Right ventricular-arterial coupling in chronic thromboembolic pulmonary hypertension patients during exercise

While exercise capacity is reduced in all forms of pulmonary hypertension, only in idiopathic pulmonary arterial hypertension (iPAH) this is known to be related to right ventricular (RV) -arterial uncoupling. Here we compare RV-arterial coupling (RVAC) during exercise between patients with chronic thromboembolic pulmonary hypertension (CTEPH) and iPAH. We prospectively included 12 CTEPH and 12 iPAH patients who performed a submaximal invasive cardiopulmonary exercise test between January 2013 and January 2019. RV contractility, defined as end-systolic elestance (Ees), and RV afterload (Ea) were assessed both at rest and during exercise by using single beat pressure-volume loop analysis. RVAC was calculated as Ees/Ea. RV afterload and contractility were similar at rest in iPAH and CTEPH (figure 1). In both groups, Ea significantly increased during exercise, while RV contractility did not change. Resting RVAC was higher in iPAH than in CPTEH (1,6 (0,6) vs. 1,2 (0,3); p CTEPH patients have a worse RV phenotype at rest compared to iPAH patients. Both groups fail to increase contractility during exercise.