CHANGES IN VE/VCO2 SLOPE OVER TIME IN LVAD RECIPIENTS

Abstract Background: Cardiopulmonary exercise testing (CPET) is essential in the evaluation of patients with heart failure (HF), including left ventricular assist devices (LVADs) recipients. Peak oxygen uptake (pVO₂) and VE/VCO₂ slope are key prognostic parameters, but their values after LVAD implantation and relationship with right ventricular (RV) dysfunction remain poorly understood. Methods: We conducted a multicentre study evaluating with advanced HF patients supported by a LVAD. Fourteen patients were retrospectively analysed and eleven prospectively enrolled between 2012 and 2025. CPET was performed using standardized ramp protocols, and results were compared with matched HF controls from the MECKI score database for sex, BMI, and pVO₂ in a 1:3 fashion. Results: Twenty-five LVAD patients (mean age 69 ± 6.5 years) were evaluated 265 [IQR 111-455] days post-implant. Exercise capacity was severely reduced (pVO₂ 12.1 ± 2.5 ml/kg/min, 47% predicted), with a significant elevation in VE/VCO₂ slope (36.6 [IQR 33.1–53.8]). Longitudinal analysis showed an increase in VE/VCO₂ slope one year from implantation, despite stable pVO₂ and workload. Comparison with matched HF controls confirmed higher VE/VCO₂ slope in LVAD recipients. Conclusions: LVAD patients show an increasing ventilatory inefficiency over time, resulting in rising VE/VCO₂ slope after one year from implantation. Evaluation of VE/VCO₂ slope may provide earlier insight into RV dysfunction and improve long-term risk stratification. Further prospective multicentre studies are needed to validate our findings.