occurred. In univariable analysis, the VE/VCO2 slope, O2 pulse, and maximal workload were significantly associated with the primary outcome, whereas peak VO2 was not. A VE/VCO2 slope > 38.2 was associated with a significantly higher 3-year event rate compared with a slope ≤ 38.2 (40% vs. 8%, p = 0.021). Conclusions: CPET is feasible and safe in highly selected patients with advanced HF requiring inotropic support, and the VE/VCO2 slope was associated with clinical outcomes in exploratory univariable analyses.