TABLE 6

Determinants of paediatric idiopathic/heritable pulmonary arterial hypertension risk

Lower riskDeterminants of riskHigher risk
NoClinical evidence of RV failureYes
NoProgression of symptomsYes
>3506MWT (>6 years old) m<350
NormalGrowthFailure to thrive
I, IIWHO FCIII, IV
Minimally elevatedSerum BNP/NT-proBNPSignificantly elevated
Rising level
EchocardiographyRA/RV enlargement
Reduced LV size
Increased RV/LV ratio
Reduced TAPSE
Low RV FAC
Pericardial effusion
Systemic CI >3.0 L·min−1·m−2HaemodynamicsSystemic CI <2.5 L·min−1·m−2
Systemic venous saturation >65%mRAP >10 mmHg
Acute vasoreactivityPVRI >20 WU·m2
Systemic venous saturation <60%
PACI <0.85 mL·mmHg−1·m−2

RV: right ventricle; 6MWT: 6-min walk test; WHO: World Health Organization; FC: Functional Class; BNP: brain natriuretic peptide; NT-proBNP: N-terminal pro-BNP; RA: right atrium; LV: left ventricle; FAC: fractional area change; TAPSE: tricuspid annular plane systolic excursion; CI: cardiac index; mRAP: mean right atrial pressure; PVRI: pulmonary vascular resistance index; WU: Wood Units; PACI: pulmonary arterial compliance index.