Table 2– 6-min walk distance (6MWD) and pulmonary haemodynamics in pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) according to functional class (FC)

	PAH^#			ANOVA p-value	CTEPH^¶			ANOVA p-value
WHO FC	I–II	III	IV		I–II	III	IV
6MWD m	442±97	343±111*	255±98*	<0.001	379±111	309±10*	210±82*	<0.001
PVR Wood units	9±5	13±6*	13±7*	<0.001	9±5	10±5	12±6	0.083
P_ra mmHg	8±5	9±5	11±6*	0.004	7±5	8±5	13±7*	0.001

Data are presented as mean±sd, unless otherwise stated. WHO: World Health Organization; PVR: pulmonary vascular resistance; P_ra: right atrial pressure. ^#: n=866; ^¶: n=162. *: p<0.05 for differences between FC I–II versus FC III and FC IV groups for both aetiologies.