Table 2.

Correlation Table

	Correlation Coefficient
	Derivation Cohort	Multicenter Cohort (Derivation and Validation)
	Group I (n = 82)	Group I (n = 132)	IPAH Only (n = 87)
Hemodynamics
RAP, mm Hg	0.1*	0.2*	0.3†
mPAP, mm Hg	0.2*	0.3‡	0.5§
PVR, Wood units	0.2*	0.3‡	0.5§
CO, L/min	−0.2*	−0.2†	−0.3‡
Cardiac index, L/min/m2	−0.2*	−0.2†	−0.3†
Demographics
Age, yr	0.3†	0.2*	0.03*
6 MWD, m	−0.4§
NYHA-FC	0.5§
Laboratory chemistries
Serum sodium	−0.2†
Serum creatinine	0.3†
NT-proBNP, pg/ml	0.4†

Definitions of abbreviations: 6 MWD = 6-minute-walk distance; CO = cardiac output; IPAH = idiopathic pulmonary arterial hypertension; mPAP = mean pulmonary artery pressure; NT-proBNP = N-terminal pro-brain natriuretic peptide; NYHA-FC = New York Heart Association functional class; PVR = pulmonary vascular resistance; RAP = right atrial pressure.

^*P ≥ 0.05.

^†P < 0.05.

^‡P < 0.005.

^§P < 0.001.