Exercise echocardiographic adaptations of right ventricular performance and pulmonary pressures in combination with gas exchange analysis in heart failure

Introduction: Echo tricuspid annular systolic plain excursion (TAPSE) is the most used non- invasive indicator of right ventricular (RV) function with strong prognostic value in heart failure (HF) patients. Rest TAPSE combined with pulmonary artery systolic pressure (PASP), as TAPSE/PASP ratio, gives additional prognostic information. Hypothesis: We aimed at describing the association between RV-pulmonary circulation (PC) behavior at rest and during exercise in HF patients. Methods:91 patients (age 65±11y, male 70%, ischemic etiology 69%, LVEF 33±10%) underwent a maximal CPET on combined with exercise-echo (tiltable cycle-ergometer, incremental personalized ramp protocol). Results: Study population was divided into three groups according to TAPSE/PASP ratio: Group A had favorable RV-PC coupling both at rest and during exercise(TAPSE/PASP>0.35), B unfavorable coupling only during exercise (rest TAPSE/PASP>0.35, peak TAPSE/PASP <0.35), C RV-PC uncoupling already at rest (TAPSE/PASP<0.35). Group C patients showed more advanced cardiac remodeling and steeper VE/VCO2 slope compared to the other two groups. Group B patients had intermediate echo and CPET phenotype, characterized by more severe mitral regurgitation during exercise and an impaired LV contractile response (lower peak cardiac output), corresponding to impaired exercise tolerance (lower peak VO2, workload and O2 pulse) and an abnormal ventilatory pattern during exercise (exercise oscillatory ventilation, EOV). Conclusions: In a broad range HFrEF patients a low TAPSE/PASP ratio is associated with worse cardiac remodeling and exercise ventilatory inefficiency. An impaired RV-PC response during exercise is characterized by more severe dynamic MR and worse functional phenotype. These findings suggest that non-invasive assessment of RV-PC exercise response is meaningful and better help to categorize HF severity.