Effect of ambrisentan in patients with systemic sclerosis and mild pulmonary arterial hypertension: long-term follow-up data from EDITA study

Abstract

Abstract Background In the EDITA trial, patients with systemic sclerosis (SSc) and mild pulmonary vascular disease (PVD) treated with ambrisentan had a significant decline of pulmonary vascular resistance (PVR) but not of mean pulmonary arterial pressure (mPAP) vs. placebo after six months. The EDITA-ON study aimed to assess long-term effects of open label therapy with ambrisentan vs. no pulmonary arterial hypertension (PAH) therapy. Methods Patients who participated in the EDITA study and received regular follow-up were included in EDITA-ON. Clinical, echocardiographic, laboratory, exercise and hemodynamic parameters during follow-up were analysed. The primary endpoint was to assess whether continued treatment with ambrisentan vs. no treatment prevented the development of PAH according to the new definition. Results Of 38 SSc patients included in the EDITA study four were lost to follow-up. Of the 34 remaining patients (age 55 ± 11 years, 82.1% female subjects), 19 received ambrisentan after termination of the blinded phase, 15 received no PAH medication. The mean follow-up time was 2.59 ± 1.47 years, during which 29 patients underwent right heart catheterization. There was a significant improvement of mPAP in catheterised patients receiving ambrisentan vs. no PAH treatment (-1.53 ± 2.53 vs. 1.91 ± 2.98 mmHg, p = 0.003). In patients without PAH treatment 6/12 patients had PAH vs. 1/17 of patients receiving ambrisentan (p < 0.0001). Conclusion In SSc patients with early PVD, the development of PAH and/or deterioration was less frequent among patients receiving ambrisentan, indicating that early treatment and close follow-up could be beneficial in this high-risk group. Future trials in this field are needed to confirm these results.