Table 2– Cox regression survival analysis to assess predictors of survival in pulmonary hypertension associated with chronic obstructive pulmonary disease

	Univariate hazard ratio (95% CI)	p-value	Multivariate hazard ratio (95% CI)	p-value
Age years	1.054 (1.024–1.086)	<0.001	1.040 (1.004–1.078)	0.031
Sex
Female	Reference
Male	1.602 (0.930–2.761)	0.090
BMI kg·m⁻²	0.958 (0.922–0.996)	0.029
WHO-FC
III	Reference		Reference
IV	2.471 (1.421–4.296)	0.002	0.485 (0.249–0.943)	0.033
ISWD m	0.996 (0.993–0.999)	0.011
Haemodynamics
Mean RAP mmHg	1.034 (0.980–1.091)	0.225
Mean PAP mmHg	1.034 (1.011–1.057)	0.003
CI L·min·m⁻²	0.481 (0.331–0.699)	<0.001
PCWP mmHg	0.945 (0.893–0.999)	0.047
PVR dyn·s·cm⁻⁵	1.001 (1.001–1.002)	<0.001
S_vO₂ %	0.918 (0.887–0.950)	<0.001	0.947 (0.910–0.986)	0.008
HRCT scores
Total emphysema	1.047 (1.008–1.088)	0.018
Total fibrosis	1.034 (0.956–1.119)	0.407
Pulmonary function
FEV₁ % pred	1.011 (1.001–1.025)	0.006
FVC % pred	1.011 (1.001–1.022)	0.039
D_LCO % pred	0.964 (0.946–0.982)	<0.001	0.975 (0.954–0.996)	0.020

BMI: body mass index; WHO-FC: World Health Organization functional class; ISWD: incremental shuttle walking distance; RAP: right atrial pressure; PAP: pulmonary arterial pressure; CI: cardiac index; PCWP: pulmonary capillary wedge pressure; PVR: pulmonary vascular resistance; S_vO₂: mixed venous oxygen saturation; HRCT: high-resolution computed tomography; FEV₁: forced expiratory volume in 1 s; % pred: % predicted; FVC: forced vital capacity; D_LCO: diffusing capacity of the lung for carbon monoxide.