Table 3. Prognostic factors associated and not associated with systemic sclerosis-associated pulmonary arterial hypertension

Prognostic factor	Estimate	Ref.
Factors associated with survival
HLA DRw6	RR 54.52 (p=0.01)	[63]
HLA DRw52	RR not reported (p=0.02)	[63]
Elevated mean P_ra	HR 20.7 (p=0.0001)	[40]
Higher mixed venous oxygen saturation	HR 0.17, 95% CI 0.09–0.33	[44]
PVR	No difference in Kaplan–Meier curves in patients with a change in PVR <20%, 20–34% or	[40]
	≥35% (p=0.8)	[55]
	HR 1.10, 95% CI 1.03–1.18 (p<0.01)	[51]
	PVR index: HR 1.05, 95% CI 1.01–1.09 (p<0.01)	[56]
	HR 1.20, 95% CI 1.02–1.41 (p=0.02)
SVI	HR 0.94, 95% CI 0.89–0.99 (p=0.02)	[55]
Pulmonary artery capacitance	HR 0.43, 95% CI 0.20–0.91 (p=0.03)	[55]
Functional class	Lower functional class has better survival:	[44]
	HR 2.26, 95% CI 1.02–4.97	[56]
	NYHA classes III/IV: HR 4.54, 95% CI 1.37–8.33 (p=0.01)	[55]
	WHO classes III/IV have worse survival than classes I/II:
	log rank test p=0.02
Sex	Males have worse survival: HR 2.02, 95% CI 0.65–6.20^¶	[64]
	Females have better survival: HR 2.20, 95% CI 1.36–3.55	[44]
Age yrs	Age >50 yrs has worse survival: HR 2.34, 95% CI 0.54–10.2^¶	[64]
	Younger age has better survival: HR 0.66, 95% CI 0.34–1.29	[44]
Estimated glomerular filtration rate^#	HR 2.63, 95% CI 1.29–5.37 (p<0.01)⁺	[55]
Signs of right heart failure	HR 2.56, 95% CI 1.02–14.28 (p=0.04)	[56]
Factors not associated with survival
Anti-centromere antibody	HR 1.67, 95% CI 0.66–4.26	[64]
	No effect on survival: data not reported	[44]
Anti-Scl-70	HR 0.28, 95% CI 0.03–1.99	[64]
	No effect on survival: data not reported	[44]

HLA: human leukocyte antigen; P_ra: right atrial pressure; PVR: pulmonary vascular resistance; SVI: stroke volume index; NYHA: New York Heart Association; WHO: World Health Organization. ^#: <60 mL·min⁻¹·1.73 m⁻²; ^¶: estimate was suggestive but not statistically significant; ⁺: estimate from univariate analysis. Multivariate models including different haemodynamic parameters estimate HR 2.56–3.41.