Long-term outcomes of pulmonary arterial hypertension under specific drug therapy in Eisenmenger syndrome

Abstract

Background: The long-term effectiveness of pulmonary arterial hypertension-specific drug therapy (PAH-SDT) in Eisenmenger syndrome is controversial. We investigated short-term and long-term hemodynamic changes under PAH-SDT and their associations with outcomes in a bicentric cohort.

Methods: Over 20 years, we included 69 patients with congenital heart disease, an indexed pulmonary vascular resistance (PVRi) >8 WU·m², and 292 standardized catheterizations at baseline and after PAH-SDT initiation or intensification. Oxygen consumption was measured and the Fick principle applied to calculate indexed pulmonary output (Qpi) and PVRi.

Results: After PAH-SDT initiation or intensification, median (interquartile range) PVRi decrease was 5.1 WU·m² (-1.4, -12.6) (p < 0.0001). Median Qpi and 6-minute walk test increases were +0.4 liter/min/m² (0.0, +0.9) (p < 0.0001) and +49 m (+15, +93) (p = 0.0003), respectively. Hemodynamic response combining increased Qpi with decreases in transpulmonary gradient and PVRi occurred in 68.0% of patients. After a median of 4.9 years, PVRi and Qpi changes were no longer significant. Over a median of 7.2 years, 23 (33.3%) patients met a composite criterion (death, n = 8; heart-lung transplantation or listing for transplantation, n = 15). The 15-year cumulative event rate was 49.2%. By multivariate analysis, independent predictors of events were superior vena cava oxygen saturation and hemodynamic response (p = 0.048 and p < 0.0001).

Conclusions: In Eisenmenger syndrome, PAH-SDT induces early hemodynamic improvements, which decline over time. Hemodynamic changes under PAH-SDT vary across patients. Hemodynamic parameters at baseline and under PAH-SDT are associated with events. PAH-SDT may need to be individualized based on hemodynamic changes.

Keywords: Eisenmenger syndrome; catheterization; congenital heart diseases; drug therapy; outcome; pulmonary arterial hypertension.