The aim of the study is to show that a low plasma volume status, assessed by the Strauss (estimated plasma volume variation) and the Duarte (instantaneous estimated plasma volume) formulas evaluated during acute right heart failure in patients presenting with PAH or CTEPH, is associated with better long-term outcomes.~Optimization of plasma volume is important for patients with PAH and CTEPH and constitutes a prognostic factor. However, plasma volume status can be difficult to assess in clinical practice. Different formulas have been developed and have shown interest in patients with congestive heart failure with an association between plasma volume estimation and long-term prognosis.~Acute right heart failure may occur in patients with PAH and CTEPH. Thus, the investigators plan to study the prognostic value of these formulas evaluating plasma volume, in patients with PAH or CTEPH, after acute right heart failure.
Assessment of the prognostic value of the estimation of plasma volume or its variation in patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) after acute right heart failure.