Fluid restriction in patients with pulmonary arterial hypertension and right heart failure

<bold>Background:</bold> In pulmonary arterial hypertension (PAH) right heart (RH) failure is associated with high mortality and poor prognosis. The objective of this study was to assess, whether reduction of fluid intake has an impact on RH size and clinical outcome in patients with PAH. <bold>Methods:</bold> In this study fluid-uptake and clinical parameters were assessed at baseline and during 8.4±5.3 months follow-up in patients with invasively diagnosed PAH and signs of RH failure. All patients were advised to reduce their fluid uptake to <2 l/day. Hydropic decompensation was defined when patients were hospitalized and needed iv-diuretics. Time to clinical worsening (TTCW) included death due to RH failure, lung transplantation and hospitalization due to PAH. Clinical parameters were compared between groups by student’s t-test. Cox regression and log-rank tests were performed to analyse survival, TTCW and their determining factors. <bold>Results:</bold> Out of 66 patients with signs of fluid retention at baseline (normal fluid intake <2 l/day, n=16; high fluid intake ≥2 l/d, n=50), 21 presented with hydropic decompensation, which was significantly associated with worse survival (p=0.004) and time to clinical worsening (p<0.001). During follow-up patients who reduced fluid intake <2 l/day improved their RV area (trend p=0.051) and time to clinical worsening (p=0.007). Hydropic decompensation and fluid intake during follow-up were independent predictors of time to clinical worsening. <bold>Conclusion:</bold> The results of this study suggest that most patients with PAH who present with signs of right heart failure drink too much (more than ≥2 l/day). Fluid restriction was highly effective to improve right ventricular size and function and TTCW