P6175CPET predicts invasive measures of right ventricular afterload in end stage HF patients

Aims: We aimed to elucidate potential relationships between cardiopulmonary exercise test (CPET) variables and invasive measures of right ventricular afterload and translate those findings into a clinical “rule out tool” for pulmonary vascular resistance (PVR) >3 WU, in end stage heart failure patients awaiting cardiac transplantation. Methods: Retrospective study that included stable end-stage heart failure patients who underwent a scheduled in-hospital evaluation for heart transplantation and performed CPET and invasive hemodynamic assessment ≤7 days apart. Results: 52 patients were included. PVR was positively correlated with VE/VCO2 slope (r=0,41, p=0,013) and negatively correlated with PETCO2 at AT and peak O2 pulse (r=-0,42, p=0,013 and r=-0,38, p=0,005, respectively). Pulmonary arterial compliance was negatively correlated with VE/VCO2 slope (r=-0,34, p=0,046) positively correlated with PETCO2 at AT and O2 pulse at AT (r=0,47, p=0,005 and r=0,46, p=0,007, respectively). A “rule out” tool for PVR>3 WU including peak O2 pulse and VE/VCO2 slope showed a sensitivity of 91%, specificity of 48%, positive likelihood ratio of 1,75 and negative likelihood ratio of 0,19, being particularly useful in the identification of low risk patients for high PVR. For an estimated pre-test prevalence of 42%, a low risk classification decreases the probability of high PVR to 12%.