Table 4.

The correlation between demographics, 6MWD, CPET parameters, and HRR1 of IPAH patients.

Parameters	r	P
NYHA FC	−0.6	<0.01
NT-proBNP (pg/ml)	−0.3	<0.01
6MWD (m)	0.4	<0.01
Peak Load (W)	0.5	<0.01
peak VO2/kg (ml/min/kg)	0.56	<0.01
Peak VO2 (ml/min)	0.6	<0.01
Peak VO2% pred	0.5	<0.01
Peak O2 pulse (ml/beat)	0.4	<0.01

The abbreviation definitions are same as Tables 1 and 2.