Table 1. Recommendations for efficacy of specific drug therapy for pulmonary arterial hypertension (group 1) according to New York Heart Association functional class (NYHA FC)

Treatment	NYHA FC
Treatment	II	III	IV
Prostanoids
Epoprostenol i.v.		I-A	I-A
Iloprost inhaled		I-A	IIa-C
Iloprost i.v.		IIa-C	IIa-C
Treprostinil subcutaneous		I-B	IIa-C
Treprostinil i.v.		IIa-C	IIa-C
Treprostinil inhaled		I-B	IIa-C
Endothelin receptor antagonists
Bosentan	I-A	I-A	IIa-C
Ambrisentan	I-A	I-A	IIa-C
Phophodiesterase type 5 inhibitors
Sildenafil		I-A	I-A
Tadalafil		I-B	I-B
Calcium channel blockers		I-C^#	I-C^#
Initial drugs combination therapy
Sequential drugs combination therapy		IIa-C	IIa-B

Data are presented as conflicting evidence (levels of evidence A–C) and/or a divergence of opinion about the usefulness/efficacy of the given treatment or procedure (termed class I–III). Class I: evidence and/or general agreement that a given treatment or procedure is beneficial, useful, effective; class II and IIa: weight of evidence/opinion is in favour of usefulness/efficacy; class IIb: usefulness/efficacy is less well established by evidence/opinion; class III: evidence or general agreement that the given treatment or procedure is not useful/effective, and in some cases may be harmful; level A: data derived from multiple, randomised clinical trials or meta-analyses; level B: data derived from a single, randomised clinical trial or large nonrandomised studies; level C: consensus of opinion of the experts and/or small studies, retrospective studies, registries. ^#: only for responders to acute vasoreactivity tests.