Table 1.

A simplified approach for risk stratification in group 1 pulmonary arterial hypertension

Prognostic criteria	Low risk	Intermediate risk	High risk
WHO functional class	I, II	III	IV
6-min walk distance (6MWD)	> 440 m	165–440 m	< 165 m
NT-proBNP BNP	< 300 ng/ml < 50 ng/l	300–1400 ng/ml 50–300 ng/l	> 1400 ng/ml > 300 ng/l
RAP	< 8 mmHg	8–14 mmHg	> 14 mmHg
CI	≥ 2.5 l/min/m2	2.0–2.4 l/min/m2	< 2.0 l/min/m2
ScvO2	> 65%	60–65%	< 60%
	Low risk: at least three low-risk criteria and no high-risk criteria	Intermediate risk: definitions of low or high risk not fulfilled	High risk: at least two high-risk criteria including CI or ScvO2