Abstract 13099: Study of Right Ventricular to Pulmonary Circulation Uncoupling at Peak Exercise in Heart Failure by gas Exchange Analysis Combined to Echocardiography

Abstract

Background: Right ventricular (RV) dysfunction and pulmonary hypertension (PH) impact on clinical status and have a prognostic value in heart (HF) patients. There is interest in assessment the RV to pulmonary circulation (PC) uncoupling during exercise even though much needs to be defined on the functional phenotypes. Aim: to define how the degrees of RV-PC uncoupling may engender specific functional phenotypes. Methods: 94 HFrEF patients (mean age 66±11 y, male 70%, ischemic etiology 71%, mean LVEF 34±9%) underwent a maximal CPET (incremental ramp protocol) combined with exercise-echo. Results: Population was divided into 4 groups using the 4 quadrant approach (Figure) based on TAPSE vs systolic PAP (PASP) relationship as a length vs developed force of the RV during exercise (cutoff based on median values of 20 mm and 57 mmHg). At peak exercise patients with more favorable TAPSE vs PASP relationship (group A) showed the better functional CPET response (higher peak VO2; lower VE/VCO2 slope and prevalence of exercise oscillatory ventilation (EOV), p= 0.000, 0.005 and 0.000). Group B and C showed similar peak VO2 and the occurrence of dynamic PH (group C) was related to dynamic mitral regurgitation (MR) and high rate of EOV (B vs C p=0.001 and 0.000). Interestingly, for similar exercise tolerance and LV function parameters, group D patients had more severely impaired ventilatory efficiency associated with very high prevalence of rest severe (MR) and EOV (p=0.005, 0.002). Conclusions: This proposed non-invasive RV functional evaluation approach at peak exercise seems appealing for stageing HF syndrome severity based on the degree of the right heart dysfunction. It appears also useful to unmask different ventilatory phenotypes irrespective of a similar impairment in functional capacity and peak VO2.