Table 3. Features present on initial CTPA at time of PE diagnosis in patients with subsequent diagnosis of CTEPH and a randomly selected control group of patients not diagnosed with CTEPH.

	CTEPH +ve (n=36)	CTEPH -ve (n=36)
Demographics:
Age, years (mean ± SD)	69.9 ± 13.9	68.5 ± 11.95
Sex M/F n, (%)	18 (50)/18 (50)	16 (44)/20(56)
Features suggestive of PH:
PA ≥ 30mm n, (%)	24 (67)	11 (31)
RV:LV ≥1 n, (%)	28 (78)	13 (36)
RVOTH ≥6mm n, (%)	16 (44)	3 (8)
All 3 features suggestive of PH present n, (%)	13 (36)	2 (6)
Features suggestive of CTEPD:
Dilated bronchial arteries, yes/no (%)*	10 (28)	2 (6)
Arterial webs or bands, yes/no (%)	4 (11)	1 (3)
Attenuated or Occluded vessels combined, n (%)	13 (36)	1 (3)
Mosaic parenchymal perfusion pattern yes/no n, (%)	8 (22)	2 (6)
2 or more features suggestive of CTEPD n, (%)	12 (33)	1 (3)
Features suggestive of CTEPH at index event:
3 features of PH and ≥ 2 features of CTEPD n, (%)	7 (19)	0 (0)

PA=pulmonary artery; RV:LV=right to left ventricular ratio; RVOTH=right ventricular outflow tract hypertrophy; PH=pulmonary hypertension; CTEPD=chronic thromboembolic pulmonary disease; CTEPH=chronic thromboembolic pulmonary hypertension.

CTPA at the time of diagnosis of sufficient diagnostic quality were available for review in 36/41 of CTEPH +ve patients and are compared to a randomly selected control group of 36 patients not diagnosed as having CTEPH during the conduct of the study. PA pulmonary artery diameter; RV:LV ratio of internal right ventricular to left ventricular diameter; RVOTH thickness of right ventricular outflow tract.

^*assessment of bronchial artery size was not possible due to lack of contrast opacification in 9 (25%) of CTEPH +ve patients and 6 (17%) of CTEPH -ve patients