Long-term outcomes with ambrisentan monotherapy in pulmonary arterial hypertension.
BACKGROUND
This study evaluated long-term outcomes in patients with pulmonary arterial hypertension (PAH) undergoing treatment with ambrisentan monotherapy, a selective oral endothelin-1 receptor antagonist.


RESULTS
Patients who participated in the Ambrisentan in Pulmonary Arterial Hypertension: A Phase 3, Randomized, Double-Blind, Placebo-Controlled Multicenter Efficacy Study (ARIES-1) clinical trial and extension phase at our institution were included. Cardiac catheterization, 6-minute walk distance (6MWD), and cardiac magnetic resonance (MRI) data were retrospectively reviewed. Twelve patients with PAH (11 idiopathic, 1 fenfluramine) had follow-up from 3 to 5.5 years from the initiation of ARIES-1. Patients received ambrisentan therapy throughout the study period and were on ambrisentan monotherapy for the first 2 years. At year 1, improvements in median mean pulmonary arterial pressure (PA), cardiac output, and pulmonary vascular resistance (PVR) were seen (P = .02, P = .03, P < .01), and the improvement in PVR persisted at 2 years. 6MWD also improved significantly between baseline (350 m) and 1 and 2 years (397 m, P < .01 and 393 m, P = .01). Cardiac MRI results were more varied, with an increase in RV ejection fraction from 29% at baseline to 46% at 2 years (P = .02), but other MRI variables did not improve.


CONCLUSIONS
Ambrisentan monotherapy led to improvements in catheterization, 6MWD, and RV ejection fraction, and shows promise as a long-term treatment for pulmonary arterial hypertension.
Childrens Medical Center Dallas, USA. sblalock98@yahoo.com
Shannon E
SE
Blalock
Susan
S
Matulevicius
Laura C
LC
Mitchell
Sharon
S
Reimold
John
J
Warner
Ronald
R
Peshock
Fernando
F
Torres
Kelly M
KM
Chin
D000293:Adolescent; D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000401:mortality* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010666:Phenylpropionates / Q000008:administration & dosage*; D011724:Pyridazines / Q000008:administration & dosage*; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D010666:Phenylpropionates; D011724:Pyridazines; C467894:ambrisentan