Ambrisentan and Tadalafil Up-front Combination Therapy in Scleroderma-associated Pulmonary Arterial Hypertension.

Abstract

BACKGROUND:

Scleroderma-associated pulmonary arterial hypertension (SSc-PAH) is a rare disease characterized by a very dismal response to therapy and poor survival. We assessed the effects of up-front combination PAH therapy in patients with SSc-PAH.

METHODS:

In this prospective, multicenter, open-label trial, 24 treatment-naive patients with SSc-PAH received ambrisentan 10 mg and tadalafil 40 mg daily for 36 weeks. Functional, hemodynamic, and imaging (cardiac magnetic resonance imaging and echocardiography) assessments at baseline and 36 weeks included changes in right ventricular (RV) mass and pulmonary vascular resistance as co-primary endpoints and stroke volume/pulmonary pulse pressure ratio, tricuspid annular plane systolic excursion, 6-minute walk distance, and N-terminal pro-brain natriuretic peptide as secondary endpoints.

RESULTS:

At 36 weeks, we found that treatment had resulted in significant reductions in median (interquartile range [IQR]) RV mass (28.0 g [IQR, 20.6-32.9] vs. 32.5 g [IQR, 23.2-41.4]; P < 0.05) and median pulmonary vascular resistance (3.1 Wood units [IQR, 2.0-5.7] vs. 6.9 Wood units [IQR, 4.0-12.9]; P < 0.0001) and in improvements in median stroke volume/pulmonary pulse pressure ratio (2.6 ml/mm Hg [IQR, 1.8-3.5] vs. 1.4 ml/mm Hg [IQR 8.9-2.4]; P < 0.0001) and mean ( ± SD) tricuspid annular plane systolic excursion (2.2 ± 0.12 cm vs. 1.65 ± 0.11 cm; P < 0.0001), 6-minute walk distance (395 ± 99 m vs. 343 ± 131 m; P = 0.001), and serum N-terminal pro-brain natriuretic peptide (647 ± 1,127 pg/ml vs. 1,578 ± 2,647 pg/ml; P < 0.05).

CONCLUSIONS:

Up-front combination therapy with ambrisentan and tadalafil significantly improved hemodynamics, RV structure and function, and functional status in treatment-naive patients with SSc-PAH and may represent a very effective therapy for this patient population. In addition, we identified novel hemodynamic and imaging biomarkers that could have potential value in future clinical trials. Clinical trial registered with www.clinicaltrials.gov (NCT01042158).

• Authors: Paul M Hassoun, Roham T Zamanian, Rachel Damico, Noah Lechtzin, Rubina Khair, Todd M Kolb, Ryan J Tedford, Olivia L Hulme, Traci Housten, Chiara Pisanello, Takahiro Sato, Erica H Pullins, Celia P Corona-Villalobos, Stefan L Zimmerman, Mohamed A Gashouta, Omar A Minai, Fernando Torres, Reda E Girgis, Kelly Chin, Stephen C Mathai
• Journal: American journal of respiratory and critical care medicine (Am J Respir Crit Care Med) Vol. 192 Issue 9 Pg. 1102-10 (Nov 01 2015) ISSN: 1535-4970 [Electronic] United States
• PMID: 26360334 (Publication Type: Journal Article, Multicenter Study, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Phenylpropionates
• Phosphodiesterase 5 Inhibitors
• Pyridazines
• Natriuretic Peptide, Brain
• Tadalafil
• ambrisentan

Topics

• Drug Therapy, Combination
• Female
• Heart Ventricles (diagnostic imaging, pathology)
• Humans
• Hypertension, Pulmonary (blood, drug therapy, etiology)
• Magnetic Resonance Imaging
• Male
• Middle Aged
• Natriuretic Peptide, Brain (blood, drug effects)
• Phenylpropionates (blood, therapeutic use)
• Phosphodiesterase 5 Inhibitors (blood, therapeutic use)
• Prospective Studies
• Pyridazines (blood, therapeutic use)
• Scleroderma, Systemic (blood, complications)
• Stroke Volume
• Tadalafil (blood, therapeutic use)
• Ultrasonography
• Vascular Resistance (drug effects)