Are there effective Pulmonary Arterial Hypertension therapies?
Yes. Conventional therapy for PAH typically includes treatment with calcium channel blockers, fluid/volume control (diuretics, fluid restriction, low salt diet), and supplemental oxygen. Chronic anticoagulation with warfarin was classically administered as an adjunctive therapy for idiopathic PAH, but its use is controversial in SSc-associated PAH due to the increased risk of bleeding relative to idiopathic PAH patients and unclear benefit in this population.
The development of PAH-specific therapies has resulted in improved survival for patients with SSc-associated PAH. These agents may be used as monotherapy, or commonly in combination with one another. There are three categories of PAH-specific therapies, each representing a novel pathophysiologic pathway: prostacyclins (inhaled [ilioprost], oral [treprostinil], subcutaneous or intravenous [epoprostenol, treprostinil]), oral endothelin receptor antagonists (bosentan, ambrisentan, macitentan) and nitric oxide potentiators (oral phosphodiesterase-type 5 inhibitors [sildenafil, tadalafil] or guanylate cyclase stimulator [riociguat]). Recent data from the AMBITION trial demonstrated that initial combination therapy with an endothelin receptor antagonist (ambrisentan) and a phosphodiesterase-type 5 inhibitor (tadalafil) was associated with less clinical deterioration than treatment with either agent alone, without an increase in the side-effect profile. The presence of multiple available therapies (including the routine implementation of combination therapy) has made the management of SSc-PAH increasingly more complex, and collaboration with PAH-treating providers is recommended.