Table 3. Percentage of New York Heart Association/World Health Organization functional class (NYHA/WHO FC) patients enrolled in randomised controlled trials (RCTs) with monotherapies.

Study drug	RCT acronym or study group	Patients	Subjects n	NYHA/WHO FC IV	Duration weeks	Primary end-point
Epoprostenol	Rubin et al. [22]	IPAH	23	NA	8	NA
	Barst et al. [23]	IPAH NYHA/WHO FC III/IV	81	26%	12	6MWD
	Badesch et al. [24]	SSc	111	17%	12	6MWD
Treprostinil	Simonneau et al. [25]	IPAH, CTD, CHD	469	7%	12	6MWD
Beraprost	ALPHABET [26]	PAH	130	0%	12	6MWD
	Barst et al. [27]	IPAH, CTD, CHD	116	0%	52	TTCW
Iloprost	AIR [28]	IPAH, CTD, CTEPH	203	41%	12	Composite
Bosentan	BREATHE-1 [29]	IPAH, CTD	213	8.5%	16	6MWD
Ambrisentan	ARIES 1 [30]	PAH	202	7%	12	6MWD
	ARIES 2 [30]	PAH	192	2.3%	12	6MWD
Sildenafil	SUPER 1 [31]	IPAH, CTD, CHD	277	3%	12	6MWD
Tadalafil	PHIRST [32]	PAH	405	1.7%	16	6MWD

PAH: pulmonary arterial hypertension; IPAH: idiopathic PAH; SSc: systemic sclerosis-associated PAH; CTD: connective tissue diseases-associated PAH; CHD: congenital heart disease-associated PAH; CTEPH: chronic thromboembolic pulmonary hypertension; NA: not applicable; 6MWD: 6-min walk distance; TTCW: time to clinical worsening.